Hubinont C J, Best L, Sener A, Malaisse W J
FEBS Lett. 1984 May 21;170(2):247-53. doi: 10.1016/0014-5793(84)81322-8.
Rat pancreatic islet homogenates display protein kinase C activity. This phospholipid-dependent and calcium-sensitive enzyme is activated by diacylglycerol or the tumor-promoting phorbol ester 12-O-tetradecanoylphorbol-13-acetate (TPA). In the presence of TPA, the Ka for Ca2+ is close to 5 microM. TPA does not affect phosphoinositide turnover but stimulates [32P]- and [3H]choline-labelling of phosphatidylcholine in intact islets. Exogenous phospholipase C stimulates insulin release, in a sustained and glucose-independent fashion. The secretory response to phospholipase C persists in media deprived of CaCl2. It is proposed that protein kinase C participates in the coupling of stimulus recognition to insulin release evoked by TPA, phospholipase C and, possibly, those secretatogues causing phosphoinositide breakdown in pancreatic islets.
大鼠胰岛匀浆显示出蛋白激酶C活性。这种依赖磷脂且对钙敏感的酶可被二酰基甘油或促肿瘤佛波酯12-O-十四烷酰佛波醇-13-乙酸酯（TPA）激活。在TPA存在的情况下，Ca2+的解离常数接近5微摩尔。TPA不影响磷酸肌醇的周转，但刺激完整胰岛中磷脂酰胆碱的[32P] - 和[3H]胆碱标记。外源性磷脂酶C以持续且不依赖葡萄糖的方式刺激胰岛素释放。在不含CaCl2的培养基中，对磷脂酶C的分泌反应仍然存在。有人提出，蛋白激酶C参与了刺激识别与TPA、磷脂酶C以及可能导致胰岛中磷酸肌醇分解的那些促分泌剂所引发的胰岛素释放之间的偶联。
