A family of proteins that bind to tyrosine-phosphorylated receptors and block their interaction with G proteins, thereby inhibiting signalling. Arrestin-S (S antigen; 405 aa, from retinal rods) competes with transducin for light-activated rhodopsin, thus inhibiting the response to light (adaptation); arrestin-C (cone arrestin (388 aa) is similar. Immune responses to arrestin-S lead to autoimmune uveitis. Similarly, β-arrestin binds to phosphorylated β-*adrenergic receptors, inhibiting their ability to activate the G protein Gs (see Ark1).
Subjects: Chemistry — Medicine and Health.