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Huang SK, Pandey A, Tran DP, Villanueva NL, Kitao A, Sunahara RK, Sljoka A, Prosser RS. Delineating the conformational landscape of the adenosine A 2A receptor during G protein coupling. Cell 2021; 184:1884-1894.e14. [PMID: 33743210 DOI: 10.1016/j.cell.2021.02.041] [Citation(s) in RCA: 72] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 12/02/2020] [Accepted: 02/17/2021] [Indexed: 12/17/2022]
Abstract
G-protein-coupled receptors (GPCRs) represent a ubiquitous membrane protein family and are important drug targets. Their diverse signaling pathways are driven by complex pharmacology arising from a conformational ensemble rarely captured by structural methods. Here, fluorine nuclear magnetic resonance spectroscopy (19F NMR) is used to delineate key functional states of the adenosine A2A receptor (A2AR) complexed with heterotrimeric G protein (Gαsβ1γ2) in a phospholipid membrane milieu. Analysis of A2AR spectra as a function of ligand, G protein, and nucleotide identifies an ensemble represented by inactive states, a G-protein-bound activation intermediate, and distinct nucleotide-free states associated with either partial- or full-agonist-driven activation. The Gβγ subunit is found to be critical in facilitating ligand-dependent allosteric transmission, as shown by 19F NMR, biochemical, and computational studies. The results provide a mechanistic basis for understanding basal signaling, efficacy, precoupling, and allostery in GPCRs.
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Affiliation(s)
- Shuya Kate Huang
- Department of Chemistry, University of Toronto, UTM, 3359 Mississauga Road North, Mississauga, Ontario L5L 1C6, Canada
| | - Aditya Pandey
- Department of Chemistry, University of Toronto, UTM, 3359 Mississauga Road North, Mississauga, Ontario L5L 1C6, Canada; Department of Biochemistry, University of Toronto, 1 King's College Circle, Toronto, Ontario M5S 1A8, Canada
| | - Duy Phuoc Tran
- School of Life Science and Technology, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8550, Japan
| | - Nicolas L Villanueva
- Department of Pharmacology, University of California San Diego School of Medicine, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Akio Kitao
- School of Life Science and Technology, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8550, Japan
| | - Roger K Sunahara
- Department of Pharmacology, University of California San Diego School of Medicine, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Adnan Sljoka
- Department of Chemistry, University of Toronto, UTM, 3359 Mississauga Road North, Mississauga, Ontario L5L 1C6, Canada; RIKEN Center for Advanced Intelligence Project, RIKEN, 1-4-1 Nihombashi, Chuo-ku, Tokyo 103-0027, Japan.
| | - R Scott Prosser
- Department of Chemistry, University of Toronto, UTM, 3359 Mississauga Road North, Mississauga, Ontario L5L 1C6, Canada; Department of Biochemistry, University of Toronto, 1 King's College Circle, Toronto, Ontario M5S 1A8, Canada.
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Jang W, Adams CE, Liu H, Zhang C, Levy FO, Andressen KW, Lambert NA. An inactive receptor-G protein complex maintains the dynamic range of agonist-induced signaling. Proc Natl Acad Sci U S A 2020; 117:30755-62. [PMID: 33199589 DOI: 10.1073/pnas.2010801117] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
G protein-coupled receptors (GPCRs) are targeted by a large fraction of approved drugs and regulate many important cellular processes. Conventional signaling by GPCRs is triggered when agonist-activated receptors associate with heterotrimeric G proteins. We found that serotonin 5-HT7 receptors couple to Gs proteins in an unconventional manner, in which agonist binding instead promotes dissociation of preexisting inactive 5-HT7–Gs complexes. Therefore, agonists can initiate signaling via two distinct mechanisms, by promoting the association of active receptors and G proteins and by promoting dissociation of inactive receptors and G proteins. Agonist binding promotes activation of G protein-coupled receptors (GPCRs) and association of active receptors with G protein heterotrimers. The resulting active-state ternary complex is the basis for conventional stimulus-response coupling. Although GPCRs can also associate with G proteins before agonist binding, the impact of such preassociated complexes on agonist-induced signaling is poorly understood. Here we show that preassociation of 5-HT7 serotonin receptors with Gs heterotrimers is necessary for agonist-induced signaling. 5-HT7 receptors in their inactive state associate with Gs, as these complexes are stabilized by inverse agonists and receptor mutations that favor the inactive state. Inactive-state 5-HT7–Gs complexes dissociate in response to agonists, allowing the formation of conventional agonist–5-HT7–Gs ternary complexes and subsequent Gs activation. Inactive-state 5-HT7–Gs complexes are required for the full dynamic range of agonist-induced signaling, as 5-HT7 receptors spontaneously activate Gs variants that cannot form inactive-state complexes. Therefore, agonist-induced signaling in this system involves two distinct receptor-G protein complexes, a conventional ternary complex that activates G proteins and an inverse-coupled binary complex that maintains the inactive state when agonist is not present.
