ALBERT

Description: 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 beta-arrestin activation and interaction with GPCRs is still lacking. Here we report the crystal structure of beta-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 beta-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 beta-arrestin-1. The structure of the beta-arrestin-1-V2Rpp-Fab30 complex shows marked conformational differences in beta-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 beta-arrestin-1. These results reveal, at high resolution, a receptor-interacting interface on beta-arrestin, and they indicate a potentially general molecular mechanism for activation of these multifunctional signalling and regulatory proteins.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3654799/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3654799/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Shukla, Arun K -- Manglik, Aashish -- Kruse, Andrew C -- Xiao, Kunhong -- Reis, Rosana I -- Tseng, Wei-Chou -- Staus, Dean P -- Hilger, Daniel -- Uysal, Serdar -- Huang, Li-Yin -- Paduch, Marcin -- Tripathi-Shukla, Prachi -- Koide, Akiko -- Koide, Shohei -- Weis, William I -- Kossiakoff, Anthony A -- Kobilka, Brian K -- Lefkowitz, Robert J -- GM072688/GM/NIGMS NIH HHS/ -- GM087519/GM/NIGMS NIH HHS/ -- HL 075443/HL/NHLBI NIH HHS/ -- HL16037/HL/NHLBI NIH HHS/ -- HL70631/HL/NHLBI NIH HHS/ -- NS028471/NS/NINDS NIH HHS/ -- P41 RR011823/RR/NCRR NIH HHS/ -- R01 HL016037/HL/NHLBI NIH HHS/ -- R01 HL070631/HL/NHLBI NIH HHS/ -- R01 NS028471/NS/NINDS NIH HHS/ -- U01 GM094588/GM/NIGMS NIH HHS/ -- U54 GM074946/GM/NIGMS NIH HHS/ -- Howard Hughes Medical Institute/ -- England -- Nature. 2013 May 2;497(7447):137-41. doi: 10.1038/nature12120. Epub 2013 Apr 21.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Medicine, Duke University Medical Center, Durham, North Carolina 27710, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/23604254" target="_blank"〉PubMed〈/a〉

Description: G-protein-coupled receptors (GPCRs) are critically regulated by beta-arrestins, which not only desensitize G-protein signalling but also initiate a G-protein-independent wave of signalling. A recent surge of structural data on a number of GPCRs, including the beta2 adrenergic receptor (beta2AR)-G-protein complex, has provided novel insights into the structural basis of receptor activation. However, complementary information has been lacking on the recruitment of beta-arrestins to activated GPCRs, primarily owing to challenges in obtaining stable receptor-beta-arrestin complexes for structural studies. Here we devised a strategy for forming and purifying a functional human beta2AR-beta-arrestin-1 complex that allowed us to visualize its architecture by single-particle negative-stain electron microscopy and to characterize the interactions between beta2AR and beta-arrestin 1 using hydrogen-deuterium exchange mass spectrometry (HDX-MS) and chemical crosslinking. Electron microscopy two-dimensional averages and three-dimensional reconstructions reveal bimodal binding of beta-arrestin 1 to the beta2AR, involving two separate sets of interactions, one with the phosphorylated carboxy terminus of the receptor and the other with its seven-transmembrane core. Areas of reduced HDX together with identification of crosslinked residues suggest engagement of the finger loop of beta-arrestin 1 with the seven-transmembrane core of the receptor. In contrast, focal areas of raised HDX levels indicate regions of increased dynamics in both the N and C domains of beta-arrestin 1 when coupled to the beta2AR. A molecular model of the beta2AR-beta-arrestin signalling complex was made by docking activated beta-arrestin 1 and beta2AR crystal structures into the electron microscopy map densities with constraints provided by HDX-MS and crosslinking, allowing us to obtain valuable insights into the overall architecture of a receptor-arrestin complex. The dynamic and structural information presented here provides a framework for better understanding the basis of GPCR regulation by arrestins.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4134437/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4134437/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Shukla, Arun K -- Westfield, Gerwin H -- Xiao, Kunhong -- Reis, Rosana I -- Huang, Li-Yin -- Tripathi-Shukla, Prachi -- Qian, Jiang -- Li, Sheng -- Blanc, Adi -- Oleskie, Austin N -- Dosey, Anne M -- Su, Min -- Liang, Cui-Rong -- Gu, Ling-Ling -- Shan, Jin-Ming -- Chen, Xin -- Hanna, Rachel -- Choi, Minjung -- Yao, Xiao Jie -- Klink, Bjoern U -- Kahsai, Alem W -- Sidhu, Sachdev S -- Koide, Shohei -- Penczek, Pawel A -- Kossiakoff, Anthony A -- Woods, Virgil L Jr -- Kobilka, Brian K -- Skiniotis, Georgios -- Lefkowitz, Robert J -- DK090165/DK/NIDDK NIH HHS/ -- GM072688/GM/NIGMS NIH HHS/ -- GM087519/GM/NIGMS NIH HHS/ -- GM60635/GM/NIGMS NIH HHS/ -- HL075443/HL/NHLBI NIH HHS/ -- HL16037/HL/NHLBI NIH HHS/ -- HL70631/HL/NHLBI NIH HHS/ -- MOP-93725/Canadian Institutes of Health Research/Canada -- NS028471/NS/NINDS NIH HHS/ -- R01 DK090165/DK/NIDDK NIH HHS/ -- R01 GM060635/GM/NIGMS NIH HHS/ -- R01 GM072688/GM/NIGMS NIH HHS/ -- R01 HL016037/HL/NHLBI NIH HHS/ -- R01 HL070631/HL/NHLBI NIH HHS/ -- R01 NS028471/NS/NINDS NIH HHS/ -- UL1 TR000430/TR/NCATS NIH HHS/ -- Howard Hughes Medical Institute/ -- England -- Nature. 2014 Aug 14;512(7513):218-22. doi: 10.1038/nature13430. Epub 2014 Jun 22.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉1] Department of Medicine, Duke University Medical Center, Durham, North Carolina 27710, USA [2] Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur 208016, India. [3]. ; 1] Life Sciences Institute and Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, Michigan 48109, USA [2]. ; 1] Department of Medicine, Duke University Medical Center, Durham, North Carolina 27710, USA [2]. ; Department of Medicine, Duke University Medical Center, Durham, North Carolina 27710, USA. ; Department of Chemistry, University of California at San Diego, La Jolla, California 92093, USA. ; Life Sciences Institute and Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, Michigan 48109, USA. ; School of Pharmaceutical &Life Sciences, Changzhou University, Changzhou, Jiangsu 213164, China. ; Terrence Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Ontario M5S 3E1, Canada. ; Department of Biochemistry, Duke University Medical Center, Durham, North Carolina 27710, USA. ; Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, Illinois 60637, USA. ; Department of Biochemistry and Molecular Biology, The University of Texas Medical School at Houston, Houston, Texas 77054, USA. ; 1] Department of Chemistry, University of California at San Diego, La Jolla, California 92093, USA [2]. ; Department of Molecular and Cellular Physiology, Stanford University School of Medicine, 279 Campus Drive, Stanford, California 94305, USA. ; 1] Department of Medicine, Duke University Medical Center, Durham, North Carolina 27710, USA [2] Department of Biochemistry, Duke University Medical Center, Durham, North Carolina 27710, USA [3] Howard Hughes Medical Institute, Duke University Medical Center, Durham, North Carolina 27710, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/25043026" target="_blank"〉PubMed〈/a〉