Di Virgilio F, Pozzan T, Wollheim C B, Vicentini L M, Meldolesi J
J Biol Chem. 1986 Jan 5;261(1):32-5.
Protein kinase C is known to be involved both in initiation and termination of cellular responses due to phosphoinositide breakdown. Here we report that in PC12 cells (a line of neurosecretory cells derived from a rat pheochromocytoma), pretreatment with nanomolar concentrations of phorbol myristate acetate, PMA, which is believed to specifically activate protein kinase C, inhibits the cytosolic-free Ca2+ concentration rise induced by depolarizing agents. In contrast, plasma membrane potential and 45Ca efflux from preloaded cells were unaffected by PMA pretreatment. Inhibition by PMA and diacylglycerol of the cytosolic-free Ca2+ concentration rise induced by depolarization was observed also in another cell line, the insulin secreting line RINm5F. These results raise the possibility that the voltage-gated Ca2+ channel is under inhibitory control by protein kinase C.
已知蛋白激酶C参与了因磷酸肌醇分解而引发的细胞反应的起始和终止过程。在此我们报告，在PC12细胞（源自大鼠嗜铬细胞瘤的神经分泌细胞系）中，用纳摩尔浓度的佛波酯肉豆蔻酸酯（PMA）进行预处理，据信PMA可特异性激活蛋白激酶C，但它会抑制由去极化剂诱导的胞质游离Ca2+浓度升高。相反，质膜电位以及预加载细胞的45Ca外流不受PMA预处理的影响。在另一种细胞系——胰岛素分泌细胞系RINm5F中，也观察到PMA和二酰基甘油对去极化诱导的胞质游离Ca2+浓度升高具有抑制作用。这些结果增加了电压门控Ca2+通道受蛋白激酶C抑制性调控的可能性。
