Regulation of human platelet membrane Ca2+ transport by cAMP- and calmodulin-dependent phosphorylation.
Regulation of human platelet membrane Ca2+ transport by cAMP- and calmodulin-dependent phosphorylation.
复制标题
通过 cAMP 和钙调蛋白依赖性磷酸化调节人血小板膜 Ca2+ 转运。
DOI：
10.1016/0167-4889(87)90013-9
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发表时间：
1987
期刊：
影响因子：
--
通讯作者：
Dean,WL
中科院分区：
文献类型：
--
作者：
Adunyah,SE;Dean,WL
我们重新研究了在纯化的人血小板内膜中加入cAMP依赖性蛋白激酶和内源性钙调素依赖性激酶对Ca 2+转运的影响。Ca ~（2+）摄取和Ca ~（2+）-ATP酶活性均被cAMP依赖性蛋白激酶刺激约2倍。环腺苷酸依赖性蛋白激酶抑制剂在一定浓度下可降低Ca 2+摄取和Ca 2 +-ATP酶活性，并抑制cAMP依赖性蛋白磷酸化。此外，还观察到外源性钙调素和添加的cAMP依赖性蛋白激酶催化亚基对Ca ~（2+）-ATP酶的协同刺激。一个22 kDa的蛋白磷酸化的cAMP依赖性和钙调素依赖性激酶在相同的速率作为刺激的Ca 2 +-ATP酶。环AMP依赖的磷酸化的22 kDa的多肽被抑制的蛋白激酶抑制剂和钙调蛋白依赖的磷酸化被抑制氯丙嗪和EGTA。这些结果与血小板中Ca 2+稳态的一种控制模式可能类似于心肌中的受磷蛋白系统的假设一致。
We have reexamined the effects of added cAMP-dependent protein kinase and endogenous calmodulin-dependent kinase on Ca2+transport in purified internal membranes from human platelets. Both Ca2+uptake and Ca2+-ATPase activity were maximally stimulated about 2-fold by addition of cAMP-dependent protein kinase. Cyclic AMP-dependent protein kinase inhibitor reduced both Ca2+uptake and Ca2+-ATPase activities at concentrations which also inhibited cAMP-dependent protein phosphorylation. In addition, concerted stimulation of Ca2+-ATPase by exogenous calmodulin and added catalytic subunit of cAMP-dependent protein kinase was observed. A 22-kDa protein was phosphorylated by both cAMP-dependent and calmodulin-dependent kinases at the same rate as stimulation of the Ca2+-ATPase. Cyclic AMP-dependent phosphorylation of the 22-kDa polypeptide was inhibited by the protein kinase inhibitor and calmodulin-dependent phosphorylation was inhibited by chlorpromazine and EGTA. These results are consistent with the hypothesis that one mode of control of Ca2+homeostasis in platelets may be similar to the phospholamban system in cardiac muscle.