1
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Baker JG, Summers RJ. Adrenoceptors: Receptors, Ligands and Their Clinical Uses, Molecular Pharmacology and Assays. Handb Exp Pharmacol 2024. [PMID: 38926158 DOI: 10.1007/164_2024_713] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/28/2024]
Abstract
The nine G protein-coupled adrenoceptor subtypes are where the endogenous catecholamines adrenaline and noradrenaline interact with cells. Since they are important therapeutic targets, over a century of effort has been put into developing drugs that modify their activity. This chapter provides an outline of how we have arrived at current knowledge of the receptors, their physiological roles and the methods used to develop ligands. Initial studies in vivo and in vitro with isolated organs and tissues progressed to cell-based techniques and the use of cloned adrenoceptor subtypes together with high-throughput assays that allow close examination of receptors and their signalling pathways. The crystal structures of many of the adrenoceptor subtypes have now been determined opening up new possibilities for drug development.
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Affiliation(s)
- Jillian G Baker
- Cell Signalling, Medical School, Queen's Medical Centre, University of Nottingham, Nottingham, UK.
- Department of Respiratory Medicine, Nottingham University Hospitals NHS Trust, Nottingham, UK.
| | - Roger J Summers
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia.
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2
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Jones AJY, Harman TH, Harris M, Lewis OE, Ladds G, Nietlispach D. Binding kinetics drive G protein subtype selectivity at the β 1-adrenergic receptor. Nat Commun 2024; 15:1334. [PMID: 38351103 PMCID: PMC10864275 DOI: 10.1038/s41467-024-45680-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Accepted: 02/01/2024] [Indexed: 02/16/2024] Open
Abstract
G protein-coupled receptors (GPCRs) bind to different G protein α-subtypes with varying degrees of selectivity. The mechanism by which GPCRs achieve this selectivity is still unclear. Using 13C methyl methionine and 19F NMR, we investigate the agonist-bound active state of β1AR and its ternary complexes with different G proteins in solution. We find the receptor in the ternary complexes adopts very similar conformations. In contrast, the full agonist-bound receptor active state assumes a conformation differing from previously characterised activation intermediates or from β1AR in ternary complexes. Assessing the kinetics of binding for the agonist-bound receptor with different G proteins, we find the increased affinity of β1AR for Gs results from its much faster association with the receptor. Consequently, we suggest a kinetic-driven selectivity gate between canonical and secondary coupling which arises from differential favourability of G protein binding to the agonist-bound receptor active state.
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Affiliation(s)
- Andrew J Y Jones
- Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge, CB2 1GA, UK
| | - Thomas H Harman
- Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge, CB2 1GA, UK
| | - Matthew Harris
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1PD, UK
| | - Oliver E Lewis
- Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge, CB2 1GA, UK
| | - Graham Ladds
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1PD, UK
| | - Daniel Nietlispach
- Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge, CB2 1GA, UK.
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3
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Yen HY, Liko I, Song W, Kapoor P, Almeida F, Toporowska J, Gherbi K, Hopper JTS, Charlton SJ, Politis A, Sansom MSP, Jazayeri A, Robinson CV. Mass spectrometry captures biased signalling and allosteric modulation of a G-protein-coupled receptor. Nat Chem 2022; 14:1375-1382. [PMID: 36357787 PMCID: PMC9758051 DOI: 10.1038/s41557-022-01041-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Accepted: 08/09/2022] [Indexed: 11/12/2022]
Abstract
G-protein-coupled receptors signal through cognate G proteins. Despite the widespread importance of these receptors, their regulatory mechanisms for G-protein selectivity are not fully understood. Here we present a native mass spectrometry-based approach to interrogate both biased signalling and allosteric modulation of the β1-adrenergic receptor in response to various ligands. By simultaneously capturing the effects of ligand binding and receptor coupling to different G proteins, we probed the relative importance of specific interactions with the receptor through systematic changes in 14 ligands, including isoprenaline derivatives, full and partial agonists, and antagonists. We observed enhanced dynamics of the intracellular loop 3 in the presence of isoprenaline, which is capable of acting as a biased agonist. We also show here that endogenous zinc ions augment the binding in receptor-Gs complexes and propose a zinc ion-binding hotspot at the TM5/TM6 intracellular interface of the receptor-Gs complex. Further interrogation led us to propose a mechanism in which zinc ions facilitate a structural transition of the intermediate complex towards the stable state.
