Phosphorylation of Gap Junction Proteins

描述（由申请人提供）：间隙连接是专门匹配的膜结构域，其含有允许交换小分子的通道，所述小分子包括离子、代谢物和第二信使（例如，Ca ~（2+）和IP_3）。这些通道是正常发育所必需的，遗传连锁分析表明连接蛋白与至少14种人类疾病有关。差距连接蛋白连接蛋白43（Cx43）受超过12个磷酸化事件调节。Cx43的短半衰期（约2小时）导致间隙连接不断组装，重塑和翻转。生长因子和创伤可以进一步减少Cx43的半衰期，并在一小时内从质膜上清除间隙连接，这一过程我们称之为急性周转。该提案的重点是Cx43磷酸化在间隙连接稳定性中的作用，以及急性营业额如何响应生长因子和皮肤损伤而增强。我们建议：（1）。确定增加的间隙连接大小是否促进急性周转;（2）.测试Cx43的Src磷酸化是否是GJ内化所必需的并指导内吞途径，和（3）。确定表皮创伤过程中Cx43磷酸化和间隙连接转换的生理后果。

DESCRIPTION (provided by applicant): Gap junctions are specialized matched membrane domains that contain channels that allow exchange of small molecules including ions, metabolites, and second messengers (e.g., Ca2+ and IP3) between neighboring cells. These channels are necessary for proper development, and genetic linkage analyses have implicated connexins in at least 14 human diseases. The gap junction protein connexin43 (Cx43) is regulated by more than 12 phosphorylation events. The short half-life of Cx43 (~2 h) causes gap junctions to be constantly assembled, remodeled and turned over. Growth factors and wounding can further reduce Cx43's half-life and clear gap junctions from the plasma membrane within an hour in a process we term acute turnover. This proposal focuses on the role that Cx43 phosphorylation plays in gap junction stability and how acute turnover is enhanced in response to growth factors and skin wounding. We propose to: (1). determine if increased gap junction size promotes acute turnover; (2). test whether Src phosphorylation of Cx43 is necessary for GJ internalization and directs the endocytic route, and (3). determine the physiological consequences of Cx43 phosphorylation and gap junction turnover during epidermal wounding.