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Two highly homologous members of the ClC chloride channel family in both rat and human kidney

Item Type:Article
Title:Two highly homologous members of the ClC chloride channel family in both rat and human kidney
Creators Name:Kieferle, S., Fong, P., Bens, M., Vandewalle, A. and Jentsch, T.J.
Abstract:We have cloned two closely related putative Cl- channels from both rat kidney (designated rClC-K1 and rClC-K2) and human kidney (hClC-Ka and hClC-Kb) by sequence homology to the ClC family of voltage-gated Cl- channels. While rClC-K1 is nearly identical to ClC-K1, a channel recently isolated by a similar strategy, rClC-K2 is 80% identical to rClC-K1 and is encoded by a different gene. hClC-Ka and hClC-Kb show approximately 90% identity, while being approximately 80% identical to the rat proteins. All ClC-K gene products are expressed predominantly in the kidney. While rClC-K1 is expressed strongly in the cortical thick ascending limb and the distal convoluted tubule, with minor expression in the S3 segment of the proximal tubule and the cortical collecting tubule, rClC-K2 is expressed in all segments of the nephron examined, including the glomerulus. Since they are related more closely to each other than to the rat proteins, hClC-Ka and hClC-Kb cannot be regarded as strict homologs of rClC-K1 or rClC-K2. After injection of ClC-K cRNAs into oocytes, corresponding proteins were made and glycosylated, though no additional Cl- currents were detectable. Glycosylation occurs between domains D8 and D9, leading to a revision of the transmembrane topology model for ClC channels.
Keywords:Amino Acid Sequence, Base Sequence, Chloride Channels, Molecular Cloning, DNA, Glycosylation, Kidney, Molecular Sequence Data, Site-Directed Mutagenesis, Amino Acid Sequence Homology, Tissue Distribution, Animals, Rats
Source:Proceedings of the National Academy of Sciences of the United States of America
Publisher:National Academy of Sciences
Page Range:6943-6947
Date:19 July 1994
Official Publication:http://www.pnas.org/content/91/15/6943.abstract
PubMed:View item in PubMed

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