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Affiliation(s)
- Hsin-Yung Yen
- Chemical Research Laboratory, University of Oxford, Oxford, UK.
- OMass Therapeutics, Oxford, UK.
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan.
| | - Idlir Liko
- Chemical Research Laboratory, University of Oxford, Oxford, UK
- OMass Therapeutics, Oxford, UK
| | - Wanling Song
- Department of Biochemistry, University of Oxford, Oxford, UK
- Rahko, London, UK
| | | | | | | | | | | | - Steven J Charlton
- OMass Therapeutics, Oxford, UK
- School of Life Sciences, Queen's Medical Centre, University of Nottingham, Nottingham, UK
| | - Argyris Politis
- Department of Chemistry, King's College London, London, UK
- Faculty of Biology, Medicine and Health, School of Biological Sciences, The University of Manchester, Manchester, UK
| | - Mark S P Sansom
- Department of Biochemistry, University of Oxford, Oxford, UK
| | | | - Carol V Robinson
- Chemical Research Laboratory, University of Oxford, Oxford, UK.
- Kavli Institute for Nanoscience Discovery, Oxford, UK.
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4
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Alegre KO, Paknejad N, Su M, Lou JS, Huang J, Jordan KD, Eng ET, Meyerson JR, Hite RK, Huang XY. Structural basis and mechanism of activation of two different families of G proteins by the same GPCR. Nat Struct Mol Biol 2021; 28:936-944. [PMID: 34759376 DOI: 10.1038/s41594-021-00679-2] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2021] [Accepted: 09/30/2021] [Indexed: 01/14/2023]
Abstract
The β1-adrenergic receptor (β1-AR) can activate two families of G proteins. When coupled to Gs, β1-AR increases cardiac output, and coupling to Gi leads to decreased responsiveness in myocardial infarction. By comparative structural analysis of turkey β1-AR complexed with either Gi or Gs, we investigate how a single G-protein-coupled receptor simultaneously signals through two G proteins. We find that, although the critical receptor-interacting C-terminal α5-helices on Gαi and Gαs interact similarly with β1-AR, the overall interacting modes between β1-AR and G proteins vary substantially. Functional studies reveal the importance of the differing interactions and provide evidence that the activation efficacy of G proteins by β1-AR is determined by the entire three-dimensional interaction surface, including intracellular loops 2 and 4 (ICL2 and ICL4).
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Affiliation(s)
- Kamela O Alegre
- Department of Physiology and Biophysics, Weill Cornell Medical College of Cornell University, New York, NY, USA
| | - Navid Paknejad
- Structural Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Minfei Su
- Department of Physiology and Biophysics, Weill Cornell Medical College of Cornell University, New York, NY, USA
| | - Jian-Shu Lou
- Department of Physiology and Biophysics, Weill Cornell Medical College of Cornell University, New York, NY, USA
| | - Jianyun Huang
- Department of Physiology and Biophysics, Weill Cornell Medical College of Cornell University, New York, NY, USA
| | - Kelsey D Jordan
- Simons Electron Microscopy Center, National Resource for Automated Molecular Microscopy, New York Structural Biology Center, New York, NY, USA
| | - Edward T Eng
- Simons Electron Microscopy Center, National Resource for Automated Molecular Microscopy, New York Structural Biology Center, New York, NY, USA
| | - Joel R Meyerson
- Department of Physiology and Biophysics, Weill Cornell Medical College of Cornell University, New York, NY, USA
| | - Richard K Hite
- Structural Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
| | - Xin-Yun Huang
- Department of Physiology and Biophysics, Weill Cornell Medical College of Cornell University, New York, NY, USA.
