Extracellular K+ concentration controls cell surface density of IKr in rabbit hearts and of the HERG channel in human cell lines.

ABSTRACT: Although the modulation of ion channel gating by hormones and drugs has been extensively studied, much less is known about how cell surface ion channel expression levels are regulated. Here, we demonstrate that the cell surface density of both the heterologously expressed K+ channel encoded by the human ether-a-go-go-related gene (HERG) and its native counterpart, the rapidly activating delayed rectifier K+ channel (IKr), in rabbit hearts in vivo is precisely controlled by extracellular K+ concentration ([K+]o) within a physiologically relevant range. Reduction of [K+]o led to accelerated internalization and degradation of HERG channels within hours. Confocal analysis revealed colocalization between HERG and ubiquitin during the process of HERG internalization, and overexpression of ubiqui

SUBMITTER: Guo J 

PROVIDER: S-EPMC2735921 | biostudies-literature | 2009 Sep

REPOSITORIES: biostudies-literature