総説 : アレスチンの構造と機能

Abstract

A review: Structure and function of arrestins Arrestin is a family of proteins that is involved in two different processes: (1) desensitization of the activated G-protein-coupled receptors, and (2) autoimmune diseases. This family consists of retinal arrestin, β-arrestin, invertebrate arrestin and their spliced variant forms. These proteins have high homologies in their functions and structures. Retinal arrestin was the first of the family to be identified and the most extensively studied so far. In vertebrate rod photoreceptors, rhodopsin absorbs light and is transformed to an active photobleaching intermediate called metarhodopsin II (mete II). Meta II activates several thousand molecules of a GTP binding protein called transducin, and is the substrate of rhodopsin kinase (RK). RK phosphorylates photoactivated rhodopsin at the C-terminal Ser and Thr residues. The phosphorylated photolyzed rhodopsin prevents transducin activation by binding arrestin. Retinal arrestin (called S-antigen) is also known to be a highly pathogenic molecule that induces uveotract inflammation in Mammalia. Recently, the author found serum autoantibodies against arrestin and β-arrestin in patients with multiple sclerosis and/or optic neuritis. In this article, I reviewed the latest information regarding the structure and functions of arrestins.