Characterization of glucagon-like peptide-1 receptor beta-arrestin 2 interaction: a high-affinity receptor phenotype

Mol Endocrinol. 2005 Mar;19(3):812-23. doi: 10.1210/me.2004-0312. Epub 2004 Nov 4.

Abstract

To dissect the interaction between beta-arrestin ((beta)arr) and family B G protein-coupled receptors, we constructed fusion proteins between the glucagon-like peptide 1 receptor and (beta)arr2. The fusion constructs had an increase in apparent affinity selectively for glucagon, suggesting that (beta)arr2 interaction locks the receptor in a high-affinity conformation, which can be explored by some, but not all, ligands. The fusion constructs adopted a signaling phenotype governed by the tethered (beta)arr2 with an attenuated G protein-mediated cAMP signal and a higher maximal internalization compared with wild-type receptors. This distinct phenotype of the fusion proteins can not be mimicked by coexpressing wild-type receptor with (beta)arr2. However, when the wild-type receptor was coexpressed with both (beta)arr2 and G protein-coupled receptor kinase 5, a phenotype similar to that observed for the fusion constructs was observed. We conclude that the glucagon-like peptide 1 fusion construct mimics the natural interaction of the receptor with (beta)arr2 with respect to binding peptide ligands, G protein-mediated signaling and internalization, and that this distinct molecular phenotype is reminiscent of that which has previously been characterized for family A G protein-coupled receptors, suggesting similarities in the effect of (beta)arr interaction between family A and B receptors also at the molecular level.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Arrestins / chemistry*
  • Arrestins / metabolism
  • Binding, Competitive
  • COS Cells
  • Cyclic AMP / metabolism
  • Dose-Response Relationship, Drug
  • GTP-Binding Proteins / metabolism
  • Glucagon-Like Peptide-1 Receptor
  • Green Fluorescent Proteins / metabolism
  • Humans
  • Kinetics
  • Ligands
  • Molecular Sequence Data
  • Phenotype
  • Protein Binding
  • Protein Conformation
  • Receptors, Glucagon / chemistry*
  • Receptors, Glucagon / metabolism
  • Recombinant Fusion Proteins / chemistry
  • Recombinant Fusion Proteins / metabolism
  • Sequence Homology, Amino Acid
  • Signal Transduction
  • Time Factors
  • Transfection
  • beta-Arrestin 2
  • beta-Arrestins

Substances

  • ARRB2 protein, human
  • Arrestins
  • GLP1R protein, human
  • Glucagon-Like Peptide-1 Receptor
  • Ligands
  • Receptors, Glucagon
  • Recombinant Fusion Proteins
  • beta-Arrestin 2
  • beta-Arrestins
  • Green Fluorescent Proteins
  • Cyclic AMP
  • GTP-Binding Proteins