Bestrophin 3 (BEST3)

BEST3 belongs to the bestrophin family of anion channels, which includes BEST1, the gene mutant in vitelliform macular dystrophy (VMD), and 2 other BEST1-like genes, BEST2 and BEST4. Bestrophins are transmembrane (TM) proteins that share a homology region containing a high content of aromatic residues, including an invariant arg-phe-pro (RFP) motif. The open reading frame encodes a putative 398-amino acid protein with a calculated molecular weight of 46.6 kD. Several putative splice variants were observed leading to truncated protein isoforms with unknown functional relevance. The expression of VMD2L3 was predominantly observed in skeletal muscle and weaker in brain, spinal cord, bone marrow, retina, thymus, and testis. The VMD2 gene product has been localized to the basolateral membrane of the retinal pigment epithelium.