β2 -Adrenergic receptor regulation by GIT1, a G protein-coupled receptor kinase-associated ADP ribosylation factor GTPase-activating protein

Journal Article

G protein-coupled receptor activation leads to the membrane recruitment and activation of G protein-coupled receptor kinases, which phosphorylate receptors and lead to their inactivation. We have identified a novel G protein-coupled receptor kinase-interacting protein, GIT1, that is a GTPase- activating protein (GAP) for the ADP ribosylation factor (ARF) family of small GTP-binding proteins. Overexpression of GIT1 leads to reduced β2- adrenergic receptor signaling and increased receptor phosphorylation, which result from reduced receptor internalization and resensitization. These cellular effects of GIT1 require its intact ARF GAP activity and do not reflect regulation of GRK kinase activity. These results suggest an essential role for ARF proteins in regulating β2-adrenergic receptor endocytosis. Moreover, they provide a mechanism for integration of receptor activation and endocytosis through regulation of ARF protein activation by GRK-mediated recruitment of the GIT1 ARF GAP to the plasma membrane.

Full Text

Duke Authors

Cited Authors

  • Premont, RT; Claing, A; Vitale, N; Freeman, JLR; Pitcher, JA; Patton, WA; Moss, J; Vaughan, M; Lefkowitz, RJ

Published Date

  • 1998

Published In

  • Proceedings of the National Academy of Sciences of the United States of America

Volume / Issue

  • 95 / 24

Start / End Page

  • 14082 - 14087

PubMed ID

  • 9826657

Digital Object Identifier (DOI)

  • 10.1073/pnas.95.24.14082