Bestrophin-1 Encodes for the Ca2+-Activated Anion Channel in Hippocampal Astrocytes

• DOI: 10.1523/jneurosci.3193-09.2009
• Publication Date: 2009-10-14T20:12:59Z
• Authors: Hyungju Park; Soo-Jin Oh; Kyung-Seok Han; Dong Ho Woo; Hyekyung Park; Guido Mannaioni; Stephen F. Traynelis; C. Justin Lee
• Keywords: Niflumic acid; HEK 293 cells; Reversal potential; Chloride channel; Channel blocker

In mammalian brain, neurons and astrocytes are reported to express various chloride anion channels, but the evidence for functional expression of Ca 2+ -activated channel (CAAC) its molecular identity have been lacking. Here we report electrophysiological CAAC by mouse Bestrophin 1 ( mBest1 ) in brain. Using imaging perforated-patch-clamp analysis, demonstrate that displayed an inward current at holding potential −70 mV was dependent on increase intracellular after G αq -coupled receptor activation. This mediated mostly anions sensitive well known blockers such as niflumic acid, 5-nitro-2(3-phenylpropylamino)-benzoic flufenamic acid. To find responsible current, analyzed candidate genes found mRNA is predominantly expressed acutely dissociated or cultured astrocytes. Whole-cell patch-clamp analysis using HEK293T cells heterologously expressing full-length showed a -dependent mBest1, with complete impairment putative pore mutation, W93C. Furthermore, mBest1-mediated from significantly reduced -specific short hairpin RNA (shRNA), suggesting encoded . Finally, hippocampal CA1 slice also because it inhibited mBest1-specific shRNA. Collectively, these data provide function