Two ryanodine receptor isoforms in nonmammalian vertebrate skeletal muscle: Possible roles in excitation-contraction coupling and other processes
Two ryanodine receptor isoforms in nonmammalian vertebrate skeletal muscle: Possible roles in excitation-contraction coupling and other processes
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DOI：
10.1016/j.pbiomolbio.2010.10.003
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发表时间：
2011-05-01
影响因子：
3.8
通讯作者：
Kurebayashi, Nagomi
中科院分区：
文献类型：
--
作者：
Murayama, Takashi;Kurebayashi, Nagomi
Ryanodine受体（RyR）是脊椎动物骨骼肌肌浆网上的一个钙释放通道，在兴奋收缩偶联中起重要作用。哺乳动物骨骼肌主要表达单一的RyR亚型RyR 1，而许多非哺乳动物脊椎动物的骨骼肌表达等量的两种不同的亚型α-RyR和β-RyR，它们分别是哺乳动物RyR 1和RyR 3的同源物。在这篇综述中，我们描述了我们目前的理解，这两个RyR异构体在非哺乳动物脊椎动物骨骼肌的功能。通过RyR通道的Ca 2+释放可以通过两种不同的模式门控：去极化诱导的Ca 2+释放（DICR）和Ca 2+诱导的Ca 2+释放（CICR）。在青蛙肌肉中，α-RyR充当DICR通道，而β-RyR充当CICR通道。然而，一些证据表明，CICR的β-RyR可能只作出微小的贡献，钙释放过程中的E-C耦合。青蛙和哺乳动物的RyR亚型的比较突出了RyR 1和RyR 3同源物介导的Ca 2+释放模式的显着差异。有趣的是，在β-RyR和RyR 1之间注意到Ca 2+释放模式的共同特征。我们将讨论这两种RyR亚型在非哺乳类脊椎动物骨骼肌的E-C偶联和其他过程中可能的作用和意义。(C)2010爱思唯尔有限公司保留所有权利。
The ryanodine receptor (RyR) is a Ca2+ release channel in the sarcoplasmic reticulum in vertebrate skeletal muscle and plays an important role in excitation contraction (E C) coupling. Whereas mammalian skeletal muscle predominantly expresses a single RyR isoform, RyR1, skeletal muscle of many nonmammalian vertebrates expresses equal amounts of two distinct isoforms, alpha-RyR and beta-RyR, which are homologues of mammalian RyR1 and RyR3, respectively. In this review we describe our current understanding of the functions of these two RyR isoforms in nonmammalian vertebrate skeletal muscle. The Ca2+ release via the RyR channel can be gated by two distinct modes: depolarization-induced Ca2+ release (DICR) and Ca2+-induced Ca2+ release (CICR). In frog muscle, alpha-RyR acts as the DICR channel, whereas beta-RyR as the CICR channel. However, several lines of evidence suggest that CICR by beta-RyR may make only a minor contribution to Ca2+ release during E C coupling. Comparison of frog and mammalian RyR isoforms highlights the marked differences in the patterns of Ca2+ release mediated by RyR1 and RyR3 homologues. Interestingly, common features in the Ca2+ release patterns are noticed between beta-RyR and RyR1. We will discuss possible roles and significance of the two RyR isoforms in E-C coupling and other processes in nonmammalian vertebrate skeletal muscle. (C) 2010 Elsevier Ltd. All rights reserved.