β-Arrestin Binding to the β2-Adrenergic Receptor Requires Both Receptor Phosphorylation and Receptor Activation

• Published in: The Journal of biological chemistry 2005-03, Vol.280 (10), p.9528
• Main Authors: Cornelius Krasel, Moritz Bünemann, Kristina Lorenz, Martin J. Lohse
• Format: Article
• Language: English
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1074/jbc.M413078200

Homologous desensitization of β 2 -adrenergic receptors has been shown to be mediated by phosphorylation of the agonist-stimulated receptor by G-protein-coupled receptor kinase 2 (GRK2) followed by binding of β-arrestins to the phosphorylated receptor. Binding of β-arrestin to the receptor is a prerequisite for subsequent receptor desensitization, internalization via clathrin-coated pits, and the initiation of alternative signaling pathways. In this study we have investigated the interactions between receptors and β-arrestin2 in living cells using fluorescence resonance energy transfer. We show that ( a ) the initial kinetics of β-arrestin2 binding to the receptor is limited by the kinetics of GRK2-mediated receptor phosphorylation; ( b ) repeated stimulation leads to the accumulation of GRK2-phosphorylated receptor, which can bind β-arrestin2 very rapidly; and ( c ) the interaction of β-arrestin2 with the receptor depends on the activation of the receptor by agonist because agonist withdrawal leads to swift dissociation of the receptor-β-arrestin2 complex. This fast agonist-controlled association and dissociation of β-arrestins from prephosphorylated receptors should permit rapid control of receptor sensitivity in repeatedly stimulated cells such as neurons.