A photic visual cycle of rhodopsin regeneration is dependent on Rgr

Autor: Pu Chen, L. Rife, Wenshan Hao, Thomas E. Ogden, Jeannie Chen, Gretchen B. Van Boemel, Daiwei Shen, Lanyin Wu, Henry K.W. Fong, Mao Yang, Xiao Peng Wang
Rok vydání: 2001
Předmět:
Zdroj: Nature genetics. 28(3)
ISSN: 1061-4036
Popis: During visual excitation, rhodopsin undergoes photoactivation and bleaches to opsin and all-trans-retinal1,2. To regenerate rhodopsin and maintain normal visual sensitivity, the all-trans isomer must be metabolized and reisomerized to produce the chromophore 11-cis-retinal in biochemical steps that constitute the visual cycle and involve the retinal pigment epithelium (RPE; refs. 3–8). A key step in the visual cycle is isomerization of an all-trans retinoid to 11-cis-retinol in the RPE (refs. 9–11). It could be that the retinochrome-like opsins, peropsin, or the retinal G protein-coupled receptor (RGR) opsin12–16 are isomerases in the RPE. In contrast to visual pigments, RGR is bound predominantly to endogenous all-trans-retinal, and irradiation of RGR in vitro results in stereospecific conversion of the bound all-trans isomer to 11-cis-retinal17. Here we show that RGR is involved in the formation of 11-cis-retinal in mice and functions in a light-dependent pathway of the rod visual cycle. Mutations in the human gene encoding RGR are associated with retinitis pigmentosa18.
Databáze: OpenAIRE