8ecy

Structural highlights

Function

BEST2_BOVIN Ligand-gated anion channel that allows the movement of anions across cell membranes when activated by calcium (Ca2+) (PubMed:32251414, PubMed:36289327). Transports a large specter of anions, namely mediates the movement of chloride, L-glutamate and iodide (PubMed:32251414, PubMed:36289327). 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 (PubMed:32251414). 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 (By similarity). Also exhibits a directional permeability for intracellular glutamine, in a similar manner as for L-glutamate (By similarity).[UniProtKB:Q8BGM5][UniProtKB:Q8NFU1]^{[1] [2]}

See Also

• Glutamine synthetase 3D structures

References

1. ↑ Owji AP, Zhao Q, Ji C, Kittredge A, Hopiavuori A, Fu Z, Ward N, Clarke OB, Shen Y, Zhang Y, Hendrickson WA, Yang T. Structural and functional characterization of the bestrophin-2 anion channel. Nat Struct Mol Biol. 2020 Apr;27(4):382-391. doi: 10.1038/s41594-020-0402-z. Epub, 2020 Apr 6. PMID:32251414 doi:http://dx.doi.org/10.1038/s41594-020-0402-z
2. ↑ Owji AP, Yu K, Kittredge A, Wang J, Zhang Y, Yang T. Bestrophin-2 and glutamine synthetase form a complex for glutamate release. Nature. 2022 Nov;611(7934):180-187. PMID:36289327 doi:10.1038/s41586-022-05373-x