Yamanishi J, Takai Y, Kaibuchi K, Sano K, Castagna M, Nishizuka Y
Biochem Biophys Res Commun. 1983 Apr 29;112(2):778-86. doi: 10.1016/0006-291x(83)91529-2.
In human platelets, thrombin activates Ca2+-activated, phospholipid-dependent protein kinase (protein kinase C) and mobilizes Ca2+ concomitantly, whereas 12-O-tetradecanoylphorbol-13-acetate (TPA) may be intercalated into membranes and directly activates protein kinase C without mobilization of Ca2+ in sufficient quantities. A series of experiments with TPA and Ca2+-ionophore (A23187) indicates that activation of protein kinase C is a prerequisite requirement for release of serotonin, and that this enzyme activation and Ca2+ mobilization act synergistically to elicit a full cellular response. Both cyclic AMP and cyclic GMP inhibit activation of protein kinase C by prohibiting the signal-dependent breakdown of inositol phospholipid to produce diacyl-glycerol, but none of these cyclic nucleotides prevents the TPA-induced activation of this enzyme.
在人血小板中，凝血酶激活钙激活的磷脂依赖性蛋白激酶（蛋白激酶C）并同时动员钙离子，而12-O-十四烷酰佛波醇-13-乙酸酯（TPA）可能插入膜中并直接激活蛋白激酶C，而不会大量动员钙离子。一系列使用TPA和钙离子载体（A23187）的实验表明，蛋白激酶C的激活是5-羟色胺释放的前提条件，并且这种酶的激活和钙离子动员协同作用以引发完整的细胞反应。环磷酸腺苷（cAMP）和环磷酸鸟苷（cGMP）都通过阻止信号依赖性的肌醇磷脂分解以产生二酰甘油来抑制蛋白激酶C的激活，但这些环核苷酸均不能阻止TPA诱导的该酶激活。
