IL183831A - Fragments of a serrate protein which bind a notch protein - Google Patents

Description

183831/2 183831 p'Ji J 453498 τηκ FRAGMENTS OF A SERRATE PROTEIN WHICH BIND A NOTCH PROTEIN 08079/0379.000 183831/3 - 1 - The present application is a divisional application from IL 101728 which relates to human Notch proteins. The present application relates to fragment of a Serrate protein. 1. INTRODUCTION The present invention relates to the human Notch and Delta genes and their encoded products. The invention also relates to sequences (termed herein "adhesive sequences") within the proteins encoded by toporythmic genes which mediate homotypic or heterotypic binding to sequences within proteins encoded by toporythmic genes. Such genes include but are not limited to Notch, Delta, and Serrate . 2. BACKGROUND OF THE INVENTION Genetic analyses in Drosophila have been extremely useful in dissecting the complexity of developmental pathways and identifying interacting loci. However, understanding the precise nature of the processes that underlie genetic interactions requires a knowledge of the biochemical properties of the protein products of the genes in question.

Null mutations in any one of the zygotic neurogenic loci — Notch (N) , Delta (Dl) , mastermind (mam) , Enhancer of Split (E (spl) , neuralized (neu) , and big brain (bib) —result in hypertrophy of the nervous system at the expense of ventral and lateral epidermal structures. This effect is due to the misrouting of epidermal precursor cells into a neuronal pathway, and implies that neurogenic gene function is necessary to divert cells within the neurogenic region from a neuronal fate to an epithelial fate. Studies that assessed the effects of laser ablation of specific embryonic neuroblasts in grasshoppers (Doe and Goodman 1985, Dev. Biol. Ill, 206-219) have shown that cellular interactions between neuroblasts and the surrounding accessory cells serve to inhibit these accessory cells from adopting a neuroblast fate. Together, these genetic and developmental observations have led to the hypothesis that the protein products of the neurogenic loci function as components of a cellular interaction mechanism necessary for proper epidermal development (Artavanis-Tsakonas , 1988, Trends Genet. 4, 95-100).

Sequence analyses (Wharton et al., 1985, Cell 43, 567-581; idd et al., 1986, Mol. Cell. Biol. 6, 3094-3108; Vassin et al., 1987, EMBO J. 6, 3431- 3440; Kopczynski et al., 1988, Genes Dev. 2, 1723- 1735) have shown that two of the neurogenic loci, Notch and Delta , appear to encode transmembrane proteins that span the membrane a single time. The Notch gene encodes a -300 kd protein (we use "Notch" to denote this protein) with a large N-terminal extracellular domain that includes 36 epidermal growth factor (EGF)-like tandem repeats followed by three other cysteine-rich repeats, designated Notch lin-12 · repeats (Wharton et al., 1985, Cell 43, 567-581; Kidd et al., 1986, Mol. Cell Biol. 6, 3094-3108; Yochem et al., 1988, Nature 335, 547-550). Delta encodes a -100 kd protein (we use "Delta" to denote DLZM, the protein product of the predominant zygotic and maternal transcripts; Kopczynski et al., 1988, Genes Dev. 2, 1723-1735) that has nine EGF-like repeats within its extracellular domain (Vassin et al., 1987, EMBO J. 6, 3431-3440; Kopczynski et al., 1988, Genes Dev. 2, 1723-1735) . Although little is known about the functional significance of these repeats, the EGF-like motif has been found in a variety of proteins, including those involved in the blood clotting cascade (Furie and Furie, 1988, Cell 53, 505-518). In particular, this motif has been found in extracellular proteins such as the blood clotting factors IX and X (Rees et al., 1988, EMBO J. 7, 2053-2061; Furie and Furie, 1988, Cell 53, 505-518), in other Drosophila genes (Knust et al., 1987, EMBO J. 761-766; Rothberg et al., 1988, Cell 55, 1047-1059), and in some cell-surface receptor proteins, such as thrombomodulin (Suzuki et al., 1987, EMBO J. 6, 1891-1897) and LDL receptor (Sudhof et al., 1985, Science 228, 815-822). A protein binding site has been mapped to the EGF repeat domain in thrombomodulin and urokinase (Kurosawa et al., 1988, J. Biol. Chem 263, 5993-5996;. Appella. et al . , 1987, J.- Biol. Chem. 262, 4437-4440).

An intriguing array of interactions between Notch and Delta mutations has been described (Vassin, et al., 1985, J. Neurogenet. 2, 291-308; Shepard et al., 1989, Genetics 122, 429-438; Xu et al., 1990, Genes Dev., 4, 464-475). A number of genetic studies (summarized in Alton- et ' al . , 1989, Dev. Genet. 10, 261-272) has indicated that the gene dosages of Notch and Delta in relation to one another are crucial for normal development. A 50% reduction in the dose of Delta in a wild-type Notch background causes a broadening of the wing veins creating a "delta" -at the base (Lindsley and Grell, 1968, Publication Number 627, Washington, D.C., Carnegie Institute of Washington). A similar phenotype is caused by a 50% increase in the dose of Notch in a wild-type Delta background (a "Confluens" phenotype; Welshons, 1965, Science 150, 1122-1129) . This Delta phenotype is partially suppressed by a reduction in the Notch dosage. Recent work in our laboratories has shown 183831/2 - 4 - that lethal interactions between alleles that correlate with alterations in the EGF-like repeats in ■ Notch can be rescued by reducing the dose of Delta (Xu et al., 1990, Genes Dev. 4, 464-475). Xu et al. (1990, Genes Dev. 4, 464-475) found that null mutations at either Delta or mam suppress lethal interactions between heterozygous combinations of certain Notch alleles, known as the Abruptex (Ax) mutations. Ax. alleles are associated with missense mutations within the EGF-like repeats of the Notch extracellular domain (Kelley et al., 1987, Cell 51, 539-548; Hartley et al., 1987, EMBO J. 6, 3407-3417) .

Notch is expressed on axonal processes during the outgrowth of embryonic neurons (Johansen et al., 1989, J. Cell Biol. 109, 2427-2440; Kidd et al., 1989, Genes Dev. 3, 1113-1129) .

A study has shown that certain Ax alleles of Notch can severely alter axon pathfinding during sensory neural outgrowth in the imaginal discs, although it is not yet known whether aberrant Notch expression in the axon itself, or the epithelium along which it grows is responsible for this defect (Palka et al., 1990, Development 109, 167-175) . 3. SUMMARY OF THE INVENTION The present invention provides a substantially purified fragment of a Serrate protein which is the portion of the Serrate protein with the greatest homology to the amino acid sequence as depicted in Figure 15 (SEQ ID NO: 9) from about amino acid numbers 79-282 or from about amino acids numbers 85-283, which fragment is characterized by the ability in vitro, when expressed on the surface of a first cell, to bind to a Notch protein expressed on the surface of a second cell.

The present invention relates to nucleotide sequences of the human Notch and Delta genes, and amino acid sequences of their encoded proteins, as well as fragments thereof containing an antigenic determinant or which are functionally active. The invention is also directed to fragments (termed herein "adhesive fragments") , and the sequences thereof, of the proteins ( "toporythmic proteins") encoded by toporythmic genes which mediate homotypic or heterotypic binding to toporythmic proteins.

Toporythmic genes, as used herein, refers to the genes Notch , Delta, and Serrate , as well as other members of the Delta/Serrate family which may be identified, e.g., by the methods described in Section 5.3, infra. Analogs and derivatives of the adhesive fragments which retain binding activity are also provided.

Antibodies to human Notch and to adhesive fragments are additionally provided.

In specific embodiments, the adhesive fragment of Notch is that fragment comprising the Notch sequence most homologous to Drosophila Notch EGF-like repeats 11 and 12; the adhesive fragment of Delta mediating heterotypic binding is that fragment comprising the sequence most homologous to Drosophila Delta amino acids 1-230; the adhesive fragment of Delta mediating homotypic binding is that fragment comprising the sequence most homologous to Drosophila Delta amino acids 32-230; and the adhesive fragment of Serrate is that fragment comprising the sequence most homologous to Drosophila Serrate amino acids 85-283 or 79-282. 3.1. DEFINITIONS As used herein, the following terms shall have the meanings indicated: AA ' = amino acid EGF = epidermal growth factor ELR = EGF-like (homologous) repeat IC = intracellular PCR = polymerase chain reaction As used herein, underscoring the name of a . gene shall indicate the gene, in contrast to its encoded protein product which is indicated by. the name of the gene in the absence of any underscoring. For example, "Notch" shall mean the Notch gene, whereas "Notch" shall indicate the protein product of the Notch gene . 4. DESCRIPTION OF THE FIGURES Figure 1. Expression Constructs and Experimental Design for Examining Notch-Delta Interactions. S2 cells at log phase growth were transiently transfected with one of the three constructs shown. Notch encoded by the Glla minigene (a cDNA/genomic chimeric construct: cDNA-derived sequences are represented by stippling, genomically derived sequences by diagonal-hatching (Ramos et al. , 1989, Genetics 123, 337-348)) was expressed following insertion into the metallothionein promoter vector pRmHa-3 (Bunch et al., 1988, Nucl. Acids Res. 16, 1043-1061) . Delta encoded by the Dll cDNA (Kopczynski et al., 1988, Genes Dev. 2, 1723-1735) was expressed after insertion into the same vector. The extracellular Notch (ECN1) variant was derived from a genomic cosmid containing the complete Notch locus (Ramos et al., 1989, Genetics 123, 337-348) by deleting the coding sequence for amino acids 1790-2625 from the intracellular domain (denoted by <5 ; Wharton et al., 1985, Cell 43, 567-581), leaving 25 membrane-proximal residues from the wild-type sequence fused to a novel 59 amino acid tail (see Experimental Procedures, Section 6.1, infra) . This construct was expressed under control of the Notch promoter region. For constructs involving the metallothionein vector, expression was induced with CuS04 following transfection . Cells were then mixed, incubated under aggregation conditions, and scored for their ability to aggregate using specific antisera and immunofluorescence microscopy to visualize expressing cells. T, metallothionein promoter; ATG, translation start site; TM, transmembrane domain; 3' N, Notch gene polyadenylation signal; 3' Adh, polyadenylation signal from Adh gene; 5' N, Notch gene promoter region.

Figure 2. Expression of Notch and Delta in Cultured Cells. (A) Lysates of nontransfected (S2) and Notch-transfected (N) cells induced with 0.7 mM CuS04 for 12-16 hr were prepared for sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) ,' run on 3%-15% gradient gels, and blotted to nitrocellulose. Notch was visualized using a monoclonal antibody (MAb C17.9C6) against the intracellular domain of Notch. Multiple bands below the major band ^at 300 kd may represent degradation products of Notch. (B) Lysates of nontransfected (S2) and Delta-transfected (Dl) cells visualized with a monoclonal antibody (MAb 201) against Delta. A single band of "105 kd is detected. In both cases, there is no detectable endogenous Notch or Delta in the S2 cell-line nor are there cross-reactive species. In each lane, 10 μΐ of sample (prepared as described in Experimental Procedures) was loaded.

Figure 3. S2 Cells That Express Notch and Delta Form Aggregates. In all panels, Notch is shown in green and Delta in red.

(A) A single Notch"1" cell. Note the prominent intracellular stain, including vesicular structures as well as an obviously unstained nucleus.

(A) Bright-field micrograph of same field, showing specificity of antibody staining.

(B) A single Delta+ cell. Staining is primarily at the cell surface.

(B) Bright-field micrograph of same- field.

(C)- Aggregate of Delta4" cells from a 24 hr aggregation experiment. Note against that staining is primarily at the cell surface.

(D) -(F) An aggregate of Notch"1" and Delta4" cells formed from a 1:1 mixture of singly transfected cell populations that was allowed to aggregate overnight at room temperature. (D) shows Notch4" cells in this aggregate; (E) shows Delta4" cells; and (F) is a double exposure showing both cell types. Bands of Notch and Delta are prominent at points of contact between Notch4" and Delta4" cells (arrows) . In (F) , these bands appear yellow because of the coincidence of green and red at these points. The apparently doubly stained single cell (')-.·. is actually two cells (one on top of the other) , one expressing Notch and the other Delta.

(G) and '(H) Pseudocolor confocal micrographs, of Notch+-Delta+ cell aggregates. Note that in (G) extensions (arrows) formed by at least two Delta4" cells completely encircle the Notch4" cell in the center of the aggregate. (H) shows an aggregate formed from a 2 hr aggregation experiment performed at 4°C. Intense bands of Notch are apparent within regions of contact with Delta4" cells.

(I) An aggregate composed of Delta4" cells and cells that express only the extracellular domain of Notch (ECN1 construct) . Scale bar = 10 μιη.

Figure 4. Notch and Delta are Associated in Cotransfected Cells. Staining for Notch is shown in the left column (A, C, and E) and that for Delta is shown in the right column (B, D, and F) .

(A) and (B) S2 cell cotransfected with both Notch and Delta constructs. In general, there was a good correlation between Notch and Delta localization at the cell surface (arrows) .

(C) and (D) Cotransfected cells were exposed to polyclonal anti-Notch antiserum (a 1:250 dilution of each anti-extracellular domain antiserum) for 1 hr at room temperature before fixation and staining with specific antisera. Note punctate staining of Notch and Delta and the correlation of their respective staining (arrows) . " (E) and (F) Cells cotransfected with the extracellular Notch (ECN1) and Delta constructs, induced, and then patched using anti-Notch polyclonal antisera. There was a close correlation between ECN1 and Delta staining at the surface as observed for full-length Notch. Scale bar = 10 μπι.

Figure 5. Coimmunoprecipitation Shows that Delta and Notch are Associated in "Lysates from Transfected S2 and Drosophila Embryonic Cells. In all experiments, Delta was precipitated from NP-40/deoxycholate lysates using a polyclonal anti-Delta rat antiserum precipitated with fixed Staph A cells, and proteins in the precipitated fraction were visualized on Western blots (for details, see Experimental Procedures). Lanes 1, 2, 3, and 5: Notch visualized with MAb C17.9C6; Lanes 4 and 6: Delta visualized using MAb 201.

In (A) , lanes 1 and 2 are controls for these experiments. Lane 1 shows a polyclonal anti-Delta immunoprecipitation from cells that express Notch alone visualized for Notch. No Notch was detectable in this sample, indicating that the polyclonal anti-Delta does not cross-react with Notch. Lane 2 shows Notch-Delta cotransfected cells immunoprecipitated with Staph A without initial treatment with ant.i-Delta antiserum and visualized for Notch, demonstrating that Notch is not precipitated nonspecifically by the Staph A or secondary antibody. Lane 3 shows protein precipitated with anti-Delta antiserum visualized for Delta (Dl) , and lane 4 shows the same sample visualized for Notch (N) . Lane 4 shows that Notch coprecipitates with immunoprecipitated Delta. Note that Notch appears as a doublet as is typical for Notch in. immunoprecipitates .

(B) shows the same experiment using embryonic lysates rather than transfected cell lysates. Lane 5 shows protein precipitated with anti-Delta antiserum visualized for Delta (Dl) , and lane 6 shows the same sample visualized for Notch (N) . These lanes demonstrate that Notch and Delta are stably associated in embryo lysates. Bands (in all lanes) below the Delta band are from Staph A '(SA) and the anti-Delta antiserum heavy (H) and light (L) chains.

Figure 6. Notch Expression Constructs and the Deletion Mapping of the Delta/ Serrate Binding Domain. S2 cells in log phase growth were transiently transfected with the series of expression constructs shown; the drawings represent the predicted protein products of the various Notch deletion mutants created. All expression constructs were derived from construct #1 pMtNMg. Transiently transfected cells were mixed with Delta expressing cells from the stably transformed line L49-6-7 or with transiently transfected Serrate expressing cells, induced with CuS04/ incubated under aggregation conditions and then scored for their ability to aggregate using specific antisera and immunofluorescence microscopy.

Aggregates were defined as clusters of four or more cells containing both Notch and Delta/Serrate expressing cells. The values given for % Aggregation refer to the percentage of all Notch expressing cells found in such clusters either with Delta (Dl) (left column) or with Serrate (Ser) (right column) . The various Notch deletion constructs are represented diagrammatically with splice lines indicating the ligation junctions. Each EGF repeat is denoted as a stippled rectangular box and numbers of the EGF repeats on either side of a ligation junction are noted. At the ligation junctions, partial EGF repeats produced by the various deletions are denoted by open boxes and closed brackets (for example see #2-3 ACla+EGF ( 10-12) ) . Constructs #3-13 represent the Clal deletion series. As diagrammed, four of the Clal sites, in repeats 7, 9, 17 and 26, break the repeat in the middle, immediately after the third cysteine (denoted by open box repeats; see Figure 7 for further clarification) , while the fifth and most 3j' site breaks neatly between EGF repeats 30 and 31 (denoted by closed box repeat 31; again see Figure 7). In construct #15 split, EGF repeat 14 which carries the split point mutation, is drawn as a striped box.- In construct. #33 ACla+XEGF (10-13 ) , the Xeno us Notch derived EGF repeats are distinguished from Drosophila repeats by a different pattern of shading. SP, signal peptide; EGF, epidermal growth factor repeat; N, Notch/ lin-12 repeat; TM, transmembrane domain; cdclO, . cdclO/ankyrin repeats; PA, putative nucleotide binding consensus sequence; opa, polyglutamine stretch termed opa; Dl, Delta; Ser, Serrate.

Figure 7. Detailed Structure of Notch Deletion Constructs #19-24: Both EGF Repeats 11 and 12 are Required for Notch-Delta Aggregation. EGF repeats 10-13 are diagrammed at the top showing the regular spacing of the six cysteine residues (C) . PCR products generated for these constructs (names and numbers as given in Figure 6) are represented by the heavy black lines and the exact endpoints are noted relative to the various EGF repeats. Ability to aggregate with Delta is recorded as ( +) or (-) for each construct. The PCR fragments either break the EGF repeats in the middle, just after the third cysteine in the same place as four out of the five Clal sites, or exactly in between two repeats in the same place as the most C-terminal Clal site.

Figure 8. Comparison of Amino. Acid Sequence of EGF Repeats 11 and 12 from Drosophila and Xenopus Notch. The amino acid sequence of EGF repeats 11 and 12 of Drosophila Notch (Wharton et al., 1985, Cell 43:567-581; Kidd et al., 1986, Mol. Cell Biol. 6:3094-3108) is aligned with that of the same two EGF repeats from Xenopus Notch (Coffman et al., 1990, Science 249:1438-1441). Identical amino acids are boxed. The six' conserved cysteine residues of each EGF repeat and the Ca++ binding consensus residues (Rees et al., 1988, EMBO J. 7:2053-2061) are marked with an asterisk (*) . The leucine to proline change found in the Xenopus PCR clone that failed to aggregate is noted underneath.

Figure 9. Constructs Employed in this Study. Schematic diagrams of the Delta variants defined in Table IV are shown. Extracellular, amino-proximal terminus is to the left in each case. S, signal peptide; "EGF", EGF-like motifs; M, membrane-spanning helix; H, stop-transfer sequence; solid lines, other Delta sequences; hatched lines, neuroglian sequences. Arrowheads indicate sites of translatable linker insertions. Sea, Seal; Nae, Nael; Bam, BamHI ; Bgl, Bglll; ELR, EGF-like repeat; Bst, BstEII; Dde, Ddel; Stu, Stul ; NG1-NG5, Delta-neuroglian chimeras.

Figure 9A. Dependence of Aggregation on Input DNA Amounts. A, Heterotypic aggregation observed using S2 cell populations transiently transfected, respectively, with varied amounts of p TDll DNA (2, 4, 10 or 20 g/plate) that were subsequently incubated under aggregation conditions with S2 cell populations transiently transfected with a constant amount of pMtNMg DNA (20 g/plate) . Data presented are mean fraction (¾) of Delta cells in aggregates of four or more cells + standard error for each input DNA amount (N = 3 replicates, except 2 μg and 10 μ<3 inputs for which N = 2) . A minimum of 100 Delta-expressing cells were counted for each replicate. B, Homotypic aggregation observed using S2 cell populations transiently transfected, respectively, with varied amounts of pMTDll DNA (2, 4, 10 or 20 /ig/plate) that were subsequently incubated under aggregation conditions. Data presented are mean fraction (%) of Delta cells in aggregates of four or more cells + standard error for each input DNA amount (N = 3 replicates) . A minimum of 500 Delta-expressing cells were counted for each replicate.

Figure 10. Delta-Serrate Amino-Terminal Sequence Alignment. Residues are numbered on the basis of conceptual translation of Delta (Dl, upper sequence (SEQ ID NO:3); beginning at amino acid 24, ending at amino acid 226) and Serrate (Ser, lower sequence (SEQ ID NO:4); beginning at amino acid 85, ending at amino acid 283) coding sequences. Vertical lines between the two sequences indicates residues that are identical within the Delta and Serrate sequences, as aligned. Dots represent gaps in the alignment. Boxes enclose cysteine residues within the aligned regions. Nl, amino-proximal domain 1; N2, amino-proximal domain 2; N3 , amino-proximal domain 3. Translatable insertions associated with STU B [replacement of Delta amino acid 132 (A) with GKIFP] -and NAE B [insertion of RKIF between Delta amino acid 197 and amino acid 198] constructs, respectively, are depicted above the wild type Delta sequence.

Figure 11. Potential Geometries of Delta-Notch Interactions. A, Potential register of Delta (left) and Notch (right) molecules interacting between opposing plasma membranes. B, Potential register of Delta (left) and Notch (right) molecules interacting within the same plasma membranes. ELR, EGF-like repeat; open boxes, EGF-like repeats; dotted boxes, LNR repeats; solid boxes, membrane-spanning helices. Delta amino-terminal domain and Delta and Notch intracellular domains represented by ovals.

Figure 12. Potential Geometries of Delta-Delta interactions. A and B, Potential register of Delta molecules interacting between opposing plasma membranes. B, Potential register of Delta molecules interacting within the same plasma membranes. Open boxes, EGF-like repeats; solid boxes, membrane-spanning helices. Delta amino-terminal extracellular and intracellular domains represented by ovals..

Figure 13. Primary Nucleotide Sequence of the Delta cDNA Dll (SEQ ID NO: 5) and Delta amino acid sequence ( SEQ ID NO: 6) The DNA sequence of the 5 ' -3 ' strand of the Dll cDNA is shown, which contains a number of corrections in comparison to that presented in Kopczynksi et al. (1988, Genes Dev. 2, 1723-1735).

Figure 14. Primary Nucleotide Sequence of the Neuroglian cDNA 1B7A-250 (SEQ ID NO: 7). This is the DNA sequence of a portion of the 5' -3' strand of the 1B7A-250 cDNA (A . J . ·■ Bieber , pers. comm.; Hortsch et al., 1990, Neuron 4, 697-709). Nucleotide 2890 corresponds to the first nucleotide of an isoleucine codon that encodes amino acid 952 of the conceptually translated neuroglian-long form protein.

Figure 15. Nucleic Acid Sequence Homologies Between Serrate and Delta . A portion of the Drosophila Serrate nucleotide sequence (SEQ ID N0:8), with the encoded Serrate protein sequence (SEQ ID N0:9) written below, (Fleming et al., 1990, Genes & Dev. 4, 2188-2201 at 2193-94) is shown. The four regions showing high sequence homology with the Drosophila Delta sequence are numbered above the line and indicated by brackets. The total region of homology spans nucleotide numbers 627 through 1290 of the Serrate nucleotide sequence (numbering as in Figure 4 of Fleming et al., 1990, Genes & Dev. 4, 2188-2201) .

Figure 16. Primers ' used' for PCR in the Cloning of Human Notch . The sequence of three primers used for PCR to amplify DNA in a human fetal brain cDNA library are shown. The three primers, cdcl (SEQ ID NO-.10), cdc2 (SEQ ID N0:11), and cdc3 (SEQ ID NO: 12), were designed to amplify either a 200 bp or a 400 bp fragment as primer pairs cdcl/cdc2 or cdcl/cdc3, respectively. I: inosine.

Figure 17. Schematic Diagram of Human Notch Clones. A schematic diagram of human Notch is shown. Heavy bold-face lines below the diagram show that portion of the Notch sequence contained in each of the four cDNA clones. The location of the primers used in PCR, and their orientation, .· are indicated by arrows.

Figure 18. Human Notch Sequences Aligned with Drosophila Notch Sequence. Numbered vertical lines correspond to Drosophila Notch coordinates.

Horizontal lines below each map show where, clones lie relative to stretches of sequence (thick horizontal lines) .

Figure 19. Nucleotide Sequences of Human Notch Contained in Plasmid cDNA Clone hN2k. Figure 19A: The DNA sequence (SEQ ID NO: 13) of a portion of the human Notch insert is shown, starting at the EcoRI site at the 3' end, and proceeding in the 3' to 5' ' .-direction. Figure 19B: The DNA sequence (SEQ ID NO: 14) of a portion of the human Notch insert is shown, starting at the EcoRI site at the 5' end, and proceeding in the 5' to 3' direction. Figure 19C: The DNA sequence (SEQ ID N0:15) of a portion of the human Notch insert is shown, starting 3' of the sequence shown in Figure 19B, and proceeding in the 5' to 3' direction. The sequences shown are tentative, subject to confirmation by determination of overlapping sequences.

Figure 20. Nucleotide Sequences of Human Notch Contained in Plasmid cDNA clone hN3k. Figure 20A: The DNA sequence (SEQ ID NO: 16) of a portion of the human Notch insert is shown, starting at the EcoRI site at the 3' end, and proceeding in the 3' to 5' direction. Figure 2 OB: The DNA sequence (SEQ ID NO: 17) of a portion of the human Notch insert. is shown, starting at the EcoRI site at the 5' end, and proceeding in the 5' to 3' direction. Figure 20C: The DNA sequence (SEQ ID NO: 18) of a portion of the human Notch insert is shown, starting 3' of the sequence shown in Figure 20B, and proceeding in the 5* to 3' direction. Figure 20D: The DNA sequence (SEQ ID NO: 19) of a portion of the human Notch insert is shown, starting 5' of the sequence shown in Figure 20A, and proceeding in the 3' to 5' direction. The sequences shown are tentative, subject to confirmation by determination of overlapping sequences.

Figure 21. Nucleotide Sequences of Human Notch Contained in Plasmid cDNA clone hN4k. Figure 21A: The DNA sequence (SEQ ID NO:20) of a portion of the human Notch insert is shown, starting at the EcoRI site at the 5' end, and proceeding in the 5' to 3' direction. Figure 2 IB: The DNA sequence (SEQ ID NO: 21) of a portion of the human Notch insert is shown, starting near the 3' end, and proceeding in the 3 ' to 5 ' direction. The sequences shown are tentative, subject to confirmation by determination of. overlapping sequences.

Figure 22. Nucleotide Sequences of Human Notch Contained in Plasmid cDNA Clone hN5k. Figure 22A: The DNA sequence (SEQ ID NO:22) of a portion of the human Notch insert is shown, starting at the EcoRI site at the 5' end, and proceeding in the 5' to 3' direction. Figure 22B: The DNA sequence (SEQ ID NO: 23) of a portion of the human Notch insert is shown, starting near the 3' end, and proceeding in the 3' to 5' direction. Figure 22C: The DNA sequence (SEQ ID NO: 24) of a portion of the human Notch insert is shown, starting 3' of the sequence shown in Figure-2-2A, and proceeding in the 5' to 3' direction. Figure 22D: The DNA sequence (SEQ ID NO: 25) of a portion of the human Notch insert is shown, starting 5' of the sequence shown in Figure 22B, and proceeding in the 3' to 5' direction. The sequences shown are tentative, subject to confirmation by determination of overlapping sequences.

Figure 23. DNA (SEQ ID NO: 31)' and Amino Acid (SEQ ID NO: 34) Sequences of Human Notch Contained in Plasmid cDNA Clone hN3k.

Figure 24. DNA (SEQ ID NO: 33) and Amino Acid (SEQ ID NO: 34) Sequences of Human Notch Contained in Plasmid cDNA Clone hN5k.

Figure 25. Comparison of hN5k With Other Notch Homologs. Figure 25A. Schematic representation of Drosophila Notch. Indicated are the signal sequence (signal) , the 36 EGF-like repeats, the three Notch/ lin-12 repeats, the transmembrane domain (TM) , the six CDC10 repeats, the OPA repeat, and the PEST (proline, glutamic acid, serine, threonine) -rich region. Figure 25B. Alignment of the deduced amino acid sequence of hN5k with sequences of other Notch homologs. Amino acids are numbered on the left side. The cdclO and PEST-rich regions are both boxed, and individual cdclO repeats are marked. Amino acids which are identical in three or more sequences are highlighted. The primers used to clone hN5k are indicated below the sequences from which they were designed.' The nuclear localization sequence (NLS) , casein kinase II (CKII) , and cdc2 kinase (cdc2) sites of the putative CcN motif of the vertebrate Notch homologs are boxed. The possible bipartite nuclear targeting sequence (BNTS) and proximal phosphorylation sites of Drosophila Notch are also boxed.

. DETAILED DESCRIPTION OF THE INVENTION The present invention relates to nucleotide sequences of the human Notch and Delta genes, and amino acid sequences of their encoded proteins. The invention further relates to fragments (termed herein "adhesive fragments") of the proteins encoded by toporythmic genes which mediate homotypic or heterotypic binding to toporythmic proteins or adhesive fragments thereof. Toporythmic genes, as used herein, shall mean the genes' Notch, Delta , and Serrate , as well as other members of the Delta/Serrate family which may be identified, e.g. by the methods described in Section 5.3, infra .

The nucleic acid and amino acid sequences and antibodies thereto of the invention can be used for the detection and quantitation of mRNA for human Notch and Delta and adhesive molecules, to study expression thereof, to produce human Notch and Delta and adhesive sequences, in the study. and manipulation of differentiation processes.

For clarity of disclosure, . and not by way of limitation, the detailed description of the invention will be divided into the following sub-sections: (i) Identification of and the sequences of toporythmic protein domains that mediate binding to toporythmic protein domains; ^ (ii) The cloning and sequencing of human Notch and Delta ; (iii) Identification of additional members of the Delta/Serrate family; (iv) The expression of toporythmic genes; (v.) Identification and purification of the expressed gene product; and (vi) Generation of. antibodies to toporythmic proteins and adhesive sequences thereof . .1. IDENTIFICATION OF AND THE SEQUENCES OF TOPORYTHMIC PROTEIN DOMAINS THAT MEDIATE BINDING TO TOPORYTHMIC PROTEIN DOMAINS The invention provides for toporythmic protein fragments, and analogs or derivatives thereof, which mediate homotypic or heterotypic binding (and thus are termed herein "adhesive") , and nucleic acid sequences relating to the foregoing.

In a specific embodiment, the adhesive fragment of Notch is that comprising the portion of Notch most homologous to ELR 11 and 12, i.e., amino acid numbers 447 through 527 (SEQ ID NO:l) of the Drosophila Notch sequence (see Figure 8) . In another specific embodiment, the adhesive" fragment of Delta mediating homotypic binding is that ' comprising the portion of Delta most homologous to about amino acid numbers 32-230 of the Drosophila Delta sequence (SEQ ID NO: 6). In yet another specific embodiment, the adhesive fragment of Delta mediating binding to Notch is that comprising the portion of Delta most homologous to about amino acid numbers 1-230 of the • Drosophila Delta sequence (SEQ ID NO: 6) . In a specific embodiment relating to an adhesive fragment of Serrate, such fragment is that comprising the portion of Serrate most homologous to about amino acid numbers 85-283 or 79-282 of the Drosophila Serrate sequence (see Figure 10 (SEQ ID NO:4), and Figure 15 (SEQ ID NO: 9) ) .

The nucleic acid sequences encoding toporythmic adhesive domains can be isolated from porcine, bovine, feline, avian, equine, or canine, as well as primate sources and any other species in which homologs of known toporythmic genes [ including , but not limited to the following genes (with the publication of sequences in parentheses): Notch (Wharton et al., 1985, Cell 43, 567-581), Delta (Vassin et al., 1987, EMBO J. 6, 3431-3440; Kopczynski et al., 1988, Genes Dev. 2, 1723-1735; note corrections to the Kopczynski et al. sequence found in Figure 13 hereof (SEQ ID NO: 5 and SEQ ID NO: 6)) and Serrate (Fleming et al., 1990, Genes & Dev. 4, 2188-2201)] can be identified. Such sequences can be altered by substitutions, additions or deletions that provide for functionally equivalent (adhesive) molecules. Due to the degeneracy of nucleotide coding sequences, other DNA sequences which encode - substantially the same amino acid sequence as the adhesive sequences may be used in the practice of the present invention. These include but are not limited to nucleotide sequences comprising all or portions of the Notch, Delta , or Serrate genes which are altered by the substitution of different codons that encode a functionally equivalent amino acid residue within the sequence, thus producing a silent change. Likewise, the adhesive protein fragments or derivatives thereof, of the invention include, but are not limited to, those containing, as a primary amino acid sequence, all or part of the amino acid sequence' of the adhesive domains including altered sequences in which functionally equivalent amino acid residues are substituted for residues within the sequence resulting in a silent change. For example, one or more amino acid residues within the sequence can .be substituted by another amino acid of a similar polarity which acts as a functional equivalent, resulting in a silent alteration. Substitutes for an amino acid within the sequence may be selected from other members of the class to which the amino acid belongs. For example, the nonpolar (hydrophobic) amino acids include alanine, leucine, isoleucine, valine, proline, phenylalanine, tryptophan and methionine. The polar neutral amino acids include glycine, serine, threonine, cysteine, tyrosine, asparagine, and glutamine. The positively charged (basic) amino acids include arginine, lysine and histidine. The negatively charged (acidic) amino acids include aspartic acid and glutamic acid.

Adhesive fragments of toporythmic proteins and potential derivatives, analogs or peptides related to adhesive toporythmic protein sequences, can be tested for the desired binding activity e.g., by the in vitro aggregation assays described in. the examples herein. Adhesive derivatives or adhesive analogs of adhesive fragments of toporythmic proteins include but are not■ limited to those peptides which are substantially homologous to the adhesive fragments, or whose encoding nucleic acid is capable of hybridizing to the nucleic acid sequence encoding the adhesive fragments, and which peptides and peptide analogs have positive binding activity e.g., as tested in vitro by an aggregation assay such as described in the examples sections infra. Such derivatives and analogs are envisioned and within the scope of the present invention.

The adhesive-protein related derivatives,. analogs, and peptides of the invention can be produced by various methods known in the art. The manipulations which result in their production can occur at the gene or protein level. For example, the cloned adhesive protein-encoding gene sequence can be modified by any of numerous strategies known in the art (Maniatis, T., 1990, Molecular Cloning, A Laboratory Manual, 2d ed. , Cold Spring Harbor Laboratory, Cold Spring Harbor, New York). The sequence can be cleaved at appropriate sites with restriction endonuclease(s) , followed by further enzymatic modification if desired, isolated, and ligated in vitro . In the production of the gene encoding a derivative, analog, or peptide related to an adhesive domain, care should be taken to ensure that the modified gene remains within the same translational reading frame as the adhesive protein, uninterrupted by translational stop signals, in the gene region where the desired adhesive activity is encoded.

Additionally, the adhesive-encoding nucleic acid sequence can be mutated in vitro or in vivo , to create and/or destroy translation, initiation, and/or termination sequences, or to create variations in coding regions and/or form new restriction endonuclease sites or destroy preexisting ones, to facilitate further in vitro modification. Any technique for mutagenesis known in the art can be used, including but not limited to, in vitro site- directed mutagenesis (Hutchinson, C. , et al., 197.8, J. Biol. Chem 253, 6551), use of TAB® linkers (Pharmacia), etc.

Manipulations of the adhesive sequence may also be made at the protein level. Included within the scope of the invention are toporythmic protein fragments, analogs or derivatives which are differentially modified during or after translation, e.g. , by gl'ycosylation , acetylation, phosphorylation, proteolytic cleavage, linkage to an antibody molecule or other cellular ligand, etc. Any of numerous chemical modifications may be carried out by known techniques, including but not limited to specific chemical cleavage by cyanogen bromide, trypsin, chymotrypsin, papain, V8 protease, NaBH4; acetylation, ■ formylation, oxidation, reduction; metabolic synthesis in the presence of tunicamycin ; etc.

In addition, analogs and peptides related to adhesive fragments can be chemically synthesized. For example, a peptide corresponding to a portion of a toporythmic protein which mediates the desired aggregation activity in vitro can be synthesized by use of a peptide synthesizer.

Another specific embodiment of the invention relates to fragments or derivatives of a Delta protein which have the ability to bind to a second Delta protein or fragment or derivative thereof, but do not bind to Notch. Such binding or lack thereof can be assayed in vitro as described in Section 8. By way of example, but not limitation, such a Delta derivative is that containing an insertion of the tetrapeptide Arg-Lys-Ile-Phe between Delta residues 198 and 199 of the Drosophila protein. .2. THE CLONING AND SEQUENCING OF HUMAN NOTCH AND DELTA The invention further relates to the amino acid sequences of human Notch and human Delta and fragments and derivatives thereof which comprise an antigenic determinant (i.e., can be recognized by an antibody) or which are functionally active, as well as nucleic acid sequences encoding the foregoing.

"Functionally active" material as used herein refers to that material displaying one or more known functional activities associated with the full-length (wild-type) protein product, e.g., in the case of , Notch, binding to Delta, binding to Serrate, antigenicity (binding to an anti-Notch antibody) , etc.

