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

NICOLAS M. DIAZ; LUIS P. MORERA; TOMAS TEMPESTI ; MARIO E. GUIDO

MOLECULAR NEUROBIOLOGY

HUMANA PRESS INC

Lugar: Oregon; Año: 2016 p. 1 - 1

0893-7648

he 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 forming tasks. Rhodopsin/cone opsin photopigments in visual PRs or melanopsin [Opn4] in ipRGCs utilize retinaldehyde as chromophore. The retinoid regeneration process denominated ?visual cycle? involves the retinal pigment epithelium (RPE) or Müller glial cells. Opn4, on the contrary, has been characterized as a bi/tristable photopigment, in which a photon of 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 metabolized in the inner retina. Nor is it yet clear whether an alternative secondary cycle occurs involving players such as the retinal G-protein-coupled receptor (RGR), a putative photoisomerase of unidentified inner retinal activity. Here we investig