A G protein directly regulates mammalian cardiac calcium channels.
A G protein directly regulates mammalian cardiac calcium channels.
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G蛋白直接调节哺乳动物心脏钙通道。
DOI：
10.1126/science.2446390
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发表时间：
1987
期刊：
影响因子：
--
通讯作者：
Brown,AM
中科院分区：
文献类型：
--
作者：
Yatani,A;Codina,J;Imoto,Y;Reeves,JP;Birnbaumer,L;Brown,AM
鸟嘌呤核苷酸结合（G）蛋白对钙通道的可能的直接影响进行了研究，在膜补丁从豚鼠心肌细胞和牛心脏肌膜囊泡纳入平面脂质双层。三磷酸鸟苷类似物GTPγS可延长离体钙通道的存活时间，而与3′，5 ′-单磷酸腺苷（cAMP）、三磷酸腺苷、cAMP激活的蛋白激酶和蛋白激酶C激活剂十四烷酰佛波醇乙酸酯的存在无关。从人红细胞质膜中纯化的一种特异性G蛋白，激活的Gs或其α亚基，延长了切除通道的存活时间，并刺激了掺入通道的活性。因此，除了通过激活细胞质激酶间接调节钙通道外，G蛋白还可以直接调节钙通道。由于它们也直接调节钾通道的子集，G蛋白现在已知直接门控两类膜离子通道。
A possible direct effect of guanine nucleotide binding (G) proteins on calcium channels was examined in membrane patches excised from guinea pig cardiac myocytes and bovine cardiac sarcolemmal vesicles incorporated into planar lipid bilayers. The guanosine triphosphate analog, GTPγS, prolonged the survival of excised calcium channels independently of the presence of adenosine 3′,5′-monophosphate (cAMP), adenosine triphosphate, cAMP-activated protein kinase, and the protein kinase C activator tetradecanoyl phorbol acetate. A specific G protein, activated Gs, or its α subunit, purified from the plasma membranes of human erythrocytes, prolonged the survival of excised channels and stimulated the activity of incorporated channels. Thus, in addition to regulating calcium channels indirectly through activation of cytoplasmic kinases, G proteins can regulate calcium channels directly. Since they also directly regulate a subset of potassium channels, G proteins are now known to directly gate two classes of membrane ion channels.