Photoaffinity labeling of two rat liver plasma membrane proteins with [32P]gamma-azidoanilido GTP in response to vasopressin. Immunologic identification as alpha subunits of the Gq class of G proteins.
Photoaffinity labeling of two rat liver plasma membrane proteins with [32P]gamma-azidoanilido GTP in response to vasopressin. Immunologic identification as alpha subunits of the Gq class of G proteins.
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DOI：
10.1016/s0021-9258(18)98970-2
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发表时间：
1991-06
期刊：
影响因子：
--
通讯作者：
Ronald L. Wange;A. Smrcka;P. Sternweis;J. Exton
中科院分区：
文献类型：
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作者：
Ronald L. Wange;A. Smrcka;P. Sternweis;J. Exton
在大鼠肝质膜中发现了两种蛋白质，它们与光反应性GTP类似物[32 P] γ-叠氮苯胺基GTP结合，以响应与Ca（2+）动员激动剂加压素的孵育。标记的蛋白质具有42和43 kDa的表观分子量。它们的标记需要Mg 2+，并且可以被GTP、其类似物和GDP抑制，但不被其他核苷酸抑制。加压素刺激的标记被V1受体选择性拮抗剂减弱。刺激标记所需的加压素浓度与肝质膜中GT3和磷酸肌醇特异性磷脂酶C活性激活所需的浓度在相同的范围内（EC 50 = 4 nM）。免疫检测和免疫沉淀的[32 P] γ-叠氮基苯胺GTP标记的42-和43-kDa的蛋白质与抗血清对α q的肽序列表明，这些蛋白质是最近描述的Gq类G蛋白的成员。
Two proteins have been identified in rat liver plasma membranes that bind a photoreactive GTP analogue, [32P]gamma-azidoanilido GTP, in response to incubation with the Ca(2+)-mobilizing agonist, vasopressin. The labeled proteins possess apparent molecular masses of 42 and 43 kDa. Their labeling requires Mg2+ and can be inhibited by GTP, its analogues, and GDP but not by other nucleotides. Vasopressin-stimulated labeling is attenuated by a V1 receptor-selective antagonist. The concentration of vasopressin required to stimulate labeling is in the same range (EC50 = 4 nM) as that required for activation of GTPase and phosphoinositide-specific phospholipase C activities in liver plasma membranes. Immunodetection and immunoprecipitation of the [32P]gamma-azidoanilido GTP-labeled 42- and 43-kDa proteins with antisera raised against peptide sequences in alpha q indicate that these proteins are members of the recently described Gq class of G proteins.