The Visual Cycle in the Inner Retina of Chicken and the involvement of Retinal G-Protein-coupled Receptor (RGR)

NICOLÁS M. DÍAZ; LUIS P. MORERA; TOMAS TEMPESTI; MARIO E. GUIDO

MOLECULAR NEUROBIOLOGY

HUMANA PRESS INC

Lugar: Oregon; Año: 2016

0893-7648

bstract The vertebrate retina contains typical photoreceptor(PR) cones and rods responsible for day/night vision, respectively,and intrinsically photosensitive retinal ganglion cells(ipRGCs) involved in the regulation of non-image-formingtasks. Rhodopsin/cone opsin photopigments in visual PRs ormelanopsin (Opn4) in ipRGCs utilizes retinaldehyde as achromophore. The retinoid regeneration process denominatedas Bvisual cycle^ involves the retinal pigment epithelium(RPE) or Müller glial cells. Opn4, on the contrary, has beencharacterized as a bi/tristable photopigment, in which a photonof one wavelength isomerizes 11-cis to all-trans retinal(Ral), with a second photon re-isomerizing it back.However, it is unknown how the chromophore is further metabolizedin the inner retina. Nor is it yet clear whether analternative secondary cycle occurs involving players such asthe retinal G-protein-coupled receptor (RGR), a putativephotoisomerase of unidentified inner retinal activity. Here,we investig