title: Characterization of glucagon-like peptide-1 receptor beta-arrestin 2 interaction: a high-affinity receptor phenotype.
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.
authors.affiliation: 7TM Pharma A/S, Horsholm, DK-2970, Denmark.
authors.forename: Rasmus
authors.initials: R
authors.lastname: Jorgensen
authors.forename: Lene
authors.initials: L
authors.lastname: Martini
authors.forename: Thue W
authors.initials: TW
authors.lastname: Schwartz
authors.forename: Christian E
authors.initials: CE
authors.lastname: Elling
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D019390:Arrestins / Q000737:chemistry* / Q000378:metabolism; D001667:Binding, Competitive; D019556:COS Cells; D000242:Cyclic AMP / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D019204:GTP-Binding Proteins / Q000378:metabolism; D000067757:Glucagon-Like Peptide-1 Receptor; D049452:Green Fluorescent Proteins / Q000378:metabolism; D006801:Humans; D007700:Kinetics; D008024:Ligands; D008969:Molecular Sequence Data; D010641:Phenotype; D011485:Protein Binding; D011487:Protein Conformation; D018027:Receptors, Glucagon / Q000737:chemistry* / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction; D013997:Time Factors; D014162:Transfection; D000071560:beta-Arrestin 2; D000071557:beta-Arrestins
chemical_list: C000605254:ARRB2 protein, human; D019390:Arrestins; C000593833:GLP1R protein, human; D000067757:Glucagon-Like Peptide-1 Receptor; D008024:Ligands; D018027:Receptors, Glucagon; D011993:Recombinant Fusion Proteins; D000071560:beta-Arrestin 2; D000071557:beta-Arrestins; D049452:Green Fluorescent Proteins; D000242:Cyclic AMP; D019204:GTP-Binding Proteins