High impact information on RGR

• 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-retinal [1].
• Mutations in RGR, encoding a light-sensitive opsin homologue, in patients with retinitis pigmentosa [2].
• Truncation and site-directed mutagenesis of the V2R C terminus revealed an involvement of an RGR sequence in this interaction [3].
• The NADPH-dependent all-trans-retinol dehydrogenase activity in isolated RPE microsomal membranes can be linked in vitro to specific binding of the chromophore to RGR [4].
• The intracellular processing of all-trans-[(3)H]retinol results in physiological binding to RGR of a radiolabeled retinoid, identified as all-trans-[(3)H]retinal [4].

Biological context of RGR

• A second form of human RGR in retina is predicted by alternative splicing of its precursor mRNA [5].
• Localization of the human RGR opsin gene to chromosome 10q23 [6].
• Analysis of the fluorescence signals on high-resolution banded chromosomes showed that the RGR gene is localized to human chromosome 10q23 [6].

Anatomical context of RGR

• We have analyzed a 32-kDa protein (p32) that co-purifies with bovine RGR from RPE microsomes [7].
• Synthesis of the all-trans-retinal chromophore of retinal G protein-coupled receptor opsin in cultured pigment epithelial cells [4].
• The human RGR gene encodes an opsin protein (retinal G protein-coupled receptor), which is expressed in Müller cells and the retinal pigment epithelium and is thought to play a role in the visual process [6].
• The 12 amino acids present in HERG(Delta147) and absent in HERG(Delta159) include a potential endoplasmic reticulum (ER) retention signal, RGR, which when mutated to LGL (HERG(Delta147-LGL)) restored I(Kr) [8].
• Exon-skipping variant of RGR opsin in human retina and pigment epithelium [9].

Associations of RGR with chemical compounds

• These results indicate that cRDH is involved in the processing of 11-cis-retinal after irradiation of RGR opsin and suggest that cRDH has a novel role in the visual cycle [7].
• The putative RPE-retinal G protein coupled receptor (RGR) covalently binds both all-trans- and 11-cis-retinal after reduction by sodium borohydride [5].
• Nitrogen dioxide at 0.5 microl liter(-1) reduced RGR and NAR by 47% and 51%, respectively [10].
• A new topical anesthetic, liposomal lidocaine 4% cream (Maxilene, RGR Pharma, Windsor, Ont.), has become available [11].

Other interactions of RGR

• A common lineage for RRH and RGR, together with their sites of expression in the RPE, indicates that peropsin may act as a retinal isomerase [12].
• Interaction of 11-cis-retinol dehydrogenase with the chromophore of retinal g protein-coupled receptor opsin [7].
• Study of the involvement of the RGR, CRPB1, and CRB1 genes in the pathogenesis of autosomal recessive retinitis pigmentosa [13].
• Exceptions to this are RGR-opsin and melanopsin, whose genes have very different intron insertion positions [12].
• The ARPE-hRGR cells contain a membrane-bound NADPH-dependent retinol dehydrogenase that reacts efficiently with all-trans-retinol but not the 11-cis isomer [4].

Analytical, diagnostic and therapeutic context of RGR

• Genomic and cDNA fragments of the human RGR gene were used as probes for fluorescence in situ hybridization [6].

References