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5
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Olfactory marker protein captures cAMP produced via Gαs-protein-coupled receptor activation. Biochem Biophys Res Commun 2020; 529:341-346. [PMID: 32703433 DOI: 10.1016/j.bbrc.2020.06.017] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Accepted: 06/05/2020] [Indexed: 11/23/2022]
Abstract
Olfactory marker protein (OMP) labels the matured stage of olfactory receptor neurons (ORN) and has promoted the investigation on the physiology of olfaction. OMP regulates olfactory sensitivity and axonal projection of ORNs, both of which are under the control of the olfactory signaling mediator cAMP. Recently, it has been reported that OMP contains cAMP-binding sites. OMP directly captures the photo-uncaged cAMP in the cytosol and rapidly terminates the olfactory cyclic nucleotide-gated (CNG) channels activity to sharpen the olfactory responses. Here, we investigate the contribution of OMP to cAMP acutely produced via activation of Gαs-protein coupled receptors (GPCR). We expressed OMP and non-desensitizing CNGA2 channels in HEK293T cells together with β1-adrenergic receptors (ADRB1) or photo-sensitive β2-adrenergic receptors (opto-β2). Continuous puff of adrenergic agonist isoproterenol to HEK29T cells with ADRB1 induced the lasting CNGA2 currents in the absence of OMP, while OMP rapidly deactivated the CNGA2 channel activity with residual currents. Photo-activation of opto-β2 in the absence of OMP induced the CNGA2 currents with a prolonged increase, while OMP swiftly deactivated the CNGA2 channels after the initial surge. Therefore, cytosolic OMP rapidly uncouples CNGA2 channels and cAMP-signaling produced via GPCRs in the submembrane compartment.
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6
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Lee Y, Warne T, Nehmé R, Pandey S, Dwivedi-Agnihotri H, Chaturvedi M, Edwards PC, García-Nafría J, Leslie AGW, Shukla AK, Tate CG. Molecular basis of β-arrestin coupling to formoterol-bound β 1-adrenoceptor. Nature 2020; 583:862-866. [PMID: 32555462 DOI: 10.1038/s41586-020-2419-1] [Citation(s) in RCA: 150] [Impact Index Per Article: 37.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Accepted: 04/07/2020] [Indexed: 12/15/2022]
Abstract
The β1-adrenoceptor (β1AR) is a G-protein-coupled receptor (GPCR) that couples1 to the heterotrimeric G protein Gs. G-protein-mediated signalling is terminated by phosphorylation of the C terminus of the receptor by GPCR kinases (GRKs) and by coupling of β-arrestin 1 (βarr1, also known as arrestin 2), which displaces Gs and induces signalling through the MAP kinase pathway2. The ability of synthetic agonists to induce signalling preferentially through either G proteins or arrestins-known as biased agonism3-is important in drug development, because the therapeutic effect may arise from only one signalling cascade, whereas the other pathway may mediate undesirable side effects4. To understand the molecular basis for arrestin coupling, here we determined the cryo-electron microscopy structure of the β1AR-βarr1 complex in lipid nanodiscs bound to the biased agonist formoterol5, and the crystal structure of formoterol-bound β1AR coupled to the G-protein-mimetic nanobody6 Nb80. βarr1 couples to β1AR in a manner distinct to that7 of Gs coupling to β2AR-the finger loop of βarr1 occupies a narrower cleft on the intracellular surface, and is closer to transmembrane helix H7 of the receptor when compared with the C-terminal α5 helix of Gs. The conformation of the finger loop in βarr1 is different from that adopted by the finger loop of visual arrestin when it couples to rhodopsin8. β1AR coupled to βarr1 shows considerable differences in structure compared with β1AR coupled to Nb80, including an inward movement of extracellular loop 3 and the cytoplasmic ends of H5 and H6. We observe weakened interactions between formoterol and two serine residues in H5 at the orthosteric binding site of β1AR, and find that formoterol has a lower affinity for the β1AR-βarr1 complex than for the β1AR-Gs complex. The structural differences between these complexes of β1AR provide a foundation for the design of small molecules that could bias signalling in the β-adrenoceptors.
