Kubo Y
Department of Neurophysiology, Tokyo Metropolitan Institute for Neuroscience, Japan.
Neurosci Res. 1994 Dec;21(2):109-17. doi: 10.1016/0168-0102(94)90152-x.
With recent cDNA cloning of members of the inward rectifying K+ channel family, it was revealed that they have only 2 putative transmembrane regions with no voltage-sensor element. Based on the deduced primary structure, possible schematic models to explain their characteristic features are proposed in this article. The features are (1) blocking by intracellular Mg2+, (2) intrinsic gating, (3) the triple barrel structure of the inward rectifier K+ channel and (4) the activation by the direct interaction with G-protein subunits of the muscarinic K+ channel. The recent findings of the mutagenesis study of voltage-gated K+ channels, which provide a clue for the structural-functional study of the inward rectifying K+ channels, are also looked at.
随着内向整流钾离子通道家族成员的cDNA近期被克隆,研究发现它们仅具有2个推测的跨膜区域,且没有电压感受器元件。基于推导的一级结构,本文提出了可能解释其特征的示意图模型。这些特征包括:(1)被细胞内Mg2+阻断;(2)固有门控;(3)内向整流钾离子通道的三桶状结构;(4)通过与毒蕈碱型钾离子通道的G蛋白亚基直接相互作用而激活。本文还探讨了电压门控钾离子通道诱变研究的最新发现,这些发现为内向整流钾离子通道的结构-功能研究提供了线索。