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Ayoub MA, Al-Senaidy A, Pin JP. Receptor-G protein interaction studied by bioluminescence resonance energy transfer: lessons from protease-activated receptor 1. Front Endocrinol (Lausanne) 2012; 3:82. [PMID: 22737145 PMCID: PMC3381121 DOI: 10.3389/fendo.2012.00082] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/25/2012] [Accepted: 06/04/2012] [Indexed: 11/27/2022] Open
Abstract
Since its development, the bioluminescence resonance energy transfer (BRET) approach has been extensively applied to study G protein-coupled receptors (GPCRs) in real-time and in live cells. One of the major aspects of GPCRs investigated in considerable details is their physical coupling to the heterotrimeric G proteins. As a result, new concepts have emerged, but few questions are still a matter of debate illustrating the complexity of GPCR-G protein interactions and coupling. Here, we summarized the recent advances on our understanding of GPCR-G protein coupling based on BRET approaches and supported by other FRET-based studies. We essentially focused on our recent studies in which we addressed the concept of preassembly vs. the agonist-dependent interaction between the protease-activated receptor 1 (PAR1) and its cognate G proteins. We discussed the concept of agonist-induced conformational changes within the preassembled PAR1-G protein complexes as well as the critical question how the multiple coupling of PAR1 with two different G proteins, Gαi1 and Gα12, but also β-arrestin 1, can be regulated.
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Affiliation(s)
- Mohammed Akli Ayoub
- Department of Molecular Pharmacology, Institute of Functional Genomics, CNRS UMR5203, Universities Montpellier 1 and 2Montpellier, France
- INSERM U661Montpellier, France
- Department of Biochemistry, College of Science, King Saud UniversityRiyadh, Kingdom of Saudi Arabia
- *Correspondence: Mohammed Akli Ayoub, Department of Biochemistry, College of Science, King Saud University P.O. Box: 2455, Riyadh – 11451 Kingdom of Saudi Arabia. e-mail: ; Jean-Philippe Pin, Department of Molecular Pharmacology, Institute of Functional Genomics, CNRS UMR5203, INSERM U661, Universities Montpellier 1 and 2 – 141, rue de la cardonille, 34094 Montpellier Cedex 05, France. e-mail:
| | - Abdulrahman Al-Senaidy
- Department of Biochemistry, College of Science, King Saud UniversityRiyadh, Kingdom of Saudi Arabia
| | - Jean-Philippe Pin
- Department of Molecular Pharmacology, Institute of Functional Genomics, CNRS UMR5203, Universities Montpellier 1 and 2Montpellier, France
- INSERM U661Montpellier, France
- *Correspondence: Mohammed Akli Ayoub, Department of Biochemistry, College of Science, King Saud University P.O. Box: 2455, Riyadh – 11451 Kingdom of Saudi Arabia. e-mail: ; Jean-Philippe Pin, Department of Molecular Pharmacology, Institute of Functional Genomics, CNRS UMR5203, INSERM U661, Universities Montpellier 1 and 2 – 141, rue de la cardonille, 34094 Montpellier Cedex 05, France. e-mail:
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