Compartmentalization and Ca2+ buffering are essential for prevention of light-induced retinal degeneration.

ABSTRACT: Fly photoreceptors are polarized cells, each of which has an extended interface between its cell body and the light-signaling compartment, the rhabdomere. Upon intense illumination, rhabdomeric calcium concentration reaches millimolar levels that would be toxic if Ca(2+) diffusion between the rhabdomere and cell body was not robustly attenuated. Yet, it is not clear how such effective attenuation is obtained. Here we show that Ca(2+) homeostasis in the photoreceptor cell relies on the protein calphotin. This unique protein functions as an immobile Ca(2+) buffer localized along the base of the rhabdomere, separating the signaling compartment from the cell body. Generation and analyses of transgenic Drosophila strains, in which calphotin-expression levels were reduced in a graded manner, sho

SUBMITTER: Weiss S 

PROVIDER: S-EPMC3492704 | biostudies-literature | 2012 Oct

REPOSITORIES: biostudies-literature