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Affiliation(s)
- Yang Lee
- MRC Laboratory of Molecular Biology, Cambridge, UK
| | - Tony Warne
- MRC Laboratory of Molecular Biology, Cambridge, UK
| | - Rony Nehmé
- MRC Laboratory of Molecular Biology, Cambridge, UK.,Creoptix AG, Wädenswil, Switzerland
| | - Shubhi Pandey
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur, India
| | | | - Madhu Chaturvedi
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur, India
| | | | - Javier García-Nafría
- Institute for Biocomputation and Physics of Complex Systems (BIFI), University of Zaragoza, BIFI-IQFR (CSIC), Zaragoza, Spain.,Laboratorio de Microscopías Avanzadas, University of Zaragoza, Zaragoza, Spain
| | | | - Arun K Shukla
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur, India
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7
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Grahl A, Abiko LA, Isogai S, Sharpe T, Grzesiek S. A high-resolution description of β 1-adrenergic receptor functional dynamics and allosteric coupling from backbone NMR. Nat Commun 2020; 11:2216. [PMID: 32371991 PMCID: PMC7200737 DOI: 10.1038/s41467-020-15864-y] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Accepted: 04/01/2020] [Indexed: 12/29/2022] Open
Abstract
Signal transmission and regulation of G-protein-coupled receptors (GPCRs) by extra- and intracellular ligands occurs via modulation of complex conformational equilibria, but their exact kinetic details and underlying atomic mechanisms are unknown. Here we quantified these dynamic equilibria in the β1-adrenergic receptor in its apo form and seven ligand complexes using 1H/15N NMR spectroscopy. We observe three major exchanging conformations: an inactive conformation (Ci), a preactive conformation (Cp) and an active conformation (Ca), which becomes fully populated in a ternary complex with a G protein mimicking nanobody. The Ci ↔ Cp exchange occurs on the microsecond scale, the Cp ↔ Ca exchange is slower than ~5 ms and only occurs in the presence of two highly conserved tyrosines (Y5.58, Y7.53), which stabilize the active conformation of TM6. The Cp→Ca chemical shift changes indicate a pivoting motion of the entire TM6 that couples the effector site to the orthosteric ligand pocket. Signal transmission and regulation of G-protein-coupled receptors (GPCRs) by ligands occurs via modulation of complex conformational equilibria. Here authors quantify these equilibria and their dynamics in the β1-adrenergic receptor in its apo form and seven ligand complexes using NMR.
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Affiliation(s)
- Anne Grahl
- Focal Area Structural Biology and Biophysics, Biozentrum, University of Basel, 4056, Basel, Switzerland
| | - Layara Akemi Abiko
- Focal Area Structural Biology and Biophysics, Biozentrum, University of Basel, 4056, Basel, Switzerland
| | - Shin Isogai
- Focal Area Structural Biology and Biophysics, Biozentrum, University of Basel, 4056, Basel, Switzerland
| | - Timothy Sharpe
- Biophysics Core Facility, Biozentrum, University of Basel, 4056, Basel, Switzerland
| | - Stephan Grzesiek
- Focal Area Structural Biology and Biophysics, Biozentrum, University of Basel, 4056, Basel, Switzerland.
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8
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Warne T, Edwards PC, Doré AS, Leslie AGW, Tate CG. Molecular basis for high-affinity agonist binding in GPCRs. Science 2019; 364:775-778. [PMID: 31072904 PMCID: PMC6586556 DOI: 10.1126/science.aau5595] [Citation(s) in RCA: 74] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2018] [Accepted: 04/29/2019] [Indexed: 12/22/2022]
Abstract
G protein-coupled receptors (GPCRs) in the G protein-coupled active state have higher affinity for agonists as compared with when they are in the inactive state, but the molecular basis for this is unclear. We have determined four active-state structures of the β1-adrenoceptor (β1AR) bound to conformation-specific nanobodies in the presence of agonists of varying efficacy. Comparison with inactive-state structures of β1AR bound to the identical ligands showed a 24 to 42% reduction in the volume of the orthosteric binding site. Potential hydrogen bonds were also shorter, and there was up to a 30% increase in the number of atomic contacts between the receptor and ligand. This explains the increase in agonist affinity of GPCRs in the active state for a wide range of structurally distinct agonists.
