Medium-wave-sensitive opsin 2 (OPN1MW2)

Medium-wave-sensitive opsin 2 (OPN1MW2) is an opsin-family G protein-coupled receptor, expressed in the cone photoreceptor cells of the retina and enabling perception of medium-wavelength (green/yellow) light. The OPN1MW2 gene is a common tandem duplication event on the X chromosome, with only the first copy generally expressed. The protein consists of seven transmembrane domains, forming the chromophore-binding site for cis-retinal. In response to photon absorption, OPN1MW2 initiates the phototransduction cascade required for color vision. Defects or structural rearrangements in OPN1MW2 underlie red-green color blindness, the most frequent form of inherited color vision deficiency. Medium-wave-sensitive opsin 2 is essential for green light perception and is evolutionarily related to other visual opsins. It is not a common drug target, and clinical interest centers on genetic diagnosis rather than pharmacological modulation.

Other names

Green cone photoreceptor pigmentGreen-sensitive opsinOpsin 1 cone pigments medium-wave-sensitive 2Medium-wave-sensitive opsin 1GOPOPN1MW2Opsin 1 (cone pigments), medium-wave-sensitive 2M-pigmentGreen cone pigmentPhotopigment apoprotein

Not applicable. No drugs are known to clinically act on this Opsin; photopigments are typically activated by light (photons) rather than exogenous ligands