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Randáková A, Nelic D, Jakubík J. A critical re-evaluation of the slope factor of the operational model of agonism: When to exponentiate operational efficacy. Sci Rep 2023; 13:17587. [PMID: 37845324 PMCID: PMC10579308 DOI: 10.1038/s41598-023-45004-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Accepted: 10/14/2023] [Indexed: 10/18/2023] Open
Abstract
Agonist efficacy denoting the "strength" of agonist action is a cornerstone in the proper assessment of agonist selectivity and signalling bias. The simulation models are very accurate but complex and hard to fit experimental data. The parsimonious operational model of agonism (OMA) has become successful in the determination of agonist efficacies and ranking them. In 1983, Black and Leff introduced the slope factor to the OMA to make it more flexible and allow for fitting steep as well as flat concentration-response curves. First, we performed a functional analysis to indicate the potential pitfalls of the OMA. Namely, exponentiation of operational efficacy may break relationships among the OMA parameters. The fitting of the Black & Leff equation to the theoretical curves of several models of functional responses and the experimental data confirmed the fickleness of the exponentiation of operational efficacy affecting estimates of operational efficacy as well as other OMA parameters. In contrast, fitting The OMA based on the Hill equation to the same data led to better estimates of model parameters. In conclusion, Hill equation-based OMA should be preferred over the Black & Leff equation when functional-response curves differ in the slope factor. Otherwise, the Black & Leff equation should be used with extreme caution acknowledging potential pitfalls.
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Affiliation(s)
- Alena Randáková
- Institute of Physiology Czech Academy of Sciences, Vídeňská 1083, 142 20 Praha, Prague, Czech Republic
| | - Dominik Nelic
- Institute of Physiology Czech Academy of Sciences, Vídeňská 1083, 142 20 Praha, Prague, Czech Republic
| | - Jan Jakubík
- Institute of Physiology Czech Academy of Sciences, Vídeňská 1083, 142 20 Praha, Prague, Czech Republic.
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2
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Panda A, Giska F, Duncan AL, Welch AJ, Brown C, McAllister R, Hariharan P, Goder JND, Coleman J, Ramakrishnan S, Pincet F, Guan L, Krishnakumar S, Rothman JE, Gupta K. Direct determination of oligomeric organization of integral membrane proteins and lipids from intact customizable bilayer. Nat Methods 2023; 20:891-897. [PMID: 37106230 PMCID: PMC10932606 DOI: 10.1038/s41592-023-01864-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Accepted: 03/23/2023] [Indexed: 04/29/2023]
Abstract
Hierarchical organization of integral membrane proteins (IMP) and lipids at the membrane is essential for regulating myriad downstream signaling. A quantitative understanding of these processes requires both detections of oligomeric organization of IMPs and lipids directly from intact membranes and determination of key membrane components and properties that regulate them. Addressing this, we have developed a platform that enables native mass spectrometry (nMS) analysis of IMP-lipid complexes directly from intact and customizable lipid membranes. Both the lipid composition and membrane properties (such as curvature, tension, and fluidity) of these bilayers can be precisely customized to a target membrane. Subsequent direct nMS analysis of these intact proteolipid vesicles can yield the oligomeric states of the embedded IMPs, identify bound lipids, and determine the membrane properties that can regulate the observed IMP-lipid organization. Applying this method, we show how lipid binding regulates neurotransmitter release and how membrane composition regulates the functional oligomeric state of a transporter.