In specific embodiments, the invention provides fragments of a human Notch protein consisting of at least 40 amino acids, or of at least 77 amino acids. In other embodiments, the proteins of the invention comprise or consist essentially of the intracellular domain, transmembrane region, extracellular domain, cdclO region, Notch/lin-12 repeats, or the EGF-homologous repeats, or any combination of the foregoing, of a human Notch protein. Fragments, or proteins comprising fragments, lacking some or all of the EGF-homologous repeats of human Notch are also provided.

In other specific embodiments, the invention is further directed to the nucleotide sequences and subsequences of human Notch and human Delta consisting of at least 25 nucleotides, at least 50 nucleotides, or at least 121 nucleotides. Nucleic acids encoding the proteins and protein fragments described above are also provided, as well as nucleic acids complementary to and capable of hybridizing to such nucleic acids. In one embodiment, such a complementary sequence may be complementary to a human Notch cDNA sequence of at least 25 nucleotides, or of at least 121 nucleotides. In a preferred aspect, the invention relates to cDNA sequences encoding human Notch or a portion thereof. In a specific embodiment, the invention relates to the nucleotide sequence of the human Notch gene or cDNA, in particular, comprising those sequences depicted in Figures 19, 20, 21 and/or 22 ( SEQ ID NO: 13 through NO:25), or contained in plasmids hN3k, hN4k, or hN5k (see Section 9, infra), and the encoded Notch protein sequences. As is readily apparent, as used herein, a "nucleic acid encoding a fragment or portion of a Notch protein" shall be construed as referring to a nucleic acid encoding only the recited fragment or portion of the Notch protein and not other portions of the Notch protein.

In a preferred, but not limiting, aspect of the invention, a human Notch DNA sequence can be cloned and sequenced by the method described in Section 9, infra .

A preferred embodiment for the cloning of human Delta , presented as a particular example but not by way of limitation follows: A human expression library is constructed by methods known in the art. For example, human mRNA is isolated, cDNA is made and ligated into an expression vector (e.g., a bacteriophage derivative) such that it is capable of being expressed by the host cell into which it is then introduced. Various screening assays can then be used to select for the expressed human Delta product. . In one embodiment, selection can be carried out on the basis of positive binding to the adhesive domain of human Notch, (i.e., that portion of human Notch most homologous to Drosophila ELR 11 and 12 (SEQ ID N0:1)). In an alternative embodiment, anti-Delta antibodies can be used for selection.

In another preferred aspect, PCR is used to amplify the desired sequence in the library, prior to selection. For example, oligonucleotide primers representing part of the adhesive domains encoded by a homologue of the desired gene can be used as primers in PCR.

The above-methods are not. meant to limit the following general description of methods by which clones of human Notch and Delta may be obtained.

Any human cell can potentially serve as the nucleic acid source for the molecular cloning of the Notch and Delta gene. The DNA may be obtained by standard procedures known in the art from cloned DNA (e.g. , a DNA "library") , by chemical synthesis, by cDNA cloning, or by the cloning of genomic DNA, or fragments thereof, purified from the desired human cell. (See, for example Maniatis et al., 1982, Molecular Cloning, A Laboratory Manual, Cold Spring Harbor Laboratory, Cold Spring Harbor, New York; Glover, D.M. (ed.), 1985, DNA Cloning: A Practical Approach, MRL Press, Ltd., Oxford, U.K. Vol. I, II.) Clones derived from genomic DNA may contain regulatory and intron DNA regions in addition to coding regions; clones derived from cDNA will contain only exon sequences. Whatever the source, the gene should be molecularly cloned into a . suitable vector for propagation of the gene.

In the molecular cloning of the gene from genomic DNA,. DNA fragments are generated, some of which, will encode the desired gene. The DNA may be cleaved at specific sites using various restriction enzymes. Alternatively, one may use DNAse in the presence of manganese to fragment the DNA, or the DNA. can be physically sheared, as for example, by sonication. The linear DNA fragments can then be separated according to size by standard techniques, including but not limited to, agarose and polyacrylamide gel electrophoresis and column chromatography.

Once the DNA fragments are generated, identification of the specific DNA fragment containing the desired gene may be accomplished in a number of ways. For example, if an amount of a portion of a Notch or Delta (of any species) gene or its specific RNA, or a fragment thereof e.g., the adhesive domain, is available and can be purified and labeled, the generated DNA fragments may be screened by nucleic acid hybridization to the labeled probe (Benton, . and Davis, R. , 1977, Science 196, 180; Grunstein, M. And Hogness, D. , 1975, Proc. Natl. Acad. Sci. U.S.A. 72, 3961). Those DNA fragments with substantial homology to the probe will hybridize. It is also possible to identify the appropriate fragment by restriction enzyme digestion (s) and comparison of fragment sizes with those expected according to a known restriction map if such is available. Further selection can be carried out on the basis of the proper-ties of the gene. Alternatively , ' the presence of the gene may be detected by assays based on the physical, chemical, or immunological properties of its. expressed product. For example, cDNA clones, or DNA clones which hybrid-select the proper mRNAs, can be selected which produce, a protein that, e.g. ,· has similar or identical electrophoretic migration, isolectric focusing behavior, proteolytic digestion maps, in vitro aggregation activity ("adhesiveness") or antigenic properties as known for Notch or Delta.

If an antibody to Notch or Delta is available, the Notch or Delta protein may be identified by binding of labeled antibody to the putatively Notch or Delta synthesizing clones, in an ELISA (enzyme-linked immunosorbent assay) -type procedure.

The Notch or Delta gene can also be identified by mRNA selection by nucleic acid hybridization followed by in vitro translation. In this procedure, fragments are used to isolate complementary mRNAs by hybridization. Such DNA fragments may represent available, purified Notch or Delta DNA of another species (e.g., Drosophila) .

Immunoprecipitation analysis or functional assays (e.g. , aggregation ability in vitro; see examples infra) of the in vitro translation products of the isolated products of the isolated mRNAs identifies the mRNA and, therefore, the complementary DNA fragments that contain the desired sequences. In addition, specific mRNAs may be selected by adsorption of polysomes isolated from cells to immobilized antibodies specifically directed against Notch or Delta protein. A radiolabelled Notch or Delta cDNA can be synthesized using the selected mRNA (from the adsorbed polysomes) as a template. The radiolabelled mRNA or cDNA may then be used as a probe to identify the Notch or Delta DNA fragments from among other genomic DNA fragments .

Alternatives to isolating the Notch or Delta genomic DNA include, but are not limited to, chemically synthesizing the gene sequence itself from a known sequence or making cDNA to the mRNA which encodes the Notch or Delta gene. For example, RNA for cDNA cloning of the Notch or Delta gene can be isolated from cells which express Notch or Delta.

Other methods are possible and within the scope of the invention.

The identified and isolated gene can then be inserted into an appropriate cloning vector. A large number of vector-host systems known in the art may be used. Possible vectors include, but are not limited to, plasmids or modified viruses, but the vector system must be compatible with the host cell used. Such vectors include, but are not limited to, bacteriophages such as lambda derivatives, or plasmids such as PBR322 or pUC plasmid derivatives. The insertion into a cloning vector can, for example, be accomplished by ligating the DNA fragment into a cloning vector which has complementary cohesive termini. However, if the complementary restriction sites used to fragment the DNA are not present in the cloning vector, the ends of the DNA molecules may be enzymatically modified. Alternatively, any site desired may be produced by ligating nucleotide sequences (linkers) onto the DNA termini; these ligated linkers may comprise specific chemically synthesized oligonucleotides encoding restriction endonuclease recognition sequences. -In an alternative method, the cleaved vector and Notch or Delta gene may be modified by homopolymeric tailing. Recombinant molecules can be introduced into host cells via transformation, transfection , infection, electroporation, etc. , so that many copies of the gene sequence are generated.

In an alternative method, the desired gene may be identified and isolated after insertion into a suitable cloning vector in a "shot gun" approach.

Enrichment for the desired gene, for example, by size fractionization, can be done before insertion into the cloning vector.

In specific embodiments, transformation of host cells with recombinant DNA molecules that incorporate the isolated Notch or Delta gene, cDNA, or synthesized DNA sequence enables generation of multiple copies of the gene. Thus, the gene may be obtained in large quantities by growing transformants , isolating' the recombinant DNA molecules from the transformants and, when necessary, retrieving the inserted gene from the isolated recombinant DNA.

The human Notch and Delta sequences provided by the instant invention include those nucleotide sequences encoding substantially the same amino acid sequences as found in human Notch and in human Delta, and those encoded amino acid sequences with functionally equivalent amino acids, all as described supra in Section 5.1 for adhesive portions of toporythmic proteins. .3. IDENTIFICATION OF ADDITIONAL MEMBERS OF THE DELTA/SERRATE FAMILY ·. : ■ A rational search for additional members of the Delta/Serrate gene family may be carried out using an approach that takes advantage of the existence of the conserved segments of strong homology between Serrate and Delta (see Figure 10, SEQ ID NO: 3 and NO:4). For example, additional members of this gene family may be identified by selecting, from among a diversity of nucleic acid sequences, those sequences that are homologous to both Serrate and Delta (see Figure 13 (SEQ ID NO: 5), and Figure 15 (SEQ ID N0:8)), and further identifying, from among the selected sequences, those that also contain nucleic acid sequences which are non-homologous to Serrate and Delta . The term "non-homologous" may be construed to mean a region which contains at least about 6 contiguous nucleotides in which at least about two nucleotides differ from Serrate and Delta sequence.

For example, a preferred specific embodiment of the invention provides the following method.

Corresponding to two conserved segments between Delta and Serrate, Delta AA 63-73 and Delta AA 195-206 (see Figure 13, SEQ ID NO:6), sets of degenerate oligonucleotide probes of about 10-20 nucleotides may be synthesized, representing all of the possible coding sequences for the amino acids found in either Delta and Serrate for about three to seven contiguous . codons. In another embodiment, oligonucleotides may be obtained corresponding to parts of the four highly conserved regions between Delta and Serrate shown in Figure 15 (SEQ ID NO: 8 and NO: 9), i.e., that represented by Serrate AA 124-134, 149-158, 214-219, and 250-259. The synthetic oligonucleotides may be utilized as primers- to amplify by PCR sequences from a source (RNA or DNA) of potential interest. (PCR can be carried out, e.g., by use of a Perkin-El er Cetus thermal cycler and Taq polymerase (Gene Amp™)). This might include mRNA or cDNA or genomic DNA from any eukaryotic species that could express a polypeptide closely related to Serrate and Delta. By carrying out the PCR reactions, it may be possible to detect a gene or gene product sharing the above-noted segments of conserved sequence between Serrate and Delta. If one chooses to synthesize several different degenerate primers, it may still be possible to carry out a complete search with a reasonably small number of PCR reactions. It is also possible to vary the stringency of hybridization conditions used in priming the PCR reactions, to allow for greater or lesser degrees of nucleotide sequence similarity between the unknown gene and Serrate or Delta . If a segment of a previously unknown member of the Serrate/Delta gene family is amplified successfully, that segment may be molecularly cloned and sequenced, and utilized as a probe to isolate a complete cDNA or genomic clone.

This, in turn, will permit the determination of the unknown gene's complete nucleotide sequence, the analysis of its expression, and the production of its protein product for functional analysis. In this fashion, additional genes encoding "adhesive" proteins may be identified.

In addition, the present invention provides for the use of the Serrate/Delta sequence homologies in the design of novel recombinant molecules which are members of the Serrate/Delta gene family but which may not occur in nature. For example, and not by way of limitation, a recombinant molecule can be constructed according to the invention, comprising portions of both Serrate and Delta genes. Such a molecule could · exhibit properties associated with both Serrate and Delta and portray a novel profile of biological activities, including agonists as well as antagonists. The primary sequence of Serrate and Delta may also be used to predict tertiary structure of the molecules using computer simulation (Hopp and Woods, 1981, Proc. Natl. Acad. Sci. U.S.A. 78, 3824-3828); Serrate/Delta chimeric recombinant genes could be designed in light of correlations between tertiary structure and biological function. Likewise, chimeric genes comprising portions of any one or more members of the toporythmic gene family (e.g., Notch) may be constructed. .4. THE EXPRESSION OF TOPORYTHMIC GENES The nucleotide sequence coding for an adhesive fragment of a toporythmic protein (preferably, Notch , Serrate, or Delta) , or an adhesive analog or derivative thereof, or human Notch or Delta or a functionally active fragment or derivative thereof, can be inserted into an appropriate expression, vector, i.e., a vector which contains the necessary elements for the transcription and translation of the inserted protein-coding sequence. The necessary transcriptional and -translational signals can also be supplied by the native toporythmic gene and/or its flanking regions. A variety of host- vector systems may be utilized to express the protein- coding sequence. These include but are not limited to mammalian cell systems infected with virus (e.g. , vaccinia virus, adenovirus, etc.); insect cell systems infected with virus (e.g. , baculovirus) ; microorganisms such as yeast containing yeast vectors, or bacteria transformed with bacteriophage, DNA, plasmid DNA, or cosmid DNA. The expression elements of vectors vary in their strengths and specificities. · Depending on the host-vector system utilized, any one of a number of suitable transcription and translation elements may be used. In a specific embodiment, the adhesive portion of the Notch gene, e.g., that' encoding EGF-like repeats 11 and 12, is expressed. In another embodiment, the adhesive portion of the Delta gene, e.g., that encoding amino acids 1-230, is expressed. In other specific embodiments, the human Notch or human Delta gene is expressed, or a sequence encoding a functionally active portion of human Notch or. Delta. In yet another embodiment, the adhesive portion of the Serrate gene is expressed.

Any of the methods previously described for the insertion of DNA fragments into a vector may be used to construct expression vectors containing a chimeric gene consisting of appropriate transcriptional/translational control signals and the protein coding sequences. These methods may include in vitro recombinant DNA and synthetic techniques and in vivo recombinants (genetic recombination) .

Expression of nucleic acid sequence encoding a toporythmic protein or peptide fragment may be regulated by a second nucleic acid sequence so that the toporythmic protein or peptide is expressed in a host transformed with the recombinant DNA molecule. For example, expression of a toporythmic protein may be controlled by any promoter/ enhancer element known in the art. Promoters which may be used to control toporythmic gene expression include, but are not limited to, the SV40 early promoter region (Bernoist and Chambon, 1981, Nature 290, 304-310), the promoter contained in the 3 ' long terminal repeat of Rous sarcoma virus (Yamamoto, et al., 1980, Cell 22, 787-797) , the herpes thymidine kinase promoter (Wagner et al., 1981, Proc. Natl. Acad. Sci. U.S.A. 78, 1441-1445) , the regulatory sequences of the metallothionein gene (Brinster et al., 1982, Nature 296, 39-42); prokaryotic expression vectors such as the /3-lactamase promoter (Villa-Kamaroff , et al., 1978, Proc. Natl. Acad. Sci. U.S.A. 75, 3727-3731), or the tac promoter (DeBoer, et al., 1983, Proc. Natl. Acad. Sci. U.S.A. 80, 21-25); see also "Useful proteins from recombinant bacteria" in Scientific American, 1980, 242, 74-94; plant expression vectors comprising the nopaline synthetase promoter region (Herrera-Estrella et al., Nature 303, 209-213) or the cauliflower mosaic virus 35S RNA promoter (Gardner, et al., 1981, Nucl. Acids Res. 9, 2871), and the promoter of the photosynthetic ' enzyme ribulose biphosphate carboxylase (Herrera-Estrella et al., 1984, Nature 310, 115-120); promoter elements from yeast or other fungi such as the Gal .4 promoter, the ADC (alcohol dehydrogenase) promoter, PGK (phosphoglycerol kinase) promoter, alkaline phosphatase promoter, and the following animal transcriptional control regions, which exhibit tissue specificity and have been utilized in transgenic animals: elastase I gene control region which is active in pancreatic acinar cells' (Swift et al., 1984, Cell 38, 639-646; Ornitz et al., 1986, Cold Spring Harbor Symp. Quant. Biol. 50, 399-409; acDonald, 1987, Hepatology 7, 425-515); insulin gene control region which is active in pancreatic beta cells (Hanahan, 1985, Nature 315, 115-122) , immunoglobulin gene control region which is active in lymphoid cells (Grc^sschedl et al., 1984, Cell 38, 647-658; Adames et al., 1985, Nature 318, 533-538; Alexander et al., 1987, Mol. Cell. Biol.. 7, 1436-1444), mouse mammary tumor virus control region which is active in testicular, breast, lymphoid and mast cells (Leder et al., 1986, Cell 45, 485-495), albumin gene control region which is active in liver (Pinkert et al., 19.87, Genes and Devel. 1, 268-276) , alpha-fetoprotein gene control region which is active in liver (Krumlauf et al., 1985, Mol. Cell. Biol. 5, 1639-1648; Hammer et al., 1987, Science 235, 53-58; alpha 1-antitrypsin gene control region which is active in the liver (Kelsey et al., 1987, Genes and Devel. 1, 161-171), beta-globin gene control region which is active in myeloid cells' (Mogram et al., 1985,' Nature 315, 338- · 340; Kollias et al., 1986, Cell 46, 89-94; myelin. basic protein gene control region which is active in oligodendrocyte cells in the brain (Readhead et al..., 1987, Cell 48, 703-712); myosin light chain-2 gene control region which is active in skeletal muscle (Sani, 1985, Nature 314, 283-286), and gonadotropic . releasing hormone gene control region which is active in the hypothalamus (Mason et al., 1986, Science 234, 1372-1378) .

Expression vectors containing toporythmic gene inserts can be identified by three general approaches: (a) nucleic acid hybridization, (b) presence or absence of "marker" gene functions, and (c) expression of inserted sequences. In the first approach, the presence of a foreign gene inserted in an expression vector can be detected by nucleic acid hybridization using probes comprising sequences that are homologous to an inserted toporythmic gene. In the second approach, the recombinant vector/host system can be identified and selected based upon the presence or absence of certain "marker" gene functions (e.g. , thymidine kinase activity, resistance to antibiotics, transformation phenotype, occlusion body formation in baculovirus, etc.) caused by the insertion of foreign genes in the vector. For example, if the toporythmic gene is inserted within the marker gene sequence of the vector, recombinants containing the toporythmic insert can be identified by the absence of the marker gene function. In the third approach, recombinant expression vectors can be identified by assaying the foreign gene product expressed by the recombinant. Such assays can be based, for example, on the physical or functional properties of the toporythmic gene product in vitro assay systems, e.g., aggregation (adhesive) . ability (see Sections 6-8, infra) .

Once a particular recombinant DNA molecule is identified and isolated, several .methods known in the art may be used to propagate it. Once a suitable host system and growth conditions are . established, recombinant expression vectors can be propagated and prepared in quantity. As previously explained, the expression vectors which can be used include, but are not limited to, the following vectors or their derivatives: human or animal viruses such as vaccinia virus or adenovirus; insect viruses such as baculovirus ;. yeast vectors; bacteriophage vectors (e.g. , lambda) , and plasmid and cosmid DNA vectors, to name but a few.

In addition, a host cell strain may be chosen which modulates the expression of the inserted sequences, or modifies and processes the gene product in the specific fashion desired. Expression from certain promoters can be elevated in the presence of certain inducers; thus, expression of the genetically engineered toporythmic protein- may be. controlled.

Furthermore, different host cells have characteristic and specific mechanisms for the translational and post-translational processing and modification (e.g. , glycosylation, cleavage) of proteins. Appropriate cell lines or host systems can be chosen to ensure the desired modification and processing of the foreign protein expressed. For example, expression in a bacterial system can be used to produce an unglycosylated core protein product. Expression in yeast will produce a glycosylated product. Expression in mammalian cells can be used to ensure "native" glycosylation of a heterologous mammalian toporythmic protein. Furthermore, different vector/host expression systems may effect processing reactions such as proteolytic cleavages to different extents.

' In other specific embodiments, the adhesive toporythmic protein, fragment, analog, or derivative may be expressed as a fusion, or chimeric protein product (comprising the protein, fragment, analog, or derivative joined to a heterologous protein sequence) . Such a chimeric product can be made by ligating the appropriate nucleic acid sequences encoding the desired amino acid sequences to each other by methods known in the art, in the proper coding frame, and expressing the chimeric product by methods commonly known in the art. Alternatively, such a chimeric product may be made by protein synthetic techniques, e.g., by use of a peptide synthesizer.

Both cDNA and genomic sequences can be cloned and expressed.

In other embodiments, a human Notch cDNA sequence may be chromosomally integrated and expressed. Homologous recombination procedures known in the art may be used. .4.1. IDENTIFICATION AND PURIFICATION OF THE EXPRESSED GENE PRODUCT.

Once a recombinant which expresses the toporyth ic gene sequence is identified, the gene product may be analyzed. This can be achieved by assays based on the physical or functional properties of the product, including radioactive labelling of the product followed by analysis by gel electrophoresis.

Once the toporythmic protein is identified, it may be isolated and purified by standard methods including chromatography (e.g. , ion exchange, affinity, and sizing column chromatography) , centrif gation, differential solubility, or by any other standard technique for the purification of proteins. The functional properties may be evaluated using any suitable assay, including, but not limited to, aggregation assays (see Sections 6-8) . .5. GENERATION OF ANTIBODIES TO TOPORYTHMIC PROTEINS AND ADHESIVE SEQUENCES THEREOF According to the invention, toporythmic protein fragments or analogs or derivatives thereof which mediate homotypic or heterotypic binding, or human Notch or human Delta proteins or fragments thereof, may be used as an immunogen to generate anti- toporythmic protein antibodies. Such antibodies can ' be polyclonal or monoclonal. In a specific embodiment, antibodies specific to EGF-like repeats 11 and 12 of Notch may be prepared. In other embodiments, antibodies reactive with the "adhesive portion" of Delta can be generated. One example of such antibodies may prevent aggregation in an in vitro assay. In another embodiment, antibodies specific to human Notch are produced.

Various procedures known in the art may be ! used for the production of polyclonal antibodies to a toporythmic protein or peptide. In a particular embodiment, rabbit polyclonal antibodies to an epitope of the human Notch protein encoded by a sequence depicted in Figure 19, 20, 21 or 22 (SEQ ID NO: 13 through NO:25), or a subsequence thereof, can be obtained. For the production of antibody, various host animals can be immunized by injection with the native toporythmic protein, or a synthetic version, or fragment thereof, including but not limited to rabbits, mice, rats, etc. Various adjuvants may be used to increase the immunological response, depending on the host species, and including but not limited to Freund's (complete and incomplete), mineral gels such as aluminum hydroxide, surface active substances such as lysolecithin, pluronic polyols, polyanions, peptides, oil emulsions, keyhold limpet hemocyanins, dinitrophenol , and potentially useful human adjuvants such as BCG (bacille Calmette-Guerin) and corynebacterium parvum..

For preparation of monoclonal antibodies directed toward a toporythmic protein sequence, any technique which provides for the production of antibody molecules by continuous cell lines in culture may be used.- For example, the hybridoma technique originally developed by Kohler and ilstein (1975, Nature 256, 495-497), as well as the trioma technique, the human B-cell hybridoma technique (Kozbor et al., 1983, Immunology Today 4, 72), and the EBV-hybridoma technique to produce human monoclonal antibodies (Cole et al., 1985, in Monoclonal Antibodies and Cancer Therapy, Alan R. Liss, Inc., pp. 77-96).

Antibody fragments which contain the idiotype of the molecule can be generated by known techniques. For example, such fragments include but are not limited to: the F(ab')2 fragment which can be produced by pepsin digestion of the antibody molecule; the Fab1 fragments which can be generated by reducing the disulfide bridges of the F(ab')2 fragment, and the Fab fragments which can be generated by treating the antibody molecule with papain and a reducing agent.

In the production of antibodies, screening for the desired antibody can be accomplished by techniques known in the art, e.g. ELISA (enzyme-linked immunosorbent assay). For example, to select antibodies which recognize the adhesive domain of a toporythmic protein, one may assay generated hybridomas for a product which binds to a protein fragment containing such domain. For selection of an antibody specific to human Notch, one can select on the basis of positive binding to human Notch and a lack of binding to Drosophila Notch.

The foregoing antibodies can be used in methods known in the art relating to the localization and activity of the protein sequences of the invention. For example, various immunoassays . known in the art can be used, including but not limited to competitive and non-competitive assay systems using techniques such as radioimmunoassays, ELISA (enzyme linked immunosorbent assay) , "sandwich" immunoassays, precipitin reactions, gel diffusion precipitin reactions, immunodiffusion assays, agglutination assays, fluorescent immunoassays, protein A immunoassays, and Immunoelectrophoresis assays, to name but a few. .6. DELIVERY OF AGENTS INTO NOTCH-EXPRESSING CELLS The invention also provides methods for delivery of agents into Notch-expressing cells. As discussed in Section 8 infra , upon binding to a Notch protein on the surface of a Notch-expressing cell, Delta protein appears to be taken up into the Notch-expressing cell. The invention thus provides for delivery of agents into a Notch-expressing cell by conjugation of an agent to a Delta protein or an adhesive fragment or derivative thereof capable of binding to Notch, and exposing a Notch-expressing cell to the conjugate, such that the conjugate is taken up by the cell. The conjugated agent can be, but is not limited to, a label or a biologically active agent. The biologically active agent can be a therapeutic agent, a toxin, a chemotherapeutic, a growth factor, an enzyme, a hormone, a drug, a nucleic acid, (e.g., antisense DNA or R A) , etc. In one embodiment, the label can be an imaging agent, including but not ' limited to heavy metal contrast agents for x-ray imaging, magnetic resonance imaging agents, and radioactive nuclides (i.e., isotopes) for radio-imaging. In a preferred aspect,, the agent is conjugated to a site in the amino terminal half of the Delta molecule.

The Delta-agent conjugate can be' delivered to the Notch-expressing cell by exposing the Notch-expressing cell to cells expressing the Delta-agent conjugate or exposing the Notch-expressing cell to the Delta-agent conjugate in a solution, suspension, or other carrier. Where delivery is in. vivo, the Delta-agent conjugate can be formulated in a pharmaceutically acceptable carrier or excipient, to comprise a pharmaceutical composition. The pharmaceutically acceptable carrier can comprise saline, phosphate buffered saline, etc. The Delta-agent conjugate can be formulated as a liquid, tablet, pill, powder, in a slow-release form, in a liposome, etc., .and can be administered orally, intravenously, intramuscularly, subcutaneous ly, intraperitoneally , to name but a few routes, with the preferred choice readily made based on the knowledge of one skilled in the art . 6. MOLECULAR INTERACTIONS BETWEEN THE PROTEIN PRODUCTS OF THE NEUROGENIC LOCI NOTCH AND DELTA , TWO EGF-HOMOLOGOUS GENES IN DROSOPHILA To examine the possibility of intermolecular association between the products of the Notch and Delta genes, we studied the effects of their expression on aggregation in Drosophila Schneider's 2 (S2) cells (Fehon et al., 1990, Cell 61, 523-534). We present herein direct evidence of intermolecular interactions between Notch and Delta, and describe an assay system that will be used in dissecting the components of this interaction. We show that normally nonadhesive Drosophila S2 cultured cells that express Notch bind specifically to cells that express Delta, and that this aggregation is calcium dependent.

Furthermore, while cells that express Notch do not bind to one another, cells that express Delta do bind to one another, suggesting that Notch and Delta can compete for binding to Delta at the cell surface. We also present evidence indicating that Notch and Delta form detergent-soluble complexes both in cultured cells and embryonic cells, suggesting that Notch and Delta interact directly at the molecular level in vitro and in vivo. Our analyses suggest. that Notch and Delta proteins interact at the cell surface via their extracellular domains. 6.1. EXPERIMENTAL PROCEDURES . 6.1.1. EXPRESSION CONSTRUCTS For the Notch expression construct, the 6 kb Hpal fragment from the 5' end ..of the Notch coding sequence in Mglla (Ramos et al., 1989, Genetics 123, 337-348) was blunt-end ligated into the metallothionein promoter vector pRmHa-3 (Bunch, et al., 1988, Nucl. Acids Res. 16, 1043-1061) after the vector had been cut with EcoRI and the ends were filled with the Klenow fragment of DNA polymerase I (Maniatis et al., 1982, Molecular Cloning: A Laboratory Manual (Cold Spring Harbor, New York: Cold Spring Harbor Laboratory) ) . A single transformant, incorrectly oriented, was isolated. DNA from this transformant was then digested with Sacl, and a resulting 3 kb fragment was isolated that contained the 5 ' end of the Notch coding sequence fused to the polylinker from pRmHa-3. This fragment was then ligated into the Sacl site of pRmHa-3 in the correct orientation. DNA from this construct was digested with Kpnl and Xbal to remove must of the Notch sequence and all of the- Adh polyadenylation signal in pRmHa-3 and ligated to an 11 kb Kpnl-Xbal fragment from Mglla containing the rest of the Notch coding -sequence and 3' sequences necessary for polyadenylation. In the resulting construct, designated pMtNMg, the metallothionein promoter in pRmHa-3 is fused to Notch sequences starting 20 nucleotides upstream of the ' translation start site.' For the extracellular Notch construct (ECN1) , the CosP479BE Notch cosmid (Ramos et. al., 1989, Genetics 123, 337-348), which contains all Notch genomic sequences necessary for normal Notch function in vivo , was partially digested with Aatll. Fragment ends were made blunt using the exonuclease activity of T4 DNA polymerase (Maniatis et al., 1982, Molecular Cloning: A Laboratory Manual (Cold Spring Harbor, New York: Cold Spring Harbor Laboratory) ) , and the fragments were then r.edigested- completely with Stul . The resulting fragments were separated in a low melting temperature agarose gel (SeaPlaque, FMC BioProducts) , and the largest fragment was excised. This fragment was then blunt-end ligated to itself. This resulted in an internal deletion of the Notch coding sequences. from amino acid 1790 to 2625 inclusive (Wharton et al., 1985, Cell 43, 567-581), and a predicted frameshift that produces a novel 59 amino acid carboxyl terminus. (The ligated junction of this construct has not been checked by sequencing.) For the Delta expression construct, the Dll cDNA (Kopczynski et al., 1988, Genes Dev. 2, 1723-1735) , which includes the complete coding capacity for Delta, was inserted into the EcoRI site of pRraHa-3. This construct was called pMTDll. 6.1.2. ANTIBODY PREPARATION Hybridoma cell line C17.9C6 was obtained from a mouse immunized with a fusion protein based on a 2.1 kb Sall-Hindlll fragment that includes coding sequences for most of the intracellular domain of Notch (amino acids 1791-2504; Wharton- et al., 1985, Cell 43, 567-581). The fragment was subcloned into pUR289 (Ruther and Muller-Hill , 1983, EMBO J. 2, 1791-1794) , and then transferred into the pATH 1 expression vector (Dieckmann and Tzagoloff, 1985, J. Biol. Chem. 260, 1513-1520) as a Bglll-Hindlll fragment. Soluble fusion protein was expressed, precipitated by 25% -(NH4)2S04, resuspended in 6 M urea, and purified by preparative isoelectric focusing using a Rotofor (Bio-Rad) (for details, see Fehon, 1989, Rotofor Review No. 7, Bulletin 1518, Richmond, California: Bio-Rad Laboratories) .

Mouse polyclonal antisera were raised against the extracellular domain of Notch using four BstYl fragments of 0.8 kb (amino acids 237-501: Wharton et al., 1985, Cell 43, 567-581), 1.1 kb (amino acids 501-868), 0.99 kb (amino acids 868-1200), and 1.4 kb (amino acids 1465-1935) length, which spanned from the fifth EGF-like repeat across the transmembrane domain, singly inserted in-frame into the appropriate pGEX expression vector (Smith and Johnson, 1988, Gene 67, 31-40). Fusion proteins were purified on glutathione-agarose beads' (SIGMA) . Mouse and rat antisera were precipitated with 50% (NH)2S04 and resuspended in PBS (150 mM NaCl, 14 mM Na2HP04, 6 mM NaH2P04) with 0.02% NaN3.

Hybridoma cell line 201 was obtained from a mouse immunized with a fusion protein based on a 0.54 kb Clal fragment that includes coding sequences from the extracellular domain of Delta (Kopczynski et al., 1988, Genes Dev. 2, 1723-1735) subcloned into the Clal site within the lacZ gene of pUR 288 (Ruther and Muller-Hill, 1983, EMBO J. 2, 1791-1794). This fragment includes sequences extending from the fourth through the ninth EGF-like repeats in Delta (amino acids 350-529) . Fusion protein was prepared by isolation of inclusion bodies (Gilmer et al., 1982, Proc. Natl. Acad. Sci. USA 79, 2152-2156); inclusion bodies were solubilized in urea (Carroll and- Laughon, 1987, in DNA Cloning, Volume III, D.M. Glover, ed.

(Oxford: IRL Press), pp. 89-111) before use in immunization.

Rat polyclonal antisera were obtained following immunization with antigen derived from the same fusion protein construct. In this case, fusion protein was prepared by lysis of IPTG-induced cells in SDS-Laemmli buffer (Carroll and Laughon, 1987, in DNA Cloning, Volume III, D.M. Glover, ed. (Oxford: IRL Press) , pp. 89-111) , separation of proteins by SDS-PAGE, excision of the appropriate band from the gel, and electroelution of antigen from the gel slice for use in immunization (Harlow and Lane, 1988, Antibodies: A Laboratory Manual (Cold Spring Harbor, New York: Cold Spring Harbor Laboratory)). 6.1.3. CELL CULTURE AND TRANSFECTION The S2 cell line (Schneider, 1972, J.

E bryol. Exp. Morph. 27, 353-365) was grown in M3' medium (prepared by Hazleton Co.) supplemented with 2.5 mg/ml Bacto-Peptone (Difco) , 1 mg/ml TC Yeastolate (Difco) , 11% heat-inactivated fetal calf serum (FCS) (Hyclone) , and 100 U/ml penicillin-100 /ig/ml streptomyein-0.25 ^g/ml fungizone (Hazleton). Cells growing in log phase at ~2 x 106 cells/ml were transfected with 20 /ig of DNA-calcium phosphate coprecipitate in 1 ml per 5 ml of culture as previously described (Wigler et al., 1979, Proc. Natl. Acad. Sci. USA 78, 1373-1376), with the exception that BES buffer (SIGMA) was used in place of.HEPES buffer (Chen and Okayama, 1987, Mol. Cell. Biol. 7, 2745- 2752) . After 16-18 hr, cells were transferred to conical centrifuge tubes, pelleted in a clinical centrifuge at full speed for 30 seconds, rinsed once with 1/4 volume of fresh complete medium, resuspended in their original volume of complete medium, and returned to the original flask. Transfected cells were then allowed to recover for 24 hr before induction. ' 6.1.4. AGGREGATION ASSAYS Expression of the Notch and Delta metallothionein constructs was induced by the addition of CuS04 to 0.7 mM. Cells transfected with the ECN1 construct were treated similarly. Two types of aggregation assays were used. In the first assay, a total of 3 ml of cells (5-10 x 106· cells/ml) was placed in a 25 ml Erlenmeyer flask and rotated at 40-50 rpm on a rotary shaker for 24-48 hr at room temperature. For these experiments, cells were mixed 1-4 hr after induction began and induction was continued throughout the aggregation period. In the second assay, -0.6 ml of cells were placed in a 0.6 ml Eppendorf tube (leaving a small bubble) after an overnight induction (12-16 hr) at room temperature and rocked gently for 1-2 hr at 4°C. The antibody inhibition and Ca2+ dependence experiments were performed using the latter assay. For Ca2+ dependence experiments, cells were first collected and rinsed in balanced saline solution (BSS) with 11% FCS (BSS-FCS; FCS was dialyzed against o.9% NaCl, 5mM Tris [pH 7.5]) or in Ca2+ free BSS-FCS containing 10 mM EGTA (Snow et al., 1989, Cell 59, 313-323) and then resuspended in the same medium at the original volume. For the antibody inhibition experiments, Notch-transfected cells were collected and rinsed in M3 medium and then treated before aggregation in M3 medium for 1 hr at 4 C with a 1:250 dilution of immune or preimmune sera from each of the four mice immunized with fusion proteins containing segments from the extracellular domain of Notch (see Antibody Preparation above) . .6.1.5. IMMUNOFLUORESCENCE Cells were collected by centrifugation (3000 rpm for 20 seconds in an Eppendorf microcentrifuge) and fixed in 0.6 ml Eppendorf tubes with 0.5 ml of freshly made 2% paraformaldehyde in PBS for 10 min at room temperature. After fixing, cells were collected by centrifugation, rinsed twice in PBS, and stained for 1 hr in primary antibody in PBS with 0.1% saponin (SIGMA) and 1% normal goat serum (Pocono Rabbit Farm, Canadensis, PA). Monoclonal antibody supernatants were diluted 1:10 and mouse or rat sera were diluted 1:1000 for this step. Cells were, then rinsed once in PBS and stained for 1 hr in specific secondary antibodies (double-labeling grade goat anti-mouse and goat anti-rat, Jackson Immunoresearch) in PBS-saponin-normal goat serum. After this incubation, cells were rinsed twice in PBS and mounted on slides in 90% glycerol, 10% 1 M Tris (pH 8.0), and 0.5% n-propyl gallate. Cells were viewed under epifluorescence on a Leitz Orthoplan 2 microscope.

