Beta-arrestin binding to the beta2-adrenergic receptor requires both
receptor phosphorylation and receptor activation
J Biol Chem, 280 (10):
9528-35 (March 2005)Krasel, Cornelius Bunemann, Moritz Lorenz, Kristina Lohse, Martin
J Research Support, Non-U.S. Gov't United States The Journal of biological
chemistry J Biol Chem. 2005 Mar 11;280(10):9528-35. Epub 2005 Jan
5..Abstract
Homologous desensitization of beta2-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 beta-arrestins to the phosphorylated receptor. Binding
of beta-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 beta-arrestin2
in living cells using fluorescence resonance energy transfer. We
show that (a) the initial kinetics of beta-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 beta-arrestin2 very rapidly; and (c) the
interaction of beta-arrestin2 with the receptor depends on the activation
of the receptor by agonist because agonist withdrawal leads to swift
dissociation of the receptor-beta-arrestin2 complex. This fast agonist-controlled
association and dissociation of beta-arrestins from prephosphorylated
receptors should permit rapid control of receptor sensitivity in
repeatedly stimulated cells such as neurons.