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Affiliation(s)
- Aniruddha Panda
- Nanobiology Institute, Yale University, West Haven, CT, USA
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT, USA
| | - Fabian Giska
- Nanobiology Institute, Yale University, West Haven, CT, USA
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT, USA
| | - Anna L Duncan
- Department of Biochemistry, University of Oxford, Oxford, UK
- Department of Chemistry, Aarhus University, Aarhus C, Denmark
| | | | - Caroline Brown
- Nanobiology Institute, Yale University, West Haven, CT, USA
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT, USA
| | - Rachel McAllister
- Nanobiology Institute, Yale University, West Haven, CT, USA
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT, USA
| | - Parameswaran Hariharan
- Department of Cell Physiology and Molecular Biophysics, School of Medicine, Texas Tech University Health Sciences Center, Lubbock, TX, USA
| | - Jean N D Goder
- Nanobiology Institute, Yale University, West Haven, CT, USA
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT, USA
| | - Jeff Coleman
- Nanobiology Institute, Yale University, West Haven, CT, USA
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT, USA
| | - Sathish Ramakrishnan
- Nanobiology Institute, Yale University, West Haven, CT, USA
- Department of Pathology, Yale University School of Medicine, New Haven, CT, USA
| | - Frédéric Pincet
- Nanobiology Institute, Yale University, West Haven, CT, USA
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT, USA
- Laboratoire de Physique de l'Ecole Normale Supérieure, ENS, CNRS, Université PSL, Sorbonne Université, Université Paris-Cité, Paris, France
| | - Lan Guan
- Department of Cell Physiology and Molecular Biophysics, School of Medicine, Texas Tech University Health Sciences Center, Lubbock, TX, USA
| | - Shyam Krishnakumar
- Nanobiology Institute, Yale University, West Haven, CT, USA
- Department of Neurology, Yale University School of Medicine, New Haven, CT, USA
| | - James E Rothman
- Nanobiology Institute, Yale University, West Haven, CT, USA
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT, USA
| | - Kallol Gupta
- Nanobiology Institute, Yale University, West Haven, CT, USA.
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT, USA.
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3
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Jakubík J, Randáková A. Insights into the operational model of agonism of receptor dimers. Expert Opin Drug Discov 2022; 17:1181-1191. [PMID: 36369915 DOI: 10.1080/17460441.2023.2147502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Accepted: 11/10/2022] [Indexed: 11/15/2022]
Abstract
INTRODUCTION Accurate ranking of efficacies and potencies of agonists is essential in the discovery of new selective agonists. For the purpose of system-independent ranking of agonists, the operational model of agonism (OMA) has become a standard. Many receptors function as oligomers which makes functional responses more complex, requiring an extension of the original OMA. AREAS COVERED Explicit equations of the operational model of agonism of receptor dimers (OMARD) were derived. The OMARD can be applied to any receptor possessing two orthosteric sites. The behavior of OMARD was analyzed to demonstrate its complexity and relation to experimental data. Properties of OMARD and OMA equations were compared to demonstrate their pros and cons. EXPERT OPINION Extension of OMA by slope factors gives simple equations of functional response that are easy to fit experimental data but results may be inaccurate because of exponentiation of operational efficacy. Also, such equations cannot accommodate bell-shaped curves. Explicit equations of OMARD give accurate results but are complex and tedious to fit experimental data. All operational models use inter-dependent parameters that are a hurdle in the fitting. A good understanding of OMARD behavior helps to overcome such obstacles.
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Affiliation(s)
- Jan Jakubík
- Laboratory of Neurochemistry, Institute of Physiology CAS, Prague, Czech Republic
| | - Alena Randáková
- Laboratory of Neurochemistry, Institute of Physiology CAS, Prague, Czech Republic
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4
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De Oliveira PA, Moreno E, Casajuana-Martin N, Casadó-Anguera V, Cai NS, Camacho-Hernandez GA, Zhu H, Bonifazi A, Hall MD, Weinshenker D, Newman AH, Logothetis DE, Casadó V, Plant LD, Pardo L, Ferré S. Preferential Gs protein coupling of the galanin Gal 1 receptor in the µ-opioid-Gal 1 receptor heterotetramer. Pharmacol Res 2022; 182:106322. [PMID: 35750299 PMCID: PMC9462584 DOI: 10.1016/j.phrs.2022.106322] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Revised: 06/18/2022] [Accepted: 06/19/2022] [Indexed: 12/25/2022]
Abstract
Recent studies have proposed that heteromers of µ-opioid receptors (MORs) and galanin Gal1 receptors (Gal1Rs) localized in the mesencephalon mediate the dopaminergic effects of opioids. The present study reports converging evidence, using a peptide-interfering approach combined with biophysical and biochemical techniques, including total internal reflection fluorescence microscopy, for a predominant homodimeric structure of MOR and Gal1R when expressed individually, and for their preference to form functional heterotetramers when co-expressed. Results show that a heteromerization-dependent change in the Gal1R homodimeric interface leads to a switch in G-protein coupling from inhibitory Gi to stimulatory Gs proteins. The MOR-Gal1R heterotetramer, which is thus bound to Gs via the Gal1R homodimer and Gi via the MOR homodimer, provides the framework for a canonical Gs-Gi antagonist interaction at the adenylyl cyclase level. These novel results shed light on the intense debate about the oligomeric quaternary structure of G protein-coupled receptors, their predilection for heteromer formation, and the resulting functional significance.