Confocal micrographs were taken using the Bio-Rad MRC 500 system connected to a Zeiss Axiovert compound microscope. Images were collected using the BHS and GHS filter sets, aligned using the ALIGN program, and merged using MERGE. Fluorescent bleed-through from the green into the red channel was reduced using the BLEED program (all software provided by Bio-Rad) . Photographs were obtained directly from the computer monitor using Kodak Ektar- 125 film. 6.1.6. CELL LYSATES , IMMUNOPRECIPITATIONS , AND WESTERN BLOTS ' Nondenaturing detergent lysates of tissue culture and wild-type Canton-S embryos were prepared on ice in -10 cell vol of lysis buffer (300 mM NaCl, 50 mM Tris [pH 8.0], 0.5% NP-40, 0.5% deoxycholate , 1 mM CaCl2/ 1 mM MgCl2) with 1 mM phenylmethysulfonyl fluoride (PMSF) and diisopropyl fluorophosphate diluted 1:2500 as protease inhibitors. Lysates were sequentially triturated using 18G, 21G, and 25G needles attached to 1 cc tuberculin syringes and then . centrifuged at full speed in a microfuge 10 min at 4°C to remove insoluble material. Immunoprecipitation was performed by adding -1 μ<3 of antibody (1-2 μΐ. of polyclonal antiserum) to 250-500 μΐ of cell lysate and incubating for 1 hr at 4°C with agitation. To this mixture, 15 μ-q of goat anti-mouse antibodies (Jackson Immunoresearch; these antibodies recognize both mouse and rat IgG) were added and allowed to incubate for 1 hr at 4°C with agitation. This was followed by the addition of 100 μΐ of fixed Staphylococcus aureus (Staph A) bacteria (Zysorbin, Zymed; resuspended according to manufacturer's instructions), which had been collected, washed five times in lysis buffer, and incubated for another hour. Staph A-antibody complexes were then pelleted by centrifugation and washed three times in lysis buffer followed by two 15 min washes in lysis buffer. After being transferred to a new tube, precipitated material was suspended in 50 μΐ of SDS-PAGE sample buffer, boiled immediately for 10 min, run on 3%-15% gradient gels, blotted to nitrocellulose, and detected using monoclonal antibodies and HRP-conjugated goat anti-mouse secondary antibodies as previously described (Johansen et al., 1989, J. Cell Biol. 109, 2427-2440). For total cellular protein samples used on Western blots (Figure 2) , cells were collected by centrifugation, lysed in 10 cell vol of sample buffer that contained 1 mM PMSF, and boiled immediately. 6.2. RESULTS 6.2.1. THE EXPRESSION OF NOTCH AND DELTA IN CULTURED CELLS To detect interactions between Notch and Delta, we examined the behavior of cells expressing these proteins on their surfaces using an aggregation assay. We chose the S2 cell line (Schneider, 1972, J. Embryol. Exp. Morph. 27, 353-365) for these studies for several reasons. First, these cells are. relatively nonadhesive, grow in suspension, and have been used previously in a similar assay to study fasciclin III function (Snow et al., 1989, Cell 59, 313-323) . Second, they are readily transfectable , and an inducible etallothionein promoter vector that has been designed for expression of exogenous genes in Drosophila cultured cells is available (Bunch et al., 1988, Nucl. Acids Res. 16, 1043-1061). Third, S2 cells express an aberrant Notch message and no detectable Notch due to a rearrangement of the 51 end of the Notch coding sequence (see below) . These cells also express ho detectable Delta (see below) .

Schematic drawings of the constructs used are shown in Figure 1 (see Experimental Procedures, Section 6.1, for details). To express Notch in cultured cells, the Notch minigene MGlla, described in Ramos et al. (1989, Genetics 123, 337-348) was inserted into the metallothionein promoter vector pRmHa-3 (Bunch et al., 1988, Nucl. Acids Res. 16, 1043-1061) . The Delta expression construct was made by inserting Dll cDNA, which contains the entire coding sequence for Delta from the major embryonic Delta -transcript (5.4Z; Kopczynski et al., 1988, Genes Dev. 2, 1723-1735), into the same vector. A third construct, designated ECN1 for "extracellular Notch 1", contains the 5' Notch promoter region and 3' Notch polyadenylation signal together with coding capacity for the extracellular and transmembrane regions of the Notch gene from genomic sequences, but lacks coding sequences for 835 amino acids of the -1000 amino acid intracellular domain. In addition, due to a predicted frameshift, the remaining 78 carboxy-terminal amino acid residues are replaced by a novel 59 amino acid carboxyterminal tail (see Experimental Procedures) .

For all of the experiments described in this paper, expression constructs were transfected into S2 cells and expressed transiently rather than in stable 1 transformants.. Expressing cells typically composed l%-5% of the total cell population, as judged by immunofluorescent staining (data not shown) . A Western blot of proteins expressed after transfection is shown in Figure 2. Nontransfected cells do not express detectable levels of Notch or Delta. However, after transfection, proteins of the predicted apparent molecular weights are readily detectable using monoclonal antibodies specific for each of these proteins, respectively. In the case of Notch, multiple bands were apparent in transfected cells below the -300 kd full-length product. We do not yet know whether these bands represent degradation of Notch during sample preparation or perhaps synthesis or processing intermediates of Notch that are present within cells, but we consistently detect them in samples from transfected cells and from embryos. In addition, we performed immunofluorescent staining of live transfected cells with antibodies specific for the extracellular domains of each protein to test for cell surface expression of these proteins. In each case we found surface staining as expected for a surface antigen. Taken together, these results clearl . show that the Notch and Delta constructs support expression of proteins. of the expected sizes and subcellular localization. 6.2.2. CELLS THAT EXPRESS NOTCH AND DELTA AGGREGATE To test the prediction that Notch and Delta interact, we designed a simple aggregation assay to detect these interactions between proteins expressed on the surface of S2 cells. We reasoned that if Notch and Delta are able to form stable heterotypic complexes at the cell surface, then cells that express these proteins might bind to one another and form aggregates under appropriate conditions. A similar •assay system has recently been described for the fasciclin III protein (Snow et al., 1989, Cell 59, 313-323) .

S2 cells in log phase growth were separately transfected with either the Notch or Delta metallothionein promoter construct. After induction with CuS04, transfected cells were mixed in equal numbers and allowed to aggregate overnight at room temperature (for details, see Experimental Procedures, Section 6.1). Alternatively, in some experiments intended to reduce metabolic activity, cells were •mixed gently at 4°C for 1-2 hr . To determine whether aggregates had formed, 'cells were processed for immunofluorescence microscopy using antibodies specific for each gene product and differently labeled fluorescent secondary antibodies. As previously mentioned, expressing cells usually constituted less than 5% of the total cell population because we used transient rather than stable transformants . The remaining cells either did not express a given protein or expressed at levels too low for detection by immunofluorescence microscopy. As controls, we performed aggregations with only a single type of transfected cell.

Figure 3 shows representative photomicrographs from aggregation experiments,., and Table I presents the results in numerical form. As is apparent from Figure 3C and Table I, while Notch-expressing (Notch"1") cells alone dp not form aggregates in our assay, Delta-expressing (Delta+) cells. do.

TABLE I PERCENTAGES OF NOTCH* AND DELTA* CELLS IN AGGREGATES* Notch* Delta* Control Aggregated Control Aggregated Overal cellab Cells' Cell3b Cells' Experiment 1 0 19 37 32 Experiment 2 1 40 54 Experiment 3 0 12 43 Experiment 4 5 5 20 47 Experiment 5gh 2 48 71 Experiment 6h 0 13 61 63 Aggregates . defined as clusters of four or more expressing cells. least 100 expressing cell units (single cells or cell clusters) Notch-expressing; Delta+, Delta expressing.

Control cells taken directly from transfection flasks without in aggregation assay.

Control cells after incubation in the aggregation assay.

Combined aggregation data for both Notch"1" and Delta"1" cells in No Aggregation data for Notch+ cells in Notch+-Delta+ aggregates. Aggregation data for Delta+ cells in Notch+-Delta+ aggregates. Cells from this experiment from same transfection as Experiment Data from 48 hr aggregation experiments. All other data are from experiments.

The tendency for Delta+ cells to aggregate was apparent even in nonaggregated control samples (Table I) , where cell clusters of 4-8 cells that probably arose from adherence between mitotic sister cells commonly occurred. However, clusters were more common after incubation under aggregation conditions (e.g., 19% of Delta+ cells in aggregates before incubation vs. 37% of Delta"1" cells in aggregates after incubation; Experiment 1 in Table I) , indicating that Delta"1" cells are able to form stable contacts with one another in this assay. It is important to note that while nonstaining cells constituted over 90% of the cells in our transient transfections , we never found them within aggregates. On rare occasions, nonstaining cells were found at the edge of an aggregate. Due to the common occurrence of weakly staining cells at the edges of aggregates, it is likely that these apparently nonexpressing cells were transfected but expressed levels of Delta insufficient to be detected by immunofluorescence.

In remarkable contrast to control experiments with Notch+ cells alone, aggregation of mixtures of Notch"1" and Delta+ cells resulted in the formation of clusters of up to 20 or more cells (Figures 3D-3H, Table I) . As Table I shows, the fraction of expressing cells found in clusters of four or more stained cells after 24 hr of aggregation ranged from 32%-54% in mixtures of Notch* and Delta+ cells. This range was similar to that seen for Delta"1" cells alone (37%-40%) but very different from that for Notch"1" cells alone (only 0%-5%) . Although a few clusters that consisted only of Delta"1" cells were found, Notch"*" cells were never found in clusters of greater than four to five cells unless Delta"1" cells were also present. Again, all cells within these clusters expressed either Notch or Delta, even though transfected cells composed only a small fraction of - the total cell population. At 48 hr (Table I, experiments 5 and 6), the degree of aggregation appeared higher (63%-71%) , suggesting that aggregation had not yet reached a maximum after 24 hr under these conditions. Also, cells cotransfected with Notch and Delta constructs (so that all transfected cells express both proteins) aggregated in a similar fashion ' under the same experimental conditions.

These results indicate that the aggregation observed in these experiments requires the expression of Notch and Delta and is not due to the fortuitous expression of another interacting protein in ■ nontransfected S2 cells. We further tested the specificity of this interaction by diluting Notch+ and Delta+ cells 10-fold with nontransfected S2 cells and allowing them to aggregate for 24 hr at room temperature. In this experiment, 39% of the expressing cells were found in aggregates with other expressing cells, although they composed less than 0.1% of the total cell population. Not surprisingly, however, these aggregates were smaller on average than those found in standard aggregation experiments. In addition, to control for the possibility that Notch+ cells are nonspecifically recruited into the Delta+ aggregates because they overexpress a single type of protein on the cell surface, we mixed Delta'1' cells with cells that expressed neuroglian, a transmembrane cell-surface protein (Bieber et al., 1989, Cell 59, 447-460), under the control of the metallothionein promoter (this metallothionein-neuroglian construct was kindly provided by A. Bieber and C. Goodman) . We observed no tendency for neuroglian" cells to adhere to Delta* aggregates, indicating that Notch-Delta aggregation is not merely the result of high levels of protein expression on the cell surface.

We also tested directly for Notch involvement in the aggregation process by examining the effect of a mixture of polyclonal antisera directed against fusion proteins that spanned almost the entire extracellular domain of Notch on aggregation (see Experimental Procedures, Section 6.1). To minimize artifacts that might arise due to a metabolic response to patching of surface antigens,, antibody treatment and the aggregation assay were performed at 4°C in these experiments. Notch* cells were incubated with either preimmune or immune mouse sera for 1 hr, Delta* cells were added, and aggregation was performed for 1-2 hr. While Notch ! cells pretreated with preimmune sera aggregated with Delta"*" cells (in one of three experiments, 23% of the Notch* cells were in Notch+-Delta+ cell aggregates) , those treated with immune sera did not (only 2% of Notch* cells were in aggregates). This result suggests that the extracellular domain of Notch is required for Notch*-Delta* cell aggregation, although we cannot rule out the possibility that the reduced aggregation was due to inhibitory steric or membrane structure effects resulting from exposure of Notch* cells to the antiserum.

Three other observations worth noting are apparent in Figure 3. First, while Delta was. almost always apparent only at the cell surface (Figures 3B and 3C) , Notch staining was always apparent both at the cell surface and intracellularly , frequently associated with vesicular structures (Figure 3A) .

Second, we consistently noted a morphological difference between Delta* and Notch* cells in mixed aggregates that were incubated overnight. Delta* cells often had long extensions that completely surrounded adjacent Notch"1" cells, while Notch+ cells were almost always rounded in appearance without noticeable cytoplasmic extensions (Figure 3G) . Third, Notch and Delta often appeared to gather within regions of contact between Notch+ and Delta* cells, producing a sharp band of immunofluorescent staining (Figures 3D-3F) . These bands were, readily visible in optical sections viewed on the confocal microscope (Figure 3H) , indicating that they were not merely due to a whole-mount artifact. We also observed that these bands formed rapidly (within 2 hr of mixing cells) and at 4°C, indicating that their formation probably did not depend upon cellular metabolism.

These observations would be expected if, within regions of cell contact, Notch and Delta bind to one another and therefore become immobilized. This pattern of expression is also consistent with that observed for other proteins that mediate cell . aggregation (Takeichi, 1988, Development 102, 639-655; Snow et al., 1989, Cell 59, 313-323). 6.2.3. NOTCH-DELTA-MEDIATED AGGREGATION IS CALCIUM DEPENDENT ; Previous studies have suggested that EGF-like repeats that contain a particular consensus sequence may serve as calcium (Ca2+) binding domains (Morita et al., 1984, J. Biol. Chem. 259, 5698-5704;. Sugo et al., 1984, J. Biol. Chem. 259, 5705-5710; Rees et al., 1988, EMBO J. 7, 2053-2061; Handford et al., 1990, EMBO J. 9, 475-480). For at least two of these proteins, C and CI, Ca2+ binding has further been shown to be a necessary component of their interactions with other proteins (Villiers et al., 1980, FEBS Lett. 117, 289-294; Es on et al., 1983, J. Biol. Chem. 258, 5548-5553; Johnson, et al., 1983, J. Biol. Chem. 258, 5554- 5560). Many of the EGF-homologous repeats within Notch and most of those within Delta contain the necessary consensus sequence for Ca2+ binding (Rees et al., 1988, EMBO J. 7, 2053-2061; Stenflo .et al., 1987, Proc. Natl. Acad. Sci. USA 84, 368-372; Kopczynski et al., 1988, Genes Dev. 2, 1723-1735; Handford et al., 1990, EMBO J. 9, 475-480), although it has not yet been determined whether or not these proteins do bind calcium. We therefore tested the ability of expressing cells to aggregate in the presence or absence of Ca2+ ions -to determine whether there is a Ca2+ ion requirement for Notch-Delta aggregation. To minimize possible nonspecific effects due to metabolic responses to the removal of Ca2+ , these experiments were performed at 4°C. Control mixtures of Notch"1" and Delta"1" cells incubated under aggregation conditions in Ca2+ -containing medium at 4°C readily formed aggregates (an average of 34% + 13%, mean ± SD, n = 3; Table II) . In contrast, cells mixed in medium that lacked Ca2+ ions and contained EGTA formed few aggregates (5% + 5%). These results clearly demonstrate a dependence of Notch-Delta-mediated aggregation on exogenous Ca+ and are in marked contrast to those recently published for the Drosophila fasciclin III and fasciclin I proteins in S2 cells (Snow et al., 1989, Cell 59, 313-323; Elkins et al., 1990, J. Cell Biol. 110, 1825-1832), which detected no effect of Ca2+ ion removal on aggregation mediated by either protein.

TABLE II EFFECT OF EXOGENOUS Ca2+ ON. NOTCH+-DELTA+ AGGREGA Without Ca2+ Ions With Ca2÷ Ions OverN = D.l . OverN Dl all" Cellsc Cells'1 all" Cells2 . Cel Experiment 1 . 4. 2 5 28. 28 2 Experiment 2 12 0 . 13. 53 .63. 5 Experiment 3 0 0 0 22 ~' 28 1 a Data presented as percentage of expressing cells found in aggrega " Combined aggregation data for both Notch+ and Delta+ cells.

' Aggregation data for Notch+ cells in Notch+-Delta+ aggregates. d Aggregation data for Delta* cells in Notch+-Delta+ aggregates. 6.2.4. NOTCH AND DELTA INTERACT WITHIN A SINGLE CELL We asked whether Notch and Delta are associated within the membrane of one cell that expresses both proteins by examining the distributions of Notch and Delta in cotransfected cells. As shown in Figures 4A and B, these two proteins often show very similar distributions at the surface of cotransfected cells. To test whether the observed colocalization was coincidental or represented a stable interaction between Notch and Delta, we treated live cells with an excess of polyclonal anti-Notch antiserum. This treatment resulted in "patching" of Notch on the surface of expressing cells into discrete patches as detected by immunofluorescence. There was a distinct correlation between the distributions of Notch and Delta on the surfaces of these cells after this treatment (Figures 4C and 4D) , indicating that these proteins are associated within the membrane. It is important to note that these experiments do not address the question of whether this association is direct or mediated by other components, such as the cytoskeleton. To control for the possibility that Delta is nonspecifically patched in this experiment, we cotransfected cells with Notch and with the previously mentioned neuroglian construct (A. Bieber and C. Goodman, unpublished data) and patched with anti-Notch antisera. In this case there was no apparent correlation between Notch and neuroglian. 6.2.5. INTERACTIONS WITH DELTA DO NOT REQUIRE THE INTRACELLULAR DOMAIN OF NOTCH In addition to a large extracellular domain that contains EGF-like repeats, Notch has a sizeable intracellular (IC) domain of -940 amino acids. The IC domain includes a phosphorylation site (Kidd et al. , 1989, Genes Dev. 3, 1113-1129) , a putative nucleotide binding domain, a polyglutamine stretch (Wharton et al., 1985, Cell 43, 567-581; idd, et al., 1986, Mol. Cell. Biol. 6, 3094-3108) , and sequences homologous to the yeast cdclO gene, which is involved in cell cycle control in yeast (Breeden and Nasmyth, 1987, Nature 329, 651-654) . Given the size and structural complexity of this domain, we wondered whether it is required for Notch-Delta interactions. We therefore used a variant Notch construct from which coding sequences for "835 amino acids of the IC domain, including all of the structural features noted above, had been deleted (leaving 25 membrane-proximal amino acids and a novel 59 amino acid carboxyl terminus; see Experimental Procedures and Figure 1 for details) . This construct, designated ECNl, was expressed constitutively under control of the normal Notch promoter in transfected cells at a level lower than that observed for the metallothionein promoter constructs, but still readily detectable by immunofluorescence.

In aggregation assays, cells that expressed the ECNl construct consistently formed aggregates with Delta+ cells (31% of ECNl-expressing cells were in aggregates in one of three experiments; see also Figure 31) , but not with themselves (only 4% in aggregates) , just as we observed for cells that expressed intact Notch. We also observed sharp bands of ECNl staining within regions of contact with Delta cells, again indicating a localization of ECNl within regions of contact between cells. To test for interactions within the membrane, we repeated the surface antigen co-patching experiments using cells cotransfected with the ECNl and Delta constructs. As observed for intact Notch, we found that when ECNl was patched using polyclonal antisera against the extracellular domain of Notch, ECN1 and Delta colocalized at the cell surface (Figures 4E and 4F) . These results demonstrate that the observed interactions between Notch and Delta within the membrane do not require the deleted portion of the IC domain of Notch and are therefore probably mediated by the extracellular domain. However, it is possible that the remaining transmembrane or IC domain sequences in ECN1 are sufficient to mediate, interactions within a single cell. 6.2.6. NOTCH AND DELTA FORM DETERGENT-SOLUBLE INTERMOLECULAR COMPLEXES Together, we take the preceding results to indicate molecular interactions between Notch and Delta present within the same membrane and between these proteins expressed on different cells. As a further test for such interactions, we asked whether these proteins would coprecipitate from nondenaturing detergent extracts of cells that express Notch and Delta. If Notch and Delta form a stable intermolecular complex either between or within cells, then it should be possible to precipitate both proteins from cell extracts using specific antisera directed against one of these proteins. We performed this analysis by immunoprecipitating Delta with polyclonal antisera from NP-40/deoxycholate lysates (see Experimental Procedures) of cells cotransfected with the Notch and Delta constructs that had been allowed to aggregate overnight or of 0-24 hr wild-type embryos. We were unable to perform the converse immunoprecipitates because it was not possible to discern unambiguously a faint Delta band among background Staph A bands. It is important to note that we tested this polyclonal anti-Delta antiserum for cross-reactivity against Notch in cell lysates (Figure 5A, lane 1) and by immunofluorescence (e.g., compare. Figures 3D and 3E) and found none. After repeated washing to remove nonspecif ically adhering proteins, we assayed for coprecipitation of Notch using a monoclonal antibody (MAb C17.9C6) against Notch on Western blots.

As Figure 5 shows, we did detect coprecipitation of Notch in Delta immunoprecipitates from cotransfected cells and embryos. However, coprecipitating Notch appeared to be present in much ■smaller quantities than Delta and was therefore difficult to detect. This disparity is most likely due to the disruption of Notch-Delta complexes during the lysis and washing steps of the procedure.

However, it is also possible that this disparity reflects a nonequimolar interaction between Notch and Delta or greatly different affinities of the antisera used to detect these proteins. The fact that immunoprecipitation of Delta results in the ■ coprecipitation of Notch constitutes direct evidence that these two proteins form stable intermolecular complexes in transfected S2 cells and in embryonic cells. 6.3. DISCUSSION We have studied interactions between the protein products of two of the neurogenic loci, Notch and Delta , in order to understand their cellular functions better. Using an in vitro aggregation assay that employs normally nonadhesive S2 cells, we showed that cells that express Notch and Delta adhere specifically to one another. The specificity of this interaction is apparent from the observation that Notch+-Delta+ cell aggregates rarely contained nonexpressing cells, even though nonexpressing cells composed the vast majority of the total cell population in these experiments. We propose that this aggregation is mediated by heterotypic binding between the extracellular domains of Notch and Delta present on the surfaces of expressing cells. Consistent with this proposal, we find that antisera directed against the extracellular domain of Notch inhibit Notch-Delta- mediated aggregation, and that the ECN1 Notch variant, which lacks almost all of the Notch intracellular domain, can mediate aggregation with cells that express Delta. We also found that cells that express only Delta aggregate with one another, while those that express^ only Notch do not. These findings suggest that Delta can participate in a homotypic interaction when present on apposed cell surfaces but that Notch cannot under our assay conditions.

The proposal that Notch and Delta interact at the cell surface is further supported by three ' lines of evidence. First, we find an intense localization of both proteins within regions of contact which Notch+ and Delta4" cells, implying that Notch and Delta interact directly, even when expressed in different cells. Second, Notch and Delta colocalize on the surface of cells that express both proteins, suggesting that these proteins can interact within the cell membrane. Third, Notch and Delta can be coprecipitated from nondenaturing detergent extracts of cultured cells that express both proteins as well as from extracts of embryonic cells.

Together, these results strongly support the hypothesis that Notch and Delta can interact heterotypically when expressed on the surfaces of either the same or different cells.

The underlying basis for the observed genetic interactions between Notch and Delta and between Notch and mam (Xu et al., 1990, Genes Dev. 4, 464-475) may be a dose-sensitive interaction between the proteins encoded by these genes.

Two lines of evidence suggest that the Notch and Delta proteins function similarly in vitro and in vivo . First, the genetic analyses have indicated that the stoichiometry of Notch and Delta is crucial for their function in development. Our observations that both Notch-Delta and Delta-Delta associations may occur in vitro imply that Notch and Delta, may compete for binding to Delta. Thus, dose-sensitive genetic interactions between Notch and Delta may be the result of competitive binding interactions between their protein products. Second, we were able to detect Notch-Delta association in lysates of cultured cells and in lysates of Drosophila embryos using immunoprecipitation. Taken together, these genetic and biochemical analyses suggest that Notch and Delta do associate in vivo in a manner similar to that which we propose on the basis of our aggregation assays.

Genetic and molecular analyses of Notch have-also raised the possibility that there may be interactions between individual Notch proteins (Portin, 1975, Genetics 81, 121-133; Kelley et al., 1987, Cell 51, 539-548; Artavanis-Tsakonas , 1988, Trends Genet. 4, 95-100). Indeed, Kidd et al. (1989, Genes Dev. 3, 1113-1129) have proposed that this protein forms disulfide cross-linked dimers, although this point has not ye been rigorously proven. With or without the formation of covalent cross-links, such interactions could presumably occur either within a single cell or between cells. However, our find that Notch+ cells do not aggregate homotypically suggests that Notch-Notch associations are likely to occur within a single cell and not between cells.

Alternatively, it is possible that homotypic Notch interactions require gene products that are not expressed in S2 cells.

The Notch-Delta interactions indicated by our analysis are probably mediated by the extracellular domains of these proteins. Aggregation experiments using the ECN1 construct, from which ' almost the entire intracellular domain of Notch has been removed or altered by in vitro mutagenesis, confirmed this conclusion. Further experiments that demonstrate ECNl-Delta associations within the membrane on the basis of their- ability to co-patch indicated that these interactions are also likely to be mediated by the extracellular domains of Notch and Delta, although in this case we cannot exclude possible involvement of the transmembrane domain or the remaining portion of the Notch intracellular domain. These results are especially interesting in light of the fact that both Notch and Delta have EGF- like repeats within their extracellular domains (Wharton et al., 1985, Cell 43, 567-581; Kidd et al., 1986, Mol. Cell Biol. 6, 3094-3108; Vassin et al., 1987, EMBO J. 6 , 3431-3 0 ; Kopczynski et al., 1988, Genes Dev. 2, 1723-1735).

A second issue of interest regarding EGF domains is the proposal that they can serve as Ca2+ binding domains when they contain a consensus sequence consisting of Asp, Asp/Asn, Asp/Asn, and Tyr/Phe residues at conserved positions within EGF-like repeats (Rees et al., 1988, EMBO J. 7, 2053-2061; Handford et al., 1990, EMBO J. 9, 475-480).

Comparisons with a proposed consensus sequence for Ca2+ binding have revealed that similar sequences are found within many of the EGF-like repeats of Notch (Rees et al., 1988, EMBO J. 7, 2053-2061) and within most of the EGF-like repeats of Delta (Kopczynski et al., 1988, Genes Dev. 2, 1723-1735). Furthermore, sequence analyses of Notch mutations have shown that certain Ax alleles are associated with changes in amino acids within this putative Ca2+ binding domain ( elley et al., 1987, Cell 51, 539-548; Hartley et al., 1987, EMBO J. 6, 3407-3417; Rees et al., 1988, EMBO J, 7, 2053-2061). For example, the AxE2 mutation, which correlates with a His to Tyr change in the 29th EGF-like repeat, appears to change this repeat toward the consensus for Ca2+ binding. Conversely, the Ax9B2 mutation appears to change the.' 24th EGF-like repeat away from this consensus as a result of an Asp to Val change. Thus, the genetic interactions between Ax alleles and Delta mutations (Xu et al., 1990, Genes Dev., 4, 464-475) raise the possibility that Ca2+ ions play a role in Notch-Delta interactions. Our finding that exogenous Ca2+ is necessary for Notch-Delta-mediated aggregation of transfected S2 cells supports this contention.

As we have argued (Johansen et al . , 1989, J. Cell Biol. 109, 2427-2440 ; Alton et al . , 1989, Dev. Genet. 10, 261-272), on the basis of previous molecular and genetic analyses one could not predict with any certainty the cellular function of either Notch or Delta beyond their involvement in cell-cell interactions. However, given the results presented here, it now seems reasonable to suggest that Notch and Delta may function in vivo to mediate adhesive interactions between cells. At the . same time, it is quite possible that the observed Notch-Delta interactions may not reflect a solely adhesive function and may in addition reflect receptor-ligand . binding interactions that occur in vivo · Indeed, the presence of a structurally complex 1000 amino acid intracellular domain within Notch may be more consistent with a role in signal transduction than with purely adhesive interactions. Given that Notch may have an adhesive function in concert with Delta, axonal expression of Notch may play some role in axon guidance . 7. EGF REPEATS 11 AND 12 OF NOTCH ARE REQUIRED AND SUFFICIENT FOR NOTCH-DELTA-MEDIATED AGGREGATION In this study, we use the same aggregation assay as described in Section 6, together with. deletion mutants of Notch to identify regions within the extracellular domain of Notch necessary for interactions with Delta. We present evidence that the EGF repeats of Notch are directly involved in this interaction and that only two of the 36 EGF repeats appear necessary. We demonstrate that these two EGF repeats are sufficient for binding to Delta and that the calcium dependence of Notch-Delta mediated aggregation also associates with these two repeats.

Finally, the two corresponding EGF repeats from the Xenopus homolog of Notch also mediate aggregation with Delta, implying that not only has the structure of Notch been evolutionarily conserved, but also its function. These results suggest that the extracellular domain of Notch is surprisingly modular, and could potentially bind a variety of proteins in addition to Delta. 7.1. EXPERIMENTAL PROCEDURES 7.1.1. EXPRESSION CONSTRUCTS The constructs described are all derivatives of the full length Notch expression construct #1 pMtNMg (see Section 6, supra) . All ligations were performed using DNA fragments cut from low melting temperature agarose gels (Sea Plaque, F C BioProducts) . The 6 kb EcoRI-XhoI fragment from pMtNMg containing the entire extracellular domain of Notch was ligated into the EcoRI-XhoI sites of the Bluescript vector ( Stratagene) , and named RI/XBS. All subsequent deletions and insertions . of EGF repeats were performed in this subclone. The Notch sequence containing the EcoRI-XhoI fragment of these RI/XBS derivatives was then mixed with the 5.5 kb Xhol-Xbal fragment from pMtNMg containing the intracellular, domain and 3' sequences needed for polyadenylation , and then inserted into the EcoRI-Xbal site of pRMHa-3 (Bunch et al., 1988, Nucl. Acids Res. 16, 1043-1061) in a three piece ligation. All subsequent numbers refer to nucleotide coordinates of the Notch sequence according to Wharton et al. (1985, Cell 43, 567-581).

For construct #2 DSph,. RI/XBS was digested to completion with Sphl and then recircularized , resulting in a 3.5 kb in-frame deletion from Sphl (996) to Sphl (4545) .

For construct #3 ACla, RI/XBS was digested to completion with Clal and then religated, producing a 2.7 kb in-frame deletion from Clal(1668) to Clal(4407). The ligation junction was checked by double strand sequencing (as described by Xu et al., 1990, Genes Dev. 4, 464-475) using the Sequenase Kit (U.S. Biochemical Corp., Cleveland). We found that although the Clal site at position 4566 exists according to the sequence, it was not recognized under our conditions by the Clal restriction enzyme.

For constructs #4-12, RI/XBS was partially digested with Clal and then religated to produce all possible combinations of in-frame deletions: construct #4 AEGF7-17 removed the sequence between Clal (1668) arid 'Clal (2820) ; Construct #5 AEGF9-26 removed the sequence between Clal (1905) and Clal(3855); construct #6 AEGF17-31 removed the sequence between Clal(2820) and Clal(4407) ; construct #7 AEGF7-9 removed the sequence between Clal (1668) and Clal(1905); construct #8 AEGF9-17 removed the sequence between Clal(1905) and Clal(2820) ; construct #9 AEGF17-26 removed the sequence between Cl'al(2820) and Clal(3855); construct #10 AEGF 26-30 removed the sequence between Clal (3855) and Clal (4407) ; construct #11 AEGF9-30 removed the sequence between Clal (1905) and Clal (4407) ; construct #12 AEGF 7-26 removed the sequence between Clal ( 1668 ) and Clal ( 3855 ) .

For constructs #13 AC-la+EGF9-17 and #14 ACla+EGF17-26, . the -0.9 kb fragment between Clal (1905) and Clal(2820) , and the -1.0 kb fragment between Clal (2820) and Clal (3855), respectively, were inserted into the unique Clal site of construct #3 ACla.

For construct #16 split, the 11 kb Kpnl/Xbal fragment of pMtNMg was replaced with the corresponding Kpnl/Xbal fragment from a Notch inigene construct containing the split mutation in EGF repeat 14.

For constructs #17-25, synthetic primers for polymerase chain reaction (PCR) were designed to amplify stretches of EGF repeats while breaking the EGF repeats, at the ends of the amplified piece in the same place as the common Clal sites just after the third cysteine of the repeat (see Figure 7) . The PCR products were gel purifiejd as usual and ligated into the Clal site of construct #3 ACla which was made blunt by filling with the Klenow fragment of DNA Polymerase I (Maniatis et al., 1990, Molecular Cloning, A Laboratory Manual, Cold Spring Harbor Laboratory, Cold Spring Harbor, New York) . The correct orientation of the inserts was determined by PCR using a sense strand primer within the insert together with an antisense strand primer in EGF repeat 35. All primers were 20-mers, and were named with the number of the nucleotide at their. 5' end, . according to the nucleotide coordinates of the Notch sequence in Wharton et al. (1985, Cell 43, 567-581), and S refers to a sense strand, primer while A refers to an antisense strand primer. Construct #16 ACla+EGF ( 9-13 ) used primers S1917 and A2367. Construct #17 ACla+EGF ( 11-15) used primers S2141 and A2591.

Construct #18 ACla+EGF ( 13-17 ) used primers S2375 and A2819. Construct #19 ACla+EGF (10-13 ) used primers S2018 and A2367. Construct #20 ACla+EGF ( 11-13 ) used primers S2141; and A2367. Construct #21 ACla+EGF(10- ί 12) used primers S2018 and A2015. Construct #22 ACla+EGF(10-ll) used primers S2018 and A2322.

Construct #23 ACla+EGF ( 10-12 ) used primers S2018 and A2322. Construct #24 ACla+EGF ( 11-12 ) used primers S2081 and A2322.

For construct #25 AEGF, construct Rl/XBS was digested to completion with Sphl(996) and partially digested with BamHI (5135) . The resulting incompatible ends were joined using a synthetic linker designed to create a unique Clal site. This produced an in frame deletion which removed all 36 EGF repeats with the exception of the first half of repeat 1. For constructs #26-29, the EGF fragments were inserted into this Clal site as previously described for the corresponding constructs #13, 16, .19, and 23.

For construct #30 AEC , . construct Rl/XBS was digested to completion with Bgll, EcoRI and Xhol . The -0.2 kb EcoRI-Bgll fragment (722-948) and the -0.7 kb Bgll-Xhol (5873-6627) fragments were ligated with · EcoRI-XhoI cut Bluescript vector and a synthetic linker designed to create a unique Clal site, resulting in an in-frame deletion from Bgll ( 941) to Bgll(5873) that removed- all 36 EGF repeats except for the first third of repeat 1 as well as the 3 Notch/lin-12 repeats. For constructs #31 and 32, the EGF fragments were inserted into the unique Clal site as previously described for constructs #19 and 23.

For constructs #33 and 34, PCR primers S1508 and A1859 based on the Xenopus Notch sequence (Coffman et al., 1990, Science 249, 1438-1441; numbers refer to nucleotide coordinates used in this paper) , were used to amplify EGF repeats 11 and 12 out of a Xenopus ■ stage 17 cDNA library (library was made by D. Melton, and kindly provided by . Danilchek) . The fragment was ligated into construct #3 DCla and sequenced. 7.1.2. CELL CULTURE AND TRANSFECTION The Drosphila S2 cell line was grown and transfected as described in Section 6, supra . The Delta-expressing stably transformed S2 cell line L-49- 6-7 (kindly established by L. Cherbas) was grown in M3 medium (prepared by Hazleton Co.) supplemented with 11% heat inactivated fetal calf serum (FCS) (Hyclone) , 100 U/ml penicillin-100 μg/ml streptomycin-0.25 g/ml fungizone (Hazleton), 2 x 10'7 M methotrexate, 0.1 mM hypoxahthine , and 0.016 mM thymidine. 7.1.3. AGGREGATION ASSAYS AND IMMUNOFLUORESCENCE Aggregation assays and Ca'++ dependence experiments were as described supra , Section 6. Cells were stained with the anti-Notch monoclonal antibody 9C6.C17 and anti-Delta rat polyclonal antisera (details described in Section 6, supra) . Surface expression of Notch constructs in unpermeabilized cells was assayed using rat polyclonal antisera raised against the 0.8 kb (amino acids 237-501; Wharton et al., 1985, Cell 43, 567-581) BstYI fragment . from the extracellular domain of Notch. Cells were viewed under epifluorescence on a Leitz Orthoplan 2 microscope. 7.2. RESULTS 7.2.1. EGF REPEATS 11 AND 12 OF NOTCH ARE REQUIRED FOR NOTCH-DELTA MEDIATED AGGREGATION We have undertaken an extensive deletion analysis of the extracellular domain of the Notch protein, which we have shown (supra, Section 6) to be involved in Notch-Delta interactions, to identify the precise domain of Notch mediating these interactions.

We tested the ability of cells transfected with the various deletion constructs to interact with Delta using the aggregation assay described in Section 6.

Briefly, Notch deletion constructs were transiently transfected into Drosophila S2 cells, induced with CuS04, and then aggregated overnight at room temperature with a small amount of cells from the stably transformed Delta expressing cell line L49-6- 7(Cherbas), yielding a population typically composed of -1% Notch expressing . cells and -5% Delta expressing cells, with the remaining cells expressing neither protein. To assay the degree of aggregation, cells were stained with antisera specific to each gene product and examined with immunofluorescent microscopy (see experimental procedures for details). Aggregates were defined as clusters of four or more cells containing both Notch and Delta expressing cells, and the values shown in Figure 6 represent the percentage of all Notch expressing cells found in such clusters.

