Adaptive evolution of the vertebrate skeletal muscle sodium channel

Autor: Jian Lu, Jianzhou Zheng, Qinggang Xu, Keping Chen, Chiyu Zhang
Jazyk: angličtina
Rok vydání: 2011
Předmět:
Zdroj: Genetics and Molecular Biology, Vol 34, Iss 2, Pp 323-328 (2011)
Druh dokumentu: article
ISSN: 1415-4757
1678-4685
47693975
DOI: 10.1590/S1415-47572011000200026
Popis: 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.
Databáze: Directory of Open Access Journals