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Affiliation(s)
| | - Estefanía Moreno
- Laboratory of Molecular Neuropharmacology, Department of Biochemistry and Molecular Biomedicine, Faculty of Biology and Institute of Biomedicine, University of Barcelona, Barcelona, Spain
| | - Nil Casajuana-Martin
- Laboratory of Computational Medicine, Biostatistics Unit, Faculty of Medicine, Autonomous University of Barcelona, Bellaterra, Spain
| | - Verònica Casadó-Anguera
- Laboratory of Molecular Neuropharmacology, Department of Biochemistry and Molecular Biomedicine, Faculty of Biology and Institute of Biomedicine, University of Barcelona, Barcelona, Spain
| | | | - Gisela Andrea Camacho-Hernandez
- Medicinal Chemistry Section, National Institute on Drug Abuse, Intramural Research Program, National Institutes of Health, Baltimore, MD, USA
| | - Hu Zhu
- Division of Preclinical Innovation, National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, MD, USA
| | - Alessandro Bonifazi
- Medicinal Chemistry Section, National Institute on Drug Abuse, Intramural Research Program, National Institutes of Health, Baltimore, MD, USA
| | - Matthew D Hall
- Division of Preclinical Innovation, National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, MD, USA
| | - David Weinshenker
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA, USA
| | - Amy Hauck Newman
- Medicinal Chemistry Section, National Institute on Drug Abuse, Intramural Research Program, National Institutes of Health, Baltimore, MD, USA
| | - Diomedes E Logothetis
- Departments of Pharmaceutical Sciences, Chemistry and Chemical Biology and Center for Drug Discovery, School of Pharmacy at the Bouvé College of Health Sciences and College of Science, Northeastern University, Boston, MA, USA
| | - Vicent Casadó
- Laboratory of Molecular Neuropharmacology, Department of Biochemistry and Molecular Biomedicine, Faculty of Biology and Institute of Biomedicine, University of Barcelona, Barcelona, Spain.
| | - Leigh D Plant
- Departments of Pharmaceutical Sciences, Chemistry and Chemical Biology and Center for Drug Discovery, School of Pharmacy at the Bouvé College of Health Sciences and College of Science, Northeastern University, Boston, MA, USA.
| | - Leonardo Pardo
- Laboratory of Computational Medicine, Biostatistics Unit, Faculty of Medicine, Autonomous University of Barcelona, Bellaterra, Spain.
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5
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Montell C. Drosophila sensory receptors-a set of molecular Swiss Army Knives. Genetics 2021; 217:1-34. [PMID: 33683373 DOI: 10.1093/genetics/iyaa011] [Citation(s) in RCA: 46] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Accepted: 11/17/2020] [Indexed: 01/01/2023] Open
Abstract
Genetic approaches in the fruit fly, Drosophila melanogaster, have led to a major triumph in the field of sensory biology-the discovery of multiple large families of sensory receptors and channels. Some of these families, such as transient receptor potential channels, are conserved from animals ranging from worms to humans, while others, such as "gustatory receptors," "olfactory receptors," and "ionotropic receptors," are restricted to invertebrates. Prior to the identification of sensory receptors in flies, it was widely assumed that these proteins function in just one modality such as vision, smell, taste, hearing, and somatosensation, which includes thermosensation, light, and noxious mechanical touch. By employing a vast combination of genetic, behavioral, electrophysiological, and other approaches in flies, a major concept to emerge is that many sensory receptors are multitaskers. The earliest example of this idea was the discovery that individual transient receptor potential channels function in multiple senses. It is now clear that multitasking is exhibited by other large receptor families including gustatory receptors, ionotropic receptors, epithelial Na+ channels (also referred to as Pickpockets), and even opsins, which were formerly thought to function exclusively as light sensors. Genetic characterizations of these Drosophila receptors and the neurons that express them also reveal the mechanisms through which flies can accurately differentiate between different stimuli even when they activate the same receptor, as well as mechanisms of adaptation, amplification, and sensory integration. The insights gleaned from studies in flies have been highly influential in directing investigations in many other animal models.
