OPN5

OPN5 is a protein that in humans is encoded by the OPN5 gene. OPN5 is a member of the opsin family of proteins, which are integral components of the visual system in most organisms.

Function

OPN5 is a UV-sensitive opsin, also known as neuropsin. It is expressed in the retina and brain, and is involved in the regulation of circadian rhythms. OPN5 is a bistable opsin, meaning it can exist in two stable states, and can be switched between these states by light. This property allows it to function as a photoreceptor, detecting light and transmitting this information to the brain.

Structure

Like other opsins, OPN5 is a G protein-coupled receptor (GPCR). It consists of seven transmembrane domains, with the chromophore retinal covalently attached to a lysine residue in the seventh domain. The structure of OPN5 is highly conserved across species, suggesting it plays a crucial role in the visual system.

Clinical significance

Mutations in the OPN5 gene have been associated with certain eye disorders, including night blindness and certain forms of color blindness. However, more research is needed to fully understand the role of OPN5 in these conditions.

See also

• Opsin
• Photoreceptor cell
• Visual system