Agonist-promoted coupling of the beta-adrenergic receptor with the guanine nucleotide regulatory protein of the adenylate cyclase system.
Agonist-promoted coupling of the beta-adrenergic receptor with the guanine nucleotide regulatory protein of the adenylate cyclase system.
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激动剂促进β-肾上腺素受体与腺苷酸环化酶系统的鸟嘌呤核苷酸调节蛋白的偶联。
DOI：
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发表时间：
1980
影响因子：
11.1
通讯作者：
R. Lefkowitz
中科院分区：
文献类型：
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作者：
L. Limbird;D. Gill;R. Lefkowitz
β-肾上腺素能激动剂[~3H]羟基苯基异丙肾上腺素与大鼠网织红细胞膜上的β-肾上腺素能受体结合，导致该受体与与腺苷环化酶系统相关的鸟嘌呤核苷酸调节蛋白偶联。这种被称为G蛋白的调节成分是通过霍乱毒素催化的特异性[32P]-ADP-核糖化来鉴定的。将[~(32)P]ADP核糖化的大鼠网织红细胞膜与[~(32)H]羟基苯基异丙肾上腺素激动剂孵育后，膜增溶和凝胶排斥层析导致42,000个MR[~(32)P]ADP核糖化的G蛋白与激动剂占据的β-肾上腺素能受体洗脱。当受体在溶解时没有被拮抗剂占据或被拮抗剂占据时，受体-G-蛋白复合体不形成。在鸟嘌呤核苷酸存在下，大鼠网织红细胞膜与[~3H]羟基苯基异丙肾上腺素孵育，可逆转或阻止这种受体-G-蛋白复合体的形成。这些数据为β-肾上腺素能受体激动剂占位促进分子相互作用提供了直接证据。受体-G-蛋白复合体的形成很可能是儿茶酚胺刺激腺苷环化酶，从而跨膜信息传递的关键。
Binding of the beta-adrenergic agonist [3H]hydroxybenzylisoproterenol to the beta-adrenergic receptor of rat reticulocyte membranes results in the coupling of the receptor to the guanine nucleotide regulatory protein associated with the adenylate cyclase system. This regulatory component, referred to as the G-protein, was identified by its specific [32P]-ADP-ribosylation catalyzed by cholera toxin. Incubation of [32P]ADP-ribosylated rat reticulocyte membranes with the [3H]hydroxybenzylisoproterenol agonist prior to membrane solubilization and gel exclusion chromatography resulted in the coelution of the 42,000 Mr [32P]ADP-ribosylated G-proteins with the agonist-occupied beta-adrenergic receptors. The receptor-G-protein complex was not formed when receptors were unoccupied or occupied with antagonists at the time of solubilization. Incubation of rat reticulocyte membranes with [3H]hydroxybenzylisoproterenol in the presence of guanine nucleotides reversed or prevented the formation of this receptor-G-protein complex. These data provide direct evidence for the molecular interactions promoted by agonist occupancy of beta-adrenergic receptors. It is probable that the formation of a receptor-G-protein complex is crucial for catecholamine stimulation of the adenylate cyclase enzyme and, hence, transmembrane information transfer.