He Jiman, de la Monte Suzanne, Wands Jack R
Liver Research Center, Warren Alpert Medical School of Brown University, Providence, RI 02913, United States.
Biochem Biophys Res Commun. 2010 Jul 2;397(3):513-9. doi: 10.1016/j.bbrc.2010.05.146. Epub 2010 May 31.
Phosphatase and tensin homolog deleted on chromosome 10 (PTEN) is a tumor suppressor gene that is frequently mutated in brain, uterine, and prostate cancers. The protein phosphatase activity is poorly defined. We demonstrate that insulin stimulates phosphorylation of tyrosine and threonine/proline residues on the p85 regulatory subunit of PI3K in Huh-7, and HEK 293 cells. The specificity of PTEN binding and dephosphorylation of PI3K appears to reside on the p85beta subunit. Therefore, the PTEN phosphatase is active against the PI3K p85beta subunit and dephosphorylates a protein involved in insulin signaling where known downstream consequences are increased cell migration, motility, and invasion.
10号染色体缺失的磷酸酶及张力蛋白同源物（PTEN）是一种肿瘤抑制基因，在脑癌、子宫癌和前列腺癌中经常发生突变。其蛋白磷酸酶活性的定义尚不明确。我们证明，胰岛素可刺激Huh-7和HEK 293细胞中PI3K的p85调节亚基上酪氨酸以及苏氨酸/脯氨酸残基的磷酸化。PTEN与PI3K结合并使其去磷酸化的特异性似乎存在于p85β亚基上。因此，PTEN磷酸酶对PI3K p85β亚基具有活性，并使参与胰岛素信号传导的一种蛋白质去磷酸化，已知其下游结果是细胞迁移、运动性和侵袭增加。
