Yassin M, Zong S, Tanabe T
Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, Connecticut 06536-0812, USA.
Biochem Biophys Res Commun. 1996 Mar 18;220(2):453-8. doi: 10.1006/bbrc.1996.0426.
GH3 cell lines stably expressing alpha 1E channel were established and the modulation of this channel by G-protein through membrane-delimited pathways was studied. Alpha 1E channel expressed in GH3 cells showed slowing of activation and reduction of current amplitude by the application of carbachol or somatostatin. Both of these effects caused by these agents were pertussis toxin (PTX) sensitive and voltage dependent. Dialysis of the cell interior with GTP gamma S mimicked the action of these externally applied neurotransmitters, indicating that the alpha 1E channel is modulated by the PTX sensitive G-protein(s) through the membrane-delimited pathway but not by the PTX insensitive pathway that has been observed in alpha 1A channel expressed in GH3 cells. Thus different types of neuronal Ca2+ channels can be modulated not only by a similar mechanism but also by a different mechanism conferring a multilateral regulation of Ca2+ entry through these channels.
建立了稳定表达α1E通道的GH3细胞系，并研究了G蛋白通过膜限定途径对该通道的调节作用。在GH3细胞中表达的α1E通道在应用卡巴胆碱或生长抑素后显示出激活减慢和电流幅度降低。这些药物引起的这两种效应均对百日咳毒素（PTX）敏感且依赖电压。用GTPγS透析细胞内部模拟了这些外部施加的神经递质的作用，表明α1E通道通过膜限定途径由PTX敏感的G蛋白调节，而不是由在GH3细胞中表达的α1A通道中观察到的PTX不敏感途径调节。因此，不同类型的神经元Ca2+通道不仅可以通过类似的机制调节，还可以通过不同的机制调节，从而对通过这些通道的Ca2+内流进行多边调节。
