Regulation of gap junctions by stomatin-like proteins

描述（申请人提供）：间隙连接是普遍存在的细胞间通道，在发育和生理中起着非常重要的作用。然而，对可能与间隙连接相互作用和调节的蛋白质知之甚少。无脊椎动物系统可以用来识别进化上保守的缝隙连接调制器，因为无脊椎动物和脊椎动物的缝隙连接的主要结构特征和功能特性是保守的。在秀丽隐杆线虫中，unc-7、unc-9、unc-1和unc-24基因的独立功能丧失突变导致类似的表型，包括运动缺陷和对挥发性麻醉剂的敏感性改变。Unc-7和unc-9编码innexins，这是一种间隙连接蛋白，而unc-1和unc-24编码口状蛋白。目前尚不清楚为什么内联蛋白和口蛋白样蛋白的功能障碍会导致类似的表型。本提案的目的是验证UNC-1和UNC-24是间隙连接调节剂的假设。具体目的是：(1)探索UNC-9与口蛋白样蛋白相互作用的分子基础；(2)确定UNC-1和UNC-24是否与UNC-9的羧基端相互作用以调节间隙连接门控；(3)确定UNC-1、UNC-24、UNC-7和UNC-9是否在神经元中相互作用以调节运动。各种电生理学、遗传学和细胞生物学方法将被用来分析秀丽隐杆线虫以及哺乳动物异种表达系统中这些蛋白质之间的相互作用。该项目的长期目标是了解间隙连接调节的进化保守机制，并确定治疗和管理间隙连接相关疾病的候选药物靶点。

DESCRIPTION (provided by applicant): Gap junctions are ubiquitous intercellular channels that play very important roles in development and physiology. However, little is known about proteins that may interact with and modulate gap junctions. Invertebrate systems could be used to identify evolutionarily conserved gap junction modulators because major structural features and functional properties are conserved between invertebrate and vertebrate gap junctions. In C. elegans, independent loss-of-function mutations of the genes unc-7, unc-9, unc-1, and unc-24 cause similar phenotypes, including locomotion defects and altered sensitivity to volatile anesthetics. unc-7 and unc-9 encode innexins, which are gap junction proteins, whereas unc-1 and unc-24 encode stomatin-like proteins. It is unknown why dysfunctions of the innexins and stomatin-like proteins cause similar phenotypes. The purpose of this proposal is to test the hypothesis that UNC-1 and UNC-24 are modulators of gap junctions. The specific aims are (1) to explore molecular basis for interactions between UNC-9 and stomatin-like proteins, (2) to determine whether UNC-1 and UNC-24 interact with the carboxyl terminus of UNC-9 to modulate gap junction gating, and (3) to determine whether UNC-1, UNC-24, UNC-7, and UNC-9 interact in neurons to modulate locomotion. A variety of electrophysiological, genetic, and cell biological approaches will be used to analyze interactions among these proteins in C. elegans as well as in a mammalian heterologous expression system. The long term goals of this project are to understand evolutionarily conserved mechanisms of gap junction regulation and to identify candidate drug targets for treatment and management of gap junction-related diseases.