Referenced in: none

Automatically associated channels: ClC2 , ClC4

Title: Splice variants of a ClC-2 chloride channel with differing functional characteristics.

Authors: L P Cid, M I Niemeyer, A Ramírez, F V Sepúlveda

Journal, date & volume: Am. J. Physiol., Cell Physiol., 2000 Oct , 279, C1198-210

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/11003600

Abstract
We identified two ClC-2 clones in a guinea pig intestinal epithelial cDNA library, one of which carries a 30-bp deletion in the NH(2) terminus. PCR using primers encompassing the deletion gave two products that furthermore were amplified with specific primers confirming their authenticity. The corresponding genomic DNA sequence gave a structure of three exons and two introns. An internal donor site occurring within one of the exons accounts for the deletion, consistent with alternative splicing. Expression of the variants gpClC-2 and gpClC-2Delta77-86 in HEK-293 cells generated inwardly rectifying chloride currents with similar activation characteristics. Deactivation, however, occurred with faster kinetics in gpClC-2Delta77-86. Site-directed mutagenesis suggests that a protein kinase C-mediated phosphorylation consensus site lost in gpClC-2Delta77-86 is not responsible for the observed change. The deletion-carrying variant is found in most tissues examined, and it appears more abundant in proximal colon, kidney, and testis. The presence of a splice variant of ClC-2 modified in its NH(2)-terminal domain could have functional consequences in tissues where their relative expression levels are different.