Long-wave-sensitive opsin 1 (human protein name often used for the red cone pigment; gene symbol OPN1LW) (OPN1LW (also LWS opsin; in non-human species often abbreviated LWS))

Long-wavelength-sensitive opsins are cone visual pigments belonging to the rhodopsin-like GPCR family that bind 11-cis retinal via a protonated Schiff base to Lys296; light absorption triggers retinal isomerization, conformational changes, and G-protein activation to initiate phototransduction. They form one of four vertebrate cone opsin classes and typically exhibit peak spectral sensitivities in the long-wavelength range (~525–565 nm for vitamin A1-based pigments), with spectral tuning influenced by specific amino acid positions (notably 180, 197, 277, 285, 308) and a unique anion (chloride) sensitivity mediated by His197 that can shift λmax to longer wavelengths. In humans, the canonical gene/protein is OPN1LW (Long-wave-sensitive opsin 1), commonly referred to as the red cone opsin. LWS opsins show evolutionary diversification across vertebrates, with paralog expansions and substitutions affecting spectral sensitivity and adaptive coloration/vision, as documented in teleosts where LWS gene duplicates can subfunctionalize and shift expression through development.

Other names

Long-wave-sensitive opsin 1 (human)LWS opsin; LWS (class)Red-sensitive opsin; red cone opsin; photopsin I (context-dependent common names)Gene symbol: OPN1LW (human); lws (generic locus in many vertebrates)

Not applicable/none established. Opsin activation physiologically occurs via photon absorption causing 11-cis retinal → all-trans retinal isomerization, leading to GPCR activation (meta II) and G-protein signaling