Insights into the ClC-4 transport mechanism from studies of Zn2+ inhibition.

ABSTRACT: The CLC family of chloride channels and transporters is a functionally diverse group of proteins important in a wide range of physiological processes. ClC-4 and ClC-5 are localized to endosomes and seem to play roles in the acidification of these compartments. These proteins were recently shown to function as Cl(-)/H(+) antiporters. However, relatively little is known about the detailed mechanism of CLC-mediated Cl(-)/H(+) antiport, especially for mammalian isoforms. We attempted to identify molecular tools that might be useful in probing structure-function relationships in these proteins. Here, we record currents from human ClC-4 (hClC-4) expressed in Xenopus oocytes, and find that Zn(2+) inhibits these currents, with an apparent affinity of approximately 50 microM. Although Cd(2+) has a

SUBMITTER: Osteen JD 

PROVIDER: S-EPMC2576391 | biostudies-literature | 2008 Nov

REPOSITORIES: biostudies-literature