Guanyl nucleotides modulate binding to steroid receptors in neuronal membranes.
Guanyl nucleotides modulate binding to steroid receptors in neuronal membranes.
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鸟苷酸调节与神经元膜中类固醇受体的结合。
DOI：
10.1073/pnas.89.9.3830
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发表时间：
1992
影响因子：
11.1
通讯作者：
F. L. Moore
中科院分区：
文献类型：
--
作者：
M. Orchinik;T. F. Murray;P. Franklin;F. L. Moore
最近发现的两栖动物神经元膜上的皮质类固醇受体似乎介导了雄性生殖行为的快速，应激诱导的变化。由于与该受体相关的转导机制尚不清楚，我们进行了放射性配体结合研究，以确定该类固醇受体是否受到鸟苷核苷酸的负调节。在平衡饱和结合和滴定研究中，非水解的鸟腈核苷酸抑制了[3H]皮质酮与神经元膜的结合。鸟苷核苷酸和未标记皮质酮的加入诱导了[3H]皮质酮与膜的快速解离，这是单独添加未标记配体所不能诱导的。此外，Mg2+增强了[3H]皮质酮的平衡结合和受体对鸟苷核苷酸调节的敏感性。这些结果与类固醇、受体和鸟嘌呤核苷酸结合蛋白的三元复合物的形成是一致的，这种复合物受鸟嘌呤核苷酸的调节。因此，通过神经元膜上皮质类固醇受体的快速信号转导似乎是由鸟嘌呤核苷酸结合蛋白介导的。
The recently characterized corticosteroid receptor on amphibian neuronal membranes appears to mediate rapid, stress-induced changes in male reproductive behaviors. Because the transduction mechanisms associated with this receptor are unknown, we performed radioligand binding studies to determine whether this steroid receptor is negatively modulated by guanyl nucleotides. The binding of [3H]corticosterone to neuronal membranes was inhibited by nonhydrolyzable guanyl nucleotides in both equilibrium saturation binding and titration studies. The addition of guanyl nucleotide plus unlabeled corticosterone induced a rapid phase of [3H]corticosterone dissociation from membranes that was not induced by addition of unlabeled ligand alone. Furthermore, the equilibrium binding of [3H]corticosterone and the sensitivity of the receptor to modulation by guanyl nucleotides were both enhanced by Mg2+. These results are consistent with the formation of a ternary complex of steroid, receptor, and guanine nucleotide-binding protein that is subject to regulation by guanyl nucleotides. Therefore, rapid signal transduction through corticosteroid receptors on neuronal membranes appears to be mediated by guanine nucleotide-binding proteins.