WO1995034201A1

WO1995034201A1 - pp60PIK: A DOWNSTREAM ELEMENT IN INSULIN SIGNALING

Info

Publication number: WO1995034201A1
Application number: PCT/US1995/007312
Authority: WO
Inventors: Morris F. White
Original assignee: Joslin Diabetes Center, Inc.
Priority date: 1994-06-10
Filing date: 1995-06-08
Publication date: 1995-12-21
Also published as: CA2192486A1; JPH10505227A; EP0768821A4; US5650293A; EP0768821A1; AU2769895A; AU710107B2

Abstract

A substantially pure nucleic acid comprising a sequence encoding a pp60PIK peptide having pp60PIK activity.

Description

pp60PI : A DOWNSTREAM ELEMENT IN INSULIN SIGNALING

Background of the Invention This invention was made with government support under National Institute of

Health Award Number DK 43808. Accordingly, the government retains certain rights in the invention.

The invention relates to insulin metabolism and more specifically to pp60^PIK, a protein which mediates insulin regulation of 3'-phosphatidyl-inositol (PI-3) kinase, and to the gene that encodes pp60^PIK.

Summary of the Invention In general, the invention features, a substantially pure nucleic acid, e.g., a DNA, which includes a sequence encoding a peptide having pp60^PI activity. In preferred embodiments: the sequence is at least 50%, more preferably at least 60%, yet more preferably at least 70%, and most preferably at least 80, 90, 95, or 99% homologous with the sequence from SEQ ID NO:l.

In another aspect, the invention features, a substantially pure nucleic acid, e.g., a DNA, which includes a nucleic acid sequence which hybridizes under high or low stringency to a nucleic acid which encodes a peptide with the same, or essentially the same, amino acid sequence as the peptide of SEQ ID NO: 1.

In another aspect, the invention features, a substantially pure nucleic acid which includes a sequence encoding a peptide of 20 or more amino acids in length, the peptide having at least 90% homology with an amino acid sequence which is the same, or essentially the same, as the amino acid sequence of SEQ ID NO:l. In another aspect, the invention includes a vector which includes a nucleic acid of the invention, preferably a substantially pure DNA of the invention, which encodes a peptide of the invention.

The invention also includes: a cell containing a nucleic acid of the invention; a cell which is capable of expressing a peptide of the invention; an essentially homogeneous population of cells, each of which includes a nucleic acid of the invention; and a method for manufacture of a peptide of the invention including culturing a cell which includes a nucleic acid of the invention in a medium to express the peptide.

In another aspect, the invention features a pp60^PIK peptide of the invention, preferably a purified peptide of the invention, e.g.: a peptide having pp60^PI activity; a peptide encoded by a nucleic acid which hybridizes under high or low stringency conditions to a nucleic acid which encodes a peptide sequence which is the same, or essentially the same, as the amino acid sequence of SEQ ID NO:l; a peptide of essentially of the same sequence as the amino acid sequence described in SEQ ID NO: 1 ; a peptide of at least 20, preferably at least 30, more preferably at least 40, more preferably at least 50, and most

RECTIFIED SHEET (RULE 91) preferably at least 60, amino acid residues in length; and, a peptide having at least 50%, more preferably at least 60%, yet more preferably at least 70%, yet more preferably at least 80%, and most preferably at least 90 or 99% homology with an amino acid sequence which is the same, or essentially the same, as the amino acid sequence of SEQ ID NO:l. In preferred embodiments the peptide is a recombinant peptide, e.g., a protein expressed from a nucleic acid of the invention.

In other aspects, the invention features: a therapeutic composition which includes a peptide of the invention and a pharmaceutically acceptable carrier; and, a therapeutic composition which includes a substantially pure nucleic acid of the invention and a pharmaceutically acceptable carrier.

In another aspect, the invention features a transgenic animal, e.g., a transgenic mammal, e.g., a mouse, having a transgene which includes an pp60^PIK encoding DNA. In preferred embodiments the pp60^PIK gene or DNA includes a mutation, e.g., a mutation that results in misexpression of pp60^PIK. In preferred embodiments the animal includes a second transgene, e.g., a transgene which includes the IRS-1 gene, e.g., an IRS-1 knockout.

In another aspect, the invention features a method of determining if a subject, e.g., a mammal, e.g., a human, is at risk for a disorder, e.g., an insulin-related disease, e.g., an insulin resistant insulin-related disease, e.g., Type II diabetes by evaluating an aspect of pp60^PIK metabolism. The method includes: determining an aspect of pp60^PIK metabolism in the subject, an abnormal level of pp60^PI metabolism being predictive of risk for the disorder.

The aspect of pp60^PIK metabolism determined can include: the amount, distribution or structure of intracellular or extracellular pp60^PIK; the level of phosphorylation of pp60^PIK; the level of kinase activity of pp60^PIK; or the amount, distribution, or structure of pp60^PIK encoding RNA.

In another aspect, the invention features a method of determining if a subject, e.g., a mammal, e.g., a human, is at risk for a disorder, e.g., an insulin-related disease, e.g., an insulin resistant insulin-related disease, e.g., Type II diabetes, by determining the structure of the pp60^PIK gene.

The method includes: determining if the structure of an allele of the pp60^PIK gene in the subject differs from wild type, an other than wild type structure being predictive of risk for the disorder. The structure of the pp60^PIK gene can be determined, e.g., by hybridization based methods, e.g., by Southern analysis, or by DNA sequencing. Gross abnormalities, e.g., deletions, inversions, or translocations, or point mutations, can be predictive of risk. The method can be used to predict risk in the individual tested or in the individual's offspring. The method can be performed prenatally. The invention also provides for a system to evaluate or screen treatments for their usefulness in the treatment a disorder, e.g., an insulin related disease, e.g., an insulin resistant disease, e.g., Type II diabetes. Accordingly, in another aspect, the invention includes a method of evaluating a treatment for use in treating a disorder. The method includes administering a treatment, e.g., adniinistering compounds to a cultured cell or a test organism e.g., a mammal, and determining the effect of the agent on an aspect of pp60^PIK metabolism. A change in an aspect of pp60^PIK metabolism indicates an effect of the agent. In preferred embodiments the insulin-related disease is an insulin resistant disease and the change in an aspect of metabolism is a change in the response to blood glucose levels. Transgenic cells and animals of the invention also provide for a system to evaluate or screen treatments for their usefulness in the treatment a disorder, e.g., an insulin related disorder, e.g., an insulin-resistant disease, e.g., type II diabetes. Accordingly, the invention includes a method of evaluating an effect of a treatment, e.g., a therapeutic agent, on insulin metabolism in a transgenic cell or a transgenic animal having a pp60^PIK transgene. The method includes: aclministering a treatment to a transgenic cell or animal having a transgene which includes pp60^PIK, e.g., a cell or animal heterozygous or homozygous for a pp60^PIK knockout; and determining the effect of the therapeutic agent on an aspect of insulin or pp60^PIK metabolism. A change in the determined parameter being indicative of the usefulness or therapeutic value of the treatment. E.g., restoration of an aspect of insulin metabolism impaired by a misexpressed pp60^PIK gene is indicative of the effectiveness of a treatment.

The invention also includes a method of assaying an effect of a therapeutic agent which mimics a first effect of insulin (the first effect mediated by pp60^PIK) without mimicking a second effect of insulin. The method includes: adniinistering the agent to a cell grown in culture or to a test organism, e.g., a mammal; evaluating the agent's ability to mimic the first, pp60^PIK - mediated effect of insulin; and evaluating the agent's ability to niirnic the second effect of insulin. In preferred embodiments evaluating the agent's ability to mimic the first, pp60^PIK - mediated effect of insulin includes: measuring a change in an aspect of pp60^PIK metabolism, e.g., the level of pp60^PI expression, the kinase activity of pp60^PIK, the cellular or intra-cellular distribution of pp60^PIK, or the level of the pp60^PIK phosphorylation. The invention also features a method of treating a subject, e.g., a mammal e.g., a human, suffering from a disease caused by an abnormality of pp60^PIK metabolism, e.g., a disease characterized by lower than desirable levels of pp60^PIK activity. The method includes administering to the subject, a therapeutically effective amount of an agent, e.g., pp60^PI , which alters an aspect of insulin metabolism, e.g., the level of PI 3' kinase phosphorylation.

The invention also features a method of treating a subject, e.g., a mammal, e.g., a human, suffering from a disease caused by unwanted tyrosine kinase activity. The method includes administering to the subject a therapeutically effective amount of a therapeutic agent, e.g., pp60^PIK antagonist, e.g., a pp60^PIK peptide which is an antagonist of pp60^PIK mediated phosphorylation of a kinase, e.g., PI 3' kinase, a pp60^PIK antisense molecule, or an anti-pp60^PIK mAb, which modifies the ability of pp60^PIK to alter the phosphorylation ofthe tyrosine kinase, thereby altering the tyrosine kinase activity. In preferred embodiments the tyrosine kinase activity results from a product of an oncogene. The invention also features a method of treating a mammal, e.g., a human, suffering from a disease characterized by abnormal cell proliferation. The method includes administering to said mammal a therapeutically effective amount of a therapeutic agent, e.g., a pp60^PIK antagonist, e.g., a pp60^PIK peptide which is an antagonist of pp60^PIK mediated phosphorylation of a kinase, e.g., PI 3' kinase, a pp60^PIK antisense molecule, or an anti- pp60^PIK mAb, which alters an aspect of pp60^PIK metabolism. In preferred embodiments the aspect of pp60^PIK metabolism is PI 3' kinase phosphorylation.

Methods of the invention can be used to diagnose the presence of diseases characterized by an abnormality in the structure or metabolism of pp60^PIK. The invention allows for the analysis of various aspects of insulin metabolism, e.g., for the detection of insulin-stimulated PI 3' kinase phosphorylation. The invention also provides useful tools for the testing and development of therapeutic agents used to treat insulin or pp60^PIK related diseases. The invention also features a method of evaluating an effect of a therapeutic agent which alters the ability of a tyrosine kinase to phosphorylate a substrate which includes the amino acid sequence YFIN. The method includes administering the agent to a cultured cell or test organism, e.g., a mammal, and measuring the level of phosphorylation of a substrate which includes the amino acid sequence YFIN, e.g., a naturally occurring YFIN- containing substrate of a tyrosine kinase or a YFIN-containing synthetic substrate.

The invention also includes a method of treating a mammal e.g., a human, suffering from a disease, disorder, or condition caused or characterized by the phosphorylation of a substrate of a tyrosine kinase, the substrate including the amino acid sequence YFIN. The tyrosine kinase may be, e.g., a receptor tyrosine kinase, e.g., insulin receptor, epidermal growth factor (EGF) receptor, platelet derived growth factor, (PDGF) receptor, or insulin-like growth factor (ILG) receptor, or an oncogene product, e.g., the src, abl, or fins gene product. The method includes administering a therapeutically effective amount of a therapeutic agent, e.g., a peptide which includes the sequence YFIN, e.g., pp60^PIK or a fragment thereof which includes the amino acid sequence YFIN, mimetic or a YFIN-continuing peptide.

In another aspect, the invention includes peptides capable of inhibiting an interaction, preferably a site specific interaction, of an SH2-doma -containing protein, e.g., a signal transduction protein, e.g., a cytoplasmic or a transmembrane signal transduction protein, a receptor protein, e.g., the insulin receptor or the PDGF receptor, or a protein which is active in the regulation of cell proliferation, e.g., an oncogene product with a second protein containing the sequence YFIN, e.g., a protein capable of altering the state of phosphorylation of a tyrosine residue, e.g., a tyrosine kinase, e.g., pp60^PI . Peptides of the invention include the sequence R FIN (wherein Rl is tyrosine, phosphotyrosine, or more preferably, an analog of phosphotyrosine having a hydrolysis resistant phosphorous moiety). The invention also includes mimetics of these peptides.

In another aspect, the invention features a method of inhibiting an interaction, preferably a site specific interaction, between a first molecule which includes an SH2 domain, e.g., a signal transduction protein, e.g., a cytoplasmic or a transmembrane signal transduction protein, a receptor protein, e.g., the insulin receptor or the PDGF receptor, or a protein which is active in the regulation of cell proliferation, e.g., an oncogene product, and a second molecule, e.g., a protein containing the sequence YFIN, a protein capable of altering the state of phosphorylation of a tyrosine residue, e.g., a tyrosine kinase, e.g., pp60^PIK. The method includes contacting the first molecule with an inhibitor molecule which includes a peptide of the invention or which includes a mimetic of a peptide of the invention.

In another aspect, the invention features a method of treating a mammal, e.g., a human, having a condition characterized by unwanted cell proliferation including administering to the mammal an amount of a YFIN-containing peptide of the invention, or a mimetic of a peptide of the invention, sufficient to prevent or inhibit the unwanted cell proliferation.

The invention also includes methods of increasing the affinity of a YFIN- containing phosphopeptide for its substrate, e.g., a protein containing a SH2-domain. The method includes replacing the phosphotyrosine of the YFIN motif with a moiety which is more electronegative than the phosphate moiety of phosphotyrosine such as in RI-OPO3H2 where R¹ can be CHF, CF , CHC1, CC1₂, or CC1F.

