Eichberg J, de Graan P N, Schrama L H, Gispen W H
Biochem Biophys Res Commun. 1986 May 14;136(3):1007-12. doi: 10.1016/0006-291x(86)90433-x.
The short chain diacylglycerol, 1,2-dioctanoylglycerol, at concentrations of 100-300 microM stimulated phosphorylation of the nervous system-specific membrane protein B-50 (Mr 48 kDa, IEP 4.5) in isolated synaptic plasma membranes both in the presence and absence of exogenous protein kinase C. Comparable enhancement of histone phosphorylation by purified protein kinase C was achieved with 1 microM neutral lipid. Phorbol dibutyrate was 100 times more potent than the diacylglycerol in stimulating endogenous B-50 kinase in the membranes, whereas 4-alpha-phorbol was without effect. These results further confirm that B-50 is phosphorylated physiologically by a C kinase. Our data are consistent with a negative feedback mechanism in which generation of 1,2-diacylglycerol by enhanced phosphatidylinositol-4,5-bisphosphate hydrolysis could stimulate B-50 phosphorylation, thereby diminishing phosphatidylinositol-4-phosphate kinase activity and decreasing phosphatidylinositol-4,5-bisphosphate biosynthesis.
短链二酰基甘油，1,2 - 二辛酰甘油，在浓度为100 - 300微摩尔时，无论有无外源性蛋白激酶C，均可刺激分离的突触质膜中神经系统特异性膜蛋白B - 50（分子量48 kDa，等电点4.5）的磷酸化。用1微摩尔中性脂质可使纯化的蛋白激酶C对组蛋白磷酸化产生类似的增强作用。在刺激膜内源性B - 50激酶方面，佛波醇二丁酸酯的效力比二酰基甘油强100倍，而4-α-佛波醇则无作用。这些结果进一步证实B - 50在生理上是由C激酶磷酸化的。我们的数据与一种负反馈机制一致，即通过增强磷脂酰肌醇-4,5 - 二磷酸水解产生1,2 - 二酰基甘油可刺激B - 50磷酸化，从而降低磷脂酰肌醇-4 - 磷酸激酶活性并减少磷脂酰肌醇-4,5 - 二磷酸的生物合成。
