Document Detail

β-Arrestin-Dependent Deactivation of Mouse Melanopsin.
MedLine Citation:
PMID:  25401926     Owner:  NLM     Status:  In-Data-Review    
In mammals, the expression of the unusual visual pigment, melanopsin, is restricted to a small subset of intrinsically photosensitive retinal ganglion cells (ipRGCs), whose signaling regulate numerous non-visual functions including sleep, circadian photoentrainment and pupillary constriction. IpRGCs exhibit attenuated electrical responses following sequential and prolonged light exposures indicative of an adaptational response. The molecular mechanisms underlying deactivation and adaptation in ipRGCs however, have yet to be fully elucidated. The role of melanopsin phosphorylation and β-arrestin binding in this adaptive process is suggested by the phosphorylation-dependent reduction of melanopsin signaling in vitro and the ubiquitous expression of β-arrestin in the retina. These observations, along with the conspicuous absence of visual arrestin in ipRGCs, suggest that a β-arrestin terminates melanopsin signaling. Here, we describe a light- and phosphorylation- dependent reduction in melanopsin signaling mediated by both β-arrestin 1 and β-arrestin 2. Using an in vitro calcium imaging assay, we demonstrate that increasing the cellular concentration of β-arrestin 1 and β-arrestin 2 significantly increases the rate of deactivation of light-activated melanopsin in HEK293 cells. Furthermore, we show that this response is dependent on melanopsin carboxyl-tail phosphorylation. Crosslinking and co-immunoprecipitation experiments confirm β-arrestin 1 and β-arrestin 2 bind to melanopsin in a light- and phosphorylation- dependent manner. These data are further supported by proximity ligation assays (PLA), which demonstrate a melanopsin/β-arrestin interaction in HEK293 cells and ipRGCs. Together, these results suggest that melanopsin signaling is terminated in a light- and phosphorylation-dependent manner through the binding of a β-arrestin within the retina.
Evan G Cameron; Phyllis R Robinson
Related Documents :
2795476 - Head-free pursuit in the human of a visual target moving in a pseudo-random manner.
2788476 - Effects of optokinetic velocity and medial vestibulo-cerebellum lesions on vestibulo-oc...
3612146 - The relationship of neck orientation to the shape of the proximal femur.
8749066 - Evaluation of the human vestibulo-ocular reflex at high frequencies with a helmet, driv...
10505606 - Comparable effects of flickering and steady patterns of light adaptation on photomechan...
12612006 - Kinematics and kinetics of multijoint reaching in nonhuman primates.
Publication Detail:
Type:  Journal Article     Date:  2014-11-17
Journal Detail:
Title:  PloS one     Volume:  9     ISSN:  1932-6203     ISO Abbreviation:  PLoS ONE     Publication Date:  2014  
Date Detail:
Created Date:  2014-11-18     Completed Date:  -     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  101285081     Medline TA:  PLoS One     Country:  United States    
Other Details:
Languages:  eng     Pagination:  e113138     Citation Subset:  IM    
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

Previous Document:  Correction: impact of light/dark cycle patterns on oxidative stress in an adriamycin-induced nephrop...
Next Document:  Use of gonadorelin[6-D-Phe] at day 0 or 12 after insemination to increase the conception rate in a l...