PTP1B: a non-receptor phospho-tyrosine protein phosphatase which acts as a regulator of endoplasmic reticulum unfolded protein response. Mediates dephosphorylation and inactivation of PERK. May play an important role in CKII- and p60c-src-induced signal transduction cascades. May regulate the EFNA5-EPHA3 signaling pathway which modulates cell reorganization and cell-cell repulsion. Negatively regulates insulin signaling by dephosphorylating the phosphotyrosine residues of insulin receptor. Also reported to dephosphorylate integrin, epidermal growth factor receptor, JAK2 and TYK2, regulating cell growth control and the cellular response to interferon. May regulate the hepatocyte growth factor receptor signaling pathway through dephosphorylation of MET. PTP1B knockout mice show resistance to dietary weight gain and enhanced insulin sensitivity, suggesting a possible role in treatment of obesity as well as type 2 diabetes.
Protein type: EC 3.1.3.48; Motility/polarity/chemotaxis; Phosphatase; Protein phosphatase, tyrosine (non-receptor)
Chromosomal Location of Human Ortholog: 2|2 H3
Cellular Component: cell-cell adherens junction; cytoplasm; cytoplasmic vesicle; cytosol; early endosome; endoplasmic reticulum; plasma membrane
Molecular Function: enzyme binding; ephrin receptor binding; insulin receptor binding; protein kinase binding; protein phosphatase 2A binding; protein tyrosine phosphatase activity; receptor tyrosine kinase binding; zinc ion binding
Biological Process: actin cytoskeleton reorganization; activation of JNK activity; insulin receptor signaling pathway; negative regulation of MAP kinase activity; negative regulation of vascular endothelial growth factor receptor signaling pathway; protein amino acid dephosphorylation; regulation of endocytosis; regulation of insulin receptor signaling pathway; regulation of intracellular protein transport; regulation of signal transduction; unfolded protein response
Show more