Referenced in: none

Automatically associated channels: ClC4 , ClCA1

Title: pCLCA1 becomes a cAMP-dependent chloride conductance mediator in Caco-2 cells.

Authors: Matthew E Loewen, Lane K Bekar, Sherif E Gabriel, Wolfgang Walz, George W Forsyth

Journal, date & volume: Biochem. Biophys. Res. Commun., 2002 Nov 8 , 298, 531-6

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/12408984

Abstract
Members of the CLCA protein family are expressed in airway and intestinal epithelium, where they may participate in secretory activity as mediators of chloride conductance. A calcium-dependent chloride conductance has been observed upon expression of CLCA proteins in non-epithelial cell lines. The pCLCA1 gene, cloned in our laboratory, codes for a product containing a unique A-kinase consensus acceptor site not found in other CLCA proteins. Calcium-dependent, but not cAMP-dependent, chloride conductance increased when pCLCA1 was expressed in NIH/3T3 fibroblasts. We transfected the Caco-2 human colon carcinoma cell line with pCLCA1 to investigate the regulation of CLCA-associated chloride conductance in this differentiated epithelial cell line. Expression of pCLCA1 in the Caco-2 cell line enhanced cAMP-responsive 36Cl efflux, short circuit current, and whole cell chloride current in these cells. This cAMP-dependent chloride conductance was localized to the apical membrane of polarized Caco-2 cells.