PHOSPHATIDYL-L-SERINE IS NECESSARY FOR PROTEIN-KINASE CS HIGH-AFFINITY INTERACTION WITH DIACYLGLYCEROL-CONTAINING MEMBRANES
PHOSPHATIDYL-L-SERINE IS NECESSARY FOR PROTEIN-KINASE CS HIGH-AFFINITY INTERACTION WITH DIACYLGLYCEROL-CONTAINING MEMBRANES
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DOI：
10.1021/bi00187a035
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发表时间：
1994-05-31
期刊：
影响因子：
2.9
通讯作者：
KERANEN, LM
中科院分区：
文献类型：
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作者：
NEWTON, AC;KERANEN, LM
考察了磷脂头基结构、甘油二酯和钙离子在调节蛋白激酶CβII与膜或洗涤剂/脂混合胶束相互作用中的作用。结合测量表明，在没有二酰甘油的情况下，蛋白激酶C除了电荷外，对头基结构没有显著的选择性：该酶与磷脂酰丝氨酸、磷脂酰丝氨酸和其他单阴离子脂类如磷脂酰甘油具有同等的亲和力。相反，头基的选择性在二酰基甘油存在的情况下发生。第二信使使蛋白激酶C对含磷脂酰基-L-丝氨酸膜或胶束的亲和力增加2个数量级，但对蛋白激酶C与其他阴离子脂类表面的亲和力影响不大。钙离子不影响二酰甘油介导的蛋白激酶C对磷脂酰丝氨酸亲和力的增加，但确实增加了该酶对酸性磷脂的亲和力。最后，离子强度研究表明，静电相互作用是蛋白激酶C与膜相互作用的主要驱动力。在没有二酰基甘油或磷脂酰丝氨酸的情况下，这些相互作用足够弱，以至于在生理离子强度下几乎没有结合；因此，在没有二酰基甘油的情况下，蛋白激酶C不太可能转移到质膜上，即使细胞内钙离子水平很高。我们的数据表明，尽管在没有二酰甘油的情况下，结合酸性脂类没有特异性，但L-丝氨酸头基的特定结构元件是蛋白激酶C与含二酰甘油的膜高亲和力结合所必需的。
The contributions of phospholipid headgroup structure, diacylglycerol, and Ca2+ in regulating the interaction of protein kinase C beta II with membranes or detergent/lipid mixed micelles were examined. Binding measurements revealed that, in the absence of diacylglycerol, protein kinase C displays no significant selectivity for headgroup structure other than charge: the enzyme binds with equal affinity to phosphatidyl-L-serine, phosphatidyl-D-serine, and other monoanionic lipids such as phosphatidylglycerol. In contrast, selectivity for headgroup occurs in the presence of diacylglycerol. This second messenger increases the affinity of protein kinase C for phosphatidyl-L-serine-containing membranes or micelles by 2 orders of magnitude, but has only moderate effects on the affinity of protein kinase C for surfaces containing other anionic lipids. Ca2+ does not affect the diacylglycerol-mediated increase in protein kinase C's affinity for phosphatidylserine, but does increase the enzyme's affinity for acidic phospholipids. Lastly, ionic strength studies reveal that electrostatic interactions are the primary driving force in the interaction of protein kinase C with membranes. In the absence of either diacylglycerol or phosphatidylserine, these interactions are sufficiently weak that little binding occurs at physiological ionic strength; thus, protein kinase C is unlikely to translocate to the plasma membranes in the absence of diacylglycerol, even if intracellular Ca2+ levels are high. Our data reveal that, although there is no specificity for binding acidic lipids in the absence of diacylglycerol, specific structural elements of the L-serine headgroup are required for the high-affinity binding of protein kinase C to diacylglycerol-containing membranes.