G Protein Activation of a Hormone-Stimulated Phosphatase in Human Tumor Cells

作者：Ming-Gui Pan, Tullio Florio, Philip A. Stork · 发表于：Science · 年份：1992 · DOI：10.1126/science.256.5060.1215 · 被引用次数：207 · 研究领域：Protein Kinase Regulation and GTPase Signaling、Cancer, Hypoxia, and Metabolism、Cellular transport and secretion

The growth-inhibiting peptide hormone somatostatin stimulates phosphotyrosine phosphatase activity in the human pancreatic cell line MIA PaCa-2. This hormonal activation was mediated by a pertussis toxin-sensitive guanosine 5'-triphosphate-binding protein (G protein) in the membranes of these cells. Activation of this G protein by somatostatin stimulated the dephosphorylation of exogenous epidermal growth factor receptor prepared from A-431 cells in vitro. This pathway may mediate the antineoplastic action of somatostatin in these cells and in human tumors and could represent a general mechanism of G protein coupling that is utilized by normal cells in the hormonal control of cell growth.