MOLECULAR STUDIES OF SODIUM CHANNELS IN SKELETAL MUSCLE

电压门控钠通道负责产生和 动作电位在电可兴奋细胞中的传播。钠 经络具有不同的药理和功能特性， 是由一个多基因家族编码的。三个高度同源的钠通道 大鼠脑内α亚基的cDNA序列分析 序列分析。赞助商的实验室已经克隆并鉴定了一个完整的- 在骨骼肌中编码一个独特的大鼠钠通道基因的长度的基因。 这项拟议研究的目标之一是阐明一种 第二个新的大鼠骨骼肌钠通道基因及其探针的制备 确定生物特性差异的结构基础 神经和骨骼肌中的钠通道。 具体目标是：1)确定有多少不同的钠通道 核苷酸序列分析表明大鼠骨骼肌中存在亚基 分离全长cDNA及其功能的鉴定 使用非洲爪哇卵母细胞表达系统的特性；2)确定 大鼠骨骼肌钠的细胞和亚细胞定位 免疫细胞化学和超微结构检测通道α亚基 技术，使用针对阿尔法的独特部分产生的抗体 3)河豚毒素分子基础的确定 (TTX)敏感和不敏感的钠通道mRNA分析 在对TTX敏感的成年肌肉和相对抗TTX的胚胎和 失去神经的肌肉。 在哺乳动物中，钠通道基因的自发突变 预计会扰乱正常的神经系统和骨骼肌功能 基于钠通道在信号和信号转导中的关键作用 信息处理，以及涉及钠的大量基因 五月组织中通道蛋白的产生。这些计划中的研究，在 结合我在遗传学方面的经验，将为 探讨可能的肌肉钠通道基因突变在心肌损伤中的作用 人类骨骼肌病。

The voltage-gated sodium channel is responsible for the generation and propagation of action potential in electrically excitable cells. Sodium channels exhibit different pharmacological and functional properties and are encoded by a multigene family. Three highly homologous sodium channel alpha subunits have been identified in rat brain by cDNA nucleotide sequence analysis. The sponsor's lab has cloned and characterized a full- length cDNA encoding a unique rat sodium channel cDNA in skeletal muscle. A goal of the proposed research is to elucidate the primary structure of a second novel rat skeletal muscle sodium channel gene and to generate probes to determine the structural basis for differences in biological properties of the sodium channels in nerve and skeletal muscle. The specific goals are: 1) to determine how many distinct sodium channel subunits are present in rat skeletal muscle by nucleotide sequence analysis of isolate full-length cDNAs and authentication of their functional properties using the Xenopus oocyte expression system; 2) to determine the cellular and subcellular localization of the rat skeletal muscle sodium channel alpha subunits by immuno-cytochemical and ultra-structural techniques, using antibodies raised against unique portions of the alpha subunit peptides; 3) to determine the molecular basis of tetrodotoxin (TTX)-sensitivity and -insensitivity utilizing sodium channel mRNA analysis in TTX-sensitive adult muscle and relatively TTX-resistant embryonic and denervated muscle. In mammals, spontaneous mutations of sodium channel genes that overtly disturb normal nervous system and skeletal muscle function are anticipated to occur, based on the key role of the sodium channel in signalling and information-processing, and the large number of genes involved in sodium channel protein production in may tissues. These planned studies, in conjunction with my experience in genetics, will provide the framework for addressing the role of putative muscle sodium channel gene mutations in disease of skeletal muscle in man.