Retinal pigment epithelium-retinal G protein-coupled receptor (RGR)

The Retinal pigment epithelium-retinal G protein-coupled receptor (RGR) is a member of the opsin family, classified among the rhodopsin-like G protein-coupled receptors. Unlike typical signaling GPCRs, RGR-opsin functions primarily as an intracellular photoisomerase, binding all-trans-retinal and catalyzing its conversion to 11-cis-retinal, thus playing an essential role in the visual cycle and regeneration of photopigments[1][2][3]. RGR is mainly expressed in the retinal pigment epithelium (RPE) and Müller glia of the eye, and more recently has been shown to be present in human skin cells such as keratinocytes, melanocytes, and fibroblasts, where it may regulate cell proliferation, migration, and apoptosis[2]. Mutations in the RGR gene have been linked to retinitis pigmentosa and peripapillary choroidal atrophy, supporting its essential role in retinal health[1][2]. Although structurally similar to other opsins, RGR lacks several key GPCR signaling motifs and is not a canonical signaling receptor[2]. No approved drugs specifically target RGR, but its roles in photoreceptor survival and tissue homeostasis suggest its dysfunction can have significant disease consequences[1][2].

Other names

RGR-opsinRP44RPE-retinal G protein-coupled receptorRGR