Referenced in: none

Automatically associated channels: ClC2 , ClC4

Title: Membrane cholesterol content modulates ClC-2 gating and sensitivity to oxidative stress.

Authors: Alexandre Hinzpeter, Janine Fritsch, Florence Borot, Stéphanie Trudel, Diane-Lore Vieu, Franck Brouillard, Maryvonne Baudouin-Legros, Jérôme Clain, Aleksander Edelman, Mario Ollero

Journal, date & volume: J. Biol. Chem., 2007 Jan 26 , 282, 2423-32

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/17110372

Abstract
ClC-2 is a broadly expressed member of the voltage-gated ClC chloride channel family. In this study, we aimed to evaluate the role of the membrane lipid environment in ClC-2 function, and in particular the effect of cholesterol and ClC-2 distribution in membrane microdomains. Detergent-resistant and detergent-soluble microdomains (DSM) were isolated from stably transfected HEK293 cells by a discontinuous OptiPrep gradient. ClC-2 was found concentrated in detergent-insoluble membranes in basal conditions and relocalized to DSM upon cholesterol depletion by methyl-beta-cyclodextrin. As assessed by patch clamp recordings, relocalization was accompanied by acceleration of the activation kinetics of the channel. A similar distribution and activation pattern were obtained when cells were treated with the oxidant tert-butyl hydroperoxide and after ATP depletion. In both cases activation was prevented by cholesterol enrichment of cells. We conclude that the cholesterol environment regulates ClC-2 activity, and we provide evidence that the increase in ClC-2 activity in response to acute oxidative or metabolic stress involves relocalization of this channel to DSM.