All numbers reflect the average result from at least two separate transfection experiments in which at least 100 Notch expressing cell units (either single cells or clusters) were scored.

Schematic drawings of the constructs tested and results of the aggregation experiments are shown in Figure 6 (see Experimental Procedures for details) . All expression constructs were derivatives of the full length Notch expression construct #1 pMtNMg (described in Section 6, supra) .

The initial constructs (#2 DSph and #3 ACla) deleted large portions of the EGF repeats. Their inability to promote Notch-Delta aggregation suggested that the EGF repeats of Notch were involved in the interaction with Delta. We took advantage of a series of six in-frame Clal restriction sites to further dissect the region between EGF repeats 7 and 30. Due to sequence homology between repeats, five of the Clal sites occur in the same relative place within the EGF repeat, just after the third cysteine, while the sixth site occurs just before the first cysteine of EGF repeat 31 (Figure 7) . Thus, by performing a partial Clal digestion and then religating, we obtained deletions that not only preserved the open reading frame of the Notch protein but in addition frequently maintained the structural integrity and conserved spacing, at least theoretically, of the three disulfide bonds in the chimeric EGF repeats produced by the religation (Figure 6, constructs #4-14) .

Unfortunately, the most 3 ' Clal site was resistant to digestion while the next most 3 ' Clal site broke between EGF repeats 30 and 31. Therefore, when various Clal digestion fragments were reinserted into the framework of the complete Clal digest (construct #3 ACla) , the overall structure of the EGF repeats was apparently interrupted at the 31 junction.

Several points about this series of constructs are worth noting. First, removal of the Clal restriction fragment breaking in EGF repeats 9 and 17 (construct #8 AEGF9-17) abolished aggregation with Delta, while reinsertion of this piece into construct #3 ACla, which lacks EGF repeats .7-30, restored aggregation to roughly wild type levels (construct #13 ACla+EGF9-17 ) , suggesting that EGF repeats 9 through 17 contain sequences important for binding to Delta. Second, all constructs in this series (#4-14) were consistent with the binding site mapping to EGF repeats 9 through 17. Expression constructs containing these repeats (#6, 7, 9, 10, 13) promoted Notch-Delta, interactions while constructs lacking these repeats (#4,. 5, 8, 11, 12, 14) did not. To confirm that inability to aggregate with Delta cells was (not simply due to failure of the mutagenized Notch protein to reach the cell surface, but actually reflected the deletion of the necessary binding site, we tested for cell surface expression of all constructs by immunofluorescently staining live transfected cells with antibodies specific to the extracellular domain of Notch. All constructs failing to mediate Notch-Delta interactions produced a protein that appeared to be expressed normally at the cell surface. Third, although the aggregation assay is not quantitative, two constructs which contained EGF repeats 9-17, #9 AEGF17-26 or most noticeably #10 AEGF26-30, aggregated at a seemingly lower level.

Cells transfected with constructs #9 AEGF17-26 and 10 AEGF26-30 showed considerably less surface staining than normal, although fixed and permeabilized cells reacted with the same antibody stained normally, indicating we had not simply deleted the epitopes recognized by the antisera. By comparing the percentage of transfected cells in either permeabilized or live cell populations, we found that roughly 50% of transfected cells for construct #9 AEGF17-26 and 10% for construct #10 AEGF26-30 produced detectable protein at the cell surface. Thus these two constructs produced proteins which often failed to reach the cell surface, perhaps because of misfolding, thereby reducing, but not abolishing, the ability of transfected cells to aggregate with Delta-expressing cells.

Having mapped the binding site to EGF repeats 9 through .17 , we checked whether any Notch mutations whose molecular lesion has been determined mapped to this region. . The only such mutation was split , a semidominant Notch allele that correlates with a point mutation in EGF repeat 14 (Hartley et al., 1987, EMBO J. 6, 3407-3417; Kelley/et al., 1987, Mol. Cell. Biol. 6, 3094-3108) . In fact, a genetic screen for second site modifiers of split revealed several alleles of Delta, suggesting a special relationship between the split allele of Notch , and Delta (Brand and Campus-Ortega, 1990, Roux's Arch. Dev. Biol. 198 ( 5 ) , 275-285 ) . To test for possible effects of the s lit mutation on Notch-Delta mediated aggregation, an 11 kb fragment containing the missense mutation associated with split was cloned into the Notch expression construct (#15 split) . However, aggregation with Delta-expressing cells was unaffected in this construct suggesting, as was confirmed by subsequent constructs, that EGF repeat 14 of Notch was not involved in the interactions' with Delta modelled by our tissue culture assay.

Thus, to further map the Delta binding domain within EGF- repeats 9-17, we used specific oligonucleotide primers and the PCR technique to generate several subfragments of this region. To be consistent with constructs #4.-14 which produced proteins that .were able to interact with Delta, we designed the primers to splice the EGF repeats just after the third cysteine, in the same place as the common Clal site (Figure 7) . The resulting PCR products were ligated into the Clal site of construct #3 ACla. Three overlapping constructs, #16, 17 and 18 . were produced, only one of which, #16 ACla+EGF9-13 , when transfected into S2 cells, allowed aggregation with Delta cells. Construct #19 ACla+EGF (10-13 ) ,. which lacks EGF repeat 9, further defined EGF repeats 10-13 as the region necessary for Notch-Delta interactions.

Constructs #20-24 represented attempts to break this domain down even further using the same PCR strategy (see Figure 7). We asked first whether both EGF repeats 11 and 12 were necessary, and second, whether the flanking sequences from EGF repeats 10 and 13 were directly involved in binding to Delta.

Constructs #20 ACla+EGF ( 11-13 ) , in which EGF repeat 12 is the only entire repeat added, and #21 ACla+EGF(10-12) , in which EGF repeat 11 is the only entire repeat added, failed to mediate aggregation, suggesting that the presence of either EGF repeat 11 or 12 alone was not sufficient for Notch-Delta interactions. However, since the 3' ligation juncture of these constructs interrupted the overall structure of the EGF repeats, it was possible that a short "buffer" zone was needed to allow the crucial repeat to function normally.

Thus for example in construct #19 ACla+EGF ( 10-13 ) , EGF repeat 12 might not be directly involved in binding to Delta but instead might contribute the minimum amount of buffer sequence needed to protect the structure of EGF repeat 11, thereby allowing interactions with Delta. Constructs #22-24 addressed this issue. We designed' PCR primers that broke at the end of the EGF repeat and therefore were less likely to disrupt the EGF disulfide formation at the 3' ligation juncture. Constructs #22 ACla+EGF ( 10-11) , which did not mediate aggregation, and #23 ACla+EGF ( 10-12 ) , which did, again suggested that both repeats 11 and 12 are required while the flanking sequence from repeat 13 clearly is not. Finally,, construct #24 ACla+EGF ( 11-12 ) , although now potentially structurally disrupted at the 5' junction, convincingly demonstrated that the sequences from EGF repeat 10 are not crucial. Thus based on entirely consistent data from 24 constructs, we propose that EGF repeats 11 and 12 of Notch together define the smallest functional unit obtainable from this analysis that contains the necessary sites for binding to Delta in transfected S2 cells. - 7.2.2. EGF REPEATS 11 AND 12 OF NOTCH ARE SUFFICIENT FOR NOTCH-DELTA MEDIATED AGGREGATION The large Clal deletion into which PCR fragments were inserted (#3 ACla) retains roughly 1/3 of the original 36 EGF repeats as well as the three Notch/'lin-12 repeats. While these are clearly not sufficient to promote aggregation, it is possible that they form a necessary framework within which specific EGF repeats can interact with Delta. To test whether only a few EGF repeats were in fact sufficient to promote aggregation, we designed two constructs, #25 AEGF which deleted all 36 EGF repeats except for the first two-thirds of repeat 1, and #30 AECN which deleted the entire extracellular portion of Notch except for the first third of EGF repeat 1 and "35 amino acids just before the transmembrane domain.

Fragments which had mediated Notch-Delta aggregation in the background of construct #3 ACla, when inserted .into construct #25 AEGF, were again able to promote interactions with Delta (constructs #26-30) .

Analogous constructs (#31,32) in which the Notch/ lin- 12 repeats were also absent, again successfully mediated Notch-Delta aggregation.. Thus EGF repeats 11 and 12 appear to function as independent modular units, which are sufficient to mediate Notch-Delta interactions in S2 cells, even in the absence of most of the extracellular domain of Notch. 7.2.3. EGF REPEATS 11 AND 12 OF NOTCH MAINTAIN THE CALCIUM DEPENDENCE OF NOTCH-DELTA MEDIATED AGGREGATION As described in Section 6, supra (Fehon et al., 1990, Cell 61, 523-534), we showed that Notch-Delta-mediated S2 cell aggregation is calcium . dependent. We therefore examined the ability of cells expressing certain deletion constructs to aggregate with Delta expressing cells in the presence or absence of Ca++ ions. We tested constructs #1 pMtNMg as a control, and #13, 16, 19, 23, 24, 26, 27 and 28, and found that cells mixed in Ca++ containing medium at 4°C readily formed aggregates while cells mixed in Ca++ free medium containing EGTA failed to aggregate (Table III) .

TABLE III EFFECT OF EXOGENOUS Ca++ ON NOTCH - DELTA AGGREGATION' Without Ca++ Ions With Ca" 1. pMtNMg 0 37 13. ACla+EGF(9-17) 0 31 16. ACla+EGF(9-13) 0 38 19. ACla+EGF(10-13) 0 42 23. ACla+EGF (10-12 ) 0 48 29. AEGF+EGF ( 10-12 ) 0 44 32. AECN+EGF ( 10-12 ) 0 39 33. ACla+XEGF(10-13 0 34 'Data presented as percentage of Notch-expressing cells found in aggregates (as in Figure 6) .

Clearly, the calcium dependence of the interaction has been preserved in even the smallest construct, consistent with the notion that the minimal constructs containing EGF repeats 11 and 12 bind to Delta in a manner similar to. that of full length Notch. This result is also interesting in light of recent studies suggesting EGF-like repeats with a particular consensus sequence may act as Ca++ binding domains (Morita et al., 1984, J. Biol. Chem. 259, 5698-5704; Sugo et al., 1984, J. Biol. Chem. 259, 5705-5710; Rees et al., 1988, EMBO J. 7, 2053-2061; Handford et al., 1990, EMBO J. 9; 475-480) .' Over half of the EGF repeats in Notch, including repeats 11 and 12, conform to this consensus, further strengthening the argument that EGF repeats 11 and 12 are responsible for promoting Notch-Delta interactions. 7.2.4. THE DELTA BINDING FUNCTION OF EGF REPEATS 11 AND 12 OF NOTCH IS CONSERVED IN THE XENOPUS • HOMOLOG OF NOTCH ; Having mapped the Delta binding site to EGF repeats 11 and 12 of Notch, we were interested in asking whether this function was conserved in the Notch homolog that has been identified in Xenopus (Coffman et al., 1990, Science 249, 1438-1441). This protein shows a striking similarity to Drosophila Notch in overall structure and organization. For example, within the EGF repeat region both the number and linear organization of the repeats has been preserved, suggesting a possible functional conservation as well. To test this, we made PCR primers based on the Xenopus Notch sequence (Coffman et al., 199.0, Science 249, 1438-1441) and used these to obtain an -350 bp fragment from a. Xenopus Stage 17 cDNA library that includes EGF repeats 11 and 12 flanked by half of repeats 10 and 13 on either side.

This fragment was cloned into construct #3 ACla, and three independent clones were tested for ability to interact with Delta in the cell culture aggregation assay. Two of the clones, #33a&bACla+XEGF ( 10-13 ) , when transfected into S2 cells were able to mediate Notch-Delta interactions at a level roughly equivalent to the analogous Drosophila Notch construct #19ACla+EGF ( 10-13 ) , and again in a calcium dependent manner (Table III).. However, the third clone #33cACla+XEGF( 10-13) failed to mediate Notch-Delta interactions although the protein was expressed normally at the cell surface as judged by staining live unpermeabilized cells. Sequence comparison of the Xenopus PCR product in constructs #33a and 33c revealed a missense mutation resulting in a leucine to proline change (amino acid #453, Coffman, et al., 1990, Science 249, 1438-1441) in EGF repeat 11 of construct #33c. Although this residue is not conserved between Drosophila and Xenopus Notch (Figure 8) , the introduction of a proline residue might easily disrupt the structure of the EGF repeat, and thus prevent it from interacting properly with Delta.

Comparison of the amino acid sequence of EGF repeats 11 and 12 of Drosophila and Xenopus Notch reveals a high degree of amino acid identity, including the calcium binding consensus sequence (Figure 8, SEQ ID N0:1 and NO:2). However the level of homology is not strikingly different from that shared between most of the other EGF repeats, which overall exhibit about 50% identity at the amino acid level. This one to one correspondence between individual EGF repeats suggests that perhaps they too may comprise conserved functional units. Delta interactions, again in a calcium ion-dependent manner. 7.3. DISCUSSION We have continued our study of interactions between the protein products of the genes Notch and Delta, using the in vitro S2. cell aggregation assay described in Section 6, supra . Based on an extensive deletion analysis of the extracellular domain of Notch, we show that the regions of Notch containing EGF-homologous repeats 11 and 12 are both necessary and sufficient for Notch-Delta- ediated aggregation, and that this Delta binding capability has been conserved in the same two EGF repeats of Xenopus Notch. Our finding that the aggregation mapped to EGF repeats 11 and 12 of Notch demonstrates that the EGF repeats of Notch also function as specific protein binding domains.

Recent studies have demonstrated that EGF domains containing a specific consensus sequence can bind Ca++ ions (Morita et al., 1984, J. Biol. Chem. 259, 5698-5704; Sugo et al., 1984, J. Biol. Chem. 259, 5705-5710; Rees et al., 1988, EMBO J. 7, 2053-2061; Handford et al., 1990, EMBO J. 9, 475-480). In fact, about one half of the EGF repeats in Notch, including repeats 11 and 12, conform to this consensus. We have shown that exogenous Ca++ was necessary for Notch-Delta mediated aggregation of transfected S2 cells (see Section 6; Fehon et al., 1990, Cell 61, 523-534). We tested a subset of our deletion constructs and found that EGF repeats 11 and 12 alone ^(#32AECN+EGF ( 11-12 ) ) were sufficient to maintain the Ca++ dependence of Notch-Delta interactions.

A number of studies have suggested that the genetic interactions between Notch and Delta may reflect a dose sensitive interaction between their protein products. Genetic studies have indicated that the relative gene dosages of Notch and Delta are crucial for normal development. For example, Xu et al. (1990, Genes Dev. 4, 464-475) found that null mutations at Delta could suppress lethal interactions between heterozygous combinations of Abruptex (Ax) alleles, a class of Notch mutations that correlate with missense mutations within the EGF repeats (Hartley et al., 1987, EMBO J. 6, 3407-3417; Kelley et al., 1987, Mol. Cell Biol. 6, 3094-3108). The in vitro interactions we have described in which we observe both Notch-Delta and Delta-Delta associations (see Section 6) imply that a competitive interaction between Notch and Delta for binding to Delta may reflect the underlying basis for the observed genetic interactions. Furthermore, we were able to coiitununoprecipitate Notch and Delta from both tissue culture and embryonic cell extracts (see Section 6) , indicating a possible in vivo association of the two proteins. In addition, mRNA in situ analyses of Notch and Delta expression patterns in the embryo suggest that expression of the two is overlapping but not identical (Kopczynski and Muskavitch, 1989, Development 107, 623-636; Hartley et al., 1987, EMBO J. 6, 3407-3417) . Detailed antibody analysis of Notch protein expression during development have recently revealed Notch expression to be more restricted at the tissue and subcellular levels than previous studies had indicated (Johansen et al., 1989, J. Cell Biol. 109, 2427-2440; Kidd et al., 1989, Genes Dev. 3, 1113-1129) .

Our finding that the same two EGF repeats from the Xenopus Notch homolog are also able to mediate interactions with Delta in tissue culture cells argues strongly that a similar function will have been conserved in vivo . Although these two EGF repeats are sufficient in vitro , it is of course possible that in vivo more of the Notch molecule may be necessary to facilitate Notch-Delta interactions. In fact, we were somewhat surprised for two reasons to find that the Delta binding site did not map to EGF repeats where several of the Ax mutations have been shown to fall, first, because of the genetic screen (Xu et al., 1990, Genes Dev. 4, 464-475) demonstrating interactions' between Ax alleles and Delta mutations, and second, because of sequence analyses that have shown certain Ax alleles are associated with single amino acid changes within the putative Ca++ binding consensus of the EGF repeats. For example, the ΑΧΏ mutation changes EGF repeat 29 toward the Ca++ binding consensus sequence while the AX9B2 mutation moves EGF repeat 24 away from the consensus. It is possible that in vivo these regions of the Notch protein may be involved in interactions, either with Delta and/or other proteins, that may not be accurately modelled by our cell culture assay.

Our in vitro mapping of the Delta binding domain to EGF repeats 11 and 12 of Notch represents the first assignment of function to a structural domain of Notch. In fact, the various deletion constructs suggest that these two EGF repeats function as a modular unit, independent of the immediate context into which they are placed. Thus, neither the remaining 34 EGF repeats nor the. three Notch/lin-12 repeats appear necessary to establish a structural framework required for EGF repeats 11 and 12 to function. Interestingly, almost the opposite effect was observed: although our aggregation assay does not measure the' strength of the interaction, as we narrowed down the binding site to smaller and smaller fragments, we observed an increase in the ability of the transfected cells to aggregate with Delta expressing cells, suggesting that the normal flanking EGF sequences actually impede association between the proteins. For two separate series of constructs, either in the background of construct #3 ACla (compare #9, 16, 19, 23) or in the background of construct #25 AEGF (compare #26, 27, 28), we observed an increase in ability to aggregate such that the smallest constructs (#19, 23, 28, 29) consistently aggregated . above wild type levels (#1 p tNMg) . These results imply that the surrounding EGF repeats may serve to limit the ability of EGF repeats 11 and 12 to access Delta, thereby perhaps modulating Notch-Delta interactions in vivo .

Notch encodes a structurally complex transmembrane protein that has been proposed to play a pleotropic role throughput Drosophila development.

The fact that EGF repeats 11 and 12 appear to function as an independent modular unit that is sufficient, at least in cell culture, for interactions with Delta, immediately presents the question of the role of the hypothesis is that these may. also form modular binding domains for other proteins interacting with Notch at various times during development.

In addition to Xenopus Notch, lin-12 and qlp-1 , two genes thought to function in cell-cell interactions involved in the specification of certain cell fates during C.. eleqans development, encode EGF homologous transmembrane proteins which are structurally quite similar to Drosophila and Xenopus Notch. All four proteins contain EGF homologous repeats followed by three other cysteine rich repeats (Notch/ lin-12 repeats) in the extracellular domain, a single transmembrane domain, and six cdclO/ankyrin repeats in the intracellular region. Unlike Xenopus Notch, which, based on both sequence comparison as well as the results of our Delta binding assay, seems likely to encode the direct functional counterpart of Drosophila Notch, lin-12 and qlp-1 probably encode distinct members of the same gene family. Comparison of the predicted protein products of lin-12 and qlp-1 with Notch reveal specific differences despite an overall similar organization of structural motifs.

The most obvious difference is that lin-12 and qlp-1 proteins contain only 13 and 10 EGF repeats, respectively, as compared to the 36 for both Xenopus and Drosophila Notch. In addition, in the nematode genes the array of EGF repeats is interrupted after the first EGF repeat by a distinct stretch of sequence absent from Notch. Furthermore, with respect to the Delta binding domain we. have defined as EGF repeats 11 and 12 of Notch, there are no two contiguous EGF repeats in the lin-12 or glp-1 proteins exhibiting the Ca++ binding consensus sequence, nor any two contiguous repeats exhibiting striking similarity to EGF repeats 11 and 12 of Notch, again suggesting that the lin-12 and qlp-1 gene products are probably functionally distinct from Notch.

Our finding that EGF repeats 11 and 12 of. Notch form. a discrete Delta binding unit represents the first concrete evidence supporting the idea that each EGF repeat or small subset of repeats may play a unique role during development, possibly through direct interactions with other proteins. The homologies seen between the adhesive domain of Delta and Serrate (see Section 8.3."'4 , infra) suggest that the homologous portion of Serrate is "adhesive" in that it mediates binding to other toporythmic proteins. In addition, the gene scabrous , which encodes a secreted protein with similarity to fibrinogen, may interact with Notch.

In addition to the EGF repeat, multiple copies of other structural motifs commonly occur in a variety of proteins. One relevant example is the cdclO/ankyrin motif, six copies of which are found in the intracellular domain of Notch. Ankyrin contains 22 of these repeats. Perhaps repeated arrays of structural motifs may in general represent a linear assembly of a series of modular protein binding units. Given these results together with the known structural, genetic and developmental complexity of Notch, Notch may interact with a number of different ligands in a precisely regulated temporal and spacial pattern throughout development. Such context specific interactions with extracellular proteins could be mediated by the EGF and Notch/ lin-12 repeats, while interactions with cytoskeletal and cytoplasmic proteins could be mediated by the intracellular cdclO/ankyrin motifs. 8. THE AMINO-TERMINUS OF DELTA IS AN EGF-BINDING DOMAIN THAT INTERACTS WITH NOTCH AND DELTA Aggregation of cultured cells programmed to express wild type and variant Delta proteins has been employed to delineate Delta sequences required for heterotypic interaction with Notch and homotypic Delta interaction. We have found that the amino terminus of the Delta extracellular domain is necessary and sufficient for the participation of Delta in heterotypic (Delta-Notch) and homotypic (Delta-Delta) interactions. We infer that the amino terminus of Delta is an EGF motif-binding domain (EBD) , given that Notch EGF-like sequences are sufficient to mediate heterotypic interaction with Delta. The Delta EBD apparently possesses two activities: the ability to bind EGF-related sequences and the ability to self-associate. We also find that Delta is taken up by . cultured cells that express Notch, which may be a reflection of a mechanism by which these proteins interact in vivo. 8.1. MATERIALS AND METHODS 8.1.1. CELL LINES The S2 Drosophila cell line (Schneider, 1972, J. - Embryo1. Exp. Morph. 27 , 353-365)) used in these experiments was grown as described in Section 6. 8.1.2. IMMUNOLOGICAL PROBES Immunohistochemistry was performed as described in Section 6, supra , or sometimes with minor modifications of this procedure. Antisera and antibodies employed included mouse polyclonal anti- Delta sera raised against a Delta ELR array segment that extends from the fourth through ninth ELRs (see Section 6) ; rat polyclonal anti-Delta sera raised against the same Delta segment (see Section 6) ; rat polyclonal anti-Notch sera raised against a Notch ELR array segment that extends from the fifth through thirteenth ELRs; mouse monoclonal antibody C17.9C6 (see Section 6) , which recognizes the Notch intracellular domain; and mouse monoclonal antibody BP-104 (Hortsch et al., 1990, Neuron 4, 697-709), which recognizes the long form of Drosophila neuroglian. 8.1.3. EXPRESSION VECTOR CONSTRUCTS Constructs employed to program expression of wild type Delta (p TDll) and wild type Notch (pMTNMg) are described in Section '6, supra . Constructs that direct expression of variant Delta proteins were generated using pMTDll, the Dll cDNA cloned into Bluescript+ (pBSDll; Kopczynski et al., 1988, Genes Dev. 2, 1723-1735), and pRmHa3-104 (A.J. Bieber, pers . comm.), which consists of the insertion of the 1B7A-250 cDNA into the metallothionein promoter vector pRmHa-3 (Bunch et al., 1988, Nucl. Acids Res. 16, 1043-1061) and supports inducible expression of the long form of Drosophila neuroglian (Hortsch et al., 1990, Neuron 4 , 697-709).

Briefly, constructs were made as follows: Del(Sca-Nae) - Cut pBSDll with Sail (complete digest) and Seal (partial) , isolate vector-containing fragment. Cut pBSDll with Nael (partial) and Sail (complete) , isolate Delta carboxyl-terminal coding fragment. Ligate fragments, transform, and isolate clones. Transfer EcoRI insert into pRmHa-3.

Del(Bam-Bgl) - Cut pBSDll with Bglll (complete) and BamHI (partial) , fill ends with Klenow DNA polymerase, ligate, transform, and isolate clones. Transfer EcoRI insert into pRmHa-3.

Del (ELR1-ELR3 ) - PCR-amplify basepairs 236- 830 of the Dll cDNA using 5-ACTTCAGCAACGATCACGGG-3 ' (SEQ ID NO: 26) and 5 ' -TTGGGTATGTGACAGTAATCG-3 ' (SEQ ID NO: 27), treat with T4 DNA polymerase, ligate into pBSDll cut with Seal (partial) and Bglll (complete) and end-filled with Klenow DNA polymerase, transform, and isolate clones. Transfer BamHI-Sall Delta carboxyl-terminal coding fragment into pRmHa-3.

Del (ELR4-ELR5) - pBSDll was digested to completion with Bglll and partially with Pstl. The 5.6 kb vector-containing fragment was isolated, circularized using T4 DNA ligase in the presence of a 100X molar excess of the oligonucleotide 51 -GATCTGCA-3', and transformed and clones were isolated. The resulting EcoRI insert was then transferred into pRmHa-3.

Ter(Dde) - Cut pBSDll with Ddel (partial), end-fill with Klenow DNA polymerase, ligate with 100X molar excess of 51 -TTAAGTTAACTTAA-31 (SEQ ID NO:28), transform, and isolate clones. Transfer EcoRI insert into pRmHa-3.

Ins(Nae)A - Cut pMTDll with Nael (partial), isolate vector-containing fragment, ligate with 100X molar excess of 51 -GGAAGATCTTCC-3 ' (SEQ ID NO: 29), transform, and isolate clones.

NAE B - pMTDll was digested . partially with Nael, and the population of tentatively linearized circles approximately 5.8 kb . in length was isolated. The fragments were recircular ized using T4 DNA ligase in the presence of a, 100X molar excess of the oligonucleotide 51 -GGAAGATCTTCC-31 (SEQ ID NO:29) and transformed, and a clone (NAE A) that contained multiple inserts of the linker was isolated. NAE A was digested to completion with Bglll, and the resulting 0.4 kb and 5.4 kb fragments were isolated, ligated and transformed , . and clones were isolated.

Ins(Stu) - Cut pMTDll with Stul (complete), isolate vector-containing fragment, ligate with 100X molar excess of 5 ' -GGAAGATCTTCC-3 ' ( SEQ ID NO:29), transform and isolate clones.

STU B - pMTDll was digested completely with Stul, and the resulting 5.8 kb fragment was isolated. The fragment was recircularized using T4 DNA ligase in the presence of a 100X molar excess of the oligonucleotide 51 -GGAAGATCTTCC-31 (SEQ ID NO: 29) and transformed, and a clone (STU A) that contained multiple inserts of the linker was isolated. STU B was digested to completion with Bglll, and the resulting 0.6 kb and 5.2 kb fragments were isolated, ligated and transformed, and clones were isolated.

NG1 - Cut pRmHa3-104 with Bglll (complete) and EcoRI (complete) , isolate vector-containing fragment. Cut Ins(Nae)A with EcoRI (complete) and Bglll (complete), isolate Delta amino-terminal coding fragment. Ligate fragments, transform and isolate clones.

NG2 - Cut pRmHa3-104 with Bglll (complete) and EcoRI (complete) , isolate vector-containing fragment . Cut Del (ELR1-ELR3 ) with EcoRI (complete) and Bglll (complete) , isolate Delta amino-terminal coding fragment. Ligate fragments, transform and isolate clones.

NG3 - Cut pRmHa3-104 with Bglll (complete) and EcoRI (complete), isolate vector-containing fragment. Cut pMTDll with EcoRI (complete), and Bglll (complete) , isolate Delta amino-terminal coding fragment. Ligate fragments, transform and isolate clones.

NG4 - Cut pRmHa3-104 with Bglll (complete) and EcoRI (complete) , isolate vector containing fragment. Cut Del(Sca-Nae) with EcoRI (complete) and Bglll (complete) , isolate Delta amino-terminal coding fragment. Ligate fragments, transform and isolate clones.

NG5 - Generate Del(Sca-Stu) as follows: cut pMTDll with Seal (complete) and Stul (complete) , isolate Scal-Scal amino-terminal coding . fragment and Stul-Scal carboxyl-terminal coding fragment, ligate, transform and isolate clones. Cut Del(Sca-Stu) with EcoRI (complete) and Bglll (complete) , isolate Delta ' amino terminal coding fragment. Cut pRmHa3-104 with Bglll (complete) and EcoRI (complete) , isolate vector- containing fragment. Ligate fragments, transform and isolate clones.

The sequence contents of the various Delta variants are shown in Table IV. Schematic diagrams of the Delta variants defined in Table IV are shown in Figure 9.

TABLE IV SEQUENCE CONTENTS OF DELTA . VARIANTS Nucleotides Amino Acids Wild type 1-2892A 1-833 Del (Sca-Nae) 1-235/734-2892 1-31/W/199- 833 Del(Bam-Bgl) 1-713/1134-2892 1-191/332-833 Del ( ELR1-ELR3 ) 1-830/1134-2892 1-230/332-833 Del (ELR4-ELR5) 1-1137./ 1405-2892 1-332/422-833 Ter (Dde) 1-2021/TTAAGTTAACTTAAE/ 1-626/H 2227-2892 Ins (Nae) A 1-733/ (GGAAGATCTTCC) J/ 1-197/ (R IF). 734-2892B 198-833 NAE B 1-733 /GGAAGATCTTCCF/ 1-197./RKIF 734-2892 198-833 Ins (Stu) 1-535/ (GGAAGATCTTCC) / 1-131/ 536-2892B G (KIFR) Q_! KIFP/133-833 STU B 1-535/GGAAGATCTTCCF/ 1-131/GKIFP 536-2892 133-833 NG1 1-733/GGAA/2889-3955 (NG)C 1-198 /K/ 952- 1302" NG2 1-830/2889-3955 (NG) 1-230/952- 1302 NG3 1-1133/2889-39-55 (NG) "1-331/952- 1302 NG4 1-235/734-1133/ 1-31/199-331/ 2889-3955 (NG) . 952-1302 NG5 1-235/536-1133/ 1-31/S/133- 2889-3955 (NG) 952-1302 A Coordinates . for Delta sequences correspond to the sequence of the Dll cDNA (Figure 12) .

The exact number of linkers inserted has not been determined for this construct.

Coordinates for neuroglian (Bieber et al., 1989, Cell 59, 447-460; Hortsch et al., 1990, Neuron 4, 697-709) nucleotide sequences present in Delta- neuroglian chimeras correspond to the sequence of the 1B7A-250 cDNA (Figure 13, SEQ ID NO:5) and are indicated in bold face type.

Neuroglian amino acid sequences are derived from conceptual translation of the 1B7A-250 cDNA nucleotide sequence (Figure 13, SEQ ID N0:5) and are indicated in bold face type.

SEQ ID NO: 28 SEQ ID NO: 29 ■ 8.1.4. AGGREGATION PROTOCOLS Cell transfection and aggregation were .' performed as described in Section 6, supra , or with minor modifications thereof. 8.2. RESULTS 8.2.1. AMINO-TERMINAL SEQUENCES WITHIN THE DELTA EXTRACELLULAR DOMAIN ARE NECESSARY AND SUFFICIENT FOR THE HETEROTYPIC INTERACTION WITH NOTCH ; Because we anticipated that some Delta variants might not be efficiently localized on the cell surface, we investigated the relationship ' between the level of expression of wild type Delta and the extent of aggregation with Notch-expressing cells by varying the input amount of Delta expression construct • in different transfections . We found that . the heterotypic Delta-Notch interaction exhibits only slight dependence on the Delta input level over a 10- fold range in this assay (Figure 9A) . Given the robustness of the heterotypic interaction over the range tested and our observations that each of the Delta variants we employed exhibited substantial surface accumulation in transfected cells, we infer that the inability of a given Delta variant to support heterotypic aggregation most probably reflects a functional deficit exhibited by that variant, as opposed to the impact of reduced levels of surface expression on heterotypic aggregation.

The results of the heterotypic aggregation experiments mediated by Delta, variants and wild-type Notch are shown in Table V.

TABLE V HETEROTYPIC AGGREGATION MEDIATED BY DELTA VARIANTS AND WILD TYPE NOTCH Aggregated Unaggregated. Aggregated Construct TotalA Total ; Expt . # Notch+ Delta+ Wild type .33(H) c" 179 1 15 18 58(H) 247 2 37 21 38 (H) 209 3 21 . 17 29(H) 174 4 18 11 175(B) 68 5 84 91 Del (Sca-Nae) 0 (H) 207 1 0 0 0(H) 226 2 0 o 0(H) 287 3 0 0 0(H) 200 4 NDD ND Del (Bam-Bgl) 4(H) 245 1 . .·,· 3 1 0(H) 200 2 0 0 0(H) 200 3 ND ND Del ( ELR1-ELR3 ) . 28(B) 296 1 11 17 (B) 90 2 9 11 22 (B) 227 3 19 13 127 (B) 97 4 19 78 Del (ELR4-ELR5 ) 38(H) 188 1 26 12 36(H) 204 2 20 16 Ter(Dde) 53(H) 236 1 24 29 51(H) 214 2 30 21 52 (H) 190 3 30 22 Ins(Nae)A 0(B) 205 1 0 0 0(B) 254 2 0 0 0(B) 201 3 . 0 0 NGl 0(B) 208 1 0 0 0(B) 114 2 0 0 0(B) 218 3 o 0 NG2 14(B) 106 1 7 7 50(B) 216 2 35 15 36(B) 168 3 12 24 NG3 71(B) 175 1 43 28 NG4 0(B) 254 1 0 0 0(B) 215 2 0. 0 0(B) 200 3 0 0 A Total number of expressing cells in aggregates that contain four B Cells that express neuroglian-based constructs (NGn) were detect antibody that recognizes the intracellular domain of neuroglian (se Methods) .

C (H) indicates that cells were aggregated in a 25 ml Erlenmeyer f that cells were aggregated in a 12-well microtiter plate (see Mater D Data for individual cell types (i.e., Delta+ and Notch"1") in aggr were not recorded.

Delta amino acids (AA) 1-230 is the current minimum sequence interval defined as being sufficient for interaction with Notch. This is based on the success of NG2-Notch aggregation. Within this interval, Delta AA198-230 are critical because their deletion in the NGl construct inactivated the Notch-binding activity observed for the NG2 construct. Also within this interval, Delta AA32-198 are critical because, their deletion in the NG4 construct also inactivated the Notch-binding activity observed for the NG3 construct. The importance of Delta AA192-230 is. also supported by the observation that the Del ( ELR1-ELR3 ) variant, which contains all Delta amino acids except AA231-331, possessed Notch-binding activity, while the Del(Bam-Bgl) variant, which contains all Delta amino acids except AA192-331, was apparently inactivated for Notch-binding activity.

Conformation and/ or primary sequence in the vicinity of Delta AA197/198 is apparently critical because a multimeric insertion of the tetrapeptide -Arg-Lys-Ile-Phe [in one letter code (see e.g.

Lehninger et al., 1975, Biochemistry, 2d ed., p. 72), R IF] (SEQ ID N0:30) - between these two residues, as in the Ins(Nae)A construct, inactivated the Notch-binding activity observed with wild type Delta.

In addition, the observation that the Del (ELR1-ELR3 ) construct supported aggregation implies that ELR1-ELR3 are not required for Delta-Notch interaction; the observation that the Del ( ELR4-ELR5) construct supported aggregation implies that ELR4 and ELR5 are not required for Delta-Notch interaction, and the observation that the Ter(Dde) construct supported aggregation implies that the Delta intracellular domain is not required for Delta-Notch interaction. 8.2.2. . AMINO-TERMINAL SEQUENCES WITHIN THE DELTA EXTRACELLULAR DOMAIN ARE NECESSARY AND SUFFICIENT FOR HOMOTYPIC INTERACTION The results of the homotypic aggregation experiments mediated by Delta variants is shown in Table VI.

TABLE VI HOMOTYPIC AGGREGATION MEDIATED BY DELTA VARIANTS Construct Aggregated Unaggregated Expt . # Wild type 38(H)A 175 1 48(H) 171 2 13(H) - 95 3 33(H) 173 4 134 (B) 72 5 Del(Sca-Nae) 0(H) 200 1 0(H) 200' 2 0 (H) 200 3 Del(Bam-Bgl) 0(H) 200 1 0(H) 200 2 0(H) 200 3 Del (ELR1-ELR3) 160(B) 62 1' 55(B) 80 2 0(B) 200 3 4(B) 203 4 41(B) 234 5 4(B) 366 6B 23 (B) 325 (1:20) 0(B) 400 7B (B) 347 (1:5) (B) 228 (1:20) . 0(B) 400 8a 16(B) ■ 346 (1:5) 4(B) 268 (1:20) 4(B) 500 18(B) 500 (1:5) 12(B) 271 (1:20) 7(B) 128 (1:50) 0(B) 500 0(B) 500 (1:5) 0(B) 500 (1:20) 21(B) 246 (1:50) 0(B) 500 (B) 500 (1:5) 8(B) 177 (1:20) '4(B) 69 (1:50) Del ( ELR4-ELR5 ) 21(H) 175 29 (H) 243 (H) 179 Ter (Dde) 53(H) 164 33(H) 178 36(H) 203 Ins(Nae)A 0(B) 200 0(B) 200 0(B) 200 A (H) indicates that cells were aggregated in a 25 ml Erlenmeyer flask; (B) indicates that cells were aggregated in a 12-well microtiter plate (see Materials and Methods) .

