β-Arrestin: a Protein that Regulates β-adrenergic Receptor Function

TLDR

Homologous or agonist‑specific desensitization of β‑adrenergic receptors is thought to be mediated by β‑adrenergic receptor kinase (β‑ARK), but recent data suggest a cofactor is required for this kinase to inhibit receptor function. It is proposed that β‑arrestin in concert with β‑ARK effects homologous desensitization of β‑adrenergic receptors. The protein, termed β‑arrestin, was expressed and partially purified. The complementary DNA for such a cofactor was cloned and found to encode a 418‑amino‑acid protein homologous to the retinal protein arrestin, and this β‑arrestin inhibited the signaling function of β‑ARK‑phosphorylated β‑adrenergic receptors by more than 75 % but not that of rhodopsin.

Abstract

Homologous or agonist-specific desensitization of beta-adrenergic receptors is thought to be mediated by a specific kinase, the beta-adrenergic receptor kinase (beta ARK). However, recent data suggest that a cofactor is required for this kinase to inhibit receptor function. The complementary DNA for such a cofactor was cloned and found to encode a 418-amino acid protein homologous to the retinal protein arrestin. The protein, termed beta-arrestin, was expressed and partially purified. It inhibited the signaling function of beta ARK-phosphorylated beta-adrenergic receptors by more than 75 percent, but not that of rhodopsin. It is proposed that beta-arrestin in concert with beta ARK effects homologous desensitization of beta-adrenergic receptors.