Affiliation:
1. Department of Regenerative Medicine and Cell Biology, Medical University of South Carolina, Charleston, SC 29425
Abstract
Connexin 43 (Cx43) is a gap junction (GJ) protein widely expressed in mammalian tissues that mediates cell-to-cell coupling. Intercellular channels comprising GJ aggregates form from docking of paired connexons, with one each contributed by apposing cells. Zonula occludens-1 (ZO-1) binds the carboxy terminus of Cx43, and we have previously shown that inhibition of the Cx43/ZO-1 interaction increases GJ size by 48 h. Here we demonstrated that increases in GJ aggregation occur within 2 h (∼Cx43 half-life) following disruption of Cx43/ZO-1. Immunoprecipitation and Duolink protein–protein interaction assays indicated that inhibition targets ZO-1 binding with Cx43 in GJs as well as connexons in an adjacent domain that we term the “perinexus.” Consistent with GJ size increases being matched by decreases in connexons, inhibition of Cx43/ZO-1 reduced the extent of perinexal interaction, increased the proportion of connexons docked in GJs relative to undocked connexons in the plasma membrane, and increased GJ intercellular communication while concomitantly decreasing hemichannel-mediated membrane permeance in contacting, but not noncontacting, cells. ZO-1 small interfering RNA and overexpression experiments verified that loss and gain of ZO-1 function govern the transition of connexons into GJs. It is concluded that ZO-1 regulates the rate of undocked connexon aggregation into GJs, enabling dynamic partitioning of Cx43 channel function between junctional and proximal nonjunctional domains of plasma membrane.
Publisher
American Society for Cell Biology (ASCB)
Subject
Cell Biology,Molecular Biology
Cited by
247 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献