K+ Channels: Function-Structural Overview
K+ Channels: Function-Structural Overview
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DOI：
10.1002/cphy.c110047
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发表时间：
2012-07-01
影响因子：
5.8
通讯作者：
Latorre, Ramon
中科院分区：
文献类型：
--
作者：
Gonzalez, Carlos;Baez-Nieto, David;Latorre, Ramon
钾通道在决定动作电位的形状和持续时间、控制膜电位、调节激素分泌、上皮功能以及在由Ca 2+激活的那些K+通道的情况下抑制兴奋性信号方面特别重要。K+通道所起的作用的多样性是其猛犸多样性的唯一可能，目前在哺乳动物中包括70个K+通道编码基因。今天，由于使用克隆，诱变，以及最近使用X射线晶体学的结构研究，我们处于一个独特的位置来了解这个离子通道超家族的巨大多样性的起源，它们在不同细胞类型中发挥的作用，以及结构和功能之间存在的关系。除了二聚体的双孔K+通道外，电压依赖性K+通道是四聚体组装体，并且共享非常保守的孔区域，其中存在离子选择性过滤器。在本综述中，我们讨论了K+通道的五个不同亚家族的功能、定位以及功能和结构之间的关系：（a）内向整流器，Kir;（B）四个跨膜片段-2孔，K-2 P;（c）电压门控，Kv;（d）Slo家族;和（e）Ca 2+激活的SK家族，SKCa。(C)2012年美国生理学会。Compr Physiol 2：2087-2149，2012年。
Potassium channels are particularly important in determining the shape and duration of the action potential, controlling the membrane potential, modulating hormone secretion, epithelial function and, in the case of those K+ channels activated by Ca2+, damping excitatory signals. The multiplicity of roles played by K+ channels is only possible to their mammoth diversity that includes at present 70 K+ channels encoding genes in mammals. Today, thanks to the use of cloning, mutagenesis, and the more recent structural studies using x-ray crystallography, we are in a unique position to understand the origins of the enormous diversity of this superfamily of ion channels, the roles they play in different cell types, and the relations that exist between structure and function. With the exception of two-pore K+ channels that are dimers, voltage-dependent K+ channels are tetrameric assemblies and share an extremely well conserved pore region, in which the ion-selectivity filter resides. In the present overview, we discuss in the function, localization, and the relations between function and structure of the five different subfamilies of K+ channels: (a) inward rectifiers, Kir; (b) four transmembrane segments-2 pores, K-2P; (c) voltage-gated, Kv; (d) the Slo family; and (e) Ca2+-activated SK family, SKCa. (C) 2012 American Physiological Society. Compr Physiol 2:2087-2149, 2012.