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Affiliation(s)
- Craig Montell
- Department of Molecular, Cellular, and Developmental Biology, The Neuroscience Research Institute, University of California, Santa Barbara, CA 93106, USA
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6
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Shivnaraine RV, Kelly B, Elmslie G, Huang XP, Dong YJ, Seidenberg M, Wells JW, Ellis J. Allostery of atypical modulators at oligomeric G protein-coupled receptors. Sci Rep 2021; 11:9265. [PMID: 33927236 PMCID: PMC8085029 DOI: 10.1038/s41598-021-88399-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Accepted: 04/06/2021] [Indexed: 01/14/2023] Open
Abstract
Many G protein-coupled receptors (GPCRs) are therapeutic targets, with most drugs acting at the orthosteric site. Some GPCRs also possess allosteric sites, which have become a focus of drug discovery. In the M2 muscarinic receptor, allosteric modulators regulate the binding and functional effects of orthosteric ligands through a mix of conformational changes, steric hindrance and electrostatic repulsion transmitted within and between the constituent protomers of an oligomer. Tacrine has been called an atypical modulator because it exhibits positive cooperativity, as revealed by Hill coefficients greater than 1 in its negative allosteric effect on binding and response. Radioligand binding and molecular dynamics simulations were used to probe the mechanism of that modulation in monomers and oligomers of wild-type and mutant M2 receptors. Tacrine is not atypical at monomers, which indicates that its atypical effects are a property of the receptor in its oligomeric state. These results illustrate that oligomerization of the M2 receptor has functional consequences.
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Affiliation(s)
- Rabindra V Shivnaraine
- Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, 144 College Street, Toronto, ON, M5S 3M2, Canada.
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, B163 Beckman Center, 279 Campus Drive, Stanford, CA, 94305, USA.
| | - Brendan Kelly
- Departments of Computer Science, Molecular and Cellular Physiology, and Structural Biology, and Institute for Computational and Mathematical Engineering, Stanford University, Stanford, CA, 94305, USA
| | - Gwendolynne Elmslie
- Departments of Psychiatry and Pharmacology, Hershey Medical Center, Penn State University College of Medicine, Hershey, PA, 17033, USA
| | - Xi-Ping Huang
- Departments of Psychiatry and Pharmacology, Hershey Medical Center, Penn State University College of Medicine, Hershey, PA, 17033, USA
- Department of Pharmacology, The National Institute of Mental Health Psychoactive Drug Screening Program (NIMH PDSP), University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Yue John Dong
- Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, 144 College Street, Toronto, ON, M5S 3M2, Canada
| | - Margaret Seidenberg
- Departments of Psychiatry and Pharmacology, Hershey Medical Center, Penn State University College of Medicine, Hershey, PA, 17033, USA
| | - James W Wells
- Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, 144 College Street, Toronto, ON, M5S 3M2, Canada.
| | - John Ellis
- Departments of Psychiatry and Pharmacology, Hershey Medical Center, Penn State University College of Medicine, Hershey, PA, 17033, USA.
- Department of Psychiatry H073, Penn State University College of Medicine, 500 University Drive, Hershey, PA, 17033, USA.