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Affiliation(s)
- Tony Warne
- Medical Research Council (MRC) Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Patricia C Edwards
- Medical Research Council (MRC) Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Andrew S Doré
- Sosei Heptares, Steinmetz Building, Granta Park, Great Abington, Cambridge CB21 6GT, UK
| | - Andrew G W Leslie
- Medical Research Council (MRC) Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Christopher G Tate
- Medical Research Council (MRC) Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK.
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9
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Insight into partial agonism by observing multiple equilibria for ligand-bound and G s-mimetic nanobody-bound β 1-adrenergic receptor. Nat Commun 2017; 8:1795. [PMID: 29176642 PMCID: PMC5702606 DOI: 10.1038/s41467-017-02008-y] [Citation(s) in RCA: 78] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Accepted: 11/01/2017] [Indexed: 11/12/2022] Open
Abstract
A complex conformational energy landscape determines G-protein-coupled receptor (GPCR) signalling via intracellular binding partners (IBPs), e.g., Gs and β-arrestin. Using 13C methyl methionine NMR for the β1-adrenergic receptor, we identify ligand efficacy-dependent equilibria between an inactive and pre-active state and, in complex with Gs-mimetic nanobody, between more and less active ternary complexes. Formation of a basal activity complex through ligand-free nanobody–receptor interaction reveals structural differences on the cytoplasmic receptor side compared to the full agonist-bound nanobody-coupled form, suggesting that ligand-induced variations in G-protein interaction underpin partial agonism. Significant differences in receptor dynamics are observed ranging from rigid nanobody-coupled states to extensive μs-to-ms timescale dynamics when bound to a full agonist. We suggest that the mobility of the full agonist-bound form primes the GPCR to couple to IBPs. On formation of the ternary complex, ligand efficacy determines the quality of the interaction between the rigidified receptor and an IBP and consequently the signalling level. β1-adrenergic receptors are expressed in cardiac tissue and stimulated by the sympathetic nervous system. Here, the authors use NMR spectroscopy to unravel the conformational diversity upon β1-adrenergic receptor activation and provide structural insights into partial agonism and basal activity.
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10
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Soave M, Cseke G, Hutchings CJ, Brown AJH, Woolard J, Hill SJ. A monoclonal antibody raised against a thermo-stabilised β 1-adrenoceptor interacts with extracellular loop 2 and acts as a negative allosteric modulator of a sub-set of β 1-adrenoceptors expressed in stable cell lines. Biochem Pharmacol 2017; 147:38-54. [PMID: 29102678 PMCID: PMC5770334 DOI: 10.1016/j.bcp.2017.10.015] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2017] [Accepted: 10/31/2017] [Indexed: 11/30/2022]
Abstract
Recent interest has focused on antibodies that can discriminate between different receptor conformations. Here we have characterised the effect of a monoclonal antibody (mAb3), raised against a purified thermo-stabilised turkey β1-adrenoceptor (β1AR-m23 StaR), on β1-ARs expressed in CHO-K1 or HEK 293 cells. Immunohistochemical and radioligand-binding studies demonstrated that mAb3 was able to bind to ECL2 of the tβ1-AR, but not its human homologue. Specific binding of mAb3 to tβ1-AR was inhibited by a peptide based on the turkey, but not the human, ECL2 sequence. Studies with [3H]-CGP 12177 demonstrated that mAb3 prevented the binding of orthosteric ligands to a subset (circa 40%) of turkey β1-receptors expressed in both CHO K1 and HEK 293 cells. MAb3 significantly reduced the maximum specific binding capacity of [3H]-CGP-12177 without influencing its binding affinity. Substitution of ECL2 of tβ1-AR with its human equivalent, or mutation of residues D186S, P187D, Q188E prevented the inhibition of [3H]-CGP 12177 binding by mAb3. MAb3 also elicited a negative allosteric effect on agonist-stimulated cAMP responses. The identity of the subset of turkey β1-adrenoceptors influenced by mAb3 remains to be established but mAb3 should become an important tool to investigate the nature of β1-AR conformational states and oligomeric complexes.