Methods of the invention allow the treatment of a variety of diseases, e.g., insulin related diseases, insulin resistant diseases, diseases characterized by abnormal cellular proliferation, and diseases caused by the phosphorylation of a substrate by a tyrosine kinase, by intervening in aspects of pp60^PIK metabolism. Other features and advantages of the invention will be apparent from the following description of the preferred embodiments and from the claims.

Detailed Description The drawings are first briefly described. Drawings Fig. 1 is a diagram of the DNA sequence of a pp60^PIK cDNA (SEQ ID NO:l) and the amino acid sequence of pp60^PIK (SEQ ID NO:l and 2).

Fig. 2 is a depiction of the results of expression/screening of an IRS-1 associated protein (51.1.1) from a mouse adipocyte library using the following probes: IRS-1 protein probe, p85α cDNA probe, and p85β cDNA probe. Fig. 3 is a schematic diagram of the three clones (λZAP 2.1, λExlox, λZAP 52.1) from which the DNA sequence of pp60^PIK cDNA was derived.

Fig.4 is a diagram of the amino acid sequences of pp60^PIK, p85α and p85β, which shows the homologous regions among the three proteins. Figs. 5 A, 5B, and 5C are depictions, of the results of experiments performed to determine the distribution of pp60^PIK in a variety of mouse tissues. Fig. 5A specifically depicts hybridization analysis; Fig. 5B, competitive PCR experiments; and Fig. 5C, relative levels in various tissues.

Figs. 6A and 6B are depictions(Fig. 6A: pi 10 immunoblot; Fig. 6B: p85 immunoblot) of the results of experiments performed to determine the expression of p 110 and pp60^PIK in insect Sf-9 cells.

Fig. 7 is a depiction of the results of experiments performed to determine the association of pi 10 and pp60^PIK in insect Sf-9 cells.

Figs. 8A, 8B and 8C are depictions of the results of experiments performed to determine the expression of pp60^PIK in CHO cells. Fig. 8 A, anti-p85 preciptiation; Fig. 8B, anti-FLAG precipitation; Fig. 8C, anti-IRS-1 precipitation.

Figs. 9 A and 9B are depictions of the results of experiments performed to show phosphorylation of pp60^PIK by the insulin receptor. Fig. 9A, In Vitro Phosphorylation; Fig. 9B, Tryptic Digest. Figs. 10A and 1 OB are depictions of the results of experiments performed to identify the tyrosine phosphorylation site in pp60^PIK. Fig. 10A, showing the predicted cycles for tryptic peptides; Fig. 10B, showing the graphical results of the experiments.

Fig. 11 is a depiction of the results of experiments performed to determine the effect of insulin on PI 3'-kinase activity on mammalian cells (Chinese hamster ovary cells) overexpressing pp60^PIK.

In general, the invention features, a substantially pure nucleic acid, e.g., a DNA, which includes (or consists essentially of) a nucleic acid sequence encoding pp60^PIK, or a pp60^PIK peptide. In preferred embodiments: the encoded peptide has pp60^PIK activity; the nucleic acid sequence is at least 50%, more preferably at least 60%, yet more preferably at least 70%, and most preferably at least 80, 90, 95, or 99%, homologous with DNA from SEQ ID NO:l; the encoded amino acid sequence is such that it can be encoded by a nucleic acid which hybridizes under high or low stringency conditions to a nucleic acid which encodes a peptide with the same, or essentially the same, amino acid sequence as the peptide of SEQ ID NO: 1 ; the pp60^PIK peptide is at least 30, more preferably at least 40, more preferably at least 50, and most preferably at least 60, 80, 100, or 120 amino acid residues in length; the pp60^PIK peptide is at least 50%, more preferably at least 60%, more preferably at least 70%, yet more preferably at least 80%, and most preferably at least 90 or 99% homologous with an amino acid sequence which is the same, or essentially the same, as the peptide sequence of 6/1 SEQ ID NO:l and, the amino acid sequence of the pp60^PI peptide is essentially the same as the peptide sequence, or a fragment of the sequence, described in SEQ ID NO:l.

- -

In preferred embodiments the encoded peptide has one or more of the following properties: it can bind to IRS-1; it can bind to the PI 3'-kinase 110 Kd catalytic subunit; it does not contain an SH3 domain; it can be phosphorylated by the insulin receptor or other tyrosine kinases; it does not contain a BCR-homology region (such as is found in p85s); it contains one and preferably two, SH2 domains; it contains one tyrosine phosphorylation site.

In another aspect, the invention features, a substantially pure nucleic acid, e.g., DNA, which includes (or consists essentially of) a nucleic acid sequence which hybridizes under high or low stringency to a nucleic acid which encodes a peptide with the same, or essentially the same, amino acid sequence as the peptide of SEQ ID NO: 1. In preferred embodiments: the DNA sequence is at least 50%, more preferably at least 60%, yet more preferably at least 70%, and most preferably at least 80, 90, 95, or 99% homologous with DNA from of SEQ ID NO: 1 ; the substantially pure DNA encodes a peptide at least 30, more preferably at least 40, more preferably at least 50, and most preferably at least 60, 80, 100, or 120 amino acid residues in length; the substantially pure DNA encodes a peptide at least 50%, more preferably at least 60%, yet more preferably at least 70%, and most preferably at least 90 or 99% homologous with an amino acid sequence which is the same, or essentially the same, as the amino acid sequence of SEQ ID NO:l; and, the substantially pure DNA encodes a peptide having essentially the same amino acid sequence, or a fragment of the amino acid sequence, described in SEQ ID NO: 1.

In another aspect, the invention features, a substantially pure nucleic acid, e.g., a DNA, which includes (or consists essentially of) a sequence encoding a peptide of 20 or more amino acids in length, the peptide having at least 90% homology with an amino acid sequence which is the same, or essentially the same, as the amino acid sequence of SEQ ID NO:l. In preferred embodiments the substantially pure nucleic acid encodes: a peptide which is at least 30, more preferably at least 40, more preferably at least 50, and most preferably at least 60, amino acid residues in length; a peptide which is at least 50%, more preferably at least 60%, yet more preferably at least 70%, yet more preferably at least 80%, and most preferably at least 90 or 99% homologous with an amino acid sequence which is the same, or essentially the same, as the amino acid sequence of SEQ ID NO:l; and, a peptide with pp60^PIK activity.

In preferred embodiments the encoded peptide has one or more of the following properties: it can bind to IRS-1 ; it can bind to the PI 3'-kinase 110 Kd catalytic - - subunit; it does not contain an SH3 domain; it can be phosphorylated by the insulin receptor or other tyrosine kinases; it does not contain a BCR-homology region (such as is found in p85s); it contains one and preferably two, SH2 domains; it contains one tyrosine phosphorylation site. In another aspect, the invention includes a vector which includes nucleic acid, e.g., a DNA, of the invention, preferably a substantially pure nucleic acid of the invention, which encodes a peptide of the invention, e.g.: DNA which includes a sequence encoding a peptide having pp60^PIK activity; DNA which hybridizes under high or low stringency conditions to a nucleic acid which encodes a peptide with the same, or essentially the same, amino acid sequence of SEQ ID NO: 1 ; DNA which encodes a peptide of essentially the sequence described in SEQ ID NO:l; DNA which includes a sequence encoding a peptide of at least 20, preferably at least 30, more preferably at least 40, more preferably at least 50, and most preferably at least 60, amino acid residues in length; and DNA which encodes a peptide at least 50%, more preferably at least 60%, yet more preferably at least 70%, yet more preferably at least 80%, and most preferably at least 90 or 99% homologous with an amino acid sequence which is the same, or essentially the same, as the amino acid sequence of SEQ ID NO: 1. Other preferred embodiments include those in which: the DNA sequence is at least 85%, more preferably at least 90%, yet more preferably at least 95%, and most preferably at least 98 or 99% homologous with the DNA sequence of SEQ ID NO:l. The invention also includes: a cell containing a nucleic acid, e.g., a DNA, preferably a substantially pure nucleic acid, of the invention, preferably, a cell which is capable of expressing a peptide of the invention; an essentially homogeneous population of cells, each of which includes a sequence, preferably a substantially pure nucleic acid, of the invention, and a method for manufacture of a peptide of the invention including culturing a cell which includes a nucleic acid, preferably a substantially pure nucleic acid of the invention in a medium to express the peptide.

In another aspect, the invention features a peptide of the invention, preferably a purified peptide of the invention, e.g.: a peptide having pp60^PIK activity; a peptide encoded by a DNA which hybridizes under high or low stringency conditions to a nucleic acid which encodes peptide sequence which is the same, or essentially the same, as the amino acid sequence of SEQ ID NO: 1 ; a peptide of essentially the sequence described in SEQ ID NO: 1 ; a peptide of at least 20, preferably at least 30, more preferably at least 40, more preferably at least 50, and most preferably at least 60, amino acid residues in length; and, a peptide having at least 50%, more preferably 60%, yet more preferably 70%, yet more preferably 80%, and most preferably at least 90 or 99% homology with an amino acid sequence which is the same, or essentially the same, as the amino acid sequence of SEQ ID NO:l.

In preferred embodiments the peptide has one or more of the following properties: it can bind to IRS-1; it can bind to the PI 3'-kinase 110 Kd catalytic subunit; it does not contain an SH3 domain; it can be phosphorylated by the insulin receptor or other - - tyrosine kinases; it does not contain a BCR-homology region (such as is found in p85s); it contains one and preferably two, SH2 domains; it contains one tyrosine phosphorylation site.

In another aspect, the invention features a peptide of the invention, preferably a purified peptide of the invention, produced by expression of a nucleic acid of the invention, preferably a substantially pure nucleic acid of the invention, e.g.: a peptide produced by the expression of : a purified DNA encoding a peptide having pp60^PIK activity; a peptide expressed from DNA which hybridizes under high or low stringency conditions to a nucleic acid which encodes a peptide with the same, or essentially the same, amino acid sequence as the peptide of SEQ ID NO: 1 ; a peptide expressed from DNA which encodes a peptide of essentially the sequence described in SEQ ID NO: 1 ; a peptide expressed from a purified DNA which includes a sequence encoding a peptide of at least 20, preferably at least 30, more preferably at least 40, more preferably at least 50, and most preferably at least 60, amino acid residues in length; and a peptide expressed from DNA having at least 50%, more preferably 60%, yet more preferably 70%, yet more preferably 80%, and most preferably at least 90 or 99% homology with an amino acid sequence which is the same, or essentially the same, as the sequence of SEQ ID NO:l.

In preferred embodiments the encoded peptide has one or more of the following properties: it can bind to IRS-1 ; it can bind to the PI 3'-kinase 110 Kd catalytic subunit; it does not contain an SH3 domain; it can be phosphorylated by the insulin receptor or other tyrosine kinases; it does not contain a BCR-homology region (such as is found in p85s); it contains one and preferably two, SH2 domains; it contains one tyrosine phosphorylation site.

In another aspect, the invention features: a therapeutic composition which includes a peptide of the invention and a pharmaceutically acceptable carrier; and, a therapeutic composition which includes a purified DNA of the invention and a pharmaceutically acceptable carrier

In another aspect, the invention features a transgenic animal, e.g., a transgenic mammal, e.g., a mouse, having a transgene which includes a pp60^PIK encoding DNA. In preferred embodiments the pp60^PIK gene or DNA includes a mutation, e.g., a mutation that results in misexpression of pp60^PIK. In other preferred embodiments, the transgenic animal includes a second transgene, e.g., a transgene which includes the IRS-1 gene, e.g., an IRS-1 knockout.

In another aspect, the invention features a method of determining if a subject, e.g., a mammal, e.g., a human, is at risk for a disorder, e.g., an insulin-related disease, e.g., an insulin resistant insulin-related disease, e.g., Type II diabetes.

The method includes evaluating or measuring an aspect of pp60^PIK metabolism in the subject, an abnormal level of pp60^PI metabolism being predictive of the disorder. Preferred embodiments include those in which: the evaluation or measurement includes determining the level of pp60^PIK; the evaluation or measurement includes - 10 - determining the level of phosphorylation of the pp60^PIK ; the evaluation or measurement includes determining the level of kinase activity of pp60^PIK; and the evaluation or measurement includes determining the amount of pp60^PIK encoding RNA.

The method includes determining, preferably prenatally, if a subject, e.g., a mammal, e.g., a human, is at risk for a disorder, e.g., an insulin-related disease, e.g., an insulin resistant insulin-related disease, e.g., Type II diabetes, in a mammal, e.g., a human, by determining the structure of the gene which expresses pp60^PIK, an abnormal structure being predictive of risk.

The invention also provides for a system to evaluate or screen treatments of usefulness in the treatment of a disorder, e.g., an insulin-related disorder. Accordingly, in another aspect, the invention includes a method of evaluating a treatment for use in treating a disorder. The method includes administering the treatment to a cultured cell or a mammal, and measuring the effect of the treatment on an aspect of pp60^PIK metabolism, e.g., measuring the level of pp60^PIK expression, the cellular or intra-cellular distribution of pp60^PIK, or the level of the pp60^PIK phosphorylation. A change in an aspect of pp60^PIK metabolism indicates an effect of the treatment. In preferred embodiments the insulin-related disease is an insulin resistant disease and the change in an aspect of metabolism is a change in the response to blood glucose levels.

Transgenic cells and animals of the invention also provide for a system to evaluate or screen treatments of usefulness in the treatment a disorder, e.g., an insulin related disorder. Accordingly, the invention includes a method of evaluating an effect of a treatment, e.g., a therapeutic agent, on insulin metabolism in a transgenic cell or a transgenic animal having a pp60^PIK transgene. The method includes administering a treatment to a transgenic cell or animal, e.g., a transgenic mammal, e.g., a mouse, having a transgene which includes pp60^PIK, and determining the effect of the therapeutic agent on an aspect of insulin metabolism. The aspect ofinsulin metabolism followed can include, e.g., measuring responsiveness to blood glucose levels or by the phosphorylation of PI 3' kinase in response to insulin administration. In preferred embodiments, the pp60^PIK gene or DNA includes a mutation, e.g., a deletion or other mutation which results in misexpression of pp60^PIK- A change in the determined parameter for insulin metabolism being indicative of the usefulness of therapeutic value of the treatment, e.g., restoration of an aspect ofinsulin metabolism impaired by a misexpressed pp60^PIK gene is indicative of the effectiveness of a treatment. The invention also includes a method of assaying an effect of a therapeutic agent which mimics a first effect ofinsulin (the first effect mediated by pp60^PIK) without mimicking a second effect ofinsulin. The method includes: administering the agent to a cell - - grown in culture or to a test organism, e.g., a mammal; evaluating the agent's ability to mimic the first, pp60^PIK - mediated effect ofinsulin; and evaluating the agent's ability to mimic the second effect ofinsulin. In preferred embodiments evaluating the agent's ability to mimic the first, pp60^PI - mediated effect ofinsulin includes: and measuring a change in an aspect of pp60^PI metabolism, e.g., the level of pp60^PIK expression, the kinase activity of pp60^PIK, the cellular or intra-cellular distribution of pp60^PIK, or the level of the pp60^PIK phosphorylation. The invention also features a method of treating a subject, e.g., a mammal e.g., a human, suffering from a disease caused by an abnormality of pp60^PIK metabolism, e.g., a disease characterizing lower than desirable levels of pp60^PIK activity. The method includes administering to the subject, a therapeutically effective amount of an agent, e.g., pp60^PIK, which alters an aspect ofinsulin metabolism, e.g., the level of PI 3' kinase phosphorylation.

The invention also features a method of treating a subject, e.g., a mammal, e.g., a human, suffering from a disease caused by unwanted tyrosine kinase activity. The method includes administering to the subject a therapeutically effective amount of a therapeutic agent, e.g., pp60^PIK antagonist, e.g., a pp60^PIK peptide which is an antagonist of pp60^PIK mediated phosphorylation of a kinase, e.g., PI 3' kinase, a pp60^PIK antisense molecule, or an anti- pp60^PI mAb, which modifies the ability of pp60^PIK to alter the phosphorylation of the tyrosine kinase, thereby altering the tyrosine kinase activity. In preferred embodiments the tyrosine kinase activity results from a product of an oncogene. The invention also features a method of treating a mammal, e.g., a human, suffering from a disease characterized by abnormal cell proliferation. The method includes administering to said mammal a therapeutically effective amount of a therapeutic agent, e.g., a pp60^PIK antagonist, e.g., a pp60^PIK peptide which is an antagonist of pp60^PIK mediated phosphorylation of a kinase, e.g., PI 3' kinase, a pp60^PIK antisense molecule, or an anti- pp60^PIK mAb, which alters an aspect of pp60^PIK metabolism. In preferred embodiments the aspect of pp60^PIK metabolism is PI 3' kinase phosphorylation.

The invention also features a method of evaluating an effect of a therapeutic agent which alters the ability of a tyrosine kinase to phosphorylate a substrate which includes the amino acid sequence YFIN. The method includes administering the agent to a cultured cell or test organism, e.g., a mammal, and measuring the level of phosphorylation of a substrate which includes the amino acid sequence YFIN, e.g., a naturally occurring YFIN- containing substrate of a tyrosine kinase or a YFIN-containing synthetic substrate. In preferred embodiments: the substrate is a peptide which includes the sequence YFIN; the substrate is pp60^PIK or a YFIN containing any fragment thereof. In preferred embodiments: the peptide or fragment is between 4 and 30 amino acids in length; the peptide or fragment is between 4 and 15 amino acids in length; the peptide or fragment is at least 40%, preferably at least 80%, and more preferably at least 95% homologous, with a segment of a naturally occurring protein, e.g., tyrosine phosphatase substrate, e.g., pp60^PIK , which interacts with an SH2 containing protein. - -

The invention also includes a method of treating a mammal e.g., a human, suffering from a disease, disorder, or condition caused or characterized by the phosphorylation of a substrate of a tyrosine kinase, the substrate including the amino acid sequence YFIN. The tyrosine kinase may be, e.g., a receptor tyrosine kinase, e.g., insulin receptor, epidermal growth factor (EGF) receptor, platelet derived growth factor, (PDGF) receptor, or insulin-like growth factor (ILG) receptor, or an oncogene product, e.g., the src, abl, or fins gene product. The method includes administering a therapeutically effective amount of a therapeutic agent, e.g., a peptide which includes the sequence YFIN, e.g., pp60^PIK or a fragment thereof which includes the amino acid sequence YFIN, or a mimetic of a YFIN-containing peptide. In preferred embodiments the substance blocks phosphorylation of the naturally occurring substrate by competitive or non-competitive inhibition of the naturally occurring substrate. In preferred embodiments: the peptide or fragment is between 4 and 30 amino acids in length; the peptide or fragment is between 4 and 15 amino acids in length; the peptide or fragment is at least 40%, preferably at least 80%, and more preferably at least 95% homologous, with a segment of a naturally occurring protein, e.g., tyrosine phosphatase substrate, e.g., pp60^PIK , which interacts with an SH2 containing protein.

In another aspect, the invention includes peptides capable of inhibiting an interaction, preferably a site specific interaction, of an SH2-domain-containing protein, e.g., a signal transduction protein, e.g., a cytoplasmic or a transmembrane signal transduction protein, a receptor protein, e.g., the insulin receptor or the PDGF receptor, or a protein which is active in the regulation of cell proliferation, e.g., an oncogene product, with a second protein containing the sequence YFIN, e.g., a protein capable of altering the state of phosphorylation of a tyrosine residue, e.g., a tyrosine kinase, e.g., pp60^PIK. Peptides of the invention include the sequence R FIN (wherein Ri is tyrosine, phosphotyrosine, or more preferably, an analog of phosphotyrosine having a hydrolysis resistant phosphorous moiety, e.g. phosphonomethylphenylalanine (Pmp), or a hydrolysis resistant phosphorous moiety which is more electronegative than the phosphate group of phosphotyrosine, for example, mono- or difluorophosphonomethylphenlalanine (FPmp or F2Pmp, respectively). The invention also includes mimetics of these peptides. In preferred embodiments: the peptide is between 4 and 30 amino acids in length; the peptide is between 4 and 15 amino acids in length; the peptide is at least 40%, preferably at least 80%, and more preferably at least 95% homologous, with a segment of a naturally occurring protein, e.g., tyrosine phosphatase substrate, e.g., pp60^PIK , which interacts with an SH2 containing protein. In another aspect, the invention features a method of inhibiting an interaction, preferably a site specific interaction, between a first molecule which includes an SH2 domain, e.g., a signal transduction protein, e.g., a cytoplasmic or a transmembrane signal transduction protein, a receptor protein, e.g., the insulin receptor or the PDGF receptor, or a protein which is active in the regulation of cell proliferation, e.g., an oncogene product, and a second - - molecule, e.g., a protein containing the sequence YFIN, a protein capable of altering the state of phosphorylation of a tyrosine residue, e.g., a tyrosine kinase, e.g., pp60^PIK. The method includes contacting the first molecule with an inhibitor molecule which includes a peptide of the invention or which includes a mimetic of a peptide of the invention. Preferred embodiments include those in which: the first molecule is a molecule which transmits a signal, e.g., an extracellular signal, across a membrane and the second molecule is an enzyme which can alter the phosphorylation state of tyrosine, e.g., a tyrosine kinase; the first molecule is an oncogene protein and the second molecule is an enzyme which can alter the phosphorylation state of tyrosine, e.g., a tyrosine kinase, e.g., pp60^PIK; the first molecule is the insulin receptor and the second molecule is an enzyme which can alter the phosphorylation state of tyrosine, e.g., a tyrosine kinase; the inhibitor molecule inhibits the first molecule from binding to the second molecule; the inhibitor molecule inhibits the phosphorylation of the first molecule; the inhibitor inhibits the binding of the first molecule to a third molecule; the inhibitor results in an alteration of a catalytic activity of the first molecule, e.g., the inhibitor alters the ability of the first molecule to alter the phosphorylation state of itself or another molecule.

In another aspect, the invention features a method of treating a mammal, e.g., a human, having a condition characterized by unwanted cell proliferation including administering to the mammal an amount of a Y7IN-containing peptide of the invention, or a mimetic of a peptide of the invention, sufficient to prevent or inhibit the unwanted cell proliferation. In a preferred embodiment the peptide prevents the association of an SH2 domain containing oncogene with a second molecule, e.g., a protein containing the sequence YFIN, e.g., a protein capable of altering the state of phosphorylation of a tyrosine residue, e.g., a tyrosine kinase. The invention also includes methods of increasing the affinity of a YFIN- containing phosphopeptide for its substrate, e.g., a protein containing a SH2-domain. The method includes replacing the phosphotyrosine of the YFIN motif with a moiety which is more electronegative than the phosphate moiety of phosphotyrosine such as in RI-OPO3H2 where R¹ can be CHF, CF2, CHC1, CCI2, or CC1F. The invention includes peptides which have been modified to make them more resistant to proteolytic degradation and include e.g., depsipeptide derivatives of the peptides disclosed herein, e.g., peptides which have been modified by the reduction of amide bonds, the inclusion of D-amino acids, or end methylation.

An interaction between an SH2 domain containing protein and a second molecule e.g., a protein, as used herein, refers to any of: binding characterized by noncovalent or covalent interactions; an interaction which includes the alteration of the phosphorylation state of either the SH2 domain containing or another molecule, e.g., the second molecule; or to an interaction which includes an alteration of a catalytic ability of the SIC domain containing proteins, or another molecule, e.g., the second molecule. - -

Analog of phosphotyrosine having a hydrolysis resistant phosphorous moiety, as used herein, refers to an amino acid with a side chain having a moiety of the formula

wherein R is a moiety which renders the phosphate group more resistant to enzymatic

1 2 3 hydrolysis than would be the case if the R was O. R and R are preferably H. A preferred example of R is CR^R^, wherein R^ is H, or a small electronegative atom, e.g., F or Cl, and R5 is H or a small electronegative atom, e.g., F or Cl. Particularly preferred embodiments of the invention include hydrolysis resistant phosphorous moieties that are more electronegative than the phosphate moiety of phosphotyrosine, for example, where R! is -CHF, -CF2, -CC1F, -CHC1, or CC-2. Increasing the electronegativity of the phosphate moiety in an analog of phosphotyrosine increases the binding affinity of peptides containing the analog to a substrate such as protein containing an SH2 domain. In some cases, the affinity can exceed that of peptides containing phosphotyrosine.

SH2 domain containing proteins are involved in cellular signaling, e.g., in the signal transduction mediated by insulin and the insulin receptor and by several classes of oncogenes. The invention provides for inhibitors of these cellular signal transduction systems by inhibiting an interaction between the SH2 domain of the signal transduction protein and a YFIN motif present on another protein. In the case of oncogenes, the invention provides for interference with the transduction of growth signals and thereby allows for control of unwanted cellular proliferation. The invention also provides peptide inhibitors of PTPases. The peptide inhibitors, or analogs, which may or may not have homology with naturally occurring protein tyrosine phosphatase substrates, include an analog of phosphotyrosine having a hydrolysis resistant phosphorous moiety, e.g., phosphonomethylphenylalanine or a hydrolysis resistant phosphorous moiety which is more electronegative than the phosphate group of phosphotyrosine, for example, FPmp or F2Pmp. The phosphotyrosine analog includes a phenyl group substituted with an -O-PO3H2 analog, e.g., -R-PO3H2, where R can be any group which confers greater resistance to hydrolysis than does -O-, e.g, CR^RS wherein R^ can be H, F or Cl and R^can be H, F or Cl. Preferred phosphotyrosine analogs are phosphonomethylphenylalanine and mono- or difluorophosphonomethylphenylalanine. Peptide inhibitors of the invention can have homology with PTPase substrates. The sequence of these inhibitors can be based on the amino acid sequences of kinase autophosphorylation and endogenous substrate phosphorylation sites.

Phosphonomethylphenylalanyl peptides and mono- and difluorophosphonomethylphenylalanyl peptides constitute classes of compounds that potently inhibit PTPase activity. Pmp-peptides appear to act as direct substrate mimics, as binding affinity closely matches that of the corresponding phosphopeptides and inhibition is competitive. F2Pmp peptides also appear to act as direct substrate mimics. However, binding affinity of the F2Pmp-peptides can match or exceed that of the corresponding phosphopeptides. Inhibitors of the invention allow the inhibition of cellular PTPases and can be used in controlling metabolic processes, e.g., abnormal processes associated with diabetes, and as therapeutic modalities for selected malignancies. The inhibitors are also useful to study the enzymatic mechanisms of PTPase activity and to investigate the metabolic and biochemical roles of PTPases. Signal transduction protein, as used herein, refers to a protein involved in transferring a signal from the cell surface into the cell and includes, e.g., membrane bound receptors, e.g., cell surface receptors, ligands of such receptors, and intracellular proteins which interact with either with a receptor, or with another intracellular protein to transfer a signal. SH2 domain, as used herein, refers to a conserved apparently noncatalytic sequence of approximately 100 amino acids found in many signal transduction proteins including Fps, Stc, Abl, GAP, PLCλ, v-Crk, Nek, p85, and Vav. See Koch et al., 1991, Science 252:668. hereby incorporated by reference. The amino acid sequences of the SH2 domain of 27 proteins is given in Koch et al., 1991. The SH2 domain mediates protein- protein interactions between the SH2 containing protein and other proteins by recognition of a specific site on a second protein. The SH2/second protein site interaction usually results in an association of the SH2 contacting protein and the second protein. As used herein, SH2 domain refers to any sequence with at least 70%, preferably at least 80%, and more preferably at least 90% sequence homology with a naturally occurring SH2 domain, and to any analog or fragment of an SH2 domain which exhibits at least 50% of the binding activity of a naturally occurring variant of that domain, when binding is measured as the ability to bind a YFIN containing peptide.

Abnormal cell proliferation, as used herein, includes both neoplastic and non-neoplastic diseases, and thus includes diseases such as cancer and atherosclerosis. A tissue sample as used herein means any suitable sample e.g., a sample including classic insulin sensitive tissue, e.g., muscle, fat or liver tissue, or a sample including more easily accessible tissue, e.g., circulating blood cells or fibroblasts.

A mutation, as used herein, means an alteration, either gross or small, in the nucleic acid which encodes pp60^PIK. Examples of common mutations are nucleotide deletions and insertions. The mutation further can be a mutation of the DNA encoding pp60^PI which results in misexpression of pp60^PIK.

A therapeutic agent, as used herein, can be any substance or treatment. The metabolism of a substance, as used herein, means any aspect of the, expression, function, action, or regulation of the substance. The metabolism of a substance - 16 - includes modifications, e.g., covalent or noncovalent modifications of the substance. The metabolism of a substance includes modifications, e.g., covalent or noncovalent modification, the substance induces in other substances. The metabolism of a substance also includes changes in the distribution of the substance. The metabolism of a substance includes changes the substance induces in the distribution of other substances.

An insulin-related disease, as used herein, is a disease, disorder, or condition in which some aspect ofinsulin expression, metabolism, or action is disrupted or, a disease in which insulin action contributes to the disease. An insulin resistant insulin related disease, as used herein, is any disease, disorder, or condition in which a normal amount ofinsulin results in a less than normal biological response. Examples of insulin resistant diseases include Type II diabetes, obesity, aging related insulin resistance, and insulin resistance that arises secondary to infections, hormonal disorders, or other causes.

A purified preparation of pp60^PIK, as used herein, means pp60^PIK that has been separated from other proteins, lipids, and nucleic acids with which it naturally occurs. Preferably, the pp60^PIK is also separated from substances, e.g., antibodies or gel matrix, e.g, polyacrylamide, which are used to purify it. Preferably, the purified preparation of pp60^PIK constitutes at least 10% dry weight of the purified preparation. Preferably, the purified preparation contains sufficient pp60^PIK to allow protein sequencing.

A substantially pure nucleic acid, e.g., a substantially pure DNA, is a nucleic acid which is one or both of: not immediately contiguous with both of the coding sequences with which it is immediately contiguous (i.e., one at the 5' end and one at the 3' end) in the naturally-occurring genome of the organism from which the nucleic acid is derived; or which is substantially free of a nucleic acid sequence with which it occurs in the organism from which the nucleic acid is derived. The term includes, for example, a recombinant DNA which is incorporated into a vector, e.g., into an autonomously replicating plasmid or virus, or into the genomic DNA of a prokaryote or eukaryote, or which exists as a separate molecule (e.g., a cDNA or a genomic DNA fragment produced by PCR or restriction endonuclease treatment) independent of other DNA sequences. Substantially pure DNA also includes a recombinant DNA which is part of a hybrid gene encoding additional pp60^PIK sequence. Homologous refers to the sequence similarity between two pp60^PIK molecules or between two nucleic acid molecules. When a position in both of the two compared sequences is occupied by the same base or amino acid monomer subunit, e.g., if a position in each of two DNA molecules is occupied by adenine, then the molecules are homologous at that position. The percent of homology between two sequences is a function of the number of matching or homologous positions shared by the two sequences divided by the number of positions compared x 100. For example, if 6 of 10, of the positions in two sequences are matched or homologous then the two sequences are 60% homologous. By way of example, the DNA sequences ATTGCC and TATGGC share 50% homology. Generally, a comparison is made when two sequences are aligned to give maximum homology. - 17 -

The terms peptides, proteins, and polypeptides are used interchangeably herein.

A transgene is defined as a piece of DNA which is inserted by artifice into a cell and becomes a part of the genome of an animal which develops in whole or part from that cell. Such a transgene may be partly or entirely heterologous to the transgenic animal. transgene can include a deletion.

A peptide has pp60^PIK biological activity if it has one or more of the following properties: 1. The peptide is capable of binding to IRS-1 ; 2. The peptide is capable of binding the PI 3'-kinase; 3. The peptide is capable of competitively inhibiting the binding of native pp60^PIK to IRS-1; 4. The peptide is capable of inhibiting pp60^PIK binding to PI 3'-kinase.

Misexpression, as used herein, refers to a non-wild type pattern of gene expression. It includes: expression at non-wild type levels, i.e., over or under expression; a pattern of expression that differs from wild type in terms of the time or stage at which the gene is expressed, e.g., increased or decreased expression (as compared with wild type) at a predetermined developmental period or stage; a pattern of expression that differs from wild type in terms of decreased expression (as compared with wild type) in a predetermined cell type or tissue type; a pattern of expression that differs from wild type in terms of the size, amino acid sequence, post-transitional modification, or biological activity of pp60^PIK; a pattern of expression that differs from wild type in terms of the effect of an environmental stimulus or extracellular stimulus on expression of the gene, e.g., a pattern of increased or decreased expression (as compared with wild type) in the presence of an increase or decrease in the strength of the stimulus.

A transgenic animal, e.g., a transgenic mouse, is an animal having cells that contain a transgene, which transgene was introduced into the animal, or an ancestor of the animal, at a prenatal, e.g., an embryonic, stage. A transgenic cell is a cell which includes a transgene.

A pp60^PIK peptide is a peptide which is encoded by a nucleic acid of the invention, preferably it has at least 80% homology with native pp60^PIK and has pp60^PIK activity.

The phosphatidylinositol (PI) 3 '-kinase is implicated in receptor-stimulated mitogenesis and differentiation, the oxidative burst in neutrophils, membrane ruffling and insulin-stimulated glucose transport. PI 3'-kinase is ordinarily composed of a 110 kDa catalytic subunit in association with an 85 kDa regulatory protein that contains two Src homology-2 (SIC) domains (p85). During insulin stimulation, the PI 3'-kinase is activated when phosphorylated YXXM motifs in IRS-1 bind to the SH2 domains of p85. While screening an expression library for new SH2-proteins that bind to IRS-1, a new cDNA encoding a 60 kDa protein was isolated. This protein, pp60^PIK, contains two SH2 domains with similarity to p85, and forms a stable complex with the catalytic subunit of the PI 3'- - 18 - kinase (pi 10). However, pp60^PIK lacks the SH3 domain and the break chain region (BCR)- homology region of the p85s, and contains a unique and short amino terminus. During insulin stimulation, pp60^PIK is tyrosine phosphorylated and the associated PI 3 '-kinase is activated, which may provide a new pathway to regulate PI 3 '-kinase.

EXAMPLES Example 1 : Isolation of cDNA encoding pp6QEIK and Characterization of pp6QBIK pp60^PIK was identified in a mouse fat cDNA expression library by screening with recombinant [³²P]IRS-1. The cDNA was confirmed in a mouse embryo library by DNA screening. See Figure 2.

Preparation of the [22p]IRS-l probe: IRS-1 has no extrinsic enzymatic activity. IRS-1 must, therefore, be labeled by incubation with an activated insulin receptor in the presence of [γ-³²P] ATP and Mn2⁺. IRS-1 was obtained from Sf-9 cells infected with a recombinant baculovirus containing the cDNA of IRS- 1. A 100 ml culture of Sf-9 cells yields approximately 1 mg of phosphotyrosine-free IRS-1 that is purified to > 95% by gel exclusion chromatography on SK300HR (Pharmacia, Piscataway, N.J.). [32p]IRS-l is prepared by incubating IRS-1 with human insulin receptor partially purified from Chinese hamster ovary cells (CHO) expressing wild-type insulin receptor cDNA. The insulin receptor (5 mg of protein in a wheat germ agglutinin eluate) is activated by autophosphorylation during a twenty minute incubation with 100 nM insulin, 50 mM [γ-32P_ATP (67,00 cpm/pmol, NEN) and 5 mM MnC-2- IRS-1 (1 mg: 8 pmol) was added to the active kinase mixture and incubated at 4°C overnight. The [32p]lRS-l in this reaction was immunoprecipitated completely with anti-phosphotyrosine antibody indicating that each labeled molecule contains phosphotyrosine. The [³²p]iRS-l was reduced with 0.1M dithiothreitol in 50 mM Tris-HCl buffer (pH 7.4) containing 250 mM NaCl and 6M guanidinium chloride for five hours at 55°C, and then carboxymethylated with iodoacetamide (Pierce, Rockford, IL). The carboxymethylated and reduced [³²P]IRS-1 was washed several times in a Centricon-30 microconcentrator (Amicon, Inc., Beverly, MA) with 10 mM Tris- HCl (pH 7.4) containing 50 mM NaCl to remove contaminating [γ-^32P3ATP. [³²P]IRS-1 is resuspended in 10 mM Tris-HCl (pH 8.0) containing 150 mM NaCl and 0.05% Tween 20 to a concentration of 2-5 x 10^ cpm/ml for use as the probe.

Expression screening with recombinant [3-2p]IRS-l : To identify IRS-1 binding proteins, an oligo(dT) primed subtraction library enriched with cDNA clones from F442a adipocytes was prepared in Uni-Zap XR as is known in the art. Adipose tissue was selected because it is a major site of insulin action in mammals. Recombinant [32p]lRS-l was used to screen F442a λZAP expression library (500,000 plaques) prepared from mRNA enriched with transcripts expressed in F442a adipose cells and depleted for transcripts predominant in ^differentiated F442a fibroblasts. The plates were incubated for 3.5 hours at 42°C, then overlaid with nitrocellulose filters (Millipore, HATF) that were impregnated - - with 10 mM isopropyl-b-D-thiogalactopyranoside (IPTG, BRL), and incubated for 10 hours at 37°C. The filters were removed, briefly washed TNT buffer (lOmM Tris-HCl), pH 8.0, 150 mM NaCl, 0.05% Tween 20) at room temperature, and then blocked in TNT buffer containing 5% Carnation instant dry milk for six hours. The filters were incubated overnight at 4°C with [³2p]iRS-l (50 mg/ml), and then washed three times at room temperature with 10 mM Tris-HCl, pH 8.0, 150 mM NaCl, 0.01% Tween 20. The dry filters were exposed to Kodak XAR-5 film with an intensifying screen at -70°C for twenty-four hours. Thirty primary positive plaques were selected, and fifteen remained positive during subsequent hybridizations with [³²P]IRS-1. Fourteen hybridized strongly with a cDNA probe for p85α, whereas one (clone-52.1.1) was unique and did not cross-react with cDNA probes to p85α or p85β under ordinary screening conditions. See Figure 2.

A full length cDNA probe of clone 52.1.1 was used to screen the F442a λZAP library and a λExlox mouse embryo (day 13) library, which revealed two independent and strongly hybridizing clones (λZAP 2.1, and λExlox 2.2) (Figure 3). Based on the complete DNA sequence of the three clones, a contiguous cDNA containing 5737 bases was obtained (Figure 1). One of the clones (λZAP 2.1) contained an apparent deletion in the 5'- untranslated region, which is presumably derived from an alternative splicing event. The complete DNA sequence contains a 5'-untranslated region of 1366 bp, an open reading frame of 1383 bp, and a 3 '-untranslated regions of 2987 bp with six putative mRNA destabilization motifs (ATTTA), and five polyadenylation signals (AATAAA).

The primary amino acid sequence encoded by the cDNA is related to the C- terminal half of the regulatory subunits of the phosphatidylinositol (PΙ)-kinase (Figure 4). The open reading frame encodes a 461 -amino acid sequence with two SH2 domains, one at its N-terminus (residues 65-163) and one at its C-terminus (residues 358-452). A Genebank search revealed a high homology at hte protein level between pp60^PIK and the carboxyl terminal half of p85α and p85β (Figure 4). The N-terminal SH2 domain of pp60^PIK was 88.9% and 83.8% identical to the corresponding region in p85α and p85β, respectively. The carboxy-terminal SH2 domain of pp60^PIK was 81.1% and 73.7% identical to the corresponding region in p85α and p85β, respectively. Moreover, a region between the SH2 domains of p85α (residues 479-492) which is suggested to mediate the association between p85 and pi 10 is completely conserved in pp60^PIK (residues 210-224). The SH3 domain or BCR (break chain region)-homology region ordinarily found in p85α or p85β is replaced in pp60^PIK by a short unique amino terminus. Unlike, p85, pp60^PIK is tyrosine phosphorylated at insulin stimulation (Figure 4, tyrosine 341).

Example 2: Expression and distribution of pp6QP-IK in mouse tissue

Using a cDNA probe specific for pp60^PIK , northern analysis revealed a single mRNA species of 5.7 kb in most mouse tissues including liver, spleen, skeletal muscle, heart, kidney, fat, brain, and testes (Figure 5, Panel A), indicating that the full length cDNA was - 20 - isolated (Figure 1). The relative expression of pp60^PIK in these tissues was measured by competitive PCR (Figure 5, Panel B). The mRNA for pp60^PIK was isolated and translated into cDNA by reverse transcriptase and amplified by PCR in the presence of various concentrations of known quantities of pp60^PIK cDNA containing a unique restriction site as an internal standard. The results of this analysis show that pp60^PIK mRNA is most highly expressed in fat, brain, and testes, but detectable in kidney to a greater degree than in heart; and in heart to a greater degree than in skeletal muscle (Figure 5, Panel B). By this analysis, the message for pp60^PIK is expressed to the lowest degree in liver. The distribution of pp60^PIK determined by competitive PCR was qualitatively similar to the northern analysis.

Example 3: ppάQP-IK associates with the catalytic subunit of PI 3'-kinase

Previous reports have suggested that a region between the SH2 domains of p85 binds the catalytic subunit of the PI 3'-kinase, pi 10. As shown in Figure 4, this region is perfectly conserved in pp60^PIK. To investigate whether pp60^PIK associates with the pi 10 catalytic subunit, the two proteins were expressed separately or together in Sf-9 cells. See Figure 6. A cDNA (bases 1365-2656) encoding the complete N-terminal SH2 domain, the intra-SH2 domain, and a portion of the C-terminal SH2 domain of pp60^PIK was subcloned into pBluebac vector and the baculovirus was obtained by its transfection to Sf-9 insect cells. The Sf-9 cells were infected with recombinant viruses and the PI kinase activity in pp60^PIK and pi 10 immunoprecipitates was measured. The antibody against the N-terminal SH2 domain of p85α recognized pp60^PIK because of a similar amino acid sequence between p85α and pp60^PI - This antibody was used for immunoprecipitation and immunoblotting of pp60^PIK- The successful expression of pp60^PIK and pi 10 by infection of pp60^PIK virus and pi 10 virus was confirmed by Western blotting (Figure 6). In double infections of baculoviruses expressing pp60^PIK and pi 10, pi 10 was co-immunoprecipitated with pp60^PIK by the antibody against the N-terminal SH2 domain of p85α. (Figure 7) In addition, this immunoprecipitate was found to possess markedly higher PI 3'-kinase activity than other immunoprecipitates from the cells infected with either pp60^PIK or pi 10. These results suggest that pp60^PIK forms a stable complex with pi 10 catalytic subunit of PI 3'-kinase.

Example 4: Activation of PT 3'-kinase associated with ppόQEI -during insulin stimulation

FLAG-tag sequence was added by using polymerase chain reaction (PCR) to the C-terminal end of pp60^PIK to distinguish pp60^PIK from endogenous p85α. The cDNA encoding pp60^PIK with FLAG-tag was subcloned into the CAGG expression vector. Parental CHO cells and CHO cells overexpressing insulin receptors (CHO/IR) were transfected with this expression vector and hygromycin-resistant DNA, and selected in the medium containing 300 μg/ml hygromycin B. As shown in Figure 8, expressed pp60^PIK was recognized by the FLAG-tag antibody with its molecular size of 63kDa. In the CHO/IR cells overexpressing pp60^PIK , the association of pp60^PIK with IRS-1 or insulin receptor were investigated in the - - presence or absence ofinsulin. In the presence ofinsulin, phosphorylated IRS-1 and insulin receptor were co-immunoprecipitated with pp60^PIK by FLAG-tag antibody (Figure 8), while no bands were observed from the control CHO/IR cells (data not shown). In addition, the immunoprecipitated pp60^PIK was demonstrated to be phosphorylated at tyrosine residues by the addition of insulin, while no phosphorylation of endogenous p85α was detected under the same conditions (data not shown).

Example 5: Phosphorylation of pόOBI by the insulin receptor pp60^PIK was isolated from CHO cells expressing pp60^PIK by immunoprecipitation with anti-FLAG antibodies. The immuncomplex was collected on protein A-Sepharose and washed in HEPES (50 mM, pH 7.5) containing 0.1% Triton. Partially purified insulin receptor was added to the immuncomplex together with Mn ⁺ (5mM) and [γ-³²P]ATP. After incubation for thirty minutes, the phosphorylated proteins were separated by SDS-PAGE and transferred to nitrocellulose. A strong phosphoprotein was detected in a sample from the CHO cells expressing pp60^PI , whereas a weak band was obtained from the control cells. (Figure 9).

The nitrocellulose containing [³²P]labeled pp60^PIK was excised and treated with 0.5% (w/v) PVP-40 (Sigma, St. Louis, MO) in 100 ml acetic acid for one hour at 37°C. The paper was then washed extensively with water and digest with 10 μg of TPCK-trypsin (Worthington, Freehold, N. J.) in NaHCO₃ (pH 8.0) containing acetonitrile at 37°C for twenty-four hours. An additional 10 μg TPCK-trypsin was added, and the digestion was continued for an additional twenty-four hours. This technique consistently eluted 90-95% of the phosphopeptides. The trypsinization was terminated by the addition of sample buffer and boiling for three minutes. The phosphopeptides were separated by Tricine/SDS/PAGE using a 32-cm acrylamide gel consisting of a 3% stacker, 10% spacing, and 16.5% resolving gel. After electrophoresis, the gels were sealed with plastic wrap and exposed to film at -80°C. A single phosphopeptide was detected which contained exclusively phophotyrosine. This phosphopeptide was eluted from the Tricine/SDS/PAGE gel and dialyzed against water for forty-eight hours. The phosphopeptide was lyophilized and resuspended in 50% acetonitrile. A portion of the peptide sample was dissolved in water and digested with 7μg of protease V8 of Asp-N (Boehringer Mannheim, Indianapolis, IN) for eighteen hours at 22°C. Peptide fragments were covalently coupled to Sequelon™-AA discs (Millipore, Bedford, MA) with l-ethyl-3-(3-dinthylaminopropyl)carboc imide and washed extensively with water, methanol, and trifluoroacetic acid. Manual Edman degradation of the phosphopeptides was performed as follows. Briefly, immobilized peptides were reacted with 0.5 ml of coupling reagent (methanol: water triethylamine:phylisothiocyanate 7:1:1:1, v/v) at 55°C for ten minutes and washed with methanol. Phenylthiohydantoin derivatives were eluted with 0.5 ml of trifluoroacetic acid (55°C, six minutes) followed by a wash with trifluoroacetic acid and 42.5% phosphoric acid (Sigma, St. Louis, MO; 9:1, v/v). The radioactivity released and - 2 - associated with the disc was monitored by Cerenkx radiation. Edman degradation was repeated for the indicated number of times.

Example 6: Insulin stimulates tyrosine phosphorylation of pρ6θP-IK attyrosine 341 The insulin-stimulated phosphorylation site in pp60^PIK was characterized by phosphoamino acid analysis, tryptic digestion, and manual Edman degradation to isolate the major site within the amino acid sequence. An immuncomplex containing pp60^PIK was prepared by incubating extracts from quiescent CHO cells or CHO/pp60^PIK cells with an anti-FLAG antibody. The immuncomplex was collected on protein-A-Sepharose. and pp60^PIK was phosphorylated by a brief incubation with activated insulin receptors and [³²P]ATP (Figure 9, left panel); phosphoamino acid analysis revealed that this was exclusively tyrosine phosphorylation (data not shown). Tryptic digestion of phosphorylated pp60^PIK yields a single phosphorylated band following separation of the peptides by Tricine SDS-PAGE. To determine the location of the phosphorylated tyrosine in the pp60^PIK sequence, the tryptic fragment was characterized by additional digestion with V8 protease or endo-Asp-N. The original tryptic peptide and the products of these additional digests were immobilized on disks and subjected to manual Edman degradation. Radioactive phosphate was released from the tryptic peptide after cycle 8, where radioactivity was released after cycles 2 or 4 from the V8 and endo-Asp-N secondary digests, respectively. This pattern of digestion unambigously predicts the phosphorylation of Tyr-341 in the pp60^PIK molecule. See Figure 10.

Example 7: Effect ofinsulin on PI 3'-kinase activity on Chinese hamster ovary (CEO) cells overexpressing ppόOEl^

The effect ofinsulin on PI 3 '-kinase activity on Chinese hamster ovary (CHO) cells overexpressing pp60^PIK was examined. See Figure 11. The expression level of pp60^PIK in

CHO/IR/pp60^PIK was very similar to that of pp60^PI in CHO/pp60^PIK . Various concentrations ofinsulin were added and PI 3'-kinase activity in the immunoprecipitates by FLAG-tag antibody or IRS-1 antibody were measured (Figure 11). As shown in Figure 10,

FLAG-tag antibody recognized pp60^PIK , but not endogenous p85. Stimulation of

CHO/pp60^PI and CHO/IR/pp60^PIK with saturating insulin concentrations increased PI 3'- kinase activity 1.5 fold and 5 fold.

Autophosphorylation contributes to the activation of the insulin and insulin- like growth factor (IGF-1) receptors, but it does not appear to mediate SH2-protein binding.

This pathway was first illustrated for the phosphatidylinositol 3 '-kinase, which is activated during its association with phosphorylated IRS-1.

Most tyrosine kinase receptors mediate biological responses by using their tyrosine autophosphorylation sites to engage downstream signaling molecules with Src- - - homology-2 domains (SH2-proteins). EGF and PDGF receptors undergo a ligand-induced autophosphorylation at multiple tyrosine residues which associate directly with various SH2 proteins, including phosphatidylinositol 3'-kinase, p 21^rasGAP, phospholipase Cγ, GRB-2, c- fyn, c-src, and probably other SH2-proteins. In contrast, these receptors phosphorylate an intermediate adapter molecule, IRS-1, which directly associates with multiple SH2-proteins. Instead, these receptors phosphorylate intermediate "docking proteins" such as IRS-1 or 4PS, which function as tyrosine phosphorylated docking protein to recruit the SH2-proteins into a signaling complex. The interleukin-4 receptor (IL-4r) illustrates an additional complexity since it phosphorylates IRS-1 even though it does not contain an intrinsic tyrosine kinase activity. The IL-4r, like other receptors in the hematopoietic family such as those for erythropoeitin, growth hormone and interferon, presumably recruit cytoplasmic tyrosine kinases, possibly similar to JAK-1, tyk-2, fyn, into a multimeric signaling complex to phosphorylate IRS-1 or related docking elements.

In addition to IRS-1 and other 180 kDa substrates described above, a number of other lower molecular weight proteins become tyrosine-phosphorylated in insulin-treated cells. A 60 kDa tyrosine-phosphorylated protein has been observed in several laboratories after insulin treatment of primary rat adipocytes and Chinese hamster ovary cells expressing human insulin receptors. More recently, a 60 kDa tyrosine-phosphorylated protein has been observed in p 21^rasGAP or PI 3'-kinase immunoprecipitates. During insulin stimulation of rat adipocytes, pp60^PIK associates with the PI 3'- kinase in a complex that appears to be distinct from IRS-1. The pp60^PIK:PI 3'-kinase complex was located in both the soluble and membrane fractions, whereas IRS-1 was entirely cytosolic. Since recombinant SH2 domains of p85 precipitate pp60^PIK from insulin- stimulated cells, Levan and Lienhard concluded that the most likely mode of association of pp60^PIK with PI 3'-kinase is through the binding of its tyrosine phosphorylation site to p85. By affinity chromatography using immobilized phosphotyrosine antibody, pp60^PIK was obtained in high percentage yield from insulin-stimulated rat adipocytes, but the low amount of the protein obtained (about 3 ng form the adipocytes of one rat) precluded sequence analysis. An additional 60 kDa substrate exists for the insulin receptor. This protein associates with p21^rasGAP and appears to be distinct from the better known GAP-associated protein, pp62. This protein is particularly interesting because it is a potential link between the insulin receptor and the ras signaling system. Ras, a monomeric membrane-bound GTP- binding protein, may be a downstream element in the insulin receptor signaling pathway which mediates certain biological functions. Insulin stimulates the accumulation of activated rasGTP in cells, and appears to play a role in insulin-stimulated Glut-4 translocation. Moreover, microinjection of anti-ras antibodies inhibits insulin-induced maturation of Xenopus oocytes and overexpression of a dominant inhibitory ras mutant blocks insulin action on both gene expression and differentiation of 3T3-L1 to adipocytes. Thus, 60 kDa - 24 - substrates of the insulin receptor are implicated in two important signaling pathways, the PI 3'-kinase and the p21^ras signaling pathways. The molecular structure of a 60 kDa insulin receptor substrate, pp60^PIK, which partially resembles the better known p85 is described herein. Use

The peptides or nucleic acids of the invention may be administered to a mammal, particularly a human, in one of the traditional modes (e.g., orally, paternally, transdermally, or transmucosally), in a sustained release formulation using a biodegradable biocompatible polymer, or by on-site delivery using micelles, pumps, e.g., osmotic drug delivery pumps, gels and liposomes or by transgenic modes. Other Embodiments

Included in the invention are: allelic variations; natural mutants; induced mutants; proteins encoded by DNA that hybridizes under high or low stringency conditions to a nucleic acid which encodes the peptide of SEQ ID NO:l (for definitions of high and low stringency see Current Protocols in Molecular Biology, John Wiley & Sons, New York, 1989, 6.3.1 - 6.3.6, hereby incorporated by reference); and, peptides or proteins specifically bound by antisera to pp60^PIK, especially by antisera to an active site or binding domain of pp60^PIK-. Also included are chimeric pp60^PIKs that include a pp60^PIK peptide or protein and a second peptide, e.g., a toxin, e.g., a chimeric molecule. The invention also includes biologically active fragments or analogs of pp60^PIK. A biologically active fragment or analog is one having any in vivo or in vitro activity which is characteristic of the pp60^PIK shown in SEQ ID NO:l, e.g., one or more of the biological activities described above. Because peptides such as pp60^PIK often exhibit a range of physiological properties and because such properties may be attributable to different portions of the molecule, a useful pp60^PIKfragment or pp60^PIK analog is one which exhibits a biological activity in any biological assay for pp60^PIK activity. Most preferably the fragment or analog possesses 10%, preferably 40%, or at least 90% of the activity of pp60^PIK (SEQ ID NO: 1), in any in vivo or in vitro pp60^PIK assay.

Analogs can differ from naturally occurring pp60^PIK in amino acid sequence or in ways that do not involve sequence, or both. Analogs of the invention will generally exhibit at least 90%, preferably 95% or even 99%, homology with a segment of 20 amino acid residues, preferably more than 40 amino acid residues, or more preferably the entire sequence of a naturally occurring pp60^PIK sequence. Non-sequence modifications include in vivo or in vitro chemical derivatization of pp60^PIKs. Non-sequence modifications include changes in acetylation, methylation, phosphorylation, carboxylation, or glycosylation.

Glycosylation can be modified, e.g., by modifying the glycosylation patterns of a pp60^PIK during its synthesis and processing or in further processing steps, e.g., by exposing the pp60^PIK to glycosylation affecting enzymes derived from cells that normally provide such - -

processing, e.g., mammalian glycosylation enzymes; phosphorylation can be modified by exposing the pp60^PIK to phosphorylation-altering enzymes, e.g., kinases or phosphatases.

Preferred analogs include pp60^PIK (or biologically active fragments thereof) whose sequences differ from the wild-type sequence by one or more conservative amino acid substitutions or by one or more non-conservative amino acid substitutions, deletions, or insertions which do not abolish the pp60^PIK's biological activity. Conservative substitutions typically include the substitution of one amino acid for another with similar characteristics, e.g., substitutions within the following groups: valine, glycine; glycine, alanine; valine, isoleucine, leucine; aspartic acid, glutamic acid; asparagine, glutamine; serine, threonine; lysine, arginine; and phenylalanine, tyrosine. Other conservative substitutions can be taken from the table below.

TABLE 1 CONSERVATIVE AMINO ACID REPLACEMENTS

For Amino Acid Code Replace with any of

Alanine A D-Ala, Gly, beta-Ala, L-Cys, D-Cys

Arginine R D-Arg, Lys, D-Lys, homo-Arg, D-homo-Arg, Met, lie, D-Met, D-Ile,Orn, D-Orn

Asparagine N D-Asn, Asp, D-Asp, Glu, D-GIu, GIn,D-GIn

Aspartic Acid D D-Asp, D-Asn, Asn, Glu, D-GIu, GIn,D-GIn

Cysteine C D-Cys, S-Me-Cys, Met, D-Met, Thr,D-Thr

Glutamine Q D-GIn, Asn, D-Asn, Glu, D-Glu, Asp,D-Asp

Glutamic Acid E D-Glu, D-Asp, Asp, Asn, D-Asn, Gln,D-Gln

Glycine G Ala, D-AIa, Pro, D-Pro, β-AlaAcp

Isoleucine I D-Ile, Val, D-Val, Leu, D-Leu, Met ,D-Met

Leucine L D-Leu, Val, D-Val, Leu, D-Leu, Met, D-Met

Lysine K D-Lys, Arg, D-Arg, homo-Arg, D-homo-Arg, Met, D- Met, He, D-He,Orn, D-Orn

Methionine M D-Met, S-Me-Cys, He, D-IIe, Leu, D-Leu, Val, D-Val

Phenylalanine F D-Phe, Tyr, D-Thr, L-Dopa, His, D-His, Trp, D-Trp, Trans-3,4, or 5-phenylproline, cis-3,4, or 5- phenylproline

Proline P D-Pro, L-I-thioazoIidine-4-carboxylic acid, D-or L-l- oxazoIidine-4-carboxyIic acid

Serine S D-Ser, Thr, D-Thr, allo-Thr, Met,D-Met, Met(O), D- Met(O), L-Cys, D-Cys

Threonine T D-Thr, Ser, D-Ser, allo-Thr, Met,D-Met, Met(O), D- Met(O), Val, D-Val

Tyrosine Y D-Tyr, Phe, D-Phe, L-Dopa, His, D-His

Valine V D-Val, Leu, D-I,eu, lie, D-Ile, Met, D-Met - 26 -

Other analogs within the invention are those with modifications which increase peptide stability; such analogs may contain, for example, one or more non-peptide bonds (which replace the peptide bonds) in the peptide sequence. Also included are: analogs that include residues other than naturally occurring L-amino acids, e.g., D-amino acids or non-naturally occurring or synthetic amino acids, e.g., β or γ amino acids; and cyclic analogs. As used herein, the term "fragment", as applied to a pp60^PIK, will ordinarily be at least about 20 residues, more typically at least about 40 residues, preferably at least about 60 residues in length. Fragments of pp60^PIK can be generated by methods known to those skilled in the art. The ability of a candidate fragment to exhibit a biological activity of pp60^PIK can be assessed by methods known to those skilled in the art as described herein. Also included are pp60^PIK's containing residues that are not required for biological activity of the peptide or that result from alternative mRNA splicing or alternative protein processing events.

Also within the invention are: a purified antibody preparation, preferably a monoclonal antibody preparation, directed against a protein or peptide of the invention.

Nucleic acid encoding all or part of the pp60^PIK gene can be used to transform cells. For example, the pp60^PIK gene, e.g., a misexpressing or mutant form of it e.g., a deletion, or other DNA encoding an pp60^PIK protein or peptide can be used to transform a cell and to produce a cell in which the cell's genomic pp60^PIK gene has been replaced by the transformed gene, producing, e.g., a cell deleted for the pp60^PIK gene. This approach can be used with cells capable of being grown in culture, e.g., cultured stem cells, to investigate the function of the gene.

Analogously, nucleic acid encoding all or part of the pp60^PIK gene, e.g., a misexpressing or mutant form of the gene, e.g., a deletion, can be used to transform a cell which subsequently gives rise to a transgenic animal, e.g. a transgenic mouse. This approach can be used to create, e.g., a transgenic animal in which the pp60^PIK gene is, e.g., inactivated, e.g., by a deletion. Homozygous transgenic animals can be made by crosses between the offspring of a founder transgenic animal. Cell or tissue cultures can be derived from a transgenic animal. In order to obtain a pp60^PIK peptide, pp60^PIK-encoding DNA is introduced into an expression vector, the vector introduced into a cell suitable for expression of the desired protein, and the peptide recovered and purified, by prior art methods. Antibodies to the peptides an proteins can be made by immunizing an animal, e.g., a rabbit or mouse, and recovering anti-pp60^PIK antibodies by prior art methods. Fragments of pp60^PIK can be made by expressing pp60^PIK DNA which has been manipulated in vitro to encode the desired fragment; e.g., by restriction digestion of the DNA sequence of SEQ ID NO:l. Analogs can be made, e.g., by in vitro DNA sequence modifications of the sequence of SEQ ID NO: 1. For example, in vitro mutagenesis can be used to convert the DNA sequence of SEQ ID NO:l into a sequence which encodes an analog - - in which one or more amino acid residues has undergone a replacement, e.g., a conservative replacement as described in Table 1. Fragments or analogs can be tested by methods known to those skilled in the art for the presence of pp60^PIK activity.

The invention also provides for the generation of ppόO^K. mimetics, e.g. peptides or non-peptide agents, which are able to modulate, e.g., inhibit, binding of a p όO^IK to another protein. Various forms of mutagenesis are generally applicable for mapping the determinants of the pp6θPIK which participate in protein-protein interactions involved in binding to a second protein. For example, homologs of pp60^K (b_om agonist and antagonist forms) can be generated and screened using, for example, alanine scanning mutagenesis and the like (Ruf et al. (1994) Biochemistry 33:1565-1572; Wang et al. (1994) J Biol Chem 269:3095-3099; Balint et al. (1993) Gene 137:109-118; Grodberg et al. (1993) EurJ Biochem 218:597-601; Nagashima et al. (1993) JBiol Chem 268:2888-2892; Lowman et al. (1991) Biochemistry 30:10832-10838; and Cunningham etal. (1989) Science 244:1081- 1085), by linker scanning mutagenesis (Gustin et al. (1993) Virology 193:653-660; Brown et al. (1992) Mol Cell Biol 12:2644-2652; McKnight et α/. (1982) Science 232:316); or by saturation mutagenesis (Meyers et al. (1986) Science 232:613).

The critical residues of peptides of the invention which are involved in molecular recognition of e.g., an SH2 domain, can be determined and used to generate peptidomimetics which competitively inhibit binding of pp60^p^ yήfa other proteins (see, for example, "Peptide inhibitors of human papillomavirus protein binding to retinoblastoma gene protein" European patent applications EP-412,7624 and EP-531,080A). By employing, for example, scanning mutagenesis to map the residues of pp60^p^ involved in its binding to the another protein, peptidomimetic compounds can be generated which mimic those residues of ppόO^IK ascertained to be involved in binding to the other protein, and which therefore can be used to inhibit binding of the authentic ppόO^K protein to the protein. For instance, non-hydrolyzable peptide analogs of such residues can be generated using benzodiazepine (e.g., see Freidinger et al. in Peptides: Chemistry and Biology, G.R. Marshall ed., ESCOM Publisher: Leiden, Netherlands, 1988), azepine (e.g., see Huffman et al. in Peptides: Chemistry and Biology, G.R. Marshall ed., ESCOM Publisher: Leiden, Netherlands, 1988), substituted gama lactam rings (Garvey et al. in Peptides: Chemistry and Biology, G.R.

Marshall ed., ESCOM Publisher: Leiden, Netherlands, 1988), keto-methylene pseudopeptides (Ewenson et al. (1986) JMed Chem 29:295; and Ewenson et al. in in Peptides: Structure and Function (Proceedings of the 9th American Peptide Symposium) Pierce Chemical Co. Rockland, IL, 1985), β-turn dipeptide cores (Nagai et al. (1985) Tetrahedron Lett 26:647; and Sato et al. (1986) JC zem SocPerkin Trans 1:1231), and β-aminoalcohols (Gordon et al.

(1985) Biochem Biophys Res Communl26:4l9; and Dann et al. (1986) Biochem Biophys Res

Commun 134:71).

Other embodiments are within the following claims. What is claimed is: - 28 -

SEQUENCE LISTING

(1) GENERAL INFORMATION:

(i) APPLICANT: White, Morris F.

(ii) TITLE OF INVENTION:pp60^PIK: A DOWNSTREAM ELEMENT IN INSULIN SIGNALING

(iii) NUMBER OF SEQUENCES: 2

(iv) CORRESPONDENCE ADDRESS:

(A) ADDRESSEE: LAHIVE & COCKFIELD (B) STREET: 60 STATE STREET, SUITE 510

(C) CITY: BOSTON

(D) STATE: MASSACHUSETTS

(E) COUNTRY: USA

(F) ZIP: 02109

(v) COMPUTER READABLE FORM:

(A) MEDIUM TYPE: Floppy disk

(B) COMPUTER: IBM PC compatible

(C) OPERATING SYSTEM: PC-DOS/MS-DOS (D) SOFTWARE: ASCII text

(vi) CURRENT APPLICATION DATA:

(A) APPLICATION NUMBER: US

(B) FILING DATE: (C) CLASSIFICATION:

(viii) ATTORNEY/AGENT INFORMATION:

(A) NAME: Myers, Louis

(B) REGISTRATION NUMBER: 35,965 (C) REFERENCE/DOCKET NUMBER: JDP-021

(ix) TELECOMMUNICATION INFORMATION:

(A) TELEPHONE: (617) 227-7400

(B) TELEFAX: (617) 227-5941

(2) INFORMATION FOR SEQ ID NO:l:

(i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 5737 base pairs

(B) TYPE: nucleic acid

(C) STRANDEDNESS: single

(D) TOPOLOGY: linear (ii) MOLECULE TYPE: cDNA

(ix) FEATURE:

(A) NAME/KEY: CDS (B) LOCATION: 1388..2749

(xi) SEQUENCE DESCRIPTION: SEQ ID NO:l: - 29 -

GGCACGAGCC AACCCCAAGC ACACTTCTGC CTGCTACTGT CTCTGAGCCC AGCACTACCT 60

CAGTGCCTGT AGAATCATCA CTGTTGTCTG GAGTTGTCAG GTCTACGAGG CCGCCTCCTA 120

CCCAGCCTGT GGTCCCCAGG CCCCACTTGG ACCCAAACTG GAACTCACAC AACAGTCCTG 180

TTCCCAGAGG ATGAGGACGA TGTATTGTTA TTGCCACTGG CTGAGCCAGA AGTCCTGGGT 240

TGGTGGAGGC AGAGGATGAA CCATTGCTTG CCTGAGGGAC TCTAGGCACA ATGGTATGAT 300

CCTTGGAAGT GGTTCAGCTT CCCCACTGAT CTATGTAGCA CAGAAAGTTA GTGTCTCTCC 360

AGCAGGGAGA GCATTCACTG TACACACCTT CTGGTATGAC AAGAGACTTC ACCACCACCC 420 TCTGCCCAGC CTGCTATCCA GGTGGCTGTG TTACAAAAGG TCCCACAAGG GTCACAGGCT 480

TGGACACTCC GTTCTTTCCA GCTCCCCACC CAAAAGTGGC CTTAACTACT AGACTGGTTG 540

GCTGGAGACC TAGCCACCAA GGGGAGGATT TGGCCAGGGT GATGGTTTTG CCAGCCTCCA 600

TCCCTGTGGT GCCTGGCCAC TTAGAGGACA CAAGTGCTTT TGCCCTGTAG CTGCATCATT 660

GTCCAGGAAA TCAAGATGAC AAAAATAAAG GAATCATAAA CTTCAGCCCT TGGTAAAAAA 720 AAACGGCACG AGGTTACCTT TACTACTCGG GCACAGTCGA GCTGACTGGA CTCTCCAAGG 780

GGTCGCCATC CCGAAGCTGC GGAAGCTTGG GTTCCCAGCC TGACGCGAAT AGAGCCCGAG 840

TCCCAATCCC AGAGGGAATC GCTCTCCGCA GACCAGTGGG ACCCCGAAAC TTGAACGCAA 900

ACCCCCTTTT CAAGCCTTTG TCACTTCCCC AGCTTTCTCC CAACGCGTTC TTTTTTCCCC 960

CTTCCTCTCC ATTCTCTCTT CTCCGAAGGA CACAAAAGTG GCTTCCGCTG AAAGATTAGG 1020 AGGCGGTGGG AGCTTTTCCC TTTGGAGAGC GATTGTGTAG GAAGGATTTT CGGGAAGCTG 1080

CTTTTTAACA CCACTGCTCT TTGCTTTCCG AGCTTCCCTG TAACCCTCTG AGGTAAAAAC 1140

CCCGTAGCTT GAAAGTTCGG GGTATTTTGT TGGGTGCTTT AGGAGGAGAG AAGAGGAGGA 1200

CCTTGTCCTC ATCCTAGTAG TTTGGCTGGA CTTGTACTGG CCGTTGGAAA CCCCCAAGTA 1260

CATTTCCGTG TGGAACTTTT GCAAATATAT ATTTAGATTT TAAATATCAG ATAAAAGATA 1320 TATATGCTTT TTATATATTT CCCGACGACC TGCCCCTGAC AGCGCGATGT ACAATACGGT 1380

GTGGAGT ATG GAC CGC GAT GAC GCA GAC TGG AGG GAG GTG ATG ATG CCC 1429 Met Asp Arg Asp Asp Ala Asp Trp Arg Glu Val Met Met Pro 1 5 10

TAT TCG ACA GAA CTG ATA TTT TAT ATT GAA ATG GAT CCT CCA GCT CTT 1477 Tyr Ser Thr Glu Leu lie Phe Tyr lie Glu Met Asp Pro Pro Ala Leu 15 20 25 30 CCA CCA AAG CCA CCT AAG CCA ATG ACT CCA GCA GTC ACA AAT GGA ATG 1525 Pro Pro Lys Pro Pro Lys Pro Met Thr Pro Ala Val Thr Asn Gly Met 35 40 45

AAG GAC AGT TTC ATT TCT CTT CAA GAT GCA GAG TGG TAC TGG GGA GAT 1573 - 30 -

Lys Asp Ser Phe lie Ser Leu Gin Asp Ala Glu Trp Tyr Trp Gly Asp 50 55 60

ATT TCC AGG GAA GAG GTA AAT GAC AAA TTG CGG GAC ATG CCA GAT GGT 1621 lie Ser Arg Glu Glu Val Asn Asp Lys Leu Arg Asp Met Pro Asp Gly 65 70 75

ACC TTC TTA GTT CGT GAT GCC TCA ACG AAA ATG CAG GGG GAT TAT ACA 1669 Thr Phe Leu Val Arg Asp Ala Ser Thr Lys Met Gin Gly Asp Tyr Thr 80 85 90

TTG ACT TTG AGG AAG GGA GGA AAT AAT AAA TTA ATA AAG ATC TAT CAT 1717

Leu Thr Leu Arg Lys Gly Gly Asn Asn Lys Leu lie Lys lie Tyr His

95 100 105 110

CGG GAT GGT AAA TAT GGC TTC TCT GAG CCC CTG ACG TTT ACT TCT GTG 1765

Arg Asp Gly Lys Tyr Gly Phe Ser Glu Pro Leu Thr Phe Thr Ser Val 115 120 125 GTG GAG CTT ATT AAC CAC TAC CAC CAC GAG TCT CTC GCT CAG TAC AAT 1813 Val Glu Leu lie Asn His Tyr His His Glu Ser Leu Ala Gin Tyr Asn 130 135 140

CCC AAA CTC GAC GTG AAG CTG ACG TAC CCA GTA TCC AGA TTC CAA CAG 1861 Pro Lys Leu Asp Val Lys Leu Thr Tyr Pro Val Ser Arg Phe Gin Gin 145 150 155

GAT CAG TTG GTA AAA GAA GAT AAC ATT GAT GCA GTA GGT AAA AAT CTG 1909 Asp Gin Leu Val Lys Glu Asp Asn lie Asp Ala Val Gly Lys Asn Leu 160 165 170

CAG GAG TTC CAC TCT CAG TAT CAG GAG AAG AGC AAA GAG TAT GAC AGG 1957 Gin Glu Phe His Ser Gin Tyr Gin Glu Lys Ser Lys Glu Tyr Asp Arg 175 180 185 190

CTG TAT GAA GAG TAC ACA AGG ACA TCA CAG GAA ATA CAA ATG AAG AGG 2005 Leu Tyr Glu Glu Tyr Thr Arg Thr Ser Gin Glu lie Gin Met Lys Arg 195 200 205 ACT GCC ATT GAA GCC TTT AAT GAA ACA ATT AAA ATA TTT GAG GAG CAG 2053 Thr Ala lie Glu Ala Phe Asn Glu Thr lie Lys lie Phe Glu Glu Gin 210 215 220

TGT CAT ACC CAA GAA CAA CAC AGT AAA GAC TAT ATC GAG CGC TTT CGC 2101 Cys His Thr Gin Glu Gin His Ser Lys Asp Tyr lie Glu Arg Phe Arg 225 230 235

AGA GAG GGG AAT GAG AAG GAG ATC GAG CGA ATT ATG ATG AAT TAT GAT 2149 Arg Glu Gly Asn Glu Lys Glu lie Glu Arg lie Met Met Asn Tyr Asp 240 245 250

AAA TTG AAA TCA CGT CTT GGT GAG ATT CAT GAT AGC AAA CTG CGT CTT 2197 Lys Leu Lys Ser Arg Leu Gly Glu lie His Asp Ser Lys Leu Arg Leu 255 260 265 270

GAG CAG GAC TTG AAG AAA CAA GCT TTG GAC AAC CGG GAA ATA GAT AAA 2245 Glu Gin Asp Leu Lys Lys Gin Ala Leu Asp Asn Arg Glu lie Asp Lys 275 280 285 - -

AAA ATG AAT AGC ATC AAA CCC GAC TTG ATC CAG CTG CGT AAG ATC CGG 2293 Lys Met Asn Ser lie Lys Pro Asp Leu lie Gin Leu Arg Lys lie Arg 290 295 300 GAT CAG CAC CTT GTA TGG CTC AAT CAC AGA GGA GTG AGG CAG AGG CGC 2341 Asp Gin His Leu Val Trp Leu Asn His Arg Gly Val Arg Gin Arg Arg 305 310 315

CTG AAT GCC TGG CTG GGG ATC AAG AAT GAG GAC TCA GAT GAA AGC TAT 2389 Leu Asn Ala Trp Leu Gly lie Lys Asn Glu Asp Ser Asp Glu Ser Tyr 320 325 330

TTT ATC AAT GAG GAA GAT GAG AAC CTG CCG CAT TAT GAT GAG AAA ACC 2437 Phe lie Asn Glu Glu Asp Glu Asn Leu Pro His Tyr Asp Glu Lys Thr 335 340 345 350

TGG TTT GTG GAG GAT ATC AAC CGA GTA CAA GCA GAG GAC TTG CTT TAT 2485 Trp Phe Val Glu Asp lie Asn Arg Val Gin Ala Glu Asp Leu Leu Tyr 355 360 365

GGG AAA CCA GAT GGT GCA TTC TTA ATT CGT GAG AGT AGC AAG AAA GGA 2533 Gly Lys Pro Asp Gly Ala Phe Leu lie Arg Glu Ser Ser Lys Lys Gly 370 375 380 TGT TAC GCT TGT TCT GTG GTT GCA GAC GGG GAA GTG AAG CAC TGT GTC 2581 Cys Tyr Ala Cys Ser Val Val Ala Asp Gly Glu Val Lys His Cys Val 385 390 395

ATC TAC AGC ACG GCT CGA GGA TAT GGC TTT GCA GAA CCC TAC AAC CTG 2629 lie Tyr Ser Thr Ala Arg Gly Tyr Gly Phe Ala Glu Pro Tyr Asn Leu 400 405 410

TAC AGC TCA CTG AAG GAG CTG GTG CTC CAT TAC CAG CAG ACA TCC CTG 2677 Tyr Ser Ser Leu Lys Glu Leu Val Leu His Tyr Gin Gin Thr Ser Leu 415 420 425 430

GTT CAG CAC AAC GAC TCC CTC AAC GTC AGG CTC GCC TAC CCT GTC CAT 2725 Val Gin His Asn Asp Ser Leu Asn Val Arg Leu Ala Tyr Pro Val His 435 440 445

GCA CAG ATG CCT ACG CTC TGC AGA TAAGCAGAGT GGAAGAGACA CACTCTCTAG 2779 Ala Gin Met Pro Thr Leu Cys Arg 450 CCGTTTTTTT CCTATGGTTT TTATTAGACT ACGATGAGGG CATTCTTTCA ACGTAGACTG 2839

CTTGTTTGCA CAAGTGATTC TGTGAATGTG AAATGGAGAG GCCAAGCAGT AGCTTGGATT 2899

TAGAAATGAG GGGCCCAGGG TCTCTGGCCT CGGCTGTGCT GCTGCACTGA TGGACTAAGC 2959

TGGAAGCAGA TATTGGTTTC ATGGGGTTTG GGTTTGTTGT CAGGCACCTT TAAAAGAACA 3019

GCTAAGGCTT GTTGTGGGTT GGGGTGGGGG TTTTATTTGG AAGTTTCTGA AGAGTCCACA 3079 TCCCTTTGTC CTCAACCCTA AGAATGCAGC AGGTCACAGT TCTGCTGGGA GTTGTTTTGA 3139

TTTGATAGTC TCTTCCCCTT TCCCCCAAAT AAAGAGCCGA TTTTGGCTCT GTGGTAAAGT 3199

GGGATTTGGT TTGGAGGGAA AAACAACCAA AGGAAAATAG GGAGGTATGG GATTACATTT 3259 - -

TCAGAATCTA AACCAAGGAG GCAAAAGACC CCTTCAGTTG ATGTTACTTC AATTTTATCA 3319

ACATAATCTA GGCTTCAGCA TCTTCACCAA CTCCTCCCTC TAAAGCACTG TGTTCAAAAA 3379

CCAACAAAGC AGCATCGCCN AGACCAAGGT CTAAGGGGAG GACAGTAGTA GCTGAATGTA 3439

CACTTCTGTA CCAAAACTTG AAAGACTAGA AATGTGAGTT TCAACAAACA CTAAAATTGG 3499 TCAGTGTATT TCCTTTTGCC CTGGCCTTGT TTCTCAGATG AGGAATAGAA TTATTTTGTG 3559

GAAATAGTAA GCTTTGAGTC ATAATGAAGT TGGTGCTTGT GTGGTGTTTC TTTAAAGAAA 3619

TGTTTGAAAC CCTTGTAAGT TGTTTTATGA GTAAAGAAAC AGTGCAATCC AGTGCTTTTA 3679

GATGGCTTGA TATACCAAAT AATGATAGAG AACAACATTG TTGTGTGCTT CCTCAAGTTT 3739

AAAAGCCTTG CCAAAACTAT ACAAGGATTA ATTTGCCTTC ATCTCCCCTT CCTTTTTTGG 3799 ATAGGGTTTA GGGAGCCATA GGTAGCTAAA GGAGGACTCG AGTTTGTGGT CAGAGACCTC 3859

AGTAAATCAC AGGCACATGA GGCCTGGTAT CCATGGTGAA GGGTCCATCA CATGACATGT 3919

TATTCAATAC TGTGGTTGAA GCGTTTGCCA GAAGAGGGGA TGACGTGGAG TTCAGACTAT 3979

CTGGGGAAAT AATCCACAGG CTTTCCTGCT TGCCCTTTTT GTGAGCCTGC TGTTAAGGCA 4039

GTGCACACAG CCTGCTCTCA TGCTTCCGTG GCTGTGGTTT AAGCCTTCAG CTAAGTGAAG 4099 TTAGATAGAG GAGAGGGCAG CCATCTATTT ATGGATTCAC ACTCATTTAA GAGTTCAGCT 4159

GCTTCAGAGT CAGTTCTGGA GCCATAACAG GCTCAGTATG ACTCAGCTGC TTGAGCCCAG 4219

TAATGTGCAG TCAGGCAGTT TAGACAAGCA GCCTGTGCCT GGGTCATCAG GCTTACAATC 4279

AGGGAAGATG AAGTTTGGGG GCCAAAATAA AGATGAATAT GACTTTCCCT GAGCACTTCC 4339

TTTGGTGACA GTGTCTAGAA GAAACCACAG TATAGAGATA GGTCAAAAGT TTTGAATAAT 4399 TGTCACAGTT GATAGGGCAT GCCATTGATG GCTTTTTCTT GTTCATGCTC CAGTGTGAAA 4459

GAGAGGAGAT TGACCACCCT CAGCCACTCT GTAAGGCCTT TTTCAAAATT GCCAGCTTAA 4519

AATCTTGCTC AGTTTACCAA GTAATGCCAG GCTATTTGTT GATTGGAATA CCTGTGACTT 4579

TGTACTGATG TTGAACTTGC TGAAGCAGTT ATATGCTCAA GATTAGGTGT GAGGAATCCC 4639

TCTGATCCAG CACTAAAATT TTAGTATGTC CTGAACGCCT TTTTAAAGAA ATCTCTTCCA 4699 AGTAAGTCAA AATGATAAAA TATACAGCTT TAGTGTTGAA TAATGTCTTT ACCTTGTAGG 4759

CAGACATGGA AGATATGCAG GAGAAAGCAG CATCTACACC TGGGCTGGAC AATGGAGAAA 4819

GACAGGTTTT CAGTCCTATA TTCTTTCCCT TTGAGTAACC ACTTTGTGGG AGCTGAGACC 4879

AGGGATCATT TAATAAATCG GAAGCTATCT TTTTATTTTT CTGCCAAGTT ACTACATGAT 4939

TTATCTGATC CTGAGCTGTG GAAATGGCAT GAGGAGCAGT CTCCTAAGAG TGGCCCTGCT 4999 - -

GTCTGAGGGA GTCTGGAAGC AGGTGTTGGT CTTCTTCTCA AGGCTAGCTC AAAGTTCTGT 5059

CTCATGATCT AGGCCCTGGG ACTATCTCTT TTGGCATCTT AACTGTAGAC TCATTGACTA 5119

AAGCAGAGGC TAGAGACAGA TTAGGACCAT AGGGGCAGGC AGATCAGCCA GTCCCCAGAT 5179

CAGCCAGTCC CCAACAGGAA AGCAGCTTTG GGTTGGCTAG ATACAGTTTT TAAAATAAAA 5239

ACAAAACAAA ACAAAGCTGT TTCCACCTGG CATAGTTCAG CTTAGGTAGG TTGTTTATGT 5299

TCTTGTCACT GCTCCAGCAA TAGATGAAGA CATCCTACAG CTCCACACTA CTAAGACACA 5359

AGCTCTCTAC ATTTACTTCA GACTCAAGCC CGAGTGGCAT CTTCCTTGTG TCCCTTCTCT 5419 GCAAGGTACC AGCTTCACCC ATTCTCCAGA ACTTTAAAGA AAAAATGTAC TTGAACAATT 5479

TCTGATTTCT AGGATGATCT CTACTGCCAG TTAGATCTTC TTGAGGTTTC CATGACATCA 5539

TACACCAGAG GTCCATTCTT GGTCCTTTGC TGCCAACTGC TCATTCTTGA CTTAGCTCTA 5599

GCCATTTGTG ACAACCACCC TTGTTTCCTT ACAAATCCTC GCATGTAACT TTGGTACTTT 5659

GTTGTTTCTT GTGAAGAATC TATTCTGTTG TCTTTGATGT AATAAAAAAA TTTCATGTAA 5719 AAAAAAAAAC TCGTGCCG 5737

(2) INFORMATION FOR SEQ ID NO:2: (i) SEQUENCE CHARACTERISTICS:

(A) LENGTH: 454 amino acids

(B) TYPE: amino acid (D) TOPOLOGY: linear (ii) MOLECULE TYPE: protein

(xi) SEQUENCE DESCRIPTION: SEQ ID NO:2:

Met Asp Arg Asp Asp Ala Asp Trp Arg Glu Val Met Met Pro Tyr Ser 1 5 10 15

Thr Glu Leu lie Phe Tyr lie Glu Met Asp Pro Pro Ala Leu Pro Pro 20 25 30 Lys Pro Pro Lys Pro Met Thr Pro Ala Val Thr Asn Gly Met Lys Asp 35 40 45

Ser Phe lie Ser Leu Gin Asp Ala Glu Trp Tyr Trp Gly Asp lie Ser 50 55 60

Arg Glu Glu Val Asn Asp Lys Leu Arg Asp Met Pro Asp Gly Thr Phe 65 70 75 80

Leu Val Arg Asp Ala Ser Thr Lys Met Gin Gly Asp Tyr Thr Leu Thr 85 90 95

Leu Arg Lys Gly Gly Asn Asn Lys Leu lie Lys lie Tyr His Arg Asp 100 105 110 - -

Gly Lys Tyr Gly Phe Ser Glu Pro Leu Thr Phe Thr Ser Val Val Glu 115 120 125

Leu lie Asn His Tyr His His Glu Ser Leu Ala Gin Tyr Asn Pro Lys 130 135 140

Leu Asp Val Lys Leu Thr Tyr Pro Val Ser Arg Phe Gin Gin Asp Gin 145 150 155 160 Leu Val Lys Glu Asp Asn lie Asp Ala Val Gly Lys Asn Leu Gin Glu

165 170 175

Phe His Ser Gin Tyr Gin Glu Lys Ser Lys Glu Tyr Asp Arg Leu Tyr 180 185 190

Glu Glu Tyr Thr Arg Thr Ser Gin Glu lie Gin Met Lys Arg Thr Ala 195 200 205 lie Glu Ala Phe Asn Glu Thr lie Lys lie Phe Glu Glu Gin Cys His 210 215 220

Thr Gin Glu Gin His Ser Lys Asp Tyr lie Glu Arg Phe Arg Arg Glu 225 230 235 240 Gly Asn Glu Lys Glu lie Glu Arg lie Met Met Asn Tyr Asp Lys Leu

245 250 255

Lys Ser Arg Leu Gly Glu lie His Asp Ser Lys Leu Arg Leu Glu Gin 260 265 270

Asp Leu Lys Lys Gin Ala Leu Asp Asn Arg Glu lie Asp Lys Lys Met 275 280 285

Asn Ser lie Lys Pro Asp Leu lie Gin Leu Arg Lys lie Arg Asp Gin 290 295 300

His Leu Val Trp Leu Asn His Arg Gly Val Arg Gin Arg Arg Leu Asn 305 310 315 320 Ala Trp Leu Gly lie Lys Asn Glu Asp Ser Asp Glu Ser Tyr Phe lie

325 330 335

Asn Glu Glu Asp Glu Asn Leu Pro His Tyr Asp Glu Lys Thr Trp Phe 340 345 350

Val Glu Asp lie Asn Arg Val Gin Ala Glu Asp Leu Leu Tyr Gly Lys 355 360 365

Pro Asp Gly Ala Phe Leu lie Arg Glu Ser Ser Lys Lys Gly Cys Tyr 370 375 380

Ala Cys Ser Val Val Ala Asp Gly Glu Val Lys His Cys Val lie Tyr 385 390 395 400 Ser Thr Ala Arg Gly Tyr Gly Phe Ala Glu Pro Tyr Asn Leu Tyr Ser

405 410 415

Ser Leu Lys Glu Leu Val Leu His Tyr Gin Gin Thr Ser Leu Val Gin 420 425 430 His Asn Asp Ser Leu Asn Val Arg Leu Ala Tyr Pro Val His Ala Gin 435 440 445

Met Pro Thr Leu Cys Arg 450

Claims

- -

1. A substantially pure nucleic acid comprising a sequence encoding a pp60^PIK peptide having pp60^PIK activity.

2. A vector comprising a nucleic acid sequence encoding a pp60^PIK protein.

3. A cell containing the nucleic acid of claim 2.

4. A method for manufacture of pp60^PIK comprising culturing the cell of claim 6 in a medium to express said pp60^PIK.

5. Recombinant pp60^PIK.

6. A purified pp60^PI peptide having pp60^PIK activity.

7. A therapeutic composition comprising the purified peptide of claim 9 and a pharmaceutically acceptable carrier.

8. A transgenic animal comprising a pp60^PIK transgene.

9. A method of determining if a subject is at risk for a disease comprising evaluating an aspect of pp60^PIK metabolism or structure in said subject, an abnormal level of said aspect of metabolism or an abnormal structure being diagnostic of said disease.

10. A method of evaluating an effect of a therapeutic agent on pp60^PIK metabolism comprising administering said agent to a test organism and measuring the effect of said agent on an aspect of pp60^PIK metabolism, a change in said aspect of pp60^PIK metabolism indicating an effect of said agent.

11. A method of treating a mammal suffering from a disease caused by a abnormality of pp60^PIK metabolism comprising administering to said mammal a therapeutically effective amount of a therapeutic agent which alters an aspect of the metabolism of pp60^PI .

12. A peptide capable of inhibiting the interaction of an SH2-domain- containing protein with a second protein said peptide comprising the sequence R^-FIN, - - wherein Rl is Tyr, phosphotyrosine or an analog of phosphotyrosine having a hydrolysis resistant phosphorous moiety.

13. A method of assaying an effect of a therapeutic agent which alters the ability of a tyrosine kinase to phosphorylate a substrate comprising the amino acid sequence

YFIN comprising administering said agent to a test organism and measuring the level of phosphorylation of a substrate which comprises the amino acid sequence YFIN.

14. A method of treating a mammal suffering from a disease caused by a phosphorylation of a substrate of a tyrosine kinase, said substrate comprising the amino acid sequence YFIN comprising aclministering a therapeutically effective amount of a substance comprising the amino acid sequence YFIN.

15. A method of inhibiting a site specific interaction between a first molecule which comprises an SH2 domain and a second molecule which interacts with said SH2 domain comprising contacting said first molecule with an inhibitor molecule which comprises a peptide comprising the sequence R -FIN. wherein Rl is tyrosine, phosphotyrosine, or an analog of phosphotyrosine having a hydrolysis resistant phosphorous moiety.

16. A method of treating a mammal having a condition characterized by unwanted cell proliferation comprising administering to said mammal an amount of a peptide sufficient to prevent said unwanted cell proliferation said peptide comprising the sequence

R -FIN, wherein Rl is tyrosine, phosphotyrosine, phosphonomethylphenylalanine or an analog of phosphotyrosine having a hydrolysis resistant phosphorous moiety.

17. A method of treating a mammal afflicted with a disease characterized by the dephosphorylation of the protein tyrosine phosphatase substrate YFIN, comprising aόnιinistering to said mammal an inhibiting amount of a peptide analog of a naturally occurring protein tyrosine phosphatase substrate, said analog comprising an analog of phosphotyrosine having a hydrolysis resistant phosphorous moiety.