BEST2

Ligand-gated anion channel that allows the movement of anions across cell membranes when activated by calcium (Ca2+). Transports a large specter of anions, namely mediates the movement of chloride, L-glutamate and iodide. Calcium-binding triggers the dilation of the aperture, but calcium-dependent gating is only effective when the size of the passing anion is bigger than the closed aperture (By similarity). Mediates the calcium-activated hydrogencarbonate movement and participates in colonic hydrogencarbonate secretion concomitant with mucin secretion (By similarity). In non-pigmented epithelium (NPE), mediates the efflux of intracellular L-glutamate; binding of intracellular L-glutamate activates and open both the neck and the aperture of the channel, leading to L-glutamate exit promoting chloride influx movement from the extracellular side in trans. Also exhibits a directional permeability for intracellular glutamine, in a similar manner as for L-glutamate..

Function from UniProtKB (Q8NFU1), read 2026-09-23. CC BY 4.0.