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Affiliation(s)
- Mark Soave
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham NG7 2UH, UK; Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, Midlands, UK
| | - Gabriella Cseke
- Heptares Therapeutics Ltd., Bio Park, Welwyn Garden City AL7 3AX, UK
| | | | | | - Jeanette Woolard
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham NG7 2UH, UK; Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, Midlands, UK.
| | - Stephen J Hill
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham NG7 2UH, UK; Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, Midlands, UK.
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11
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Carpenter B, Tate CG. Engineering a minimal G protein to facilitate crystallisation of G protein-coupled receptors in their active conformation. Protein Eng Des Sel 2016; 29:583-594. [PMID: 27672048 PMCID: PMC5181381 DOI: 10.1093/protein/gzw049] [Citation(s) in RCA: 71] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Revised: 08/01/2016] [Accepted: 08/23/2016] [Indexed: 11/13/2022] Open
Abstract
G protein-coupled receptors (GPCRs) modulate cytoplasmic signalling in response to extracellular stimuli, and are important therapeutic targets in a wide range of diseases. Structure determination of GPCRs in all activation states is important to elucidate the precise mechanism of signal transduction and to facilitate optimal drug design. However, due to their inherent instability, crystallisation of GPCRs in complex with cytoplasmic signalling proteins, such as heterotrimeric G proteins and β-arrestins, has proved challenging. Here, we describe the design of a minimal G protein, mini-Gs, which is composed solely of the GTPase domain from the adenylate cyclase stimulating G protein Gs. Mini-Gs is a small, soluble protein, which efficiently couples GPCRs in the absence of Gβγ subunits. We engineered mini-Gs, using rational design mutagenesis, to form a stable complex with detergent-solubilised β1-adrenergic receptor (β1AR). Mini G proteins induce similar pharmacological and structural changes in GPCRs as heterotrimeric G proteins, but eliminate many of the problems associated with crystallisation of these complexes, specifically their large size, conformational dynamics and instability in detergent. They are therefore novel tools, which will facilitate the biochemical and structural characterisation of GPCRs in their active conformation.
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Affiliation(s)
- Byron Carpenter
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus , Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Christopher G Tate
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus , Francis Crick Avenue, Cambridge CB2 0QH, UK
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12
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Emtage AL, Mistry SN, Fischer PM, Kellam B, Laughton CA. GPCRs through the keyhole: the role of protein flexibility in ligand binding to β-adrenoceptors. J Biomol Struct Dyn 2016; 35:2604-2619. [DOI: 10.1080/07391102.2016.1226197] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Affiliation(s)
- Abigail L. Emtage
- School of Pharmacy and Centre for Biomolecular Sciences, The University of Nottingham, University Park, Nottingham NG7 2RD, UK
| | - Shailesh N. Mistry
- School of Pharmacy and Centre for Biomolecular Sciences, The University of Nottingham, University Park, Nottingham NG7 2RD, UK
| | - Peter M. Fischer
- School of Pharmacy and Centre for Biomolecular Sciences, The University of Nottingham, University Park, Nottingham NG7 2RD, UK
| | - Barrie Kellam
- School of Pharmacy and Centre for Biomolecular Sciences, The University of Nottingham, University Park, Nottingham NG7 2RD, UK
| | - Charles A. Laughton
- School of Pharmacy and Centre for Biomolecular Sciences, The University of Nottingham, University Park, Nottingham NG7 2RD, UK
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13
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Isogai S, Deupi X, Opitz C, Heydenreich FM, Tsai CJ, Brueckner F, Schertler GFX, Veprintsev DB, Grzesiek S. Backbone NMR reveals allosteric signal transduction networks in the β1-adrenergic receptor. Nature 2016; 530:237-41. [DOI: 10.1038/nature16577] [Citation(s) in RCA: 128] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2014] [Accepted: 12/04/2015] [Indexed: 01/20/2023]
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14
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Heydenreich FM, Vuckovic Z, Matkovic M, Veprintsev DB. Stabilization of G protein-coupled receptors by point mutations. Front Pharmacol 2015; 6:82. [PMID: 25941489 PMCID: PMC4403299 DOI: 10.3389/fphar.2015.00082] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2015] [Accepted: 03/31/2015] [Indexed: 11/13/2022] Open
Abstract
G protein-coupled receptors (GPCRs) are flexible integral membrane proteins involved in transmembrane signaling. Their involvement in many physiological processes makes them interesting targets for drug development. Determination of the structure of these receptors will help to design more specific drugs, however, their structural characterization has so far been hampered by the low expression and their inherent instability in detergents which made protein engineering indispensable for structural and biophysical characterization. Several approaches to stabilize the receptors in a particular conformation have led to breakthroughs in GPCR structure determination. These include truncations of the flexible regions, stabilization by antibodies and nanobodies, fusion partners, high affinity and covalently bound ligands as well as conformational stabilization by mutagenesis. In this review we focus on stabilization of GPCRs by insertion of point mutations, which lead to increased conformational and thermal stability as well as improved expression levels. We summarize existing mutagenesis strategies with different coverage of GPCR sequence space and depth of information, design and transferability of mutations and the molecular basis for stabilization. We also discuss whether mutations alter the structure and pharmacological properties of GPCRs.
