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Molecular and Functional Characterization of Murine Bestrophin 1 Cloned from Heart
Author(s) -
O’Driscoll Kate Eileen,
Leblanc Normand,
Britton Fiona C
Publication year - 2008
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.22.1_supplement.1201.25
Subject(s) - niflumic acid , chloride channel , complementary dna , hek 293 cells , dids , chemistry , transfection , microbiology and biotechnology , patch clamp , molecular cloning , biochemistry , biology , gene , receptor , membrane
Calcium‐activated chloride channels (Cl Ca ) are widely distributed in cardiac tissues and play important roles in the regulation of cardiac excitability. However, the molecular identity of this channel remains unknown. Bestrophins were recently shown to form Cl Ca when expressed heterologously. We hypothesize that Bestrophins are candidates for the calcium‐activated chloride current (I ClCa ) in cardiac tissues. We demonstrate that several members of this family are expressed in heart. Previous studies have reported the functional expression of two members of the murine Bestrophin family, mBest2 and mBest3. Here we report the functional characterization of mBest1. We isolated the cDNA transcript of mBest1 from mouse heart and cloned it into a mammalian expression vector so that functional analysis could be performed to determine if it encodes a Cl Ca . Whole‐cell patch clamp experiments with HEK cells transfected with mBest1 revealed a calcium sensitive, time independent chloride current. This DIDS‐ and niflumic acid‐sensitive current displayed slight voltage dependence and exhibited a lyotropic sequence of anion permeability, SCN − >I − >Cl − . Our data contributes to the characterization of the biophysical properties of Bestrophins and helps further the investigation into the molecular candidate of cardiac I ClCa .