Adaptive evolution of the vertebrate skeletal muscle sodium channel

Genetics and Molecular Biology

Jian Lu¹  Jianzhou Zheng¹  Qinggang Xu¹  Keping Chen¹  Chiyu Zhang¹ 

[1] ,Institute of Life Sciences Jiangsu University Jiangsu PR ,China

关键词: skeletal muscle voltage-gated Na (Na v1.4) channel;    tetrodotoxin (TTX);    positive selection;    pufferfish;    garter snake;   

DOI  :  10.1590/S1415-47572011000200026

来源: SciELO

【 摘 要 】

Tetrodotoxin (TTX) is a highly potent neurotoxin that blocks the action potential by selectively binding to voltage-gated sodium channels (Na v). The skeletal muscle Na v (Na v1.4) channels in most pufferfish species and certain North American garter snakes are resistant to TTX, whereas in most mammals they are TTX-sensitive. It still remains unclear as to whether the difference in this sensitivity among the various vertebrate species can be associated with adaptive evolution. In this study, we investigated the adaptive evolution of the vertebrate Na v1.4 channels. By means of the CODEML program of the PAML 4.3 package, the lineages of both garter snakes and pufferfishes were denoted to be under positive selection. The positively selected sites identified in the p-loop regions indicated their involvement in Na v1.4 channel sensitivity to TTX. Most of these sites were located in the intracellular regions of the Na v1.4 channel, thereby implying the possible association of these regions with the regulation of voltage-sensor movement.

【 授权许可】

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