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Affiliation(s)
- Franziska M Heydenreich
- Laboratory of Biomolecular Research, Paul Scherrer Institut Villigen, Switzerland ; Department of Biology, ETH Zürich Zürich, Switzerland
| | - Ziva Vuckovic
- Laboratory of Biomolecular Research, Paul Scherrer Institut Villigen, Switzerland ; Department of Biology, ETH Zürich Zürich, Switzerland
| | - Milos Matkovic
- Laboratory of Biomolecular Research, Paul Scherrer Institut Villigen, Switzerland ; Department of Biology, ETH Zürich Zürich, Switzerland
| | - Dmitry B Veprintsev
- Laboratory of Biomolecular Research, Paul Scherrer Institut Villigen, Switzerland ; Department of Biology, ETH Zürich Zürich, Switzerland
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15
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Ahles A, Engelhardt S. Polymorphic Variants of Adrenoceptors: Pharmacology, Physiology, and Role in Disease. Pharmacol Rev 2014; 66:598-637. [DOI: 10.1124/pr.113.008219] [Citation(s) in RCA: 75] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
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The importance of interactions with helix 5 in determining the efficacy of β-adrenoceptor ligands. Biochem Soc Trans 2013; 41:159-65. [PMID: 23356277 DOI: 10.1042/bst20120228] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Structures of the inactive state of the thermostabilized β1-adrenoceptor have been determined bound to eight different ligands, including full agonists, partial agonists, inverse agonists and biased agonists. Comparison of the structures shows distinct differences within the binding pocket that correlate with the pharmacological properties of the ligands. These data suggest that full agonists stabilize a structure with a contracted binding pocket and a rotamer change of serine (5.46) compared with when antagonists are bound. Inverse agonists may prevent both of these occurrences, whereas partial agonists stabilize a contraction of the binding pocket but not the rotamer change of serine (5.46). It is likely that subtle changes in the interactions between transmembrane helix 5 (H5) and H3/H4 on agonist binding promote the formation of the activated state.
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Crystal structure of oligomeric β1-adrenergic G protein-coupled receptors in ligand-free basal state. Nat Struct Mol Biol 2013; 20:419-25. [PMID: 23435379 PMCID: PMC3618578 DOI: 10.1038/nsmb.2504] [Citation(s) in RCA: 215] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2012] [Accepted: 01/03/2013] [Indexed: 01/23/2023]
Abstract
G protein-coupled receptors (GPCRs) mediate transmembrane signaling. Before ligand binding, GPCRs exist in a basal state. Crystal structures of several GPCRs bound with antagonists or agonists have been solved. However, the crystal structure of the ligand-free basal state of a GPCR, the starting point of GPCR activation and function, has not been determined. Here we report the X-ray crystal structure of the first ligand-free basal state of a GPCR in a lipid membrane-like environment. Oligomeric turkey β1-adrenergic receptors display two alternating dimer interfaces. One interface involves the transmembrane domain (TM) 1, TM2, the C-terminal H8, and the extracellular loop 1. The other interface engages residues from TM4, TM5, the intracellular loop 2 and the extracellular loop 2. Structural comparisons show that this ligand-free state is in an inactive conformation. This provides the structural information regarding GPCR dimerization and oligomerization.
