McCool B A, Harpold M M, Stauderman K A, Brust P F, Lovinger D M
Department of Medical Pharmacology and Toxicology, Texas A and M University Health Science Center, College Station 77843-1114, USA.
Neurosci Lett. 1997 Dec 19;239(2-3):89-92. doi: 10.1016/s0304-3940(97)00893-8.
The voltage-dependent modulation of neuronal voltage-gated calcium channels by heterotrimeric G protein-coupled receptors potentially provides a means for activity-dependent modulation of synaptic efficacy. Recent attention has focused upon the molecular mechanisms by which such G proteins influence the biophysical properties of calcium channels. We have used an HEK 293-based heterologous system which stably expresses human neuronal calcium channels to address the relative contributions of receptor, G protein, and channel to voltage-dependent inhibition. We find that the receptor and channel subtype only insignificantly influence the time it takes to re-establish modulation following voltage-dependent relief of inhibition. In contrast, the G protein subtype mediating inhibition appears to play a significant part in this process. These results emphasize the importance of G protein subtype in the modulation of neuronal calcium channels.
异源三聚体G蛋白偶联受体对神经元电压门控钙通道的电压依赖性调节可能为突触效能的活动依赖性调节提供一种方式。最近的研究重点集中在这类G蛋白影响钙通道生物物理特性的分子机制上。我们使用了一个基于HEK 293的异源系统，该系统稳定表达人神经元钙通道，以研究受体、G蛋白和通道对电压依赖性抑制的相对贡献。我们发现，受体和通道亚型对电压依赖性抑制解除后重新建立调节所需的时间影响不大。相比之下，介导抑制的G蛋白亚型似乎在这一过程中起重要作用。这些结果强调了G蛋白亚型在神经元钙通道调节中的重要性。