B Transfected cells were incubated under aggregation conditions overnight, then diluted into the appropriate volume of log-phase S2 cells in the presence of inducer and incubated under . aggregation conditions for an additional four to si hours . · .. . ' C Transfected cells to which inducer had been added were diluted into the appropriate volume of log- phase S2 cells to which inducer had been added, and the cell mixture was incubated under aggregation conditions overnight.

Deletion of Delta AA32-198 [ Del ( Sca-Nae) ] or Delta AA192-331 [Del (Bam-Bgl) ] from the full-length Delta protein eliminated the Delta-Delta interaction.

Deletion of Delta AA231-331 [ Del ( ELR1-ELR3 ) ] did not eliminate the Delta-Delta interaction. Therefore, sequences within the Delta AA32-230 are required for the Delta-Delta interaction.

Conformation and/or primary sequence in the vicinity of Delta AA197/198 is apparently critical for the Delta-Delta interaction because a multimeric insertion of the tetrapeptide -Arg-Lys-Ile-Phe- (SEQ ID NO: 30) between these two residues, as in the Ins(Nae)A construct, inactivated Delta-Delta interaction.

In addition, the observation that the Del (ELR1-ELR3 ) construct could support aggregation implies that ELR1-ELR3 are. not required for Delta-Delta interaction; the observation that the Del (ELR-ELR5) construct supported aggregation implies that ELR4 and ELR5 are not required for Delta-Delta interaction, and the observation that the Ter(Dde) construct supported aggregation implies that the Delta intracellular domain is not required for Delta-Delta interaction.

A summary of the results 'of assays for heterotypic and homotypic aggregation with various constructs are shown in Table VI A.

TABLE. VI A a: Mean fraction (%) of Delta or Notc ce s m aggregates of four or more cells (+ standard error) . N=3 replicates, unless otherwise noted, b: Mean fraction (%) of Delta cells in aggregates of four or more cells (+ standard error) . N= 3 replicates, unless otherwise noted, c: N = 5 replicates. d: N = 4 replicates. 8.2.3. DELTA SEQUENCES INVOLVED IN HETEROTYPIC AND HOMOTYPIC INTERACTIONS ARE QUALITATIVELY DISTINCT ■ The respective characteristics of Delta sequences repaired for heterotypic and homotypic interaction were further defined using Delta variants in which short, in-frame, translatable linker insertions were introduced into the Delta amino terminus ( i . e. , NAE B and STU B; Figure 9, Table VI A) . Replacement of Delta residue 132 (A) with the pentapeptide GKIFP (STU B variant) leads to the inactivation of heterotypic and homotypic interaction activities of the Delta amino terminus. This suggests that some Delta sequences required for these two distinct interactions are coincident and reside in proximity to residue 132. On the other hand, insertion of the tetrapeptide RKIF between Delta residues 198 and 199 (NAE B variant) eliminates the •ability of the Delta amino terminus to mediate heterotypic interaction with Notch, but has no apparent effect on the ability of the altered amino terminus to mediate homotypic interaction. The finding that the NAE B insertion affects only one. of the two activities of the Delta- amino terminus implies that the Delta sequences that mediate heterotypic and homotypic interactions, while coincident, are qualitatively distinct. 8.2.4. DELTA IS. AKEN UP BY CELLS THAT EXPRESS NOTCH During the course of many heterotypic aggregation experiments, we have noted that Delta protein can sometimes be found within cells that have been programmed to express Notch, but not Delta. We conduct heterotypic aggregation assays by mixing initially separate populations of S2 cells that have been independently transfected with expression constructs that program expression of either Delta or Notch. Yet, we often detect punctate staining of Delta within Notch-expressing cells found in heterotypic aggregates using Delta-specific antisera. Our observations are consistent with Delta binding directly to Notch at the cell surface and subsequent clearance of this Delta-Notch complex from the cell surface via endocytosis. 8.3. DISCUSSION 8.3.1. AMINO-TERMINAL SEQUENCES UNRELATED TO EGF ARE INVOLVED IN THE INTERACTION BETWEEN DELTA AND NOTCH We have employed cell aggregation assays to define a region within the amino-proximal region of the Delta extracellular domain that is necessary and ■sufficient to. mediate the Delta-Notch interaction.

Functional analyses of a combination of deletion and sufficiency constructs revealed that this region extends, maximally, from AA1 through AA230. It is striking that this region does not include any of the EGF-like sequences that reside within the Delta extracellular domain. It is probable that the particular Delta sequences within the sufficient interval required for interaction with Notch include AA198-230 because deletion of these residues eliminates Notch-binding activity. The fact that deletion of AA32-198 also inactivates Notch-binding activity suggests that sequences amino-proximal to AA198 are also required, although the deleterious impact of this deletion could result from the removal of additional amino acids in the immediate vicinity of AA198.

Sequences within Delta sufficient for interaction with Notch can be grouped into three subdomains - Nl, N2, and N3 - that differ in their respective contents of cysteine residues (Figure 10, SEQ ID NO: 3) . The Nl and N3 domains each contain six cysteine residues, while the N2 domain contains none. The even number of cysteines present in Nl and N3 , respectively, allows for the possibility that the respective structures of these subdomains are dictated, in part, by the formation of particular disulfide bonds. The broad organizational pattern of the Delta amino-terminus is also generally analogous to that of the extracellular domain of the vertebrate EGF receptor (Lax et al., 1988, Mol. Cell. Biol. 8, 1970-1978), in which sequences believed to interact with EGF are bounded by two cysteine-rich subdomains. 8.3.2. DELTA SEQUENCES REQUIRED FOR HOMOTYPIC AND FOR HOMOTYPIC HETEROTYPIC INTERACTIONS APPEAR TO BE COINCIDENT Our results also indicate that sequences essential for homotypic Delta interaction reside within the interval AA32-230. Deletion of sequences or insertion of additional amino acids within this amino-proximal domain eliminate the ability of such Delta variants to singly promote cell aggregation.

Thus, sequences' required for Delta-Delta interaction map within the s'ame domain of the protein as those required for Delta-Notch interaction. 8.3.3. THE DELTA AMINO TERMINUS CONSTITUTES AN EGF-BINDING MOTIF The work described in examples supra has revealed that Notch sequences required for Delta-Notch interaction in the cell aggregation assay map within the EGF-like repeat array of the Notch extracellular domain. This finding implies that Delta and Notch interact by virtue. of the binding of the Delta amino-term.inus to EGF-like sequences within Notch and, therefore, that the amino-terminus of the Delta extracellular domain constitutes an EGF-binding domain (Figure 11) .

These results also raise the possibility that homotypic Delta interaction involves the binding of the Delta amino-terminus to EGF-like sequences within the Delta extracellular domain (Figure 12). However, none of the EGF-like repeats within the Delta extracellular domain are identical to any of the EGF- like repeats within the Notch extracellular domain (Figure 13, SEQ ID NO: 6; Wharton et al., 1985, Cell 43, 567-581). Given this fact, if Delta homotypic interactions are indeed mediated by interaction between the Delta amino-terminus and Delta EGF-like ·. repeats, then the Delta EGF-binding domain has the capacity to. interact with at least two distinct EGF-like sequences. 8.3.4. DELTA SEQUENCES INVOLVED IN THE DELTA-NOTCH INTERACTION ARE CONSERVED IN THE SERRATE PROTEIN Alignment of amino acid sequences from the amino termini of the Delta (Figure 13, SEQ ID NO: 6, and Figure 15, SEQ ID NO:9) and Serrate (Fleming et al., 1990, Genes & Dev. 4, 2188-2201; Thomas et al., 1991, Devel. Ill, 749-761) reveals a striking conservation of structural character and sequence composition. The general N1-N2-N3 subdomain structure of the Delta amino terminus is also observed within the Serrate amino terminus, as is the specific occurrence of six cysteine residues within the Delta Nl- and Delta N3 -homologous domains of the Serrate protein.. Two notable blocks' of conservation correspond to Delta AA63-73 (8/11 residues identical) and Delta AA195-206 (10/11 residues identical) . The latter block is of particular interest because insertion of additional amino acids in this interval can eliminate the ability of Delta to bind to Notch or Delta. 8.3.5..CIS AND TRANS INTERACTIONS BETWEEN DELTA AND NOTCH MAY INVOLVE DIFFERENT SEQUENCES WITHIN NOTCH Inspection of the overall structures of Delta and Notch suggests that Delta-Notch interaction could involve contacts between the Delta EGF-binding domain with either of two regions within Notch, depending on whether the interaction were between molecules that reside on opposing membranes or within the same membrane (Figure 11) . The cell aggregation 5 assays, which presumably detect the interaction of molecules in opposing membranes, imply that the Delta EGF-binding domain interacts with Notch EGF-like repeats 11 and 12 (see examples supra) . If tandem arrays of EGF-like motifs do form rod-like structures 0 (Engel, 1989, FEBS Lett. 251, 1-7) within the Delta and Notch proteins, then the estimated displacement of the Delta EGF-binding domain from the cell surface would presumably be sufficient to accommodate the rigid array of Notch EGF-like repeats 1-10. It is 1 also intriguing to note that the displacement of the Delta EGF-binding domain from the cell surface could place this domain in the vicinity of the Notch EGF- like repeats (25-29) that are affected by Abruptex mutations (Hartley et al., 1987, EMBO J. 6, 3407-3417; Kelley et al., 1987, ol. Cell. Biol. 6, 3094-3108) and could allow for interaction of Delta and Notch proteins present within the same membrane. 8.3.6. INTERACTIONS ANALOGOUS TO THE DELTA-NOTCH- INTERACTION IN VERTEBRATES . 1 ' Given the interaction between Delta and Notch in Drosophila, it is quite probable that a Delta homologue (Helta?) exists in vertebrates and that the qualitative and molecular aspects of the Delta-Notch 30 and Delta-Delta interactions that we have defined in Drosophila will be highly conserved in vertebrates, including humans. Such ho ologs can be cloned and sequenced as described supra , Section 5.2. ■ ■ 9. SEQUENCES WHICH MEDIATE NOTCH-SERRATE INTERACTIONS We report a novel molecular interaction between Notch and Serrate, and show that the two EGF repeats of Notch which mediate interactions with Delta, namely EGF repeats 11 and 12, also constitute a Serrate binding domain.

To test whether Notch and Serrate directly interact, S2 cells were transfected with a . Serrate expression construct and mixed with Notch expressing cells in our aggregation assay. For the Serrate expression construct, a synthetic primer containing an artificial BamHI site . immediately 5' to the initiator AUG at position 442 (all sequence numbers are according to Fleming et al., 1990, Genes & Dev. 4,: 2188-2201) and homologous through position 464, was used in conjunction with a second primer from position 681-698 to generate a DNA fragment of -260 base pairs. This fragment was cut with BamHI and Kpnl (position 571) and ligated into Bluescript KS+ (Stratagene) .

This construct, BTSer5'PCR, was checked by sequencing, then cut with Kpnl. The Serrate Kpnl fragment (571 -2981) was inserted and the proper orientation selected, to generate BTSer5 ' PCR-Kpn . The 5' SacII fragment of BTSer5 'PCR-Kpn (SacII sites in Bluescript polylinker and in Serrate (1199)) was isolated and used to replace the 5' SacII fragment of cDNA CI (Fleming et al., 1990, Genes & Dev. 4:2188-2201), thus regenerating the full length Serrate cDNA minus the 5' untranslated regions. This insert was isolated by a Sail and partial BamHI digestion and shuttled into the, BamHI and Sail sites of pRmHa-3 to generate the final expression construct, Ser-mtn.

We found that Serrate expressing cells adhere to Notch expressing cells in a calcium dependent manner (Figure 6 and Table VII). However, unlike Delta, under the experimental conditions tested, Serrate does not appear to interact homotypically . In addition, we detect no interactions between Serrate and Delta.

TABLE VII Effect of Exogenous Ca++ on Notch -. Serrate Aggregation" Notch-Serrate Without Ca" With Ca pMtNMg 0 15 AECN+EGF (10-12 ) 0 13 ACla+XEGF( 10-13) 0 15 Data presented as percentage of Notch expressing cells found in aggregates (as in Figure 6) . All numbers are from single transfection experiments (rather than an average of values from several separate experiments as in Figure 6) .

We have tested a subset of our Notch deletion constructs to map the Serrate-binding domain and have found that EGF repeats 11 and 12, in addition to binding to Delta, also mediate interactions with Serrate (Figure 6; Constructs #1, 7-10, 13, 16, 17, 19,. 28, and 32) . In addition, the Serrate-binding function of these repeats also appears to have been conserved in the corresponding two EGF repeats of Xenopus Notch (#33ACla+XEGF ( 10-13 )) . These results unambiguously show that Notch interacts with both Delta and Serrate, and that the same two EGF repeats of Notch mediate both interactions. We were also able to define the Serrate region which is essential for - Ill - the Notch/Serrate aggregation. Deleting nucleotides 676-1287 (i.e. amino acids 79-282) (See Figure 15) eliminates the ability of the Serrate protein to aggregate with Notch.

Notch and Serrate appear to aggregate less efficiently than Notch and Delta, perhaps because the Notch-Serrate interaction is weaker. For example, when scoring Notch-Delta aggregates, we detect -40% of all Notch expressing cells in clusters with Delta expressing cells (Figure 6, #1 pMtNMg) and -40% of all ' Delta expressing cells in contact with Notch expressing cells.- For Notch-Serrate, we find only . -20% of all Notch expressing cells (Figure 6; pMtNMg) and -15% of all Serrate expressing cells in aggregates. For the various Notch deletion constructs tested, we consistently detect a reduction in the amount of aggregation between Notch and Serrate as compared to the corresponding Notch-Delta levels (Figure 6) , with the possible exception of constructs #9 and 10 which exhibit severely reduced levels of aggregation even with Delta. One trivial explanation for this reduced amount of aggregation could be that our Serrate construct . simply· does not express as much protein at the cell surface as the Delta construct, . thereby diminishing the strength of the interaction. Alternatively, the difference in strength of interaction may indicate a fundamental functional difference between Notch-Delta and Notch-Serrate interactions that may be significant in vivo .

. THE CLONING, SEQUENCING , AND EXPRESSION OF HUMAN NOTCH .1. ISOLATION AND SEQUENCING OF HUMAN NOTCH Clones for the human Notch sequence were originally obtained using the polymerase chain reaction (PCR) to amplify DNA from a 17-1-8 week human fetal brain. cDNA library in the Lambda Zap II vector (Stratagene) . Degenerate primers to be used in this reaction were designed by comparing the amino acid sequences of the Xenopus homolog of Notch with Drosophila Notch . Three primers (cdcl (SEQ ID NO: 10), cdc2 (SEQ ID NO: 11)/ and cdc3 ( SEQ ID N0:12); Figure 16) were designed to amplify either a 200 bp or a 400. bp fragment as primer pairs cdcl/cdc2 or cdcl/cdc3, respectively.

The 400 bp fragment obtained in this manner was then used as a probe with which to screen the same library for human Notch clones. The original screen yielded three unique clones, hN3k, hN2K, and hN5k, all of which were shown by subsequent sequence analysis to fall in the 3' end of human Notch (Figure 17). A second screen using the 51 end of hN3k as probe was undertaken to search for clones encompassing the 5' end of human Notch . One unique clone, hN4k, was obtained from this screen, and preliminary sequencing data indicate that it contains most of the 5 ' . end of the gene (Figure 17). Together, clones hN4k, hN3k and hN5k encompass about 10 kb.of the human Notch homolog, beginning early in. the EGF-repeats and extending into the 3' untranslated region of the gene. All three clones are cDNA inserts in the EcoRI site of pBluescript SK" (Stratagene). The host E. coli strain is XLl-Blue (see aniatis, T., 1990, Molecular Cloning, A Laboratory Manual, 2d ed., Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, p. A12) .

The sequence of various portions of Notch, contained in the cDNA clones was determined (by use of Sequenase®, U.S. Biochemical Corp.) and is shown in Figures 19-22 (SEQ ID NO: 13 through NO:25).

The complete nucleotide sequences of the human Notch cDNA contained in hN3k and hN5k was determined by the dideoxy chain termination method using the Sequenase® kit (U.S. Biochemical Corp.)., Those nucleotide sequences encoding human Notch, in the appropriate reading frame, were readily identified since translation in only one out of the three possible reading frames 'yields a sequence which, upon comparison with the published Drosophila Notch deduced amino acid sequence, yields a sequence with a substantial degree of homology to the Drosophila Notch sequence. Since there are no introns, translation of all three possible reading frames and comparison with Drosophila Notch was easily accomplished, leading to the ready identification of the coding region. The DNA and deduced protein sequences of the human Notch cDNA in hN3k and hN5k are presented in Figures 23 and 24, respectively. Clone hN3k encodes a portion of a Notch polypeptide starting at approximately the third Notch/lin-12 repeat to several amino acids short of the carboxy-terminal amino acid. Clone hN5k encodes a portion of a Notch polypeptide starting approximately before the cdclO region through the end of the polypeptide, and also contains a 3 ' untranslated region.

Comparing the DNA and protein sequences presented in Figure 23 (SEQ ID NO: 31 and NO: 32) with' those in Figure 24 (SEQ ID NO: 33 and NO: 34) reveals significant differences between the sequences, suggesting that hN3k and hN5k represent part, of two distinct Notch-homologous genes. Our data thus suggest that the human genome harbors more than one Notch-homologous gene. This is unlike Drosophila . where Notch appears to be a single-copy gene.

Comparison of the DNA and amino acid sequences of the human Notch homologs contained in hN3k and hN5k with the corresponding Drosophila Notch sequences (as published in Wharton et al., 1985, Cell 43:567-581) and. with the corresponding Xenopus Notch sequences (as published in Coffman et al., 1990, Science 249:1438-1441 or available from Genbank® (accession number M33874)) also revealed differences.

The amino acid sequence shown in Figure 23 (hN3k) was compared with the predicted sequence of the TAN-1 polypeptide shown in Figure 2 of Ellisen et al., August 1991, Cell 66:649-661. Some differences were found between the deduced amino acid sequences; however, overall the hN3k Notch polypeptide sequence is 99% identical to the corresponding TAN-1 region (TAN-1 amino acids 1455 to 2506) . Four differences were noted: in the region between the third Notch/lin-12 repeat and the first cdclO motif, there is an arginine (hN3k) instead of an X (TAN-1 amino acid 1763) ; (2) there is a proline (hN3k) instead of an X (TAN-1, amino acid 1787); (3) there is a conservative change of an aspartic acid residue (hN3k) instead of a glutamic acid residue (TAN-1, amino acid 2495) ; and (4) the carboxyl-terminal region differs substantially between TAN-1 amino acids 2507 and 2535.

The amino acid sequence shown in Figure 24 (hN5k) was compared with the predicted sequence of the TAN-1 polypeptide shown in Figure 2 of Ellisen et al., August 1991, Cell 66:649-661. Differences were found between the deduced amino acid sequences. The deduced Notch polypeptide of hN5k is 79% identical to the TAN-1 polypeptide (64% identical to Drosophila Notch) in the cdclO region that encompasses both the cclO motif. (TAN-1 amino acids 1860 to 2217) and. the well-conserved flanking regions (Fig. 25) . The cdclO region covers amino acids 1860 through 2217 of the TAN-1 sequence. In addition, the hN5k encoded polypeptide is 65% identical to the TAN-1 polypeptide (44% identical to Drosophila Notch) at the carboxy-terminal end of the molecule containing a PEST (proline, glutamic acid, serine, threonine) -rich region (TAN-1 amino acids 2482 to 2551) (Fig. 25B) .. The stretch of 215 amino acids lying between the aforementioned regions is not well conserved among any of the Notch-homologous clones represented by hN3k, hN5k, and TAN-1. Neither the hN5k polypeptide nor Drosophila Notch shows significant levels of amino acid identity to the other proteins in this region (e.g., hN5k/TAN-l - 24% identity; hN5k/Drosophila Notch = 11% identity; TAN-l/Drosophila Notch = 17% identity). In contrast, Xenopus Notch (Xotch) (SEQ ID NO:35), rat Notch (SEQ ID NO:36), and TAN-1 (SEQ ID NO:37), continue to share significant levels of sequence identity with one another . (e . g . , TAN-l/rat Notch = 75% identity, TAN-1 / enopus Notch = 45% identity, rat Notch/Xenopus Notch = 50% identity) .

Finally,, examination of the sequence of the intracellular domains of the vertebrate Notch homologs shown in Figure 25B revealed an unexpected finding: all of these proteins, including hN5k, contain a putative CcN . motif, associated with nuclear targeting function, in the conserved region following the last of the six cdclO repeats (Fig. 25B) . Although Drosophila Notch lacks such a defined motif, closer inspection of its sequence revealed the presence of a possible bipartite nuclear localization sequence (Robbins et al., 1991, Cell 64:615-623), as well as of possible CK II and cdc2 phosphorylation sites, all in relative proximity to one another, thus possibly defining an alternative type of CcN motif (Fig. 25B) . .2. EXPRESSION OF HUMAN NOTCH Expression constructs were made using the human Notch cDNA clones discussed in Section 10.1 above. In the cases of hN3k and hN2k, the entire : clone was excised from its vector as an EcoRI restriction fragment and subcloned into the EcoRI restriction site of each of the three pGEX vectors (Glutathione S-Transferase expression vectors; Smith and Johnson, 1988, Gene 7, 31-40). This allows for the expression of the Notch protein product from the subclone in the correct reading frame. In the case of hN5k, the clone contains two internal EcoRI restriction sites, producing 2.6, 1.5 and .0.6 kb fragments. Both the 2.6 and. the 1.5 kb fragments have also been subcloned into each of the pGEX vectors.

The pGEX vector system was used to obtain expression of human Notch fusion (chimeric) proteins from the constructs described below. The cloned otch DNA in each case was inserted, in phase, into the appropriate pGEX vector. Each construct was then electroporated into bacteria (E. coli) , and was expressed as a fusion protein .containing the Notch protein sequences fused to the carboxyl terminus of glutathione S-transferase protein. . Expression of the fusion proteins was confirmed by analysis of bacterial protein extracts by polyacrylamide gel electrophoresis, comparing protein extracts obtained from bacteria containing the pGEX plasmids with and without the. inserted Notch DNA. The fusion proteins were soluble in aqueous solution, and were purified from bacterial lysates by affinity chromatography using glutathione-coated agarose (since the carboxyl terminus of glutathione S-transferase binds to gl tathionine) . The expressed fusion proteins were bound by an antibody to Drosophila Notch, as assayed by Western blotting.

The constructs used to make human Notch-glutathione S-transferase fusion proteins were as follows: hNFP#2 - PCR was used to obtain a fragment starting just before the cdclO repeats at nucleotide 192 of the hN5k insert to just before the PEST-rich region at nucleotide 1694. _ The DNA was then digested with BamHI and Smal and the resulting fragment was ligated into pGEX-3...

After expression, the fusion protein was purified by binding to glutathione agarose. The purified polypeptide was quantitated on a 4—15% gradient polyacrylamide gel. The resulting fusion protein had an approximate molecular weight of 83 kD. hN3FP#l - The entire hN3k DNA insert (nucleotide 1 to 3235) was excised from the Bluescript (SK) vector by digesting with EcoRI . The DNA was ligated into pGEX-3. hN3FP#2 - A segment of hN3k DNA (nucleotide 1847 to 3235) plus some of the polylinker was cut out of the Bluescript (SK) vector by digesting with Xmal . The fragment was ligated into pGEX-1.

Following purification, these fusion proteins are used to make either polyclonal and/ or monoclonal antibodies to human Notch. 11. DEPOSIT OF MICROORGANISMS The following recombinant bacteria, each carrying a . lasmid encoding a portion of human Notch were deposited on May 2, 1991 with the American Type Culture Collection, 1201 Parklawn Drive, Rockville, Maryland 20852, under the provisions of the Budapes Treaty on the International Recognition . of the Deposit of Microorganisms for the Purposes of Patent Procedures .

Bacteria carrying Plasmid . ATCC Accession No. E. coli XLl-Blue . hN4k 68610.

E. coli XLl-Blue hN3k 68609 E. coli XLl-Blue hN5k 686.11 The present invention is not to be limited in scope by the microorganisms deposited or the specific embodiments described herein. Indeed, various modifications of the invention in addition to those described herein will become apparent to those skilled in the. art from the foregoing description and accompanying figures. Such modifications are intended , to fall within the scope of the appended claims.

Various publications are cited herein, the disclosures of. which are incorporated by reference in their entireties.

Treaty on the International Recognition . of the Deposit of Microorganisms for the Purposes of Patent Procedures .

Bacteria carrying Plasmid . ATCC Accession No.

E. coli XLl-Blue hN4k 68610 E. coli XLl-Blue hN3k 68609 E. coli XLl-Blue hN5k 68611 The present invention is not to be limited in scope by the microorganisms deposited or the specific embodiments described herein. Indeed, various modifications of the invention in addition to those described herein will become apparent to those skilled in the art from the foregoing description and accompanying figures. Such modifications are intended to fall within the scope of the appended claims.

Various publications are cited herein, the disclosures of which are incorporated by reference in their entireties.

Those portions of the specification beyond the scope of the allowed claims are not part of the invention. - 119 - SEQUENCE LISTING ) GENERAL INFORMATION: (i) APPLICANT: Artavanis-Tsakonas , Spyridon et al. (ii) TITLE OF INVENTION: Human Notch And Delta, Binding D In Toporythmic Proteins, And Methods Based Thereo (iii) NUMBER OF SEQUENCES: 37 (iv) CORRESPONDENCE ADDRESS: (A) ADDRESSEE: Pennie & Edmonds (B) STREET: 1155 Avenue of the Americas (C) CITY: New York (D) STATE: New York (E) COUNTRY: U.S.A.