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18
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Crystal structures of a stabilized β1-adrenoceptor bound to the biased agonists bucindolol and carvedilol. Structure 2012; 20:841-9. [PMID: 22579251 PMCID: PMC3384003 DOI: 10.1016/j.str.2012.03.014] [Citation(s) in RCA: 181] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2011] [Revised: 02/06/2012] [Accepted: 03/03/2012] [Indexed: 01/02/2023]
Abstract
The β1-adrenoceptor (β1AR) is the site of action of beta blockers used in the treatment of cardiac-related illnesses. Two beta blockers, carvedilol and bucindolol, show distinctive activities compared to other beta blockers and have been proposed as treatments tailored to the Arg/Gly3898.56 polymorphism of the human β1AR. Both carvedilol and bucindolol are classified as biased agonists, because they stimulate G protein-independent signaling, while acting as either inverse or partial agonists of the G protein pathway. We have determined the crystal structures of a thermostabilized avian β1AR mutant bound to bucindolol and to carvedilol at 3.2 and 2.3 Å resolution, respectively. In comparison to other beta blockers, bucindolol and carvedilol interact with additional residues, in extracellular loop 2 and transmembrane helix 7, which may promote G protein-independent signaling. The structures also suggest that there may be a structural explanation for the pharmacological differences arising from the Arg/Gly3898.56 polymorphism.
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19
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A crystal clear solution for determining G-protein-coupled receptor structures. Trends Biochem Sci 2012; 37:343-52. [PMID: 22784935 DOI: 10.1016/j.tibs.2012.06.003] [Citation(s) in RCA: 106] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2012] [Revised: 05/31/2012] [Accepted: 06/05/2012] [Indexed: 11/21/2022]
Abstract
G-protein-coupled receptors (GPCRs) are medically important membrane proteins that are targeted by over 30% of small molecule drugs. At the time of writing, 15 unique GPCR structures have been determined, with 77 structures deposited in the PDB database, which offers new opportunities for drug development and for understanding the molecular mechanisms of GPCR activation. Many different factors have contributed to this success, but if there is one single factor that can be singled out as the foundation for producing well-diffracting GPCR crystals, it is the stabilisation of the detergent-solubilised receptor-ligand complex. This review will focus predominantly on one of the successful strategies for the stabilisation of GPCRs, namely the thermostabilisation of GPCRs using systematic mutagenesis coupled with thermostability assays. Structures of thermostabilised GPCRs bound to a wide variety of ligands have been determined, which has led to an understanding of ligand specificity; why some ligands act as agonists as opposed to partial or inverse agonists; and the structural basis for receptor activation.
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20
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Lebon G, Warne T, Tate CG. Agonist-bound structures of G protein-coupled receptors. Curr Opin Struct Biol 2012; 22:482-90. [PMID: 22480933 DOI: 10.1016/j.sbi.2012.03.007] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2012] [Revised: 03/12/2012] [Accepted: 03/14/2012] [Indexed: 01/14/2023]
Abstract
G protein-coupled receptors (GPCRs) play a major role in intercellular communication by binding small diffusible ligands (agonists) at the extracellular surface. Agonist-binding induces a conformational change in the receptor, which results in the binding and activation of heterotrimeric G proteins within the cell. Ten agonist-bound structures of non-rhodopsin GPCRs published last year defined for the first time the molecular details of receptor activated states and how inverse agonists, partial agonists and full agonists bind to produce different effects on the receptor. In addition, the structure of the β(2)-adrenoceptor coupled to a heterotrimeric G protein showed how the opening of a cleft in the cytoplasmic face of the receptor as a consequence of agonist binding results in G protein coupling and activation of the G protein.
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Affiliation(s)
- Guillaume Lebon
- Institut de Génomique Fonctionnelle, UMR 5203 CNRS - U 661 INSERM - Univ. Montpellier I & II, 141, rue de la cardonille, 34094 Montpellier Cedex 05, France
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