Adaptive evolution of the vertebrate skeletal muscle sodium channel
Lu, Jian, Zheng, Jianzhou, Xu, Qinggang, Chen, Keping, Zhang, Chiyu
Genetics and Molecular Biology
DATA DE PUBLICAÇÃO
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.
- Modulation of sodium-channel mRNA levels in rat skeletal muscle.
- RFLP for BgIII at the human skeletal muscle sodium channel locus
- Sodium channel distribution in normal and denervated rodent and snake skeletal muscle.
- Single-channel analysis of inactivation-defective rat skeletal muscle sodium channels containing the F1304Q mutation.
- Chemical modification of sodium channel surface charges in frog skeletal muscle by trinitrobenzene sulphonic acid.