Epitopes described in "Structure of active β-arrestin-1 bound to a G-protein-coupled receptor phosphopeptide."

Article Authors:Arun K Shukla; Aashish Manglik; Andrew C Kruse; Kunhong Xiao; Rosana I Reis; Wei-Chou Tseng; Dean P Staus; Daniel Hilger; Serdar Uysal; Li-Yin Huang; Marcin Paduch; Prachi Tripathi-Shukla; Akiko Koide; Shohei Koide; William I Weis; Anthony A Kossiakoff; Brian K Kobilka; Robert J Lefkowitz
Article Title:Structure of active β-arrestin-1 bound to a G-protein-coupled receptor phosphopeptide.
Reference Detail
Reference ID:1026901
Abstract:The functions of G-protein-coupled receptors (GPCRs) are primarily mediated and modulated by three families of proteins: the heterotrimeric G proteins, the G-protein-coupled receptor kinases (GRKs) and the arrestins. G proteins mediate activation of second-messenger-generating enzymes and other effectors, GRKs phosphorylate activated receptors, and arrestins subsequently bind phosphorylated receptors and cause receptor desensitization. Arrestins activated by interaction with phosphorylated receptors can also mediate G-protein-independent signalling by serving as adaptors to link receptors to numerous signalling pathways. Despite their central role in regulation and signalling of GPCRs, a structural understanding of -arrestin activation and interaction with GPCRs is still lacking. Here we report the crystal structure of -arrestin-1 (also called arrestin-2) in complex with a fully phosphorylated 29-amino-acid carboxy-terminal peptide derived from the human V2 vasopressin receptor (V2Rpp). This peptide has previously been shown to functionally and conformationally activate -arrestin-1 (ref. 5). To capture this active conformation, we used a conformationally selective synthetic antibody fragment (Fab30) that recognizes the phosphopeptide-activated state of -arrestin-1. The structure of the -arrestin-1-V2Rpp-Fab30 complex shows marked conformational differences in -arrestin-1 compared to its inactive conformation. These include rotation of the amino- and carboxy-terminal domains relative to each other, and a major reorientation of the 'lariat loop' implicated in maintaining the inactive state of -arrestin-1. These results reveal, at high resolution, a receptor-interacting interface on -arrestin, and they indicate a potentially general molecular mechanism for activation of these multifunctional signalling and regulatory proteins.
Affiliations:Department of Medicine, Duke University Medical Center, Durham, North Carolina 27710, USA.
Reference Type:Literature
PubMed ID:23604254
Journal Volume:497
Article Pages:137-41
Journal ISSN:1476-4687
Article Chemical List:Arrestins;Immunoglobulin Fab Fragments;Phosphopeptides;Receptors, Vasopressin;beta-arrestin
Article MeSH List:Animals; Arrestins(chemistry; immunology; metabolism); Crystallography, X-Ray; Humans; Immunoglobulin Fab Fragments(chemistry; immunology; metabolism); Models, Molecular; Phosphopeptides(chemistry; metabolism); Phosphorylation; Protein Binding; Protein Conformation; Protein Stability; Rats; Receptors, Vasopressin(chemistry); Rotation
Curation Last Updated:2015-06-07 20:28:33