Opsin-5 receptor (OPN5)

Opsin-5 receptor (OPN5), also known as neuropsin or G-protein coupled receptor 136, is a member of the opsin class within the G protein-coupled receptor superfamily[2][3]. It is a UV-sensitive photoreceptor protein expressed in various tissues, including the eye, brain, spinal cord, and testes[2][3][4][5]. OPN5 plays a role in nonvisual photoreception by activating Gi-mediated (and possibly Gq-mediated) signaling pathways upon UV-light-induced isomerization of its chromophore, 11-cis-retinal[2][3][4][5]. This receptor contributes to circadian rhythm entrainment, vascular development in the eye, regulation of choroidal thickness, and suppression of thermogenesis[1][4]. Although its direct involvement in specific human diseases is still under investigation, OPN5 is important for physiological light sensing outside canonical vision[1][2][3][4]. No clinically used drugs or established biomarkers are currently associated with OPN5, and therapeutic interventions targeting this receptor have not been established as of current knowledge[2][3][4][5].

Other names

G-protein coupled receptor 136neuropsinPGR12TMEM13GPR136transmembrane protein 13dJ402H5.1

Activation of Gi-type (and possibly Gq-type) heterotrimeric G protein signaling following UV light absorption[2][3][5]