Dynein regulates Kv7.4 channel trafficking from the cell membrane

作者：Jennifer van der Horst, Salomé Rognant, Geoffrey W. Abbott, Lijo Cherian Ozhathil, Per Hägglund, Vincenzo Barrese, Christine Y. Chuang, Thomas Jespersen, Michael J. Davies, Iain A. Greenwood, Pontus Gourdon, Christian Aalkjær, Thomas A. Jepps · 发表于：The Journal of General Physiology · 年份：2021 · DOI：10.1085/jgp.202012760 · 被引用次数：20 · 研究领域：Microtubule and mitosis dynamics、Cellular transport and secretion、Ion channel regulation and function

The dynein motor protein transports proteins away from the cell membrane along the microtubule network. Recently, we found the microtubule network was important for regulating the membrane abundance of voltage-gated Kv7.4 potassium channels in vascular smooth muscle. Here, we aimed to investigate the influence of dynein on the microtubule-dependent internalization of the Kv7.4 channel. Patch-clamp recordings from HEK293B cells showed Kv7.4 currents were increased after inhibiting dynein function with ciliobrevin D or by coexpressing p50/dynamitin, which specifically interferes with dynein motor function. Mutation of a dynein-binding site in the Kv7.4 C terminus increased the Kv7.4 current and prevented p50 interference. Structured illumination microscopy, proximity ligation assays, and coimmunoprecipitation showed colocalization of Kv7.4 and dynein in mesenteric artery myocytes. Ciliobrevin D enhanced mesenteric artery relaxation to activators of Kv7.2-Kv7.5 channels and increased membrane abundance of Kv7.4 protein in isolated smooth muscle cells and HEK293B cells. Ciliobrevin D failed to enhance the negligible S-1-mediated relaxations after morpholino-mediated knockdown of Kv7.4. Mass spectrometry revealed an interaction of dynein with caveolin-1, confirmed using proximity ligation and coimmunoprecipitation assays, which also provided evidence for interaction of caveolin-1 with Kv7.4, confirming that Kv7.4 channels are localized to caveolae in mesenteric artery myocytes. La...