(F) ZIP: 10036 (v) COMPUTER READABLE FORM: (A) MEDIUM TYPE: Floppy disk (B) COMPUTER: IBM PC compatible (C) OPERATING SYSTEM: PC-DOS/MS-DOS (D) SOFTWARE: Patentln Release #1.0, Version #1.25 (vi) CURRENT APPLICATION DATA: (A) APPLICATION NUMBER: (B) FILING DATE: (C) CLASSIFICATION: (viii) ATTORNEY/AGENT INFORMATION: (A) NAME: Misrock, S. Leslie (B) REGISTRATION NUMBER: 18,872 (C) REFERENCE/DOCKET NUMBER: 7326-009 (ix) TELECOMMUNICATION INFORMATION: (A) TELEPHONE: 212 790-9090 (B) TELEFAX: 212 8698864/9741 (C) TELEX: 66141 PENNIE ) INFORMATION FOR SEQ ID NO:l: (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 77 amino acids (B) TYPE: amino acid (C) STRANDEDNESS : single (D) TOPOLOGY: unknown (ii) MOLECULE TYPE: peptide (xi) SEQUENCE DESCRIPTION: SEQ ID NO:l: Glu Asp lie Asp Glu Cys Asp Gin Gly Ser Pro Cys Glu His Asn Gly 1 1 5 10 15 lie Cys Val Asn Thr Pro Gly Ser Tyr Arg Cys Asn Cys Ser Gin Gly 25 30 Phe Thr Gly Pro Arg Cys Glu Thr Asn lie Asn Glu Cys Glu Ser His 40 45 Pro Cys Gin Asn Glu Gly Ser Cys Leu Asp Asp Pro Gly Thr Phe Arg 50 55 60 Cys Val Cys Met Pro Gly Phe Thr Gly Thr Gin Cys Glu 65 70 75 - 120 - INFORMATION FOR SEQ ID NO: 2: (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 78 amino acids (B) TYPE: amino acid (C) STRANDEDNESS: single (D) TOPOLOGY: unknown (ii) MOLECULE TYPE: peptide (xi) SEQUENCE DESCRIPTION: SEQ ID NO: 2: Asn Asp Val Asp Glu Cys Ser Leu Gly Ala Asn Pro Cys Glu His Gly 1 5 10 15 Gly Arg Cys Thr Asn Thr Leu Gly Ser Phe Gin Cys Asn Cys Pro Gin 25 30 Gly Tyr Ala Gly Pro Arg Cys Glu He Asp Val Asn Glu Cys Leu Ser 40 45 Asn Pro Cys Gin Asn Asp Ser Thr Cys Leu Asp Gin He Gly Glu Phe 50 55 60 Gin Cys He Cys Met Pro Gly Tyr Glu Gly Leu Tyr Cys Glu 65 70 75 INFORMATION FOR SEQ ID NO: 3: (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 203 amino acids ( B ) TYPE: amino acid (C) STRANDEDNESS: single (D) TOPOLOGY: unknown (ii) MOLECULE TYPE: peptide (xi) SEQUENCE DESCRIPTION: SEQ ID NO: 3: Gly Ser Phe Glu Leu Arg Leu Lys Tyr Phe Ser Asn Asp His Gly Arg 1 5 10 15 Asp Asn Glu Gly Arg Cys Cys Ser Gly Glu Ser Asp Gly Ala Thr Gly 25 30 Lys Cys Leu Gly Ser Cys Lys Thr Arg Phe Arg Val Cys Leu Lys His 40 45 Tyr Gin Ala Thr He Asp Thr Thr Ser Gin Cys Thr Tyr Gly Asp Val 50 55 60 He Thr Pro He Leu Gly Glu Asn Ser Val Asn Leu Thr Asp Ala Gin 65 70 . 75 80 Arg Phe Gin Asn Lys Gly Phe Thr Asn Pro He Gin Phe Pro Phe. Ser 85 90 95 Phe Ser Trp Pro Gly Thr Phe Ser Leu He Val Glu Ala Trp His Asp 100 105 110 Thr Asn Asn Ser Gly Asn Ala Arg Thr Asn Lys Leu Leu He Gin Arg 115 120 125 Leu Leu Val Gin Gin Val Leu Glu Val Ser Ser Glu Trp Lys Thr Asn 130 135 140 - 121 - Lys Ser Glu Ser Gin Tyr Thr Ser Leu Glu Tyr Asp Phe Arg Val Thr 145 150 155 160 Cys Asp Leu Asn Tyr Tyr Gly Ser Gly Cys Ala Lys Phe Cys Arg Pro 165 170 175 Arg Asp Asp Ser Phe Gly His Ser Thr Cys Ser Glu Thr Gly Glu He 180 185 190 He Cys Leu Thr Gly Trp Gin Gly Asp Tyr Cys 195 200 INFORMATION FOR SEQ ID NO: 4: (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 199 amino acids (B) TYPE: amino acid (C) STRANDEDNESS: single (D) TOPOLOGY: unknown (ii) MOLECULE TYPE: peptide (xi) SEQUENCE DESCRIPTION: SEQ ID NO: 4: Gly Asn Phe Glu Leu Glu He Leu Glu He Ser Asn Thr Asn Ser His 1 5 10 15 Leu Leu Asn Gly Tyr Cys Cys Gly Met Pro Ala Glu Leu Arg Ala Thr 25 30 Lys Thr He Gly Cys Ser Pro Cys Thr Thr Ala Phe Arg Leu Cys Leu 40 45 Lys Glu Tyr Gin Thr Thr Glu Gin Gly Ala Ser He Ser Thr Gly Cys 50 55 60 Ser Phe Gly Asn Ala Thr Thr Lys He Leu Gly Gly Ser Ser Phe Val 65 70 75 80 Leu Ser Asp Pro Gly Val Gly Ala He Val Leu Pro Phe Thr Phe Arg 85 90 95 Trp Thr Lys Ser Phe Thr Leu He Leu Gin Ala Leu Asp Met Tyr Asn 100 105 110 Thr Ser Tyr Pro Asp Ala Glu Arg Leu lie Glu Glu Thr Ser Tyr Ser 115 120 125 Gly Val He Leu Pro Ser Pro Glu Trp Lys Thr Leu Asp His He Gly 130 135 140 Arg Asn Ala Arg He Thr Tyr Arg Val Arg Val Gin Cys Ala Val Thr 145 150 155 160 Tyr Tyr Asn Thr Thr Cys Thr Thr Phe Cys Arg Pro Arg Asp Asp Gin 165 170 175 Phe Gly His Tyr Ala Cys Gly Ser Glu Gly Gin Lys Leu Cys Leu Asn 180 185 190 Gly Trp Gin Gly Val Asn Cys 195 INFORMATION FOR SEQ ID NO: 5: (i) SEQUENCE CHARACTERISTICS: - (A) LENGTH: 2892 base pairs (B) TYPE: nucleic acid - 122 - (C) STRANDEDNESS: double (D) TOPOLOGY: unknown MOLECULE TYPE: cDNA ( ix ) FEATURE : (A) NAME/KEY: CDS (B) LOCATION: 142..2640 (xi) SEQUENCE DESCRIPTION: SEQ ID NO: 5: GAATTCGGAG GAATTATTCA AAACATAAAC ACAATAAACA ATTTGAGTAG TTGCCGCACA CACACACACA CACAGCCCGT GGATTATTAC ACTAAAAGCG ACACTCAATC CAAAAAATCA GCAACAAAAA CATCAATAAA C ATG CAT TGG ATT AAA TGT TTA TTA ACA GCA Met His Trp lie Lys Cys Leu Leu Thr Ala 1 5 10 TTC ATT TGC TTC ACA GTC ATC GTG CAG GTT CAC AGT TCC GGC AGC TTT Phe lie Cys Phe Thr Val lie Val Gin Val His Ser Ser Gly Ser Phe 20 25 GAG TTG CGC CTG AAG TAC TTC AGC AAC GAT CAC GGG CGG GAC AAC GAG Glu "Leu Arg Leu Lys Tyr Phe Ser Asn Asp His Gly Arg Asp Asn Glu , 35 40 I GGT CGC TGC TGC AGC GGG GAG TCG GAC GGA GCG ACG GGC AAG TGC CTG Gly Arg Cys Cys Ser Gly Glu Ser Asp Gly Ala Thr Gly Lys Cys Leu 45 50 55 GGC AGC TGC AAG ACG CGG TTT CGC GTC TGC CTA AAG CAC TAC CAG GCC Gly Ser Cys Lys Thr Arg Phe Arg Val Cys Leu Lys His Tyr Gin Ala 60 65 70 ACC ATC GAC ACC ACC TCC CAG TGC ACC TAC GGG GAC GTG ATC ACG CCC Thr lie Asp Thr Thr Ser Gin Cys Thr Tyr Gly Asp Val lie Thr Pro 75 80 85 90 ATT CTC GGC GAG AAC TCG GTC AAT CTG ACC GAC GCC CAG CGC TTC CAG lie Leu Gly Glu Asn Ser Val Asn Leu Thr Asp Ala Gin Arg Phe Gin 95 100 105 AAC AAG GGC TTC ACG AAT CCC ATC CAG TTC CCC TTC TCG TTC TCA TGG Asn Lys Gly Phe Thr Asn Pro lie Gin Phe Pro Phe Ser Phe Ser Trp 110 115 120 CCG GGT ACC TTC TCG CTG ATC GTC GAG GCC TGG CAT GAT ACG AAC AAT Pro Gly Thr Phe Ser Leu lie Val Glu Ala Trp His Asp Thr Asn Asn 125 130 135 AGC GGC AAT GCG CGA ACC AAC AAG CTC CTC ATC CAG CGA CTC TTG GTG Ser Gly Asn Ala Arg Thr Asn Lys Leu Leu lie Gin Arg Leu Leu Val 140 145 150 CAG CAG GTA CTG GAG GTG TCC TCC GAA TGG AAG ACG AAC AAG TCG GAA Gin Gin Val Leu Glu Val Ser Ser Glu Trp Lys Thr Asn Lys Ser Glu 155 160 165 170 TCG CAG TAC ACG TCG CTG GAG TAC GAT TTC CGT GTC ACC TGC GAT CTC Ser Gin Tyr Thr Ser Leu Glu Tyr Asp Phe Arg Val Thr Cys Asp Leu 175 180 185 AAC TAC TAC GGA TCC GGC TGT GCC AAG TTC TGC CGG CCC CGC GAC GA Asn Tyr Tyr Gly Ser Gly Cys Ala Lys Phe Cys Arg Pro Arg Asp Asp 190 195 200 TCA TTT GGA . CAC TCG ACT TGC TCG GAG ACG GGC GAA ATT ATC TGT TTG 795 - 123 - Ser Phe Gly His Ser Thr Cys Ser Glu Thr Gly Glu lie lie Cys Leu 205 210 215 ACC GGA TGG CAG GGC GAT TAC TGT CAC ATA CCC AAA TGC GCC AAA GGC Thr Gly Trp Gin Gly Asp Tyr Cys His lie Pro Lys Cys Ala Lys Gly 220 225 230 TGT GAA CAT GGA CAT TGC GAC AAA CCC AAT CAA TGC GTT TGC CAA CTG Cys Glu His Gly His Cys Asp Lys Pro Asn Gin Cys Val Cys Gin Leu 235 240 - 245 250 GGC TGG AAG GGA GCC TTG TGC AAC GAG TGC GTT CTG GAA CCG AAC TGC Gly Trp Lys Gly Ala Leu Cys Asn Glu Cys Val Leu Glu Pro Asn Cys 255 260 265 ATC CAT GGC ACC TGC AAC AAA CCC TGG ACT TGC ATC TGC AAC GAG GGT lie His Gly Thr Cys Asn Lys Pro Trp Thr Cys lie Cys Asn Glu Gly 270 275 280 TGG GGA GGC TTG TAC TGC AAC CAG GAT CTG AAC TAC TGC ACC AAC CAC Trp Gly Gly Leu Tyr Cys Asn Gin Asp Leu Asn Tyr Cys Thr Asn His 285 290 295 AGA CCC TGC AAG AAT GGC GGA ACC TGC TTC AAC ACC GGC GAG GGA TTG Arg Pro Cys Lys Asn Gly Gly Thr Cys Phe Asn Thr Gly Glu Gly Leu. 300 305 ■ 310 TAC ACA TGC AAA TGC GCT CCA GGA TAC AGT GGT GAT GAT TGC GAA AAT Tyr Thr Cys Lys Cys Ala Pro Gly Tyr Ser Gly Asp Asp Cys Glu Asn 315 320 325 330 GAG ATC TAC TCC TGC GAT GCC GAT GTC AAT CCC TGC CAG AAT GGT GGT Glu lie Tyr Ser Cys Asp Ala Asp Val Asn Pro Cys Gin Asn Gly Gly 335 340 345 ACC TGC ATC GAT GAG CCG CAC ACA AAA ACC GGC TAC AAG TGT CAT TGC Thr Cys lie Asp Glu Pro His Thr Lys Thr Gly Tyr Lys Cys His Cys 350 355 360 GCC AAC GGC TGG AGC GGA AAG ATG TGC GAG GAG AAA GTG CTC ACG TGT Ala Asn Gly Trp Ser Gly Lys Met Cys Glu Glu Lys Val Leu Thr Cys 365 370 375 TCG GAC AAA CCC TGT CAT CAG GGA ATC TGC CGC AAC GTT CGT CCT GGC Ser Asp Lys Pro Cys His Gin Gly lie Cys Arg Asn Val Arg Pro Gly 380 385 390 TTG GGA AGC AAG GGT CAG GGC TAC CAG TGC GAA TGT CCC ATT GGC TAC Leu Gly Ser Lys Gly Gin Gly Tyr Gin Cys Glu Cys Pro lie Gly Tyr 395 400 405 410 AGC GGA CCC AAC TGC GAT CTC CAG CTG GAC AAC TGC AGT CCG AAT CCA Ser Gly Pro Asn Cys Asp Leu Gin Leu Asp Asn Cys Ser Pro Asn Pro 415 420 425 TGC ATA AAC GGT GGA AGC TGT CAG CCG AGC GGA AAG TGT ATT TGC CCA Cys lie Asn Gly Gly Ser Cys Gin Pro Ser Gly Lys Cys lie Cys Pro 430 435 ' 440 GCG GGA TTT TCG GGA ACG AGA TGC GAG ACC AAC ATT GAC GAT TGT CTT Ala Gly Phe Ser Gly Thr Arg Cys Glu Thr Asn lie Asp Asp Cys Leu 445 450 455 GGC CAC CAG TGC GAG AAC GGA GGC. ACC TGC ATA GAT ATG GTC AAC CAA Gly His Gin Cys Glu Asn Gly Gly Thr Cys lie Asp Met Val Asn Gin 460 46'5 470 TAT CGC TGC CAA TGC GTT CCC GGT TTC CAT GGC ACC CAC TGT AGT AGC Tyr Arg Cys Gin Cys Val Pro Gly Phe His Gly Thr His Cys Ser Ser 475 480 485 490 - 124 - AAA GTT GAC TTG TGC CTC ATC AGA CCG TGT GCC AAT GGA GGA ACC TGC Lys Val Asp Leu Cys Leu lie Arg Pro Cys Ala Asn Gly Gly Thr Cys 495 500 505 TTG AAT CTC AAC AAC GAT TAC CAG TGC ACC TGT CGT GCG GGA TTT ACT Leu Asn Leu Asn Asn Asp Tyr Gin Cys Thr Cys Arg Ala Gly Phe Thr 510 515 520 GGC AAG GAT TGC TCT GTG GAC ATC GAT GAG TGC AGC AGT GGA CCC TGT Gly Lys Asp Cys Ser Val Asp lie Asp Glu Cys Ser Ser Gly Pro Cys 525 530 535 CAT AAC GGC GGC ACT TGC ATG AAC CGC GTC AAT TCG TTC GAA TGC GTG His Asn Gly Gly Thr Cys Met Asn Arg Val Asn Ser Phe Glu Cys Val 540 545 550 TGT GCC AAT GGT TTC AGG GGC AAG CAG TGC GAT GAG GAG TCC TAC GAT Cys Ala Asn Gly Phe Arg Gly Lys Gin Cys Asp Glu Glu Ser Tyr Asp 555 560 565 570 TCG GTG ACC TTC GAT GCC CAC CAA TAT GGA GCG ACC ACA CAA GCG AGA Ser Val Thr Phe Asp Ala His Gin Tyr Gly Ala Thr Thr Gin Ala Arg 575 580 585 GCC GAT GGT TTG ACC AAT GCC CAG GTA GTC CTA ATT GCT GTT TTC TCC Ala Asp Gly Leu Thr Asn Ala Gin Val Val Leu lie Ala Val Phe Ser 590 595 600 GTT GCG ATG CCT TTG GTG GCG GTT ATT GCG GCG TGC GTG GTC TTC TGC Val Ala Met Pro Leu Val Ala Val lie Ala Ala Cys Val Val Phe Cys 605 610 615 ATG AAG CGC AAG CGT AAG CGT GCT CAG GAA AAG GAC GAC GCG GAG GCC Met Lys Arg Lys Arg Lys Arg Ala Gin Glu Lys Asp Asp Ala Glu Ala 620 625 630 AGG AAG CAG AAC GAA CAG AAT GCG GTG GCC ACA ATG CAT CAC AAT GGC Arg Lys Gin Asn Glu Gin Asn Ala Val Ala Thr Met His His Asn Gly 635 640 645 650 AGT GGG GTG GGT GTA GCT TTG GCT TCA GCC TCT CTG GGC GGC AAA ACT Ser Gly Val Gly Val Ala Leu Ala Ser Ala Ser Leu Gly Gly Lys Thr 655 660 665 GGC AGC AAC AGC GGT CTC ACC TTC GAT GGC GGC AAC CCG AAT ATC ATC Gly Ser Asn Ser Gly Leu Thr Phe Asp Gly Gly Asn Pro Asn lie lie 670 675 680 AAA AAC ACC TGG GAC AAG TCG GTC AAC AAC ATT TGT GCC TCA GCA GCA Lys Asn Thr Trp Asp Lys Ser Val Asn Asn lie Cys Ala Ser Ala Ala 685 690 695 GCA GCG GCG GCG GCG GCA GCA GCG GCG GAC GAG TGT CTC ATG TAC GGC Ala Ala Ala Ala Ala Ala Ala Ala Ala Asp Glu Cys Leu Met Tyr Gly 700 705 710 GGA TAT GTG GCC TCG GTG GCG GAT AAC AAC AAT GCC AAC TCA GAC TTT Gly Tyr Val Ala Ser Val Ala Asp Asn Asn Asn Ala Asn Ser Asp Phe 715 720 725 730 TGT GTG GCT CCG CTA CAA AGA GCC AAG TCG CAA AAG CAA CTC AAC ACC Cys Val Ala Pro Leu Gin Arg Ala Lys Ser Gin Lys Gin Leu Asn Thr 735 740 ■ 745 GAT CCC ACG CTC ATG CAC CGC GGT TCG CCG GCA GGC AGC TCA GCC AAG Asp Pro Thr Leu Met His Arg Gly Ser Pro Ala Gly Ser Ser Ala Lys 750 755 760 GGA GCG TCT GGC GGA GGA CCG GGA GCG GCG GAG GGC AAG AGG ATC TCT Gly Ala Ser Gly Gly Gly Pro Gly Ala Ala Glu Gly Lys Arg lie Ser - 125 - 765 770 775 GTT TTA GGC GAG GGT TCC TAC TGT AGC CAG CGT TGG CCC TCG TTG GCG Val Leu Gly Glu Gly Ser Tyr Cys Ser Gin Arg Trp Pro Ser Leu Ala 780 785 790 GCG GCG GGA GTG GCC GGA GCC TGT TCA TCC CAG CTA ATG GCT GCA GCT Ala Ala Gly Val Ala Gly Ala Cys Ser Ser Gin Leu Met Ala Ala Ala 795 800 805 810 TCG GCA GCG GGC AGC GGA GCG GGG ACG GCG CAA CAG CAG CGA TCC GTG 2619 Ser Ala Ala Gly Ser Gly Ala Gly Thr Ala Gin Gin Gin Arg Ser Val 815 820 825 GTC TGC GGC ACT CCG CAT ATG TAACTCCAAA AATCCGGAAG GGCTCCTGGT 2670 Val Cys Gly Thr Pro His Met 830 AAATCCGGAG AAATCCGCAT GGAGGAGCTG ACAGCACATA CACAAAGAAA AGACTGGGTT 2730 GGGTTCAAAA TGTGAGAGAG ACGCCAAAAT GTTGTTGTTG ATTGAAGCAG TTTAGTCGTC 2790 ACGAAAAATG AAAAATCTGT AACAGGCATA ACTCGTAAAC TCCCTAAAAA ATTTGTATAG 2850 TAATTAGCAA AGCTGTGACC CAGCCGTTTC GATCCCGAAT TC 2892 (2) INFORMATION FOR SEQ ID NO: 6: (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 833 amino acids (B) TYPE: amino acid (D) TOPOLOGY: unknown (ii) MOLECULE TYPE: protein (xi) SEQUENCE DESCRIPTION: SEQ ID NO:6: Met His Trp lie Lys Cys Leu Leu Thr Ala Phe lie Cys Phe Thr Val 1 5 10 15 lie Val Gin Val His Ser Ser Gly Ser Phe Glu Leu Arg Leu Lys Tyr 25 30 Phe Ser Asn Asp His Gly Arg Asp Asn Glu Gly Arg Cys Cys Ser Gly 40 45 Glu Ser Asp Gly Ala Thr Gly Lys Cys Leu Gly Ser Cys Lys Thr Arg 50 55 60 Phe Arg Val Cys Leu Lys His Tyr Gin Ala Thr lie Asp Thr Thr Ser 65 70 75 80 Gin Cys Thr Tyr Gly Asp Val lie Thr Pro lie Leu Gly Glu Asn Ser 85 90 95 Val Asn Leu Thr Asp Ala Gin Arg Phe Gin Asn Lys Gly Phe Thr Asn 100 105 110 Pro lie Gin Phe Pro Phe Ser Phe Ser Trp Pro Gly Thr Phe Ser Leu 115 120 125 He Val Glu Ala Trp His Asp Thr Asn Asn Ser Gly Asn Ala Arg Thr 130 135 140 Asn Lys Leu Leu He Gin Arg Leu Leu Val Gin Gin Val Leu Glu Val 145 150 155 160 Ser Ser Glu Trp Lys Thr Asn Lys Ser Glu Ser Gin Tyr Thr Ser Leu 165 170 175 - 126 - Glu Tyr Asp Phe Arg Val Thr Cys Asp Leu Asn Tyr Tyr Gly Ser Gly 180 185 190 Cys Ala Lys Phe Cys Arg Pro Arg Asp Asp Ser Phe Gly His Ser Thr 195 200 205 Cys Ser Glu Thr Gly Glu lie He Cys Leu Thr Gly Trp Gin Gly Asp 210 215 220 Tyr Cys His He Pro Lys Cys Ala Lys Gly Cys Glu His Gly His Cys 225 230 235 240 Asp Lys Pro Asn Gin Cys Val Cys Gin Leu Gly Trp Lys Gly Ala Leu 245 250 255 Cys Asn Glu Cys Val Leu Glu Pro Asn Cys lie His Gly Thr Cys Asn 260 265 270 Lys Pro Trp Thr Cys He Cys Asn Glu Gly Trp Gly Gly Leu Tyr Cys 275 280 285 Asn Gin Asp Leu Asn Tyr Cys Thr Asn His Arg Pro Cys Lys Asn Gly 290, 295 300 Gly Thr Cys Phe Asn Thr Gly Glu Gly Leu Tyr Thr Cys Lys Cys Ala 305 310 315 320 i Pro Gly Tyr Ser Gly Asp Asp Cys Glu Asn Glu He Tyr Ser Cys Asp 1 325 330 335 Ala Asp Val Asn Pro Cys Gin Asn Gly Gly Thr Cys He Asp Glu Pro 340 345 350 His Thr Lys Thr Gly Tyr Lys Cys His Cys Ala Asn Gly Trp Ser Gly 355 360 365 Lys Met Cys Glu Glu Lys Val Leu Thr Cys Ser Asp Lys Pro Cys His 370 375 380 Gin Gly He Cys Arg Asn Val Arg Pro Gly Leu Gly Ser Lys Gly Gin 385 390 395 400 Gly Tyr Gin Cys Glu Cys Pro He Gly Tyr Ser Gly Pro Asn Cys Asp 405 410 415 Leu Gin Leu Asp Asn Cys Ser Pro Asn Pro Cys He Asn Gly Gly Ser 420 425 430 Cys Gin Pro Ser Gly Lys Cys He Cys Pro Ala Gly Phe Ser Gly Thr .435 440 445 Arg Gys Glu Thr Asn He Asp Asp Cys Leu Gly His Gin Cys Glu Asn 450 455 460 Gly Gly Thr Cys He Asp Met Val Asn Gin Tyr Arg Cys Gin Cys Val 465 470 475 480 Pro Gly Phe His Gly Thr His Cys Ser Ser Lys Val Asp Leu Cys Leu 485 490 495 He Arg Pro Cys Ala Asn Gly Gly Thr Cys Leu Asn Leu Asn Asn Asp 500 505 510 Tyr Gin Cys Thr Cys Arg Ala Gly Phe Thr Gly Lys Asp Cys Ser Val 515 520 525 Asp He Asp Glu Cys Ser Ser Gly Pro Cys His Asn Gly Gly Thr Cys 530 535 540.

Met Asn Arg Val Asn Ser Phe Glu Cys Val Cys Ala Asn Gly Phe Arg - 127 - 545 550 555 560 Gly Lys Gin Cys Asp Glu Glu Ser Tyr Asp Ser Val Thr Phe Asp Ala 565 570 575 His Gin Tyr Gly Ala Thr Thr Gin Ala Arg Ala Asp Gly Leu Thr Asn 580 585 590 Ala Gin Val Val Leu lie Ala Val Phe Ser Val Ala Met Pro' Leu Val 595 600 605 Ala Val lie Ala Ala Cys Val Val Phe Cys Met Lys Arg Lys Arg Lys 610 615 620 Arg Ala Gin Glu Lys Asp Asp Ala Glu Ala Arg Lys Gin Asn Glu Gin 625 630 635 .640 Asn Ala Val Ala Thr Met His His Asn Gly Ser Gly Val Gly Val Ala 645 650 655 Leu Ala Ser Ala Ser Leu Gly Gly Lys Thr Gly Ser Asn Ser Gly Leu 660 665 670 Thr Phe Asp Gly Gly Asn Pro Asn lie lie Lys Asn Thr Trp Asp Lys 675 680 685 Ser Val Asn Asn lie Cys Ala Ser Ala Ala Ala Ala Ala Ala Ala Ala 690 695 .. 700 Ala Ala Ala Asp Glu Cys Leu Met Tyr Gly Gly Tyr Val Ala Ser Val 705 710 715 720 Ala Asp Asn Asn Asn Ala Asn Ser Asp Phe Cys Val Ala Pro Leu Gin 725 730 735 Arg Ala Lys Ser Gin Lys Gin Leu Asn Thr Asp Pro Thr Leu Met His 740 745 750 Arg Gly Ser Pro Ala Gly Ser Ser Ala Lys Gly Ala Ser Gly Gly Gly 755 760 765 Pro Gly Ala Ala Glu Gly Lys Arg lie Ser Val Leu Gly Glu Gly Ser 770 775 780 Tyr Cys Ser Gin Arg Trp Pro Ser Leu Ala Ala Ala Gly Val Ala Gly 785 790 795 800 Ala Cys Ser Ser Gin Leu Met Ala Ala Ala Ser Ala Ala Gly Ser Gly 805 810 815 Ala Gly Thr Ala Gin Gin Gin Arg Ser Val Val Cys Gly Thr Pro His 820 825 830 Met (2) INFORMATION FOR SEQ ID NO: 7: (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 1067 base pairs (B) TYPE: nucleic acid (C) STRANDEDNESS: double (D) TOPOLOGY: unknown (ii) MOLECULE TYPE: cDNA (xi) SEQUENCE DESCRIPTION: SEQ ID NO: 7: - 128 - GATCTACTAC GAGGAGGTTA AGGAGAGCTA TGTGGGCGAG CGACGCGAAT ACGATCCCCA 60 CA CACCGAT CCCAGGGTCA CACGCATGAA GATGGCCGGC CTGAAGCCCA ACTCCAAATA 120 CCGCATCTCC ATCACTGCCA CCACGAAAAT GGGCGAGGGA TCTGAACACT ATATCGAAAA 180 GACCACGCTC AAGGATGCCG TCAATGTGGC CCCTGCCACG CCATCTTTCT CCTGGGAGCA 240 ACTGCCATCC GACAATGGAC TAGCCAAGTT CCGCATCAAC TGGCTGCCAA GTACCGAGGG 300 TCATCCAGGC ACTCACTTCT TTACGATGCA CAGGATCAAG GGCGAAACCC AATGGATACG 360 CGAGAATGAG GAAAAGAACT CCGATTACCA GGAGGTCGGT GGCTTAGATC CGGAGACCGC 420 CTACGAGTTC CGCGTGGTGT CCGTGGATGG CCACTTTAAC ACGGAGAGTG CCACGCAGGA 480 GATCGACACG AACACCGTTG AGGGACCAAT AATGGTGGCC AACGAGACGG TGGCCAATGC 540 CGGATGGTTC ATTGGCATGA TGCTGGCCCT GGCCTTCATC ATCATCCTCT TCATCATCAT 600 CTGCATTATC CGACGCAATC GGGGCGGAAA GTACGATGTC CACGATCGGG AGCTGGCCAA 660 CGGCCGGCGG GATTATCCCG AAGAGGGCGG ATTCCACGAG TACTCGCAAC CGTTGGATAA 720 CAAGAGCGCT GGTCGCCAAT CCGTGAGTTC AGCGAACAAA CCGGGCGTGG AAAGCGATAC 780 TGATTCGATG GCCGAATACG GTGATGGCGA TACAGGACAA TTTACCGAGG ATGGCTCCTT 840 CATTGGCCAA TATGTTCCTG GAAAGCTCCA ACCGCCGGTT AGCCCACAGC CACTGAACAA 900 TTCCGCTGCG GCGCATCAGG CGGCGCCAAC TGCCGGAGGA TCGGGAGCAG CCGGATCGGC 960 AGCAGCAGCC GGAGCATCGG GTGGAGCATC GTCCGCCGGA GGAGCAGCTG CCAGCAATGG 1020 AGGAGCTGCA GCCGGAGCCG TGGCCACCTA CGTCTAAGCT TGGTACC 1067 (2) INFORMATION FOR SEQ ID NO: 8: (i) SEQUENCE CHARACTERISTICS : (A) LENGTH: 1320 base pairs (B) TYPE: nucleic acid (C) STRANDEDNESS: double ( 0 ) TOPOLOGY: unknown (ii) MOLECULE TYPE: cDNA (ix) FEATURE: (A) NAME/KEY: CDS (B) LOCATION: 442..1320 (xi) SEQUENCE DESCRIPTION: SEQ ID NO: 8: CCGAGTCGAG CGCCGTGCTT CGAGCGGTGA TGAGCCCCTT TTCTGTCAAC GCTAAAGATC TACAAAACAT CAGCGCCTAT CAAGTGGAAG TGTCAAGTGT GAACAAAACA AAAACGAGAG AAGCACATAC TAAGGTCCAT ATAAATAATA AATAATAATT GTGTGTGATA ACAACATTAT CCAAACAAAA CCAAACAAAA CGAAGGCAAA GTGGAGAAAA TGATACAGCA TCCAGAGTAC GGCCGTTATT CAGCTATCCA GAGCAAGTGT AGTGTGGCAA AATAGAAACA AACAAAGGCA CCAAAATCTG CATACATGGG CTAATTAAGG CTGCCCAGCG AATTTACATT TGTGTGGTGC CAATCCAGAG TGAATCCGAA ACAAACTCCA TCTAGATCGC CAACCAGCAT CACGCTCGCA AACGCCCCCA GAATGTACAA A ATG TTT AGG AAA CAT TTT CGG CGA AAA CCA Met Phe Arg Lys His Phe Arg Arg Lys Pro - 129 - 1 5 10 GCT ACG TCG TCG TCG TTG GAG TCA ACA ATA GAA TCA GCA GAC AGC CTG Ala Thr Ser Ser Ser Leu Glu Ser Thr lie Glu Ser Ala Asp Ser Leu 20. 25 GGA ATG TCC AAG AAG ACG GCG ACA AAA AGG CAG CGT CCG AGG CAT CGG Gly Met Ser Lys Lys Thr Ala Thr Lys Arg Gin Arg Pro Arg His Arg 35 . 40 GTA CCC AAA ATC GCG ACC CTG CCA TCG ACG ATC CGC GAT TGT CGA TCA Val Pro Lys lie Ala Thr Leu Pro Ser Thr lie Arg Asp Cys Arg Ser 45 50 . 55 TTA AAG TCT GCC TGC AAC TTA ATT GCT TTA ATT TTA ATA CTG TTA GTC Leu Lys Ser Ala Cys Asn Leu lie Ala Leu lie Leu lie Leu Leu Val 60 65 70 CAT AAG ATA TCC GCA GCT GGT AAC TTC GAG CTG GAA ATA TTA GAA ATC His Lys lie Ser Ala Ala Gly Asn Phe Glu Leu Glu lie Leu Glu lie 75 80 85 90 TCA AAT ACC AAC AGC CAT CTA CTC AAC GGC TAT TGC TGC GGC ATG CCA Ser Asn Thr Asn Ser His Leu Leu Asn Gly Tyr Cys Cys Gly Met Pro 95 100 105 GCG GAA CTT AGG GCC ACC AAG ACG ATA GGC TGC TCG CCA TGC ACG ACG Ala Glu Leu Arg Ala Thr Lys Thr lie Gly Cys Ser Pro Cys Thr Thr 110 115 · 120 GCA TTC CGG CTG TGC CTG AAG GAG TAC CAG ACC ACG GAG CAG GGT GCC Ala Phe Arg Leu Cys Leu Lys Glu Tyr Gin Thr Thr Glu Gin Gly Ala 125 130 135 AGC ATA TCC ACG GGC TGT TCG TTT GGC AAC GCC ACC ACC AAG ATA CTG Ser lie Ser Thr Gly Cys Ser Phe Gly Asn Ala Thr Thr Lys He Leu 140 145 150 GGT GGC TCC AGC TTT GTG CTC AGC GAT CCG GGT GTG GGA GCC ATT GTG Gly Gly Ser Ser Phe Val Leu Ser Asp Pro Gly Val Gly Ala He Val 155 160 165 170 CTG CCC TTT ACG TTT CGT TGG ACG AAG TCG TTT ACG CTG ATA CTG CAG Leu Pro Phe Thr Phe Arg Trp Thr Lys Ser Phe Thr Leu lie Leu Gin 175 180 185 GCG TTG GAT ATG TAC AAC ACA TCC TAT CCA GAT GCG GAG AGG TTA ATT Ala Leu Asp Met Tyr Asn Thr Ser Tyr Pro Asp Ala Glu Arg Leu He 190 195 200 GAG GAA ACA TCA TAC TCG GGC GTG ATA CTG CCG TCG CCG GAG TGG AAG Glu Glu Thr Ser Tyr Ser Gly Val He Leu Pro Ser Pro Glu Trp Lys 205 210 215 ACG CTG GAC CAC ATC GGG CGG AAC GCG CGG ATC ACC TAC CGT GTC CGG Thr Leu Asp His He Gly Arg Asn Ala Arg He Thr Tyr Arg Val Arg 220 225 230 GTG CAA TGC GCC GTT ACC TAC TAC AAC ACG ACC TGC ACG ACC TTC TGC Val Gin Cys Ala Val Thr Tyr Tyr Asn Thr Thr Cys Thr Thr Phe Cys 235 240 245 250 CGT CCG CGG GAC GAT CAG TTC GGT CAC TAC GCC TGC GGC TCC GAG GGT Arg Pro Arg Asp Asp Gin Phe Gly His Tyr Ala Cys Gly Ser Glu Gly 255 260 265 CAG AAG CTC TGC CTG AAT GGC TGG CAG GGC GTC AAC TGC GAG GAG GCC Gin Lys Leu Cys Leu Asn Gly Trp Gin Gly Val Asn Cys Glu Glu Ala 270 275 280 - 130 - ATA TGC AAG GCG GGC TGC GAC CCC GTC CAC GGC He Cys Lys Ala Gly Cys Asp Pro Val His Gly 285 290 (2) INFORMATION FOR SEQ ID NO: 9:. (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 293 amino acids (B) TYPE: amino acid (D) TOPOLOGY: unknown (ii) MOLECULE TYPE: protein (xi) SEQUENCE DESCRIPTION: SEQ ID NO: 9: Met Phe Arg Lys His Phe Arg Arg Lys Pro Ala Thr Ser Ser Ser Leu 1 5 10 15 Glu Ser Thr lie .Glu Ser Ala Asp Ser Leu Gly Met Ser Lys Lys Thr 25 30 Ala Thr Lys Arg Gin Arg Pro Arg His Arg Val Pro Lys He Ala Thr 40 45 Leu Pro Ser Thr He Arg Asp Cys Arg Ser Leu Lys Ser Ala Cys Asn 50 55 60 Leu He Ala Leu He Leu He Leu Leu Val His Lys He Ser Ala Ala 65 70 75 80 Gly Asn Phe Glu Leu Glu He Leu Glu He Ser Asn Thr Asn Ser His 85 90 95 Leu Leu Asn Gly Tyr Cys Cys Gly Met Pro Ala Glu Leu Arg Ala Thr 100 105 110 Lys Thr He Gly Cys Ser Pro Cys Thr Thr Ala Phe Arg Leu Cys Leu 115 120 125 Lys Glu Tyr Gin Thr Thr Glu Gin Gly Ala Ser He Ser Thr Gly Cys .130 135 140 Ser Phe Gly Asn Ala Thr Thr Lys He Leu Gly Gly Ser Ser Phe Val 145 150 155 160 Leu Ser Asp Pro Gly Val Gly Ala He Val Leu Pro Phe Thr Phe Arg 165 170 175 Trp Thr Lys Ser Phe Thr. Leu He Leu Gin Ala Leu Asp Met Tyr Asn 180 185 190 Thr Ser Tyr Pro Asp Ala Glu Arg Leu He Glu Glu Thr Ser Tyr Ser 195 200 205 Gly Val He Leu Pro Ser Pro Glu Trp Lys Thr Leu Asp His He Gly 210 215 220 Arg Asn Ala Arg lie Thr Tyr Arg Val Arg Val Gin Cys Ala Val Thr 225 230 235 240 Tyr Tyr Asn Thr Thr Cys Thr Thr Phe Cys Arg Pro Arg Asp Asp Gin 245 250 255 Phe Gly His Tyr Ala Cys Gly Ser Glu Gly Gin Lys Leu Cys Leu Asn 260 265 270 Gly Trp Gin Gly Val Asn Cys Glu Glu Ala He Cys Lys Ala Gly Cys 275 280 285 - 131 - Asp Pro Val His Gly 290 (2) INFORMATION FOR SEQ ID NO: 10: (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 26 base pairs (B) TYPE: nucleic acid (C) STRANDEDNESS: single (D) TOPOLOGY : unknown (ii) MOLECULE TYPE: cDNA (ix) FEATURE: (A) NAME/KEY : modified_base (B) LOCATION: 6 (D) OTHER INFORMATION: /mod_base= /label= N ( ix ) FEATURE : (A) NAME/KE : modified_base (B) LOCATION: 12 (D) OTHER INFORMATIO : /mod_base= /label= N I (xi) SEQUENCE DESCRIPTION: SEQ ID NO: 10 GAYGCNAAYG TNCARGAYAA YATGGG (2) INFORMATION FOR SEQ ID NO: 11: (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 25 base pairs (B) TYPE: nucleic acid (C) STRANDEDNESS: single (D) TOPOLOGY: unknown (ii) MOLECULE TYPE: cDNA ( ix ) FEATURE : (A) NAME/KEY: modified_base (B) LOCATION: 3 (D) OTHER INFORMATION: /mod_base= /label= N (ix) FEATURE: (A) NAME/KEY: modified_base (B) LOCATION: 12 (D) OTHER INFORMATION : /mod_base= /label= N (ix) FEATURE: (A) NAME/KEY: modified_base (B) LOCATION: 18 (D) OTHER INFORMATION: /mod_base= /label= N (xi) SEQUENCE DESCRIPTION: SEQ ID NO: 11 ATNARRTCYT CNACCATNCC YTCDA (2) INFORMATION FOR SEQ ID NO: 12: (i) SEQUENCE CHARACTERISTICS: - 132 - (A) LENGTH: 26 base pairs (B) TYPE: nucleic acid (C) STRANDEDNESS : single (D) TOPOLOGY: unknown MOLECULE TYPE: CDNA ( i ) FEATURE : (A) NAME/KEY : modified_base (B) LOCATION: 12 (D) OTHER INFORMATION: /mod_base= i /label= N ( ix ) FEATURE : (A) NAME/KEY: modified_base (B) LOCATION: 18 (D) OTHER INFORMATION: /mod_base= i /label= N (ix) FEATURE: (A) NAME/KEY : modified_base (B) LOCATION: 21 (D) OTHER INFORMATION: /mod_base= i /label= N (xi) SEQUENCE DESCRIPTION: SEQ ID NO: 12: TCCATRTGRT CNGTDATNTC NCKRTT (2) INFORMATION FOR SEQ ID NO: 13: (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 267 base pairs (B) TYPE: nucleic acid (C) STRANDEDNESS: double (D) TOPOLOGY: unknown (ii) MOLECULE TYPE: cDNA (xi) SEQUENCE DESCRIPTION: SEQ ID NO: 13: GAATTCCGCT GGGAGAATGG TCTGAGCTAC CTGCCCGTCC TGCTGGGGCA TCAATGGCAA GTGGGGAAAG CCACACTGGG CAAACGGGCC AGGCCATTTC TGGAATGTGG TACATGGTGG 120 GCAGGGGGCC CGCAACAGCT GGAGGGCAGG TGGACTGAGG CTGGGGATCC CCCGCTGGTT 180 GGGCAATACT GCCTTTACCC ATGAGCTGGA AAGTCACAAT GGGGGGCAAG GGCTCCCGAG 240 GGTGGTTATG TGCTTCCTTC AGGTGGC 267 (2) INFORMATION FOR SEQ ID NO: 14: (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 574 base pairs (B) TYPE: nucleic acid (C) STRANDEDNESS: double (D) TOPOLOGY: unknown (ii) MOLECULE TYPE: cDNA (xi) SEQUENCE DESCRIPTION: SEQ ID NO.-14:. - 133 - GAATTCCTTC CATTATACGT GACTTTTCTG AAACTGTAGC CACCCTAGTG TCTCTAACTC CCTCTGGAGT TTGTCAGCTT TGGTCTTTTC AAAGAGCAGG CTCTCTTCAA GCTCCTTAAT GCGGGCATGC TCCAGTTTGG TCTGCGTCTC AAGATCACCT TTGGTAATTG ATTCTTCTTC AACCCGGAAC TGAAGGCTGG CTCTCACCCT CTAGGCAGAG CAGGAATTCC GAGGTGGATG TGTTAGATGT GAATGTCCGT GGCCCAGATG GCTGCACCCC ATTGATGTTG GCTTCTCTCC GAGGAGGCAG CTCAGATTTG AGTGATGAAG ATGAAGATGC AGAGGACTGT TCTGCTAACA TCA CACAGA CTTGGTCTAC CAGGGTGCCA GCCTCCAGNC CAGACAGACC GGACTGGTGA GATGGCCCTG CACCTTGCAG CCCGCTACTC ACGGGCTGAT GCTGCCAAGC GTCTCCTGGA TGCAGGTGCA GATGCCAATG CCCAGGACAA CATGGGCCGC TGTCCACTCC ATGCTGCAGT GGCACGTGAT GCCAAGGTGT ATTCAGATCT GTTA (2) INFORMATION FOR SEQ ID NO: 15: (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 295 base pairs (B) TYPE: nucleic acid (C) STRANDEDNESS : double (D) TOPOLOGY: unknown (ii) MOLECULE TYPE: cDNA (xi) SEQUENCE DESCRIPTION: SEQ ID NO: 15: TCCAGATTCT GATTCGCAAC CGAGTAACTG ATCTAGATGC CAGGATGAAT GATGGTACTA CACCCCTGAT CCTGGCTGCC CGCCTGGCTG TGGAGGGAAT GGTGGCAGAA CTGATCAACT GCCAAGCGGA TGTGAATGCA GTGGATGACC ATGGAAAATC TGCTCTTCAC TGGGCAGCTG CTGTCAATAA TGTGGAGGCA ACTCTTTTGT TGTTGAAAAA TGGGGCCAAC CGAGACATGC AGGACAACAA GGAAGAGACA CCTCTGTTTC TTGCTGCCCG GGAGGAGCTA TAAGC (2) INFORMATION FOR SEQ ID NO: 16: (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 333 base pairs (B) TYPE: nucleic acid (C) STRANDEDNESS: double (D) TOPOLOGY: unknown (ii) MOLECULE TYPE: cDNA (xi) SEQUENCE DESCRIPTION: SEQ ID NO: 16: GAATTCCCAT GAGTCGGGAG CTTCGATCAA AATTGATGAG CCTTTAGAAG GATCCGAAGA TCGGATCATT ACCATTACAG GAACAGGCAC CTGTAGCTGG TGGCTGGGGG TGTTGTCCAC AGGCGAGGAG TAGCTGTGCT GCGAGGGGGG CGTCAGGAAC TGGGCTGCGG TCACGGGTGG GACCAGCGAG GATGGCAGCG ACGTGGGCAG GGCGGGGCTC TCCTGGGGCA GAATAGTGTG CACCGCCAGG CTGCTGGGGC CCAGTACTGC ACGTCTGCCT GGCTCGGCTC TCCACTCAGG AAGCTCCGGC CCAGGTGGCC GCTGGCTGCT GAG - 134 - (2) INFORMATION FOR SEQ ID NO: 17: (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 582 base pairs (B) TYPE: nucleic acid (C) STRANDEDNESS : double (D) TOPOLOGY: unknown (ii) MOLECULE TYPE: cDNA (xi) SEQUENCE DESCRIPTION: SEQ ID NO:17: GAATTCCTGC CAGGAGGACG CGGGCAACAA GGTCTGCAGC CTGCAGTGCA ACAACCACGC GTGCGGCTGG GACGGCGGTG ACTGCTCCCT CAACTTCACA ATGACCCCTG GAAGAACTGC ACGCAGTCTC TGCAGTGCTG GAAGTACTTC AGTGACGGCC ACTGTGACAG CCAGTGCAAC TCAGCCGGCT GCCTCTTCGA CGGCTTTGAC TGCCAGCGGC GGAAGGCCAG TTGCAACCCC CTGTACGACC AGTACTGCAA GGACCACTTC AGCGACGGGC ACTGCGACCA GGGCTGCAAC AGCGCGGAGT NCAGNTGGGA CGGGCTGGAC TGTGCGGCAG TGTACCCGAG AGCTGGCGGC GCACGCTGGT GGTGGTGGTG CTGATGCCGC CGGAGCAGCT GCGCAACAGC TCCTTCCACT TCCTGCGGGA CGTCAGCCGC GTGCTGCACA CCAACGTGTC TTCAAGCGTG ACGCACACGG CCAGCAGATG ATGTTCCCCT ACTACGGCCG CGAGGAGGAG CTGCGCAAGC CCCATCAAGC GTGCCGCCGA GGGCTGGGCC GCACCTGACG CCTGCTGGGC CA (2) INFORMATION FOR SEQ ID NO: 18: (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 150 base pairs (B) TYPE: nucleic acid (C) STRANDEDNESS: double (D) TOPOLOGY: unknown (ii) MOLECULE TYPE: cDNA (xi) SEQUENCE DESCRIPTION: SEQ ID NO: 18: TCAGCCGAGT GCTGCACACC AACGTGTCTT CAAGCGTGAC GCACACGGCC AGCAGATGAT GTTCCCCTAC TACGGCCGCG AGGAGGAGCT GCGCAAGCCC CATCAAGCGT GCCGCCGAGG GCTGGGCCGC ACCTGACGCC TGCTGGGCCA (2) INFORMATION FOR SEQ ID NO: 19: (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 247 base pairs (B) TYPE: nucleic acid (C) STRANDEDNESS: double (D) TOPOLOGY: unknown (ii) MOLECULE TYPE: cDNA (xi) SEQUENCE DESCRIPTION: SEQ ID NO: 19: TTACCATTAC AGGAACAGGC ACCTGTAGCT GGTGGCTGGG GGTGTTGTCC ACAGGCGAGG - 135 - AGTAGCTGTG CTGCGAGGGG GGCGTCAGGA ACTGGGCTGC GGTCACGGGT GGGACCAGCG AGGATGGCAG CGACGTGGGC AGGGCGGGGC TCTCCTGGGG CAGAATAGTG TGCACCGCCA GCTGCTGGGG CCCAGTGCTG CACGTCTGCC TGGCTCGGCT CTCCACTCAG GAAGCTCCGG CCCAGGT (2) INFORMATION FOR SEQ ID NO: 20: (i) SEQUENCE CHARACTERISTICS : (A) LENGTH: 248 base pairs (B) TYPE: nucleic acid (C) STRANDEDNESS: double (D) TOPOLOGY: unknown (ii) MOLECULE TYPE: cDNA (xij SEQUENCE DESCRIPTION: SEQ ID NO: 20: GAATTCCATT CAGGAGGAAA GGGTGGGGAG AGAAGCAGGC ACCCACTTTC CCGTGGCTGG ACTCGTTCCC AGGTGGCTCC ACCGGCAGCT GTGACCGCCG CAGGTGGGGG CGGAGTGCCA TTCAGAAAAT TCCAGAAAAG CCCTACCCCA ACTCGGACGG CAACGTCACA CCCGTGGGTA GCAACTGGCA CACAAACAGC CAGCGTGTCT GGGGCACGGG GGGATGGCAC CCCCTGCAGG CAGAGCTG (2) INFORMATION FOR SEQ ID NO: 21: (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 323 base pairs (B) TYPE: nucleic acid (C) STRANDEDNESS: double (D) TOPOLOGY: unknown (ii) MOLECULE TYPE: cDNA (xi) SEQUENCE DESCRIPTION: SEQ ID NO: 21: CTAAAGGGAA CAAAAGCNGG AGCTCCACCG CGGGCGGCNC NGCTCTAGAA CTAGTGGANN 60 NCCCGGGCTG CAGGAATTCC GGCGGACTGG GCTCGGGCTC AGAGCGGCGC TGTGGAAGAG 120 ATTCTAGACC GGGAGAACAA GCGAATGGCT GACAGCTGGC CTCCAAAGTC ACCAGGCTCA 180 AATCGCTCGC CCTGGACATC GAGGGATGCA GAGGATCAGA ACCGGTACCT GGATGGCATG 240 ACTCGGATTT ACAAGCATGA CCAGCCTGCT TACAGGGAGC GTGANNTTTT CACATGCAGT 300 CGACAGACAC GAGCTCTATG CAT 323 INFORMATION FOR SEQ ID NO: 22: (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 330 base pair (B) TYPE: nucleic acid (C) STRANDEDNESS: double (D) TOPOLOGY: unknown (ii) MOLECULE TYPE: . cDNA (xi) SEQUENCE DESCRIPTION: SEQ ID NO: 22: GAATTCCGAG GTGGATGTGT TAGATGTGAA TGTCCGTGGC CCAGATGGCT GCACCCCATT GATGTTGGCT TCTCTCCGAG GAGGCAGCTC AGATTTGAGT GATGAAGATG AAGATGCAGA GGACTCTTCT GCTAACATCA TCACAGACTT GGTCTTACCA GGGTGCCAGC CTTCCAGGCC CAAGAACAGA CCGGACTTGG TGAGATGGCC CTGCACCTTG CAGCCCGCTA CTACGGGCTG ATGCTGCCAA GGTTCTGGAT GCAGGTGCAG ATGCCAATGC CCAGGACAAC ATGGGCCGCT GTCCACTCCA TGCTGCAGTG GCACTGATGC (2) INFORMATION FOR SEQ ID NO: 23: (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 167 baae pairs (B) TYPE: nucleic acid (C) STRANDEDNESS: double (D) TOPOLOGY : unknown (ii) MOLECULE TYPE: cDNA (xi) SEQUENCE DESCRIPTION: SEQ ID NO: 23: CAGAGGATGG TGAGGGTCCA TGCAGATAGG TTCTCCCCAT CCTGTGAATA ATAAATGGGT GCAAGGGCAG AGAGTCACCA TTTAGAATGA TAAAATGTTT GCACACTATG AAAGAGGCTG ACAGAATGTT GCCACATGGA GAGATAAAGC AGAGAATGAA CAAACTT (2) INFORMATION FOR SEQ ID NO: 24: (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 225 base pairs ( B ) TYPE: nucleic acid (C) STRANDEDNESS: double (D) TOPOLOGY: unknown (ii) MOLECULE TYPE: cDNA (xi) SEQUENCE DESCRIPTION: SEQ ID NO:24: AGGATGAATG ATGGTACTAC ACCCCTGATC CTGGCTGCCC GCCTGGCTGT GGAGGGAATG GTGGCAGAAC TGATCAACTG CCAAGCGGAT GTGAATGCAG TGGATGACCA TGGAAAATCT GCTCTTCACT GGGCAGCTGC TGTCAATAAT GTGGAGGCAA CTCTTTTGTT GTTGAAAAAT GGGGCCAACC GAGACATGCA GGACAACAAG GAAGAGACAC CTCTG (2) INFORMATION FOR SEQ ID NO: 25: (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 121 base pairs (B) TYPE: nucleic acid (C) STRANDEDNESS: double (D) TOPOLOGY: unknown (ii) MOLECULE TYPE:. cDNA (xi) SEQUENCE DESCRIPTION: SEQ ID NO: 25: i - 137 - AATAATAAAT GGGTGCAAGG GCAGAGAGTC ACCATTTAGA ATGATAAAAT GTTTGCACAC 60 TATGAAAGAG GCTGACAGAA TGTTGCCACA TGGAGAGATA AAGCAGAGAA TGAACAAACT 120 T 121 INFORMATION FOR SEQ ID NO: 26: (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 20 base pairs (B) TYPE: nucleic acid (C) STRANDEDNESS: single (D) TOPOLOGY : unknown (ii) MOLECULE TYPE: cDNA (xi) SEQUENCE DESCRIPTION: SEQ ID NO: 26: ACTTCAGCAA CGATCACGGG 20 (2) INFORMATION FOR SEQ ID NO: 27: (i) SEQUENCE CHARACTERISTICS: .

