The C-Terminus and Third Cytoplasmic Loop Cooperatively Activate Mouse Melanopsin Phototransduction.

ABSTRACT: Melanopsin, an atypical vertebrate visual pigment, mediates non-image-forming light responses including circadian photoentrainment and pupillary light reflexes and contrast detection for image formation. Melanopsin-expressing intrinsically photosensitive retinal ganglion cells are characterized by sluggish activation and deactivation of their light responses. The molecular determinants of mouse melanopsin's deactivation have been characterized (i.e., C-terminal phosphorylation and β-arrestin binding), but a detailed analysis of melanopsin's activation is lacking. We propose that an extended third cytoplasmic loop is adjacent to the proximal C-terminal region of mouse melanopsin in the inactive conformation, which is stabilized by the ionic interaction of these two regions. This model is su

SUBMITTER: Valdez-Lopez JC 

PROVIDER: S-EPMC7376183 | biostudies-literature | 2020 Jul

REPOSITORIES: biostudies-literature