Davis J S, Clark M R
Biochem J. 1983 Aug 15;214(2):569-74. doi: 10.1042/bj2140569.
A new species of protein kinase has been identified in cytosol preparations from bovine corpora lutea. Enzyme activity required the simultaneous presence of Ca2+ and phospholipid, and was also enhanced by glyceryl dioleate. Phosphatidylserine was the most effective phospholipid for stimulating histone phosphorylation. Other phospholipids capable of supporting enzymic activity were, in order of decreasing activity, phosphatidylinositol, phosphatidic acid, cardiolipin and phosphatidylglycerol. Several other phospholipids tested were ineffective. A cyclic AMP-dependent protein kinase was also present in the luteal cytosol. This enzyme activity was eliminated by protein kinase inhibitor without affecting the Ca2+- and phospholipid-stimulated activity. Lysine-rich histone (IIIS) was a much better substrate than type-IIA histone for Ca2+- and phospholipid-dependent phosphorylation. Ca2+ and phospholipid also enhanced phosphorylation of endogenous luteal cytosol protein. Calmodulin, alone or in the presence of Ca2+, was unable to increase phosphorylation. Trifluoperazine inhibited protein kinase activity stimulated by Ca2+ and phospholipid. These data suggest that a phospholipid-sensitive, Ca2+-dependent protein kinase may provide an important link between hormonally-induced changes in phospholipid metabolism and corpus-luteum function.
在牛黄体的胞质溶胶制剂中发现了一种新的蛋白激酶。酶活性需要同时存在Ca2+和磷脂，并且甘油二油酸酯也能增强其活性。磷脂酰丝氨酸是刺激组蛋白磷酸化最有效的磷脂。其他能够支持酶活性的磷脂，按活性递减顺序依次为磷脂酰肌醇、磷脂酸、心磷脂和磷脂酰甘油。测试的其他几种磷脂则无效。黄体胞质溶胶中还存在一种环磷酸腺苷依赖性蛋白激酶。该酶活性可被蛋白激酶抑制剂消除，而不影响Ca2+和磷脂刺激的活性。富含赖氨酸的组蛋白（IIIS）比IIA型组蛋白更适合作为Ca2+和磷脂依赖性磷酸化的底物。Ca2+和磷脂也增强了黄体胞质溶胶内源性蛋白的磷酸化。单独的钙调蛋白或在Ca2+存在下，都无法增加磷酸化。三氟拉嗪抑制由Ca2+和磷脂刺激的蛋白激酶活性。这些数据表明，一种对磷脂敏感、Ca2+依赖性的蛋白激酶可能在激素诱导的磷脂代谢变化与黄体功能之间提供重要联系。