(A) LENGTH: 21 base pairs (B) TYPE: nucleic acid (C) STRANDEDNESS: single (D) TOPOLOGY : unknown (ii) MOLECULE TYPE: cDNA (xi) SEQUENCE DESCRIPTION: SEQ ID NO: 27: TTGGGTATGT GACAGTAATC G 21 INFORMATION FOR SEQ ID NO: 28: (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 14 base pair (B) TYPE: nucleic acid (C) STRANDEDNESS: single (D) TOPOLOGY: unknown (ii) MOLECULE TYPE: cDNA (xi) SEQUENCE DESCRIPTION: SEQ ID NO:28: TTAAGTTAAC TTAA 14 (2) INFORMATION FOR SEQ ID NO: 29: (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 12 base pairs (B) TYPE: nucleic acid (C) STRANDEDNESS: single (D) TOPOLOGY: unknown (ii) MOLECULE TYPE: cDNA (xi) SEQUENCE DESCRIPTION: SEQ ID NO:29: GGAAGATCTT CC 12 - 138 - INFORMATION FOR SEQ ID NO: 30: (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 4 amino acid (B) TYPE: amino acid (C) STRANDEDNESS: single (D) TOPOLOGY : unknown (ii) MOLECULE TYPE: peptide (xi) SEQUENCE DESCRIPTION: SEQ ID Arg Lys lie Phe 1 INFORMATION FOR SEQ ID NO: 31: (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 3234 base pairs ( B ) TYPE: nucleic acid (C) STRANDEDNESS: double (D) TOPOLOGY: unknown MOLECULE TYPE: cDNA (ix) FEATURE : (A) NAME/KEY : CDS (B) LOCATION: 1..3234 (xi) SEQUENCE DESCRIPTION: SEQ ID NO: 31: TGC CAG GAG GAC GCG GGC AAC AAG GTC TGC AGC CTG CAG TGC AAC AAC 48 Cys Gin Glu Asp Ala Gly Asn Lys Val Cys Ser Leu Gin Cys Asn Asn 1 5 10 15 CAC GCG TGC GGC TGG GAC GGC GGT GAC TGC TCC CTC AAC TTC AAT GAC 96 His Ala Cys Gly Trp Asp Gly Gly Asp Cys Ser Leu Asn Phe Asn Asp 25 30 CCC TGG AAG AAC TGC ACG CAG TCT CTG CAG TGC TGG AAG TAC TTC AGT 144 Pro Trp Lys Asn Cys Thr Gin Ser Leu Gin Cys Trp Lys Tyr Phe Ser 40 45 GAC GGC CAC TGT GAC AGC CAG TGC AAC TCA GCC GGC TGC CTC' TTC GAC 192 Asp Gly His Cys Asp Ser Gin Cys Asn Ser Ala Gly Cys Leu Phe Asp 50 55 60 GGC TTT GAC TGC CAG CGT GCG GAA GGC CAG TGC AAC CCC CTG TAC GAC 240 Gly Phe Asp Cys Gin Arg Ala Glu Gly Gin Cys Asn Pro Leu Tyr Asp 65 70 75 80 CAG TAC TGC AAG GAC CAC TTC AGC GAC GGG CAC TGC GAC CAG GGC TGC 288 Gin Tyr Cys Lys Asp His Phe Ser Asp Gly His Cys Asp Gin Gly Cys 85 90 95 AAC AGC GCG GAG TGC GAG TGG GAC GGG CTG GAC TGT GCG GAG CAT GTA 336 Asn Ser Ala Glu Cys Glu Trp Asp Gly Leu Asp Cys Ala Glu His Val 100 105 110 CCC GAG AGG CTG GCG GCC GGC ACG CTG GTG GTG GTG GTG CTG ATG CCG 384 Pro Glu Arg Leu Ala Ala Gly Thr Leu Val Val Val Val Leu Met Pro 115 120 125 CCG GAG CAG CTG CGC AAC AGC TCC TTC CAC TTC CTG CGG GAG CTC AGC 432 Pro Glu Gin Leu Arg Asn Ser Ser Phe His Phe Leu Arg Glu Leu Ser 130 135 140 - 139 - CGC GTG CTG CAC ACC AAC GTG GTC TTC AAG CGT GAC GCA CAC GGC CAG Arg Val Leu His Thr Asn Val Val Phe Lys Arg Asp Ala His Gly Gin 145 150 155 160 CAG ATG ATC TTC CCC TAC TAC GGC CGC GAG GAG GAG CTG CGC AAG CAC Gin Met lie Phe Pro Tyr Tyr Gly Arg Glu Glu Glu Leu Arg Lys His 165 170 175 CCC ATC AAG CGT GCC GCC GAG GGC TGG GCC GCA CCT GAC GCC CTG CTG Pro lie Lys Arg Ala Ala Glu Gly Trp Ala Ala Pro Asp Ala Leu Leu 180 185 190 GGC CAG GTG AAG GCC TCG CTG CTC CCT GGT GGC AGC GAG GGT GGG CGG Gly Gin Val Lys Ala Ser Leu Leu Pro Gly Gly Ser Glu Gly Gly Arg 195 200 205 CGG CGG AGG GAG CTG GAC CCC ATG GAC GTC CGC GGC TCC ATC GTC TAC Arg Arg Arg Glu Leu Asp Pro Met Asp Val Arg Gly Ser He Val Tyr 210 215 220 CTG GAG ATT . GAC AAC CGG CAG TGT GTG CAG GCC TCC TCG CAG TGC TTC Leu Glu He Asp Asn Arg Gin Cys Val Gin Ala Ser Ser Gin Cys Phe 225 230 235 240 CAG AGT GCC ACC GAC GTG GCC GCA TTC CTG GGA GCG CTC GCC TCG CTG Gin Ser Ala Thr Asp Val Ala Ala Phe Leu Gly Ala Leu Ala Ser Leu 245 250 255 GGC AGC CTC AAC ATC CCC TAC AAG ATC GAG GCC GTG CAG AGT GAG ACC Gly Ser Leu Asn He Pro Tyr Lys He Glu Ala Val Gin Ser Glu Thr 260 265 270 GTG GAG CCG CCC CCG CCG GCG CAG CTG CAC TTC ATG TAC GTG GCG GCG Val Glu Pro Pro Pro Pro Ala Gin Leu His Phe Met Tyr Val Ala Ala 275 280 285 GCC GCC TTT GTG CTT CTG TTC TTC GTG GGC TGC GGG GTG CTG CTG TCC Ala Ala Phe Val Leu Leu Phe Phe Val Gly Cys Gly Val Leu Leu Ser 290 295 300 CGC AAG CGC CGG CGG CAG CAT GGC CAG CTC TGG TTC CCT GAG GGC TTC Arg Lys Arg Arg Arg Gin His Gly Gin Leu Trp Phe Pro Glu Gly Phe 305 310 315 320 AAA GTG TCT GAG GCC AGC AAG AAG AAG CGG CGG GAG CCC CTC GGC GAG Lys Val Ser Glu Ala Ser Lys Lys Lys Arg Arg Glu Pro Leu Gly Glu 325 330 335 GAC TCC GTG GGC CTC AAG CCC CTG AAG AAC GCT TCA GAC GGT GCC CTC Asp Ser Val Gly Leu Lys Pro Leu Lys Asn Ala Ser Asp Gly Ala Leu 340 345 350 ATG GAC GAC AAC CAG AAT GAG TGG GGG GAC GAG GAC CTG GAG ACC AAG Met Asp Asp Asn Gin Asn Glu Trp Gly Asp Glu Asp Leu Glu Thr Lys 355 360 365 AAG TTC CGG TTC GAG GAG CCC GTG GT CTG CCT GAC CTG GAC GAC CAG Lys Phe Arg Phe Glu Glu Pro Val Val Leu Pro Asp Leu Asp Asp Gin 370 375 380 ACA GAC CAC CGG CAG TGG ACT CAG CAG CAC CTG GAT GCC GCT GAC CTG Thr Asp His Arg Gin Trp Thr Gin Gin His Leu Asp Ala Ala Asp Leu 385 390 395 400 CGC ATG TCT GCC ATG GCC CCC ACA CCG CCC CAG GGT GAG GTT GAC GCC Arg Met Ser Ala Met Ala Pro Thr Pro Pro Gin Gly Glu Val Asp Ala 405 410 415 GAC TGC ATG GAC GTC AAT GTC CGC GGG CCT GAT GGC TTC ACC CCG CTC Asp Cys Met Asp Val Asn Val Arg Gly Pro Asp Gly Phe Thr Pro Leu - 140 - 420 425 430 ATG ATC GCC TCC TGC AGC GGG GGC GGC CTG GAG ACG GGC AAC AGC GAG Met He Ala Ser Cys Ser Gly Gly Gly Leu Glu Thr Gly Asn Ser Glu 435 440 445 GAA GAG GAG GAC GCG CCG GCC GTC ATC TCC GAC TTC ATC TAC CAG GGC Glu Glu Glu Asp Ala Pro Ala Val He Ser Asp Phe He Tyr Gin Gly 450 455 460 GCC AGC CTG CAC AAC CAG ACA GAC CGC ACG GGC GAG ACC GCC TTG CAC Ala Ser Leu His Asn Gin Thr Asp Arg Thr Gly Glu Thr Ala Leu His 465 470 475 480 CTG GCC GCC CGC TAC TCA CGC TCT GAT GCC GCC AAG CGC CTG CTG GAG Leu Ala Ala Arg Tyr Ser Arg Ser Asp Ala Ala Lys Arg Leu Leu Glu 485 490 495 GCC AGC GCA GAT GCC AAC ATC CAG GAC AAC ATG GGC CGC ACC CCG CTG Ala Ser Ala Asp Ala Asn He Gin Asp Asn Met Gly Arg Thr Pro Leu 500 505 510 CAT GCG GCT GTG TCT GCC GAC GCA CAA GGT GTC TTC CAG ATC CTG ATC His Ala Ala Val Ser Ala Asp Ala Gin Gly Val Phe Gin He Leu- He 515 520 525 CGG AAC CGA GCC ACA GAC CTG GAT GCC CGC ATG CAT GAT GGC ACG ACG Arg Asn Arg Ala Thr Asp Leu Asp Ala Arg Met His Asp Gly jThr Thr 530 535 540 CCA CTG ATC CTG GCT GCC CGC CTG GCC GTG GAG GGC ATG CTG GAG GAC Pro Leu He Leu Ala Ala Arg Leu Ala Val Glu Gly Met Leu Glu Asp 545 550 555 560 CTC ATC AAC TCA CAC GCC GAC GTC AAC GCC GTA GAT GAC CTG GGC AAG Leu He Asn Ser His Ala Asp Val Asn Ala Val Asp Asp Leu Gly Lys 565 570 575 TCC GCC CTG CAC TGG GCC GCC GCC GTG AAC AAT GTG GAT GCC GCA GTT Ser Ala Leu His Trp Ala Ala Ala Val Asn Asn Val Asp Ala Ala Val 580 585 590 GTG CTC CTG AAG AAC GGG GCT AAC AAA GAT ATG CAG AAC AAC AGG GAG Val Leu Leu Lys Asn Gly Ala Asn Lys Asp Met Gin Asn Asn Arg Glu 595 600 605 GAG. ACA CCC CTG TTT CTG GCC GCC CGG GAG GGC AGC TAC GAG ACC GCC Glu Thr Pro Leu Phe Leu Ala Ala Arg Glu Gly Ser Tyr Glu Thr Ala 610 615 620.

AAG GTG CTG CTG GAC CAC TTT GCC AAC CGG GAC ATC ACG GAT CAT ATG Lys Val Leu Leu Asp His Phe Ala Asn Arg Asp He Thr Asp His Met 625 630 635 640 GAC CGC CTG CCG CGC GAC ATC GCA CAG GAG CGC ATG CAT CAC GAC ATC Asp Arg Leu Pro Arg Asp He Ala Gin Glu Arg Met His His Asp He 645 650 655 GTG AGG CTG CTG GAC GAG TAC AAC CTG GTG CGC AGC CCG CAG CTG CAC Val Arg Leu Leu Asp Glu Tyr Asn Leu Val Arg Ser Pro Gin Leu His- 660 665 670 GGA GCC CCG CTG GGG GGC ACG CCC ACC CTG TCG CCC CCG CTC TGC TCG Gly Ala Pro Leu Gly Gly Thr Pro Thr Leu Ser Pro Pro Leu Cys Ser 675 680 685 CCC AAC GGC TAC CTG GGC AGC CTC AAG CCC GGC GTG CAG GGC AAG AAG Pro Asn Gly Tyr Leu Gly Ser Leu Lys Pro Gly Val Gin Gly Lys Lys 690 695 700 - 141 - GTC CGC AAG CCC AGC AGC AAA GGC CTG GCC TGT GGA AGC AAG GAG GCC Val Arg Lys Pro Ser Ser Lys Gly Leu Ala Cys Gly Ser Lys Glu Ala 705 710 . 715 720 AAG GAC CTC AAG GCA CGG AGG AAG AAG TCC CAG GAT GGC A G GGC TGC Lys Asp Leu Lys Ala Arg Arg Lys Lys Ser Gin Asp Gly Lys Gly Cys 725 730 735 CTG CTG GAC AGC TCC GGC ATG CTC TCG CCC GTG GAC TCC CTG GAG TCA Leu Leu Asp Ser Ser Gly Met Leu Ser Pro Val Asp Ser Leu Glu Ser 740 745 750 CCC CAT GGC TAC CTG TCA GAC GTG GCC TCG CCG CCA CTG CTG CCC TCC Pro His Gly Tyr Leu Ser Asp Val Ala Ser Pro Pro Leu Leu Pro Ser 755 760 765 CCG TTC CAG CAG TCT CCG TCC GTG CCC CTC AAC CAC CTG CCT GGG ATG Pro Phe Gin Gin Ser Pro Ser Val Pro Leu Asn His Leu Pro Gly Met 770 775 780 CCC GAC ACC CAC CTG GGC ATC GGG CAC CTG AAC GTG GCG GCC AAG CCC Pro Asp Thr His Leu Gly He Gly His Leu Asn Val Ala Ala Lys Pro 785 790 795 800 GAG ATG GCG GCG CTG GGT GGG GGC GGC CGG CTG GCC TTT GAG ACT GGC Glu Met Ala Ala Leu Gly Gly Gly Gly Arg Leu Ala Phe Glu Thr Gly 805 810 815 CCA CCT CGT CTC TCC CAC CTG CCT GTG GCC TCT GGC ACC AGC ACC GTC Pro Pro Arg Leu Ser His Leu Pro Val Ala Ser Gly Thr Ser Thr Val 820 825 830 CTG GGC TCC AGC AGC GGA GGG GCC CTG AAT TTC ACT GTG GGC GGG TCC Leu Gly Ser Ser Ser Gly Gly Ala Leu Asn Phe Thr Val Gly Gly Ser 835 840 845 ACC AGT TTG AAT GGT CAA TGC GAG TGG CTG TCC CGG CTG CAG AGC GGC Thr Ser Leu Asn Gly Gin Cys Glu Trp Leu Ser Arg Leu Gin Ser Gly 850 855 860 ATG GTG CCG AAC CAA TAC AAC CCT CTG CGG GGG AGT GTG GCA CCA GGC Met Val Pro Asn Gin Tyr Asn Pro Leu Arg Gly Ser Val Ala Pro Gly 865 870 875 880 CCC CTG AGC ACA CAG GCC CCC TCC CTG CAG CAT GGC ATG GTA GGC CCG Pro Leu Ser Thr Gin Ala Pro Ser Leu Gin His Gly Met Val Gly Pro 885 890 895 CTG CAC AGT AGC CTT GCT GCC AGC GCC CTG TCC CAG ATG ATG AGC TAC Leu His Ser Ser Leu Ala Ala Ser Ala Leu Ser Gin Met Met Ser Tyr 900 905 910 CAG GGC CTG CCC AGC ACC CGG CTG GCC ACC CAG CCT CAC CTG GTG CAG Gin Gly ,Leu Pro Ser Thr Arg Leu Ala Thr Gin Pro His Leu Val Gin 915 920 925 ACC CAG CAG GTG CAG CCA CAA AAC TTA CAG ATG CAG CAG CAG AAC CTG Thr Gin Gin Val Gin Pro Gin Asn Leu Gin Met Gin Gin Gin Asn Leu 930 935 940 CAG CCA GCA AAC ATC CAG CAG CAG CAA AGC CTG CAG CCG CCA CCA CCA Gin Pro Ala Asn He Gin Gin Gin Gin Ser Leu Gin Pro Pro Pro Pro 945 950 955 .960 CCA CCA CAG CCG CAC CTT GGC GTG AGC TCA GCA GCC AGC GGC CAC CTG Pro Pro Gin Pro His Leu Gly Val Ser Ser Ala Ala Ser Gly His Leu 965 970 975 GGC CGG AGC TTC CTG AGT GGA GAG CCG AGC CAG GCA GAC GTG CAG CCA Gly Arg Ser Phe Leu Ser Gly Glu Pro Ser Gin Ala Asp Val Gin Pro - 142 - 980 985 990 CTG GGC CCC AGC AGC CTG GCG GTG CAC ACT ATT CTG CCC CAG GAG AGC 3024 Leu Gly Pro Ser Ser Leu Ala Val His Thr lie Leu Pro Gin Glu Ser 995 1000 1005 CCC GCC CTG CCC ACG TCG CTG CCA TCC TCG CTG GTC CCA CCC GTG ACC 3072 Pro Ala Leu Pro Thr Ser Leu Pro Ser Ser Leu Val Pro Pro Val Thr 1010 1015 1020 GCA GCC CAG TTC CTG ACG CCC CCC TCG CAG CAC AGC TAC TCC TCG CCT 3120 Ala Ala Gin Phe Leu Thr Pro Pro Ser Gin His Ser Tyr Ser Ser Pro 1025 1030 1035 1040 GTG GAC AAC ACC CCC AGC CAC CAG CTA CAG GTG CCT GTT CCT GTA ATG 3168 Val Asp Asn Thr Pro Ser His Gin Leu Gin Val Pro Val Pro Val Met 1045 1050 1055 GTA ATG ATC CGA TCT TCG GAT CCT TCT AAA GGC TCA TCA ATT TTG ATC 3216 Val Met lie Arg Ser Ser Asp Pro Ser Lys Gly Ser Ser He Leu He 1060 1065 1070 GAA GCT CCC GAC TCA TGG 3234 Glu Ala Pro Asp Ser Trp 1075 (2) INFORMATION FOR SEQ ID NO: 32: (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 1078 amino acids (B) TYPE: amino acid ( D ) TOPOLOGY : unknown (ii) MOLECULE TYPE: protein (xi) SEQUENCE DESCRIPTION: SEQ ID NO: 32: Cys Gin Glu Asp Ala Gly Asn Lys Val Cys Ser Leu Gin Cys Asn Asn 1 5 10 15 His Ala Cys Gly Trp Asp Gly Gly Asp Cys Ser Leu Asn Phe Asn Asp 25 30 Pro Trp Lys Asn Cys Thr Gin Ser Leu Gin Cys Trp Lys Tyr Phe Ser ' 35 40 45 Asp Gly His Cys Asp Ser Gin Cys Asn Ser Ala Gly Cys Leu Phe Asp 50 55 60 Gly Phe Asp Cys Gin Arg Ala Glu Gly Gin Cys Asn Pro Leu Tyr Asp 65 70 75 80 Gin Tyr Cys Lys Asp His Phe Ser As Gly His Cys Asp Gin Gly Cys 85 90 95 Asn Ser Ala Glu Cys Glu Trp Asp Gly Leu Asp Cys Ala Glu His Val 100 105 110 Pro Glu Arg Leu Ala Ala Gly Thr Leu Val Val Val Val Leu Met Pro 115 120 125 Pro Glu Gin Leu Arg Asn Ser Ser Phe His Phe Leu Arg Glu Leu Ser 130 135 140 Arg Val Leu His Thr Asn Val Val Phe Lys Arg Asp Ala His Gly Gin 145 150 155 160 Gin Met He Phe Pro Tyr Tyr Gly Arg Glu Glu Glu Leu Arg Lys His 165 170 175 - 143 - Pro lie Lys Arg Ala Ala Glu Gly Trp Ala Ala Pro Asp Ala Leu Leu 180 185 190 Gly Gin Val Lys Ala Ser Leu Leu Pro Gly Gly Ser Glu Gly Gly Arg 195 200 205 Arg Arg Arg Glu Leu Asp Pro Met Asp Val Arg Gly Ser lie Val Tyr 210 215 220 Leu Glu He Asp Asn Arg Gin Cys Val Gin Ala Ser Ser Gin Cys Phe 225 230 235 240 Gin Ser Ala Thr Asp Val Ala Ala Phe Leu Gly Ala Leu Ala Ser Leu 245 250 255 Gly Ser Leu Asn He Pro Tyr Lys He Glu Ala Val Gin Ser Glu Thr 260 265 270 Val Glu Pro Pro Pro Pro Ala Gin Leu His Phe Met Tyr Val Ala Ala 275 280 285 Ala Ala Phe Val Leu Leu Phe Phe Val Gly Cys Gly Val Leu Leu Ser 290 295 300 Arg Lys Arg Arg Arg Gin His Gly Gin Leu Trp Phe Pro Glu Gly Phe 305, 310 315 320 Lys Val Ser Glu Ala Ser Lys Lys Lys Arg Arg Glu Pro Leu Gly Glu J 325 330 335 Asp Ser Val Gly Leu Lys Pro Leu Lys Asn Ala Ser Asp Gly Ala Leu 340 345 350 Met Asp Asp Asn Gin Asn Glu Trp Gly Asp Glu Asp Leu- Glu Thr Lys 355 360 365 Lys Phe Arg Phe Glu Glu Pro Val Val Leu Pro Asp Leu As Asp Gin 370 375 380 Thr Asp His Arg Gin Trp Thr Gin Gin His Leu Asp Ala Ala Asp Leu 385 390 395 400 Arg Met Ser Ala Met Ala Pro Thr Pro Pro Gin Gly Glu Val Asp Ala 405 410 415 Asp Cys Met Asp Val Asn Val Arg Gly Pro Asp Gly Phe Thr Pro Leu 420 425 430 Met He Ala Ser Cys Ser Gly Gly Gly Leu Glu Thr Gly Asn Ser Glu 435 440 445 Glu Glu Glu Asp Ala Pro Ala Val He Ser Asp Phe He Tyr Gin Gly -450 455 460 Ala Ser Leu His Asn Gin Thr Asp Arg Thr Gly Glu Thr Ala Leu His 465 470 475 480 Leu Ala Ala Arg Tyr Ser Arg Ser Asp Ala Ala Lys Arg Leu Leu Glu 485 490 495 Ala Ser Ala Asp Ala Asn He Gin Asp Asn Met Gly Arg Thr Pro Leu 500 505 510 His Ala Ala Val Ser Ala Asp Ala Gin Gly Val Phe Gin He Leu He 515 520 525 Arg Asn Arg Ala Thr Asp Leu Asp Ala Arg Met His Asp Gly Thr Thr 530 535 540 Pro Leu He Leu Ala Ala Arg Leu Ala Val Glu Gly Met Leu Glu Asp - 144 - 545 550 555 560 Leu lie Asn Ser His Ala Asp Val Asn Ala Val Asp Asp Leu Gly Lys 565 570 575 Ser Ala Leu His Trp Ala Ala Ala Val Asn Asn Val Asp Ala Ala Val 580 585 59.0 Val Leu Leu Lys Asn Gly Ala Asn Lys Asp Met Gin Asn Asn Arg Glu 595 600 605 Glu Thr Pro Leu Phe Leu Ala Ala Arg Glu Gly Ser Tyr Glu Thr Ala 610 615 620 Lys Val Leu Leu Asp His Phe Ala Asn Arg Asp He Thr Asp His Met 625 630 635 640 Asp Arg Leu Pro Arg Asp lie Ala Gin Glu Arg Met His His Asp He 645 650 655 Val Arg Leu Leu Asp Glu Tyr Asn Leu Val Arg Ser Pro Gin Leu His 660 665 670 Gly Ala Pro Leu Gly Gly Thr Pro Thr Leu Ser Pro Pro Leu Cys Ser 675 680 685 Pro Asn Gly Tyr Leu Gly Ser Leu Lys Pro Gly Val Gin Gly Lys Lys 690 695 700 Val Arg Lys Pro Ser Ser Lys Gly Leu Ala Cys Gly Ser Lys Glu Ala 705 710 715 720 Lys Asp Leu Lys Ala Arg Arg Lys Lys Ser Gin Asp Gly Lys Gly Cys 725 730 735 Leu Leu Asp Ser Ser Gly Met Leu Ser Pro Val Asp Ser Leu Glu Ser 740 745 750 Pro His Gly Tyr Leu Ser Asp Val Ala Ser Pro Pro Leu Leu Pro Ser 755 760 765 Pro Phe Gin Gin Ser Pro Ser Val Pro Leu Asn His Leu Pro Gly Met 770 . 775 780 Pro Asp Thr His Leu Gly He Gly His Leu Asn Val Ala Ala Lys Pro 785 790 795 800 Glu Met Ala Ala Leu Gly Gly Gly Gly Arg Leu Ala Phe Glu Thr Gly 805 810 815 Pro Pro Arg Leu Ser His Leu Pro Val Ala Ser Gly Thr Ser Thr Val 820 825 830 Leu Gly Ser Ser Ser Gly Gly Ala Leu Asn Phe Thr Val Gly Gly Ser 835 840 845 Thr Ser Leu Asn Gly Gin Cys Glu Trp Leu Ser Arg Leu Gin Ser Gly 850 855 860 Met Val Pro Asn Gin Tyr Asn Pro Leu Arg Gly Ser Val Ala Pro Gly 865 870 875 880 Pro Leu Ser Thr Gin Ala Pro Ser Leu Gin His Gly Met Val Gly Pro 885 890 895 Leu His Ser Ser Leu Ala Ala Ser Ala Leu Ser Gin Met Met Ser Tyr 900 905 910 Gin Gly Leu Pro Ser Thr Arg Leu Ala Thr Gin Pro His Leu Val Gin 915 920 925 - 145 - Thr Gin Gin Val Gin Pro Gin Asn Leu Gin Met Gin Gin. Gin Asn Leu 930 935 940 Gin Pro Ala Asn lie Gin Gin Gin Gin Ser Leu Gin Pro Pro Pro Pro 945 950 955 960 Pro Pro Gin Pro His Leu Gly Val Ser Ser Ala Ala Ser Gly His Leu 965 970 975 Gly Arg Ser Phe Leu Ser Gly Glu Pro Ser Gin Ala Asp Val Gin Pro 980 985 990 Leu Gly Pro Ser Ser Leu Ala Val His Thr lie Leu Pro Gin Glu Ser 995 1000 1005 Pro Ala Leu Pro Thr Ser Leu Pro Ser Ser Leu Val Pro Pro Val Thr 1010 1015 1020 Ala Ala Gin Phe Leu Thr Pro Pro Ser Gin His Ser Tyr Ser Ser Pro 1025 1030 1035 1040 Val Asp Asn Thr Pro Ser His Gin Leu Gin Val Pro Val Pro Val Met 1045 1050 1055 Val Met lie Arg Ser Ser Asp Pro Ser Lys Gly Ser Ser lie Leu lie 1060 1065 1070 Glu Ala Pro Asp Ser Trp 1075 (2) INFORMATION FOR SEQ ID NO: 33: (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 4268 base pairs (B) TYPE: nucleic acid . (C) STRANDEDNESS : double ( D ) TOPOLOGY : unknown (ii) MOLECULE TYPE: cDNA (ix) FEATURE: (A) NAME/KEY: CDS (B) LOCATION: 2..1972 (xi) SEQUENCE DESCRIPTION: SEQ ID NO: 33: G GAG GTG GAT GTG TTA GAT GTG AAT GTC CGT GGC CCA GAT GGC TGC Glu Val Asp Val Leu Asp Val Asn Val Arg Gly Pro Asp Gly Cys 1 5 10 15 ACC CCA TTG ATG TTG GCT TCT CTC CGA GGA GGC AGC TCA GAT TTG AGT Thr Pro Leu Met Leu Ala Ser Leu Arg Gly Gly Ser Ser Asp Leu Ser 25 30 GAT GAA GAT GAA GAT GCA GAG GAC TCT TCT GCT AAC ATC ATC ACA GAC Asp Glu Asp Glu Asp Ala Glu Asp Ser Ser Ala Asn lie lie Thr Asp 40 45 TTG GTC TAC CAG GGT GCC AGC CTC CAG GCC CAG ACA GAC CGG ACT GGT Leu.. Val Tyr Gin Gly Ala Ser Leu Gin Ala Gin Thr Asp Arg Thr Gly 50 55 60 GAG ATG GCC CTG CAC CTT GCA GCC CGC TAC TCA CGG GCT GAT GCT GCC Glu Met Ala Leu His Leu Ala Ala Arg Tyr Ser Arg Ala Asp. Ala Ala 65 70 75 AAG CGT CTC CTG GAT GCA GGT GCA GAT GCC AAT GCC CAG GAC AAC ATG 286 Lys Arg Leu Leu Asp Ala Gly Ala Asp Ala Asn Ala Gin Asp Asn Met - 146 - 80 85 90 95 GGC CGC TGT CCA CTC CAT GCT GCA GTG GCA GCT GAT GCC CAA GGT GTC Gly Arg Cys Pro Leu His Ala Ala Val Ala Ala Asp Ala Gin Gly Val 100 105 110 TTC CAG ATT CTG ATT CGC AAC CGA GTA ACT GAT CTA" GAT GCC AGG ATG Phe Gin lie Leu lie Arg Asn Arg Val Thr Asp Leu Asp Ala Arg Met 115 120 125 AAT GAT GGT ACT ACA CCC CTG ATC CTG GCT GCC CGC CTG GCT GTG GAG Asn Asp Gly Thr Thr Pro Leu lie Leu Ala Ala Arg Leu Ala Val Glu 130 135 140 GGA ATG GTG GCA GAA CTG ATC AAC TGC CAA GCG GAT GTG AAT GCA GTG Gly Met Val Ala Glu Leu lie Asn Cys Gin Ala Asp Val Asn Ala Val 145 150' 155 GAT GAC CAT GGA AAA TCT GCT CTT CAC TGG GCA GCT GCT GTC AAT AA Asp Asp His Gly Lys Ser Ala Leu His Trp Ala Ala Ala Val Asn Asn 160 165 170 175 GTG GAG GCA ACT CTT TTG TTG TTG AAA AAT GGG GCC AAC CGA GAC ATG Val Glu Ala Thr Leu Leu Leu Leu Lys Asn Gly Ala Asn Arg Asp Met 180 185 190 CAG GAC AAC AAG GAA GAG ACA CCT CTG TTT CTT GCT GCC CGG GAG GGG Gin Asp Asn Lys Glu Glu Thr Pro Leu Phe Leu Ala Ala Arg Glu Gly 195 200 205 AGC TAT GAA GCA GCC AAG ATC CTG TTA GAC CAT TTT GCC AAT CGA GAC Ser Tyr Glu Ala Ala Lys lie Leu Leu Asp His Phe Ala Asn Arg Asp 210 215 220 ATC ACA GAC CAT ATG GAT CGT CTT CCC CGG GAT GTG GCT CGG GAT CGC lie Thr Asp His Met Asp Arg Leu Pro Arg Asp Val Ala Arg Asp Arg 225 230 235 ATG CAC CAT GAC ATT GTG CGC CTT CTG GAT GAA TAC AAT GTG ACC CCA Met His His Asp lie Val Arg Leu Leu Asp Glu Tyr Asn Val Thr Pro 240 245 250 255 AGC CCT CCA GGC ACC GTG TTG ACT TCT GCT CTC TCA CCT GTC ATC TGT Ser Pro Pro Gly Thr Val Leu Thr Ser Ala Leu Ser Pro Val lie Cys 260 265 270 GGG CCC AAC AGA TCT TTC CTC AGC CTG AAG CAC ACC CCA ATG GGC AAG Gly Pro Asn Arg Ser Phe Leu Ser Leu Lys His Thr Pro Met Gly Lys 275 280 285 AAG TCT AGA CGG CCC AGT GCC AAG AGT ACC ATG CCT ACT AGC CTC CCT Lys Ser Arg Arg Pro Ser Ala Lys Ser Thr Met Pro Thr Ser Leu Pro 290 295 300 AAC CTT GCC AAG GAG GCA AAG GAT GCC AAG GGT AGT AGG AGG AAG AAG Asn Leu Ala Lys Glu Ala Lys Asp Ala Lys Gly Ser Arg Arg Lys Lys 305 310 315 TCT CTG AGT GAG AAG GTC CAA CTG TCT GAG AGT TCA GTA ACT TTA TCC Ser Leu Ser Glu Lys Val Gin Leu Ser Glu Ser Ser Val Thr Leu Ser 320 325 330 335 CCT GTT GAT TCC CTA GAA TCT CCT CAC ACG TAT GTT TCC GAC ACC ACA Pro Val Asp Ser Leu Glu Ser Pro His Thr Tyr Val Ser Asp Thr Thr 340 345 350 TCC TCT CCA ATG ATT ACA TCC CCT GGG ATC TTA CAG GCC TCA CCC AAC Ser Ser Pro Met lie Thr Ser Pro Gly lie Leu Gin Ala Ser Pro Asn 355 360 365 - 147 - CCT ATG TTG GCC ACT GCC GCC CCT CCT GCC CCA GTC CAT GCC CAG CAT Pro Met Leu Ala Thr Ala Ala Pro Pro Ala Pro Val His Ala Gin His 370 375 380 GCA CTA TCT TTT TCT AAC CTT CAT GAA ATG CAG CCT TTG GCA CAT GGG Ala Leu Ser Phe Ser Asn Leu His Glu Met Gin Pro Leu Ala His Gly 385 390 . 395 GCC AGC ACT GTG CTT CCC TCA GTG AGC CAG TTG CTA TCC CAC CAC CAC Ala Ser Thr Val Leu Pro Ser Val Ser Gin Leu Leu Ser His His His 400 405 410 415 ATT GTG1 TCT CCA GGC AGT GGC AGT GCT GGA AGC TTG AGT .AGG CTC CAT lie Val Ser Pro Gly Ser Gly Ser Ala Gly Ser Leu Ser Arg Leu His 420 425 430 CCA GTC CCA GTC CCA GCA GAT TGG ATG AAC CGC ATG GAG GTG AAT GAG Pro Val Pro Val Pro Ala Asp Trp Met Asn Arg Met Glu Val Asn Glu 435 . 440 445 ACC CAG TAC AAT GAG ATG TTT GGT ATG GTC CTG GCT CCA GCT GAG GGC Thr Gin Tyr Asn Glu Met Phe Gly Met Val Leu Ala Pro Ala Glu Gly 450 455 460 ACC CAT CCT GGC ATA GCT CCC CAG AGC AGG CCA CCT GAA GGG AAG CAC Thr His Pro Gly lie Ala Pro Gin Ser Arg Pro Pro Glu Gly Lys His 465 470 475 ATA! ACC ACC CCT CGG GAG CCC TTG CCC CCC ATT GTG ACT TTC CAG CTC lie. Thr Thr Pro Arg Glu Pro Leu Pro Pro He Val Thr Phe Gin Leu 480 485 490 495 ATC CCT AAA GGC AGT ATT GCC CAA CCA GCG GGG GCT CCC CAG CCT CAG He Pro Lys Gly Ser He Ala Gin Pro Ala Gly Ala Pro Gin Pro Gin 500 505 510 TCC ACC TGC CCT CCA GCT GTT GCG GGC CCC CTG CCC ACC ATG TAC CAG Ser Thr Cys Pro Pro Ala Val Ala Gly Pro Leu Pro Thr Met Tyr Gin 515 520 525 ATT CCA GAA ATG GCC CGT TTG CCC AGT GTG GCT TTC CCC ACT GCC ATG He Pro Glu Met Ala Arg Leu Pro Ser Val Ala Phe Pro Thr Ala Met 530 535 540 ATG CCC CAG CAG GAC GGG CAG GTA GCT CAG ACC ATT CTC CCA GCC TAT Met Pro Gin Gin Asp Gly Gin Val Ala Gin Thr He Leu Pro Ala Tyr 545 550 555 CAT CCT TTC CCA GCC TCT GTG GGC AAG TAC CCC ACA CCC CCT TCA CAG His Pro Phe Pro Ala Ser Val Gly Lys Tyr Pro Thr Pro Pro Ser Gin 560 565 570 575 CAC AGT TAT GCT TCC TCA AAT GCT GCT GAG CGA ACA CCC AGT CAC AGT His Ser Tyr Ala Ser Ser Asn Ala Ala Glu Arg Thr Pro Ser His Ser 580 585 590 GGT CAC CTC CAG GGT GAG CAT CCC TAC CTG ACA CCA TCC CCA GAG TCT Gly His Leu Gin Gly Glu His Pro Tyr Leu Thr Pro Ser Pro Glu Ser 595 600 605 CCT GAC CAG TGG TCA AGT TCA TCA CCC CAC TCT GCT TCT GAC TGG TCA Pro Asp Gin Trp Ser Ser Ser Ser Pro His Ser Ala Ser Asp Trp Ser 610 615 620 GAT GTG ACC ACC AGC CCT ACC CCT GGG GGT GCT GGA GGA GGT CAG CGG Asp Val Thr Thr Ser Pro Thr Pro Gly Gly Ala Gly Gly Gly Gin Arg 625 630 635 GGA CCT GGG ACA CAC ATG TCT GAG CCA CCA CAC, AAC AAC ATG CAG GTT Gly Pro Gly Thr His Met Ser Glu Pro Pro His Asn Asn Met Gin Val - 148 - 640 645 650 655 TAT GCG TGAGAGAGTC CACCTCCAGT GTAGAGACAT AACTGACTTT TGTAAATGCT 2022 Tyr Ala GCTGAGGAAC AAATGAAGGT CATCCGGGAG AGAAATGAAG AAATCTCTGG AGCCAGCTTC 2082 TAGAGGTAGG AAAGAGAAGA TGTTCTTATT CAGATAATGC AAGAGAAGCA ATTCGTCAGT 2142 TTCACTGGGT ATCTGCAAGG CTTATTGATT ATTCTAATCT AATAAGACAA GTTTGTGGAA 2202 ATGCAAGATG AATACAAGCC TTGGGTCCAT GTTTACTCTC TTCTATTTGG AGAATAAGAT 2262 GGATGCTTAT TGAAGCCCAG ACATTCTTGC AGCTTGGACT GCATTTTAAG CCCTGCAGGC 2322 TTCTGCCATA TCCATGAGAA GATTCTACAC TAGCGTCCTG TTGGGAATTA TGCCCTGGAA 2382 TTCTGCCTGA ATTGACCTAC GCATCTCCTC CTCCTTGGAC ATTCTTTTGT CTTCATTTGG 2442 TGCTTTTGGT TTTGCACCTC TCCGTGATTG TAGCCCTACC AGCATGTTAT AGGGCAAGAC 2502 CTTTGTGCTT TTGATCATTC TGGCCCATGA AAGCAACTTT GGTCTCCTTT CCCCTCCTGT 2562 CTTCCCGGTA TCCCTTGGAG TCTCACAAGG TTTACTTTGG TATGGTTCTC AGCACAAACC 2622 TTTCAAGTAT GTTGTTTCTT TGGAAAATGG ACATACTGTA TTGTGTTCTC CTGCATATAT 2682 CATTCCTGGA GAGAGAAGGG GAGAAGAATA CTTTTCTTCA ACAAATTTTG GGGGCAGGAG 2742 ATCCCTTCAA GAGGCTGCAC CTTAATTTTT CTTGTCTGTG TGCAGGTCTT CATATAAACT 2802 TTACCAGGAA GAAGGGTGTG AGTTTGTTGT TTTTCTGTGT ATGGGCCTGG TCAGTGTAAA 2862 GTTTTATCCT TGATAGTCTA GTTACTATGA CCCTCCCCAC TTTTTTAAAA CCAGAAAAAG 2922 GTTTGGAATG TTGGAATGAC CAAGAGACAA GTTAACTCGT GCAAGAGCCA GTTACCCACC 2982 CACAGGTCCC CCTACTTCCT GCCAAGCATT CCATTGACTG CCTGTATGGA ACACATTTGT 3042 CCCAGATCTG AGCATTCTAG GCCTGTTTCA CTCACTCACC CAGCATATGA AACTAGTCTT 3102 AACTGTTGAG CCTTTCCTTT CATATCCACA GAAGACACTG TCTCAAATGT TGTACCCTTG 3162 CCATTTAGGA CTGAACTTTC CTTAGCCCAA GGGACCCAGT GACAGTTGTC TTCCGTTTGT 3222 CAGATGATCA GTCTCTACTG ATTATCTTGC TGCTTAAAGG CCTGCTCACC AATCTTTCTT 3282 TCACACCGTG TGGTCCGTGT TACTGGTATA CCCAGTATGT TCTCACTGAA GACATGGACT 3342 TTATATGTTC AAGTGCAGGA ATTGGAAAGT TGGACTTGTT TTCTATGATC CAAAACAGCC 3402 CTATAAGAAG GTTGGAAAAG GAGGAACTAT ATAGCAGCCT TTGCTATTTT CTGCTACCAT 3462 TTCTTTTCCT CTGAAGCGGC CATGACATTC CCTTTGGCAA CTAACGTAGA AACTCAACAG 3522 AACATTTTCC TTTCCTAGAG TCACCTTTTA GATGATAATG GACAACTATA GACTTGCTCA 3582 TTGTTCAGAC TGATTGCCCC TCACCTGAAT CCACTCTCTG TATTCATGCT CTTGGCAATT 3642 TCTTTGACTT TCTTTTAAGG GCAGAAGCAT TTTAGTTAAT TGTAGAT AA GAATAGTTTT 3702 CTTCCTCTTC TCCTTGGGCC AGTTAATAAT TGGTCCATGG CTACACTGCA ACTTCCGTCC 3 62 AGTGCTGTGA TGCCCATGAC ACCTGCAAAA TAAGTTCTGC CTGGGCATTT TGTAGATATT 3822 AACAGGTGAA TTCCCGACTC TTTTGGTTTG AATGACAGTT CTCATTCCTT CTATGGCTGC 3882 AAGTATGCAT CAGTGCTTCC CACTTACCTG ATTTGTCTGT CGGTGGCCCC ATATGGAAAC 3942 - 149 - CCTGCGTGTC TGTTGGCATA ATAGTTTACA AATGGTTTTT TCAGTCCTAT CCAAATTTAT 4002 TGAACCAACA AAAATAATTA CTTCTGCCCT GAGATAAGCA GATTAAGTTT GTTCATTCTC 4062 TGCTTTATTC TCTCCATGTG GCAACATTCT GTCAGCCTCT TTCATAGTG GCAAACATTT 4122 TATCATTCTA AATGGTGACT CTCTGCCCTT GGACCCATTT ATTATTCACA GATGGGGAGA 4182 ACCTATCTGC ATGGACCCTC ACCATCCTCT GTGCAGCACA CACAGTGCAG GGAGCCAGTG 4242 GCGATGGCGA TGACTTTCTT CCCCTG 4268 (2) INFORMATION FOR SEQ ID NO: 34: (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 657 amino acids (B) TYPE: amino acid (D) TOPOLOGY: unknown (ii) MOLECULE TYPE: protein (xi) SEQUENCE DESCRIPTION: SEQ ID, NO: 34: Glu Val Asp Val Leu Asp Val Asn Val Arg Gly Pro Asp Gly Cys Thr 1 5 10 15 Pro Leu Met Leu Ala Ser Leu Arg Gly Gly Ser Ser Asp Leu Ser Asp 25 30 Glu Asp Glu Asp Ala Glu Asp Ser Ser Ala Asn lie lie Thr Asp Leu 40 45 Val Tyr Gin Gly Ala Ser Leu Gin Ala Gin Thr Asp Arg Thr Gly Glu 50 55 60 Met Ala Leu His Leu Ala Ala Arg Tyr Ser Arg Ala Asp Ala Ala Lys 65 70 75 80 Arg Leu Leu Asp Ala Gly Ala Asp Ala Asn Ala Gin Asp Asn Met Gly 85 90 95 Arg Cys Pro Leu His Ala Ala. Val Ala Ala Asp Ala Gin Gly Val Phe 100 105 110 Gin lie Leu lie Arg Asn Arg Val Thr Asp Leu Asp Ala Arg Met Asn 115 120 125 Asp Gly Thr Thr Pro Leu lie Leu Ala Ala Arg Leu Ala Val Glu Gly 130 135 140 Met Val Ala Glu Leu lie Asn Cys Gin Ala Asp Val Asn Ala Val Asp 145 150 155 160 Asp His Gly Lys Ser Ala Leu His Trp Ala Ala Ala Val Asn Asn Val 165 170 175 Glu Ala Thr Leu Leu Leu Leu Lys Asn Gly Ala Asn Arg Asp Met Gin 180 185 190 Asp Asn Lys Glu Glu Thr Pro Leu Phe Leu Ala Ala Arg Glu Gly Ser 195 200 205 Tyr Glu Ala Ala Lys lie Leu Leu Asp His Phe Ala Asn Arg Asp lie 210 215 220 Thr Asp His Met Asp Arg Leu Pro Arg Asp Val Ala Arg Asp Arg Met 225 230 235 240 His His Asp lie Val Arg Leu Leu Asp Glu Tyr Asn Val Thr Pro Ser - 150 - 245 250 255 Pro Pro Gly Thr Val Leu Thr Ser Ala Leu Ser Pro Val lie Cys Gly 260 265 270 Pro Asn Arg Ser Phe Leu Ser Leu Lys His Thr Pro Met Gly Lys Lys 275 280 285 Ser Arg Arg Pro Ser Ala Lys Ser Thr Met Pro Thr Ser Leu Pro Asn 290 295 300 Leu Ala Lys Glu Ala Lys Asp Ala Lys Gly Ser Arg Arg Lys Lys Ser 305 310 315 320 Leu Ser Glu Lys Val Gin Leu Ser Glu Ser Ser Val Thr Leu Ser Pro 325 330 335 Val Asp Ser Leu Glu Ser Pro His Thr Tyr Val Ser Asp Thr Thr Ser 340 345 350 Ser Pro Met lie Thr Ser Pro Gly lie Leu Gin Ala Ser Pro Asn Pro 355 360 365 Met Leu Ala Thr Ala Ala Pro Pro Ala Pro Val His Ala Gin His Ala 370 375 380 Leu Ser Phe Ser Asn Leu His Glu Met Gin Pro Leu Ala His Gly Ala 385 390 395 400 Ser Thr Val Leu Pro Ser Val Ser Gin Leu Leu Ser His His His lie 405 410 415 Val Ser Pro Gly Ser Gly Ser Ala Gly Ser Leu Ser Arg Leu His Pro 420 425 430 Val Pro Val Pro Ala Asp Trp Met Asn Arg Met Glu Val Asn Glu Thr 435 440 445 Gin Tyr Asn Glu Met Phe Gly Met Val Leu Ala Pro Ala Glu Gly Thr 450 455 460 His Pro Gly lie Ala Pro Gin Ser Arg Pro Pro Glu Gly Lys His lie 465 470 475 480 Thr Thr Pro Arg Glu Pro Leu Pro Pro lie Val Thr Phe Gin Leu lie 485 490 495 Pro Lys Gly Ser lie Ala Gin Pro Ala Gly Ala Pro Gin Pro Gin Ser 500 505 510 Thr Cys Pro Pro Ala Val Ala Gly Pro Leu Pro Thr Met Tyr Gin lie 515 520 525 Pro Glu Met Ala Arg Leu Pro Ser Val Ala Phe Pro Thr Ala Met Met 530 535 540 Pro Gin Gin Asp Gly Gin Val Ala Gin Thr lie Leu Pro Ala Tyr His 545 550 555 560 Pro Phe Pro Ala Ser Val Gly Lys Tyr Pro Thr Pro Pro Ser Gin His 565 570 575 Ser Tyr Ala Ser Ser Asn Ala Ala Glu Arg Thr Pro Ser His Ser Gly 580 585 590 His Leu Gin Gly Glu His Pro Tyr Leu Thr Pro Ser Pro .Glu Ser Pro 595 600 605 Asp Gin Trp Ser Ser Ser Ser Pro His Ser Ala Ser Asp Trp Ser Asp 610 615 620 - 151 - Val Thr Thr Ser Pro Thr Pro Gly Gly Ala Gly Gly Gly Gin Arg Gly 625 630 635 640 Pro Gly Thr His Met Ser Glu Pro Pro His Asn Asn Met Gin Val Tyr 645 650 655 Ala (2) INFORMATION FOR SEQ ID NO: 35: (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 654 amino acids.

