Highly effective phosphorylation by G protein-coupled receptor kinase 7 of light-activated visual pigment in cones.

ABSTRACT: Cone photoreceptors show briefer photoresponses than rod photoreceptors. Our previous study showed that visual pigment phosphorylation, a quenching mechanism of light-activated visual pigment, is much more rapid in cones than in rods. Here, we measured the early time course of this rapid phosphorylation with good time resolution and directly compared it with the photoresponse time course in cones. At the time of photoresponse recovery, almost two phosphates were incorporated into a bleached cone pigment molecule, which indicated that the visual pigment phosphorylation coincides with the photoresponse recovery. The rapid phosphorylation in cones is attributed to very high activity of visual pigment kinase [G protein-coupled receptor kinase (GRK) 7] in cones. Because of this high activity, c

SUBMITTER: Tachibanaki S 

PROVIDER: S-EPMC1166601 | biostudies-literature | 2005 Jun

REPOSITORIES: biostudies-literature