Strong M, Chandy K G, Gutman G A
Department of Physiology and Biophysics, University of California, Irvine 92717.
Mol Biol Evol. 1993 Jan;10(1):221-42. doi: 10.1093/oxfordjournals.molbev.a039986.
We have analyzed nucleic acid and amino acid sequence alignments of a variety of voltage-sensitive ion channels, using several methods for phylogenetic tree reconstruction. Ancient duplications within this family gave rise to three distantly related groups, one consisting of the Na+ and Ca++ channels, another the K+ channels, and a third including the cyclic nucleotide-binding channels. A series of gene duplications produced at least seven mammalian homologues of the Drosophila Shaker K+ channel; clones of only three of these genes are available from all three mammalian species examined (mouse, rat, and human), pointing to specific genes that have yet to be recovered in one or another of these species. The Shaw-related K+ channels and the Na+ channel family have also undergone considerable expansion in mammals, relative to flies. These expansions presumably reflect the needs of the high degree of physiological and neuronal complexity of mammals. Analysis of the separate domains of the four-domain channels (Ca++ and Na+) supports their having evolved by two sequential gene duplications and implies the historical existence of a functional two-domain channel.
我们使用多种系统发育树重建方法，分析了多种电压敏感离子通道的核酸和氨基酸序列比对。该家族内的远古基因复制产生了三个远缘相关的组，一组由Na⁺和Ca²⁺通道组成，另一组是K⁺通道，第三组包括环核苷酸结合通道。一系列基因复制产生了至少七个果蝇Shaker K⁺通道的哺乳动物同源物；在所研究的所有三种哺乳动物物种（小鼠、大鼠和人类）中，仅获得了其中三个基因的克隆，这表明在这些物种中的某一个或另一个中尚未发现特定的基因。与果蝇相比，与Shaw相关的K⁺通道和Na⁺通道家族在哺乳动物中也有了相当大的扩展。这些扩展大概反映了哺乳动物高度生理和神经元复杂性的需求。对四结构域通道（Ca²⁺和Na⁺）的各个结构域进行分析，支持它们是通过两次连续的基因复制进化而来的，并暗示了功能性两结构域通道的历史存在。
