Rhodopsin kinase

Rhodopsin kinase (also known as GRK1) is an enzyme that in humans is encoded by the GRK1 gene. It is a member of the G protein-coupled receptor kinase (GRK) family and plays a key role in the visual phototransduction pathway.

Function

Rhodopsin kinase is a key player in the visual phototransduction cascade, which is a process that converts light into electrical signals in the photoreceptor cells of the retina. The kinase is responsible for the phosphorylation of the light-activated form of rhodopsin (metarhodopsin II), which initiates the deactivation and recovery processes of the phototransduction cascade.

Structure

The structure of rhodopsin kinase is similar to that of other protein kinases. It has a catalytic domain and a regulatory domain. The catalytic domain is responsible for the phosphorylation of rhodopsin, while the regulatory domain is involved in the recognition and binding of the substrate.

Clinical significance

Mutations in the GRK1 gene can lead to various forms of night blindness. For example, Oguchi disease, a rare form of stationary night blindness, is caused by mutations in either the GRK1 gene or the arrestin gene.

See also

• G protein-coupled receptor kinase
• Rhodopsin
• Phototransduction