A Potential Cytosolic Function of Bestrophin-1
Mutations in the BEST1 gene lead to a variety of retinal degenerations. In the eye, the BEST1 gene product bestrophin-1 is expressed in the retinal pigment epithelium (RPE). It is likely that retinal degenerations are caused by a change of the RPE function. Recent publications indicated that endogenously expressed bestrophin-1 function as a cytosolic Cl channel in Ca2+ stores of the endoplasmic reticulum influences intracellular Ca2+ signaling. Possible cytosolic function of BEST1 could help to understand discrepancies between the bestrophin-1 function in overexpression systems and in animal models as well as to develop new ways to understand BEST1-associated retinal degenerations.