RUI: Molecular Biophysical Studies of Cysteine Residues in the CFTR Cl- Channel

囊性纤维化跨膜传导调节剂（CFTR）是一种在全身上皮细胞中发现的独特氯离子通道。虽然CFTR在功能上是一个离子通道，但在结构上属于atpase依赖性转运蛋白家族，称为ABC转运蛋白。然而，CFTR是唯一已知的主要作为离子通道起作用的成员。由于其独特的分子进化，CFTR通道是离子通道结构和功能生物物理研究的一个有趣而重要的模型。组成这个项目的实验是基于初步研究，这些研究表明通道的门控是由蛋白质的还原/氧化（氧化还原）状态改变的。该实验结合了分子生物学和电生理学技术来研究氧化还原敏感的半胱氨酸残基在调节通道门控中的作用。该结果将用于鉴定蛋白质内对通道功能重要的结构域相互作用。要测试的主要假设是：(1)通道的门控受到特定半胱氨酸残基的氧化还原状态的影响，如果发生突变，通道性质会发生变化；(2)将半胱氨酸重新引入突变蛋白质的策略区域将恢复正常活性，并有助于识别对通道功能重要的蛋白质区域；(3)当细胞产生一氧化氮时，它充当CFTR通道的内源性氧化还原调节剂。这项研究将涉及本科生的直接参与，从而将改善莫尔豪斯学院生物系的研究和教育环境

The cystic fibrosis transmembrane conductance regulator (CFTR) is a unique chloride channel found in epithelial cells throughout the body. While functionally an ion channel, structurally CFTR belongs to a family of ATPase-dependent transporters known as ABC transporters. CFTR, however, is the only known member to function primarily as an ion channel. Because of its unique molecular evolution, the CFTR channel is an interesting and important model for biophysical studies of ion channel structure and function. The experiments that comprise this project are based on preliminary studies which show that the gating of the channel is altered by the reduction/oxidation (redox) state of the protein. The experiments use a combination of molecular biological and electrophysiological techniques to examine the role of redox-sensitive cysteine residues in modulating channel gating. The results will be used to identify domain interactions within the protein that are important for channel function. The major hypotheses to be tested are (1) that gating of the channel is influenced by the redox state of specific cysteine residues which if mutated change channel properties, (2) that reintroducing cysteines into strategic areas of mutated proteins will restore normal activity and will help identify regions of the protein important for channel function, and (3) that nitric oxide, when produced by cells, acts as an endogenous redox regulator of the CFTR channel. The research will involve the direct participation of undergraduates, and thus will enhance both the research and educational environment of the Biology Department at Morehouse College