(B) TYPE : amino acid (C) STRANDEDNESS : single (D) TOPOLOGY: unknown (ii) MOLECULE TYPE: peptide (xi) SEQUENCE DESCRIPTION: SEQ ID NO: 35: Thr Pro Pro Gin Gly Glu He Glu Ala Asp Cys Met Asp Val Asn Val 1 5 10 15 Arg Gly Pro Asp Gly Phe Thr Pro Leu Met lie Ala Ser Cys Ser Gly 25 30 Gly Gly Leu Glu Thr Gly Asn Ser Glu Glu Glu Glu Asp Ala Ser Ala 40 45 Asn Met He Ser Asp Phe He Gly Gin Gly Ala Gin Leu His Asn Gin 50 55 60 Thr Asp Arg Thr Gly Glu Thr Ala Leu His Leu Ala Ala Arg Tyr Ala 65 70 75 80 Arg Ala Asp Ala Ala Lys Arg Leu Leu Glu Ser Ser Ala Asp Ala Asn 85 90 95 Val Gin Asp Asn Met Gly Arg Thr Pro Leu His Ala Ala Val Ala Ala 100 105 110 Asp Ala Gin Gly Val Phe Gin He Leu He Arg Asn Arg Ala Thr Asp 115 120 125 Leu Asp Ala Arg Met Phe Asp Gly Thr Thr Pro Leu He Leu Ala Ala 130 135 140 Arg Leu Ala Val Glu Gly Met Val Glu Glu Leu He Asn Ala His Ala 145 150 155 160 Asp Val Asn Ala Val Asp Glu Phe Gly Lys Ser Ala Leu His Trp Ala 165 170 175 Ala Ala Val Asn Asn Val Asp Ala Ala Ala Val Leu Leu Lys Asn Ser 180 185 190 Ala Asn Lys Asp Met Gin Asn Asn Lys Glu Glu Thr Ser Leu Phe Leu 195 200 205 Ala Ala Arg Glu Gly Ser Tyr Glu Thr Ala Lys Val Leu Leu Asp His 210 215 220 Tyr Ala Asn Arg Asp He Thr Asp His Met Asp Arg Leu Pro Arg Asp 225 230 235 240 - 152 -lie Ala Gin Glu Arg Met His His Asp He Val His Leu Leu Asp Glu 245 250 255 Tyr Asn Leu Val Lys Ser Pro Thr Leu His Asn Gly Pro Leu Gly Ala 260 265 270 Thr Thr Leu Ser Pro Pro He Cys Ser Pro Asn Gly Tyr Met Gly Asn 275 280 285 Met Lys Pro Ser Val Gin Ser Lys Lys Ala Arg Lys Pro Ser He Lys 290 295 300 Gly Asn Gly Cys Lys Glu Ala Lys Glu Leu Lys Ala Arg Arg Lys Lys 305 310 315 320 Ser Gin Asp Gly Lys Thr Thr Leu Leu Asp Ser Gly Ser Ser Gly Val 325 330 335 Leu Ser Pro Val Asp Ser Leu Glu Ser Thr His Gly Tyr Leu Ser Asp 340 345 350 Val Ser Ser Pro Pro Leu Met Thr Ser Pro Phe Gin Gin Ser Pro Ser 355 360 365 Met Pro Leu Asn His Leu Thr Ser Met Pro Glu Ser Gin Leu Gly Met 370 375 380 Asn His lie Asn Met Ala Thr Lys Gin Glu Met Ala Ala Gly Ser Asn 385 390 395 400 Arg Met Ala Phe Asp Ala Met Val Pro Arg Leu Thr His Leu Asn Ala 405 410 415 Ser Ser Pro Asn Thr He Met Ser Asn Gly Ser Met His Phe Thr Val 420 425 430 Gly Gly Ala Pro Thr Met Asn Ser Gin Cys Asp Trp Leu Ala Arg Leu 435 440 445 Gin Asn Gly Met Val Gin Asn Gin Tyr Asp Pro He Arg Asn Gly He 450 455 460 Gin Gin Gly Asn Ala Gin Gin Ala Gin Ala Leu Gin His Gly Leu Met 465 470 475 480 Thr Ser Leu His Asn Gly Leu Pro Ala Thr Thr Leu Ser Gin Met Met 485 490 495 Thr Tyr Gin Ala Met Pro Asn Thr Arg Leu Ala Asn Gin Pro His Leu 500 505 510 Met Gin Ala Gin Gin Met Gin Gin Gin Gin Asn Leu Gin Leu His Gin 515 520 525 Ser Met Gin Gin Gin His His Asn Ser Ser Thr Thr Ser Thr His He 530 535 540 Asn Ser Pro Phe Cys Ser Ser Asp He Ser Gin Thr Asp Leu Gin Gin 545 550 555 560 Met Ser Ser Asn Asn He His Ser Val Met Pro Gin Asp Thr Gin He 565 570 575 Phe Ala Ala Ser Leu Pro Ser Asn Leu Thr Gin Ser Met Thr Thr Ala 580 585 590 Gin Phe Leu Thr Pro Pro Ser Gin His Ser Tyr Ser Ser Pro Met Asp 595 600 . 605 Asn Thr Pro Ser His Gin Leu Gin Val Pro Asp His Pro Phe Leu Thr - 153 - 610 615 620 Pro Ser Pro Glu Ser Pro Asp Gin Trp Ser Ser Ser Ser Pro His Ser 625 630 635 640 Asn Met Ser Asp Trp Ser Glu Gly lie Ser -Ser Pro Pro Thr 645 650 (2) INFORMATION FOR SEQ ID NO:36: (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 666 amino acids (B) TYPE: amino acid (C) STRANDEDNESS: single (D) TOPOLOGY : unknown (ii) MOLECULE TYPE: peptide (xi) SEQUENCE DESCRIPTION: SEQ ID NO:36: Thr Pro Pro Gin Gly Glu Val Asp Ala Asp Cys Met Asp Val Asn Val 1 5 10 ' 15 Arg Gly Pro Asp Gly Phe Thr Pro Leu Met lie Ala Ser Cys Ser Gly 25 30 Gly Gly Leu Glu Thr Gly Asn Ser Glu Glu Glu Glu Asp Ala Pro Ala 40 45 Val lie Ser Asp Phe lie Tyr Gin Gly Ala Ser Leu His Asn Gin Thr 50 55 60 Asp Arg Thr Gly Glu Thr Ala Leu His Leu Ala Ala Arg Tyr Ser Arg 65 70 75 80 Ser Asp Ala Ala Lys Arg Leu Leu Glu Ala Ser Ala Asp Ala Asn lie 85 90 95 Gin Asp Asn Met Gly Arg Thr Pro Leu His Ala Ala Val Ser Ala Asp 100 105 110 Ala Gin Gly Val Phe Gin lie Leu Leu Arg Asn Arg Ala Thr Asp Leu 115 120 125 Asp Ala Arg Met His Asp Gly Thr Thr Pro Leu lie Leu Ala Ala Arg 130 135 140 Leu Ala Val Glu Gly Met Leu Glu Asp Leu lie Asn Ser His Ala Asp 145 150 155 160 Val Asn Ala Val Asp Asp Leu Gly Lys Ser Ala Leu His Trp Ala Ala 165 170 175 Ala Val Asn Asn Val Asp Ala Ala Val Val Leu Leu Lys Asn Gly Ala 180 185 190 Asn Lys Asp Met Gin Asn Asn Lys Glu Glu Thr Pro Leu Phe Leu Ala 195 200 205 Ala Arg Glu Gly Ser Tyr Glu Thr Ala Lys Val Leu Leu Asp His Phe 210 215 220 Ala Asn Arg Asp He Thr Asp His Met Asp Arg Leu Pro Arg Asp He 225 230 235 240 Ala Gin Glu Arg Met His His Asp He Val Arg Leu Leu Asp Glu Tyr 245 250 255 - 154 - Asn Leu Val Arg Ser Pro Gin Leu His Gly Thr Ala Leu Gly Gly Thr 260 265 270 Pro Thr Leu Ser Pro Thr Leu Cys Ser Pro Asn Gly Tyr Leu Gly Asn 275 280 285 Leu Lys Ser Ala Thr Gin Gly Lys Lys Ala Arg Lys Pro Ser Thr Lys 290 295 300 Gly Leu Ala Cys Ser Ser Lys Glu Ala Lys Asp Leu Lys Ala Arg Arg 305 310 315 320 Lys Lys Ser Gin Asp Gly Lys Gly Cys Leu Leu Asp Ser Ser Ser Met 325 330 335 Leu Ser Pro Val Asp Ser Leu Glu Ser Pro His Gly Tyr Leu Ser Asp 340 345 350 Val Ala Ser Pro Pro Leu Pro Ser Pro Phe Gin Gin Ser Pro Ser Met 355 360 365 Pro Leu Ser His Leu Pro Gly :Met Pro Asp Thr His Leu Gly lie Ser 370 375 380 His Leu Asn Val Ala Ala Lys Pro Glu Met Ala Ala Leu Ala Gly Gly 385 390 395 400 Ser Arg Leu Ala Phe Glu Pro Pro Pro Pro Arg Leu Ser His Leu Pro 405 410 415 Val Ala Ser Ser Ala Ser Thr Val Leu Ser Thr Asn Gly Thr Gly Ala 420 425 430 Met Asn Phe Thr Val Gly Ala Pro Ala Ser Leu Asn Gly Gin Cys Glu 435 440 445 Trp Leu Pro Arg Leu Gin Asn Gly Met Val Pro Ser Gin Tyr Asn Pro 450 455 460 Leu Arg Pro Gly Val Thr Pro Gly Thr Leu Ser Thr Gin Ala Ala Gly 465 470 475 480 Leu Gin His Gly Met Met Ser Pro He His Ser Ser Leu Ser Thr Asn 485 490 495 Thr Leu Ser Pro He lie Tyr Gin Gly Leu Pro Asn Thr Arg Leu Ala 500 505 510 Thr Gin Pro His Leu Val Gin Thr Gin Gin Val Gin Pro Gin Asn Leu 515 520 525 Gin He Gin Pro Gin Asn Leu Gin Pro Pro Ser Gin Pro His Leu Ser 530 535 540 Val Ser Ser Ala Ala Asn Gly His Leu Gly Arg Ser Phe Leu Ser Gly 545 550 555 560 Glu Pro Ser Gin Ala Asp Val Gin Pro Leu Gly Pro Ser Ser Leu Pro 565 570 575 Val His Thr lie Leu Pro Gin Glu Ser Gin Ala Leu Pro Thr Ser Leu 580 585 590 Pro Ser Ser Met Val Pro Pro Met Thr Thr Thr Gin Phe Leu Thr Pro 595 600 605 Pro Ser Gin His Ser Tyr Ser Ser Ser Pro Val Asp Asn Thr Pro Ser 610 615 620 His Gin Leu Gin Val Pro Glu His Pro Phe Leu Thr Pro Ser Pro Glu - 155 - 625 630 635 640 Ser Pro Asp Gin Trp Ser Ser Ser Ser Arg His Ser Asn He Ser Asp 645 650 655 Trp Ser Glu Gly He Ser Ser Pro Pro Thr 660 665 (2) INFORMATION FOR SEQ ID NO: 37: (i) SEQUENCE CHARACTERISTICS : (A) LENGTH: 681 amino acids (B) TYPE: amino acid (C) STRA DEDNESS : single (D) TOPOLOGY : unknown (ii) MOLECULE TYPE: peptide (xi) SEQUENCE DESCRIPTION: SEQ ID NO: 37: Thr Pro Pro Gin Gly Glu Val Asp Ala Asp Cys Met Asp Val Asn Val 1 5 10 15 Arg Gly Pro Asp Gly Phe Thr Pro Leu Met He Ala Ser Cys Ser Gly 25 30 Gly Gly Leu Glu Thr Gly Asn Ser Glu Glu Glu Glu Asp Ala Pro Ala 40 45 Val He Ser Asp Phe He Tyr Gin Gly Ala Ser Leu His Asn Gin Thr 50 . 55 60 Asp Arg Thr Gly Glu Thr Ala Leu His Leu Ala Ala Arg Tyr Ser Arg 65 70 75 80 Ser Asp Ala Ala Lys Arg Leu Leu Glu Ala Ser Ala Asp Ala Asn He 85 90 95 Gin Asp Asn Met Gly Arg Thr Pro Leu His Ala Ala Val Ser Ala Asp 100 105 110 Ala Gin Gly Val Phe Gin He Leu He Arg Asn Arg Ala Thr Asp Leu 115 120 125 Asp Ala Arg Met His Asp Gly Thr Thr Pro Leu He Leu Ala Ala Arg 130 135 140 Leu Ala Val Glu Gly Met Leu Glu Asp Leu He Asn Ser His Ala Asp 145 150 155 160 Val Asn Ala Val Asp Asp Leu Gly Lys Ser Ala Leu His Trp Ala Ala 165 170 175 Ala Val Asn Asn Val Asp Ala Ala Val Val Leu Leu Lys Asn Gly Ala 180 185 190 Asn Lys Asp Met Gin Asn Asn Arg Glu Glu Thr Pro Leu Phe Leu Ala 195 200 205 Ala Arg Glu Gly Ser Tyr Glu Thr Ala Lys Val Leu Leu Asp His Phe 210 215 220 Ala Asn Arg Asp He Thr Asp His Met Asp Arg Leu Pro Arg Asp He 225 230 .235 240 Ala Gin Glu Arg Met His His Asp He Val Arg Leu Leu Asp Glu Tyr 245 250 255 - 156 - Asn Leu Val Arg Ser Pro Gin Leu His Gly Ala Pro Leu Gly Gly Thr 260 265 270 Pro Thr Leu Ser Pro Pro Leu Cys Ser Pro Asn Gly Tyr Leu Gly Ser 275 280 285 Leu Lys Pro Gly Val Gin Gly Lys Lys Val Arg Lys Pro Ser Ser Lys 290 295 300 Gly Leu Ala Cys Gly Ser Lys Glu Ala Lys Asp Leu Lys Ala Arg Arg 305 310 315 320 Lys Lys Ser Gin Asp Gly Lys Gly Cys Leu Leu Asp Ser Ser Gly Met 325 330 335 Leu Ser Pro Val Asp Ser Leu Glu Ser Pro His Gly Tyr Leu Ser Asp 340 345 350 Val Ala Ser Pro Pro Leu Leu Pro Ser Pro Phe Gin Gin Ser Pro Ser 355 360 365 Val Pro Leu Asn His Leu Pro Gly Met Pro Asp Thr His Leu Gly lie 370 375 380 Gly His Leu Asn Val Ala Ala Lys Pro Glu Met Ala Ala Leu Gly Gly 385 390 395 400 Gly Gly Arg Leu Ala Phe Glu Thr Gly Pro Pro Arg Leu Ser His Leu 405 410 415 Pro Val Ala Ser Gly Thr Ser Thr Val Leu Gly Ser Ser Ser Gly Gly 420 425 430 Ala Leu Asn Phe Thr Val Gly Gly Ser Thr Ser Leu Asn Gly Gin Cys 435 440 445 Glu Trp Leu Ser Arg Leu Gin Ser Gly Met Val Pro Asn Gin Tyr Asn 450 455 460 Pro Leu Arg Gly Ser Val Ala Pro Gly Pro Leu Ser Thr Gin Ala Pro 465 470 475 480 Ser Leu Gin His Gly Met Val Gly Pro Leu His Ser Ser Leu Ala Ala 485 490 495 Ser Ala Leu Ser Gin Met Met Ser Tyr Gin Gly Leu Pro Ser Thr Arg 500 505 510 Leu Ala Thr Gin Pro His Leu Val Gin Thr Gin Gin Val Gin Pro Gin 515 520 525 Asn Leu Gin Met Gin Gin Gin Asn Leu Gin Pro Ala Asn lie Gin Gin 530" 535 540 Gin Gin Ser Leu Gin Pro Pro Pro Pro Pro Pro Gin Pro Leu Gly 545 550 555 560 Val Ser Ser Ala Ala Ser Gly His Leu Gly Arg Ser Phe Leu Ser Gly 565 570 575 Glu Pro Ser Gin Ala Asp Val Gin Pro Leu Gly Pro Ser Ser Leu Ala 580 585 590 Val His Thr He Leu Pro Gin Glu Ser Pro Ala Leu Pro Thr Ser Leu 595 600 605 Pro Ser Ser Leu Val Pro Pro Val Thr Ala Ala Gin Phe Leu Thr Pro 610 615 620 Pro Ser Gin His Ser Tyr Ser Ser Pro Val Glu Asn Thr Pro Ser His - 157 - 625 630 635 640 Gin Leu Gin Val Pro Glu His Pro Phe Leu Thr Pro Ser Pro Glu Ser 645 650· 655 Pro Asp Gin Trp Ser Ser Ser Ser Pro His Ser Asn Val Ser Asp Trp 660 665 670· Ser Glu Gly Val Ser Ser Pro Pro Thr 675 680

Claims (14)

1. 83831/3 - 158 - Claims 1. A substantially purified fragment of a Serrate protein which is the portion of the Serrate protein with the greatest homology to the amino acid sequence as depicted in Figure 15 (SEQ ID NO:9) from about amino acid numbers 79-282, which fragment is characterized by the ability in vitro, when expressed on the surface of a first cell, to bind to a Notch protein expressed on the surface of a second cell.

2. A fragment as claimed in claim 1 which fragment consists of amino acids 79-282 depicted in Figure 15 (SEQ ID NQ:9).

3. A substantially purified fragment of a Serrate protein which is the portion of the Serrate protein with the greatest homology to the amino acid sequence as depicted in Figure 1.5 (SEQ ID NO:9) from about amino acid numbers 85-283, which fragment is characterized by the ability in vitro, when expressed on the surface of a first cell, to bind to a Notch protein expressed on the surface of a second cell.

4. A fragment as claimed in claim 3 which fragment consists of amino acids 85-283 depicted in Figure 15 (SEQ ID NO:9).

5. A chimeric protein comprising a fragment as claimed in any one of claims 1 to 4 joined to a heterologous protein sequence.

6. A derivative of a fragment as claimed in any one of claims 1 to 4, which derivative has the amino acid sequence of said fragment in which one or more amino acid residues within the sequence are substituted by another amino acid of a similar polarity which acts as a functional equivalent, and which derivative has the ability in vitro, when expressed on the surface of a first cell, to bind to a Notch protein expressed on the surface of a second cell.

7. A chimeric protein comprising a derivative as claimed in claim 6 joined to a heterologous protein sequence.

8. A substantially purified nucleic acid encoding a fragment as claimed in any one of claims 1 to 4 or a chimeric protein as claimed in claim 5 or claim 7.

9. A nucleic acid vector comprising a nucleic acid as claimed in claim 8.

10. A cell transformed with a nucleic acid vector as claimed in claim 9.

11. A method for producing a fragment of a Serrate protein comprising growing a cell as claimed in claim 10 such that the fragment is expressed by the cell; and isolating the expressed fragment of a Serrate protein.

12. ;; The substantially purified fragment according to any one of claims 1-4, as herein described with reference to the examples and drawings.

13. / The chimeric protein according to any one of claims 5 and 7, as herein described with reference to the examples and drawings. 183831/3 - 159 -

14. The derivative of a fragment according to claim 6, as herein described with reference to the examples and drawings. 15Ϊ The substantially purified nucleic acid according to claim 8, as herein described with reference to the examples and drawings. 16 The nucleic acid vector according to claim 9, as herein described with reference to the examples and drawings. 17. ' The cell according to claim 10, as herein described with reference to the examples and drawings. 18. ; The method according to claim 1 1 , as herein described with reference to the examples and drawings. G:\petros2010\8079\379\Amended claims v3.doc\vp