The interaction of beta-arrestin with the AP-2 adaptor is required for the clustering of beta 2-adrenergic receptor into clathrin-coated pits.

Published

Journal Article

Beta-arrestins are cytosolic proteins that regulate the signaling and the internalization of G protein-coupled receptors (GPCRs). Although termination of receptor coupling requires beta-arrestin binding to agonist-activated receptors, GPCR endocytosis involves the coordinate interactions between receptor-beta-arrestin complexes and other endocytic proteins such as adaptor protein 2 (AP-2) and clathrin. Clathrin interacts with a conserved motif in the beta-arrestin C-terminal tail; however, the specific molecular determinants in beta-arrestin that bind AP-2 have not been identified. Moreover, the respective contributions of the interactions of beta-arrestin with AP-2 and clathrin toward the targeting of GPCRs to clathrin-coated vesicles have not been established. Here, we identify specific arginine residues (Arg(394) and Arg(396)) in the beta-arrestin 2 C terminus that mediate beta-arrestin binding to AP-2 and show, in vitro, that these domains in beta-arrestin 1 and 2 interact equally well with AP-2 independently of clathrin binding. We demonstrate in HEK 293 cells by fluorescence microscopy that beta(2)-adrenergic receptor-beta-arrestin complexes lacking the beta-arrestin-clathrin binding motif are still targeted to clathrin-coated pits. In marked contrast, receptor-beta-arrestin complexes lacking the beta-arrestin/AP-2 interactions are not effectively compartmentalized in punctated areas of the plasma membrane. These results reveal that the binding of a receptor-beta-arrestin complex to AP-2, not to clathrin, is necessary for the initial targeting of beta(2)-adrenergic receptor to clathrin-coated pits.

Full Text

Duke Authors

Cited Authors

  • Laporte, SA; Oakley, RH; Holt, JA; Barak, LS; Caron, MG

Published Date

  • July 28, 2000

Published In

Volume / Issue

  • 275 / 30

Start / End Page

  • 23120 - 23126

PubMed ID

  • 10770944

Pubmed Central ID

  • 10770944

International Standard Serial Number (ISSN)

  • 0021-9258

Digital Object Identifier (DOI)

  • 10.1074/jbc.M002581200

Language

  • eng

Conference Location

  • United States