Rehm H, Tempel B L
Pharmakologisches Institut, Universität Zürich, Switzerland.
FASEB J. 1991 Feb;5(2):164-70. doi: 10.1096/fasebj.5.2.2004663.
Research on voltage-gated K+ channels of the mammalian brain has seen a flood of new data in the last 2 years. A genetic approach, based on the Shaker mutation of Drosophila, led to cDNA clones for mammalian voltage-gated K+ channels. K+ channel proteins were detected independently and purified with the help of channel specific toxins. From these studies the structure of two families of mammalian K+ channels emerged. One family is defined molecularly by the sequence homology of its members, the other by binding sites for the snake toxin dendrotoxin. The two families have several members in common. The voltage-gated K+ channels of mammalian brain are oligomers of glycosilated peptides of 65-95 kDa. The primary structure of these subunits is characterized by six to eight potential transmembrane regions, including the S4 region, the voltage-sensor of the channels. Associated with at least some K+ channels are 38- and 42-kDa peptides of unknown function. The channels give rise to non- or slow-inactivating K+ currents that are regulated through phosphorylation by both cAMP-dependent and an endogenous kinase.
在过去两年中，有关哺乳动物大脑电压门控钾通道的研究涌现出大量新数据。一种基于果蝇Shaker突变的遗传学方法，得到了哺乳动物电压门控钾通道的cDNA克隆。钾通道蛋白被独立检测出来，并借助通道特异性毒素进行了纯化。通过这些研究，出现了两类哺乳动物钾通道的结构。一类家族在分子层面由其成员的序列同源性定义，另一类则由蛇毒素树突毒素的结合位点定义。这两类家族有几个共同的成员。哺乳动物大脑的电压门控钾通道是由65 - 95 kDa的糖基化肽组成的寡聚体。这些亚基的一级结构的特征是有六到八个潜在的跨膜区域，包括通道的电压感受器S4区域。与至少一些钾通道相关的是功能未知的38 kDa和42 kDa肽。这些通道产生非失活或缓慢失活的钾电流，这些电流通过cAMP依赖性激酶和一种内源性激酶的磷酸化作用进行调节。
