OPN1SW

G protein-coupled photoreceptor that selectively activates transducin G alpha protein (G(t)) in response to short-wavelength (blue-violet) light, thereby stimulating the G(t)/transducin protein pathway. This activation leads to increased cGMP phosphodiesterase activity, resulting in decreased intracellular cGMP and subsequent closure of cGMP-gated ion channels (By similarity). The process is initiated when the opsin-bound cis-retinal chromophore absorbs a photon and isomerizes to all-trans-retinal, inducing a conformational change in the opsin that triggers the G protein-mediated phototransduction cascade (By similarity). Required for the maintenance of cone outer segment organization in the ventral retina, but not essential for the maintenance of cone photoreceptor function (By similarity). Involved in ensuring the correct abundance and localization of retinal membrane proteins (By similarity). Mediates visual perception of blue light. May contribute to increased spectral sensitivity under dim light conditions (By similarity). Is not UV-sensitive (By similarity)..

Function from UniProtKB (P03999), read 2026-09-23. CC BY 4.0.