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7
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Jakubík J, El-Fakahany EE. Allosteric Modulation of GPCRs of Class A by Cholesterol. Int J Mol Sci 2021; 22:1953. [PMID: 33669406 PMCID: PMC7920425 DOI: 10.3390/ijms22041953] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Revised: 02/11/2021] [Accepted: 02/12/2021] [Indexed: 12/16/2022] Open
Abstract
G-protein coupled receptors (GPCRs) are membrane proteins that convey extracellular signals to the cellular milieu. They represent a target for more than 30% of currently marketed drugs. Here we review the effects of membrane cholesterol on the function of GPCRs of Class A. We review both the specific effects of cholesterol mediated via its direct high-affinity binding to the receptor and non-specific effects mediated by cholesterol-induced changes in the properties of the membrane. Cholesterol binds to many GPCRs at both canonical and non-canonical binding sites. It allosterically affects ligand binding to and activation of GPCRs. Additionally, it changes the oligomerization state of GPCRs. In this review, we consider a perspective of the potential for the development of new therapies that are targeted at manipulating the level of membrane cholesterol or modulating cholesterol binding sites on to GPCRs.
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Affiliation(s)
- Jan Jakubík
- Department of Neurochemistry, Institute of Physiology Czech Academy of Sciences, 142 20 Prague, Czech Republic
| | - Esam E. El-Fakahany
- Department of Experimental and Clinical Pharmacology, University of Minnesota College of Pharmacy, Minneapolis, MN 55455, USA
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8
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Lavington S, Watts A. Lipid nanoparticle technologies for the study of G protein-coupled receptors in lipid environments. Biophys Rev 2020; 12:10.1007/s12551-020-00775-5. [PMID: 33215301 PMCID: PMC7755959 DOI: 10.1007/s12551-020-00775-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Accepted: 11/06/2020] [Indexed: 12/12/2022] Open
Abstract
G protein-coupled receptors (GPCRs) are a large family of integral membrane proteins which conduct a wide range of biological roles and represent significant drug targets. Most biophysical and structural studies of GPCRs have been conducted on detergent-solubilised receptors, and it is clear that detergents can have detrimental effects on GPCR function. Simultaneously, there is increasing appreciation of roles for specific lipids in modulation of GPCR function. Lipid nanoparticles such as nanodiscs and styrene maleic acid lipid particles (SMALPs) offer opportunities to study integral membrane proteins in lipid environments, in a form that is soluble and amenable to structural and biophysical experiments. Here, we review the application of lipid nanoparticle technologies to the study of GPCRs, assessing the relative merits and limitations of each system. We highlight how these technologies can provide superior platforms to detergents for structural and biophysical studies of GPCRs and inform on roles for protein-lipid interactions in GPCR function.
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Affiliation(s)
- Steven Lavington
- Biochemistry Department, University of Oxford, South Parks Road, Oxford, OX1 3QU, UK
| | - Anthony Watts
- Biochemistry Department, University of Oxford, South Parks Road, Oxford, OX1 3QU, UK.
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9
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Jones AJY, Gabriel F, Tandale A, Nietlispach D. Structure and Dynamics of GPCRs in Lipid Membranes: Physical Principles and Experimental Approaches. Molecules 2020; 25:E4729. [PMID: 33076366 PMCID: PMC7587580 DOI: 10.3390/molecules25204729] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Revised: 10/11/2020] [Accepted: 10/12/2020] [Indexed: 02/06/2023] Open
Abstract
Over the past decade, the vast amount of information generated through structural and biophysical studies of GPCRs has provided unprecedented mechanistic insight into the complex signalling behaviour of these receptors. With this recent information surge, it has also become increasingly apparent that in order to reproduce the various effects that lipids and membranes exert on the biological function for these allosteric receptors, in vitro studies of GPCRs need to be conducted under conditions that adequately approximate the native lipid bilayer environment. In the first part of this review, we assess some of the more general effects that a membrane environment exerts on lipid bilayer-embedded proteins such as GPCRs. This is then followed by the consideration of more specific effects, including stoichiometric interactions with specific lipid subtypes. In the final section, we survey a range of different membrane mimetics that are currently used for in vitro studies, with a focus on NMR applications.
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Affiliation(s)
| | | | | | - Daniel Nietlispach
- Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge CB2 1GA, UK; (A.J.Y.J.); (F.G.); (A.T.)
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10
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Leung NY, Thakur DP, Gurav AS, Kim SH, Di Pizio A, Niv MY, Montell C. Functions of Opsins in Drosophila Taste. Curr Biol 2020; 30:1367-1379.e6. [PMID: 32243853 DOI: 10.1016/j.cub.2020.01.068] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Revised: 01/16/2020] [Accepted: 01/22/2020] [Indexed: 12/31/2022]
Abstract
Rhodopsin is a light receptor comprised of an opsin protein and a light-sensitive retinal chromophore. Despite more than a century of scrutiny, there is no evidence that opsins function in chemosensation. Here, we demonstrate that three Drosophila opsins, Rh1, Rh4, and Rh7, are needed in gustatory receptor neurons to sense a plant-derived bitter compound, aristolochic acid (ARI). The gustatory requirements for these opsins are light-independent and do not require retinal. The opsins enabled flies to detect lower concentrations of aristolochic acid by initiating an amplification cascade that includes a G-protein, phospholipase Cβ, and the TRP channel, TRPA1. In contrast, responses to higher levels of the bitter compound were mediated through direct activation of TRPA1. Our study reveals roles for opsins in chemosensation and raise questions concerning the original roles for these classical G-protein-coupled receptors.
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Affiliation(s)
- Nicole Y Leung
- Neuroscience Research Institute, University of California, Santa Barbara, CA 93106, USA; Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, CA 93106, USA
| | - Dhananjay P Thakur
- Neuroscience Research Institute, University of California, Santa Barbara, CA 93106, USA; Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, CA 93106, USA
| | - Adishthi S Gurav
- Neuroscience Research Institute, University of California, Santa Barbara, CA 93106, USA; Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, CA 93106, USA
| | - Sang Hoon Kim
- Department of Biological Chemistry, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Antonella Di Pizio
- Institute of Biochemistry, Food Science and Nutrition, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, 76100 Rehovot, Israel; The Fritz Haber Center for Molecular Dynamics, The Hebrew University of Jerusalem, 91904 Jerusalem, Israel; Leibniz-Institute for Food Systems Biology at the Technical University of Munich, 85354 Freising, Germany
| | - Masha Y Niv
- Institute of Biochemistry, Food Science and Nutrition, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, 76100 Rehovot, Israel; The Fritz Haber Center for Molecular Dynamics, The Hebrew University of Jerusalem, 91904 Jerusalem, Israel
| | - Craig Montell
- Neuroscience Research Institute, University of California, Santa Barbara, CA 93106, USA; Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, CA 93106, USA.
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11
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Ferré S, Ciruela F, Casadó V, Pardo L. Oligomerization of G protein-coupled receptors: Still doubted? PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2020; 169:297-321. [DOI: 10.1016/bs.pmbts.2019.11.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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12
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Zhao DY, Pöge M, Morizumi T, Gulati S, Van Eps N, Zhang J, Miszta P, Filipek S, Mahamid J, Plitzko JM, Baumeister W, Ernst OP, Palczewski K. Cryo-EM structure of the native rhodopsin dimer in nanodiscs. J Biol Chem 2019; 294:14215-14230. [PMID: 31399513 PMCID: PMC6768649 DOI: 10.1074/jbc.ra119.010089] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2019] [Revised: 08/02/2019] [Indexed: 02/03/2023] Open
Abstract
Imaging of rod photoreceptor outer-segment disc membranes by atomic force microscopy and cryo-electron tomography has revealed that the visual pigment rhodopsin, a prototypical class A G protein-coupled receptor (GPCR), can organize as rows of dimers. GPCR dimerization and oligomerization offer possibilities for allosteric regulation of GPCR activity, but the detailed structures and mechanism remain elusive. In this investigation, we made use of the high rhodopsin density in the native disc membranes and of a bifunctional cross-linker that preserves the native rhodopsin arrangement by covalently tethering rhodopsins via Lys residue side chains. We purified cross-linked rhodopsin dimers and reconstituted them into nanodiscs for cryo-EM analysis. We present cryo-EM structures of the cross-linked rhodopsin dimer as well as a rhodopsin dimer reconstituted into nanodiscs from purified monomers. We demonstrate the presence of a preferential 2-fold symmetrical dimerization interface mediated by transmembrane helix 1 and the cytoplasmic helix 8 of rhodopsin. We confirmed this dimer interface by double electron-electron resonance measurements of spin-labeled rhodopsin. We propose that this interface and the arrangement of two protomers is a prerequisite for the formation of the observed rows of dