Abstract: Compositions and methods are provided for the treatment of conditions associated with cell proliferation, cell differentiation and cell survival. In particular, the dual-specificity phosphatase DSP-15, and polypeptide variants thereof that stimulate dephosphorylation of DSP-15 substrates, are provided. The polypeptides may be used, for example, to identify antibodies and other agents that inhibit DSP-15 activity. The polypeptides and agents may be used to modulate cell proliferation, differentiation and survival.

Abstract: Compositions and methods relating to small interfering RNA (siRNA) polynucleotides are provided as pertains to modulation of biological signal transduction. Shown are siRNA polynucleotides that interfere with expression of TCPTP, a member of the protein tyrosine phosphatase (PTP) class of enzymes that mediate signal transduction. In certain preferred embodiments siRNA modulate signal transduction pathways comprising human or murine TCPTP and, in certain further embodiments, insulin receptor, c-jun kinase (JNK) and/or Jak2. Modulation of TCPTP-mediated biological signal transduction has uses in diseases associated with defects in cell proliferation, cell differentiation and/or cell survival, such as metabolic disorders (including diabetes and obesity), cancer, autoimmune disease, infectious and inflammatory disorders and other conditions.

Abstract: Compositions and methods relating to small interfering RNA (siRNA) polynucleotides are provided as pertains to modulation of biological signal transduction. Shown are siRNA polynucleotides that interfere with expression of members of the protein tyrosine phosphatase (PTP) class of enzymes that mediate signal transduction, and with certain MAP kinase kinases (MKK). In certain preferred embodiments siRNA modulate signal transduction pathways comprising SHP2, cdc14a/b, cdc25A/B/C, KAP, PTP-&egr;, PRL-3, CD45, dual specificity phosphatase-3 (DSP-3), MKK-4, and/or MKK-7. Modulation of PTP-mediated biological signal transduction has uses in diseases associated with defects in cell proliferation, cell differentiation and/or cell survival, such as metabolic disorders (including diabetes and obesity), cancer, autoimmune disease, infectious and inflammatory disorders and other conditions.

Abstract: Compositions and methods are provided for the treatment of conditions associated with cell proliferation, cell differentiation and cell survival. In particular, the dual-specificity phosphatase DSP-11, and polypeptide variants thereof that stimulate dephosphorylation of DSP-11 substrates, are provided. The polypeptides may be used, for example, to identify antibodies and other agents that inhibit DSP-11 activity. The polypeptides and agents may be used to modulate cell proliferation, differentiation and survival.

Abstract: Compositions and methods relating to small interfering RNA (siRNA) polynucleotides are provided as pertains to modulation of biological signal transduction. Shown are siRNA polynucleotides that interfere with expression of PTP1B, a member of the protein tyrosine phosphatase (PTP) class of enzymes that mediate signal transduction. In certain preferred embodiments siRNA modulate signal transduction pathways comprising human or murine PTP-1B and, in certain further embodiments, insulin receptor and/or Jak2. Modulation of PTP1B-mediated biological signal transduction has uses in diseases associated with defects in cell proliferation, cell differentiation and/or cell survival, such as metabolic disorders (including diabetes and obesity), cancer, autoimmune disease, infectious and inflammatory disorders and other conditions.

Abstract: The invention relates to a method of identifying any protein tyrosine phosphatase (PTP) that undergoes reversible modification of PTP active site invariant cysteine within a cell, such that the phosphatase is transiently protected from irreversible active site invariant cysteine-directed PTP inactivating agents. Methods related to regulation of PTPs by reactive oxygen species (ROS) in a cellular environment are provided. Multiple PTPs are shown to be reversibly oxidized and inactivated following treatment of cells with H2O2 or with physiological stimuli that promote ROS formation, and inhibition of PTP function is shown to contribute to ROS-induced mitogenesis. Transient oxidation of the PTP catalytic site invariant cysteine is exploited in methods to identify which of multiple candidate PTPs are components of a given biological signal transduction pathway, without a requirement for first specifically purifying any particular candidate PTP.

Abstract: Compositions and methods are provided for the treatment of conditions associated with cell proliferation, cell differentiation and cell survival. In particular, the dual-specificity phosphatase DSP-11, and polypeptide variants thereof that stimulate dephosphorylation of DSP-11 substrates, are provided. The polypeptides may be used, for example, to identify antibodies and other agents that inhibit DSP-11 activity. The polypeptides and agents may be used to modulate cell proliferation, differentiation and survival.

Abstract: Compositions and methods are provided for the treatment of conditions associated with cell proliferation, cell differentiation and cell survival. In particular, the dual-specificity phosphatase DSP-5, and polypeptide variants thereof that stimulate dephosphorylation of DSP-5 substrates, are provided. The polypeptides may be used, for example, to identify antibodies and other agents that inhibit DSP-5 activity. The polypeptides and agents may be used to modulate cell proliferation, differentiation and survival.

Abstract: Compositions and methods are provided for the treatment of conditions associated with cell proliferation, cell differentiation and cell survival. In particular, the dual-specificity phosphatase DSP-4, and polypeptide variants thereof that stimulate dephosphorylation of DSP-4 substrates, are provided. The polypeptides may be used, for example, to identify antibodies and other agents that inhibit DSP-4 activity. The polypeptides and agents may be used to modulate cell proliferation, differentiation and survival.

Abstract: Compositions and methods are provided for the treatment of conditions associated with cell proliferation, cell differentiation and cell survival. In particular, the dual-specificity phosphatase DSP-10, and polypeptide variants thereof that stimulate dephosphorylation of DSP-10 substrates, are provided. The polypeptides may be used, for example, to identify antibodies and other agents that inhibit DSP-10 activity. The polypeptides and agents may be used to modulate cell proliferation, differentiation and survival.

Abstract: Compositions and methods are provided for the treatment of conditions associated with cell proliferation, cell differentiation and cell survival. In particular, the dual-specificity phosphatase DSP-9, and polypeptide variants thereof that stimulate dephosphorylation of DSP-9 substrates, are provided. The polypeptides may be used, for example, to identify antibodies and other agents that inhibit DSP-9 activity. The polypeptides and agents may be used to modulate cell proliferation, differentiation and survival.

Abstract: Compositions and methods are provided for the treatment of conditions associated with cell proliferation, cell differentiation and/or cell survival. In particular, the dual-specificity phosphatase DSP-18 isoforms DSP-18a-f, and polypeptide variants thereof that stimulate dephosphorylation of DSP-18 substrates, are provided. The polypeptides may be used, for example, to identify antibodies and other agents that inhibit DSP-18 activity. The polypeptides and agents may be used to modulate cell proliferation, cell differentiation and cell survival.

Abstract: Compositions and methods are provided for the treatment of conditions associated with cell proliferation, cell differentiation and cell survival. In particular, the dual-specificity phosphatase DSP-10, and polypeptide variants thereof that stimulate dephosphorylation of DSP-10 substrates, are provided. The polypeptides may be used, for example, to identify antibodies and other agents that inhibit DSP-10 activity. The polypeptides and agents may be used to modulate cell proliferation, differentiation and survival.

Abstract: Compositions and methods are provided for the treatment of conditions associated with cells proliferation, cells differentiation and cell survival. In particular, the dual-specificity phosphatase DSP-9, and polypeptide variants thereof that stimulate dephosphorylation of DSP-9 substrates, are provided. The polypeptides may be used, for example, to identify antibodies and other agents that inhibit DSP-9 activity. The polypeptides and agents may be used to modulate cell proliferation, differentiation and survival.

Abstract: Compositions and methods are provided for the treatment of conditions associated with cell proliferation, cell differentiation and cell survival. In particular, the dual-specificity phosphatase DSP-15, and polypeptide variants thereof that stimulate dephosphorylation of DSP-15 substrates, are provided. The polypeptides may be used, for example, to identify antibodies and other agents that inhibit DSP-15 activity. The polypeptides and agents may be used to modulate cell proliferation, differentiation and survival.

Abstract: Compositions and methods are provided for the treatment of conditions associated with cell proliferation, cell differentiation and cell survival. In particular, the dual-specificity phosphatase DSP-16, and polypeptide variants thereof that stimulate dephosphorylation of DSP-16 substrates, are provided. The polypeptides may be used, for example, to identify antibodies and other agents that inhibit DSP-16 activity. The polypeptides and agents may be used to modulate cell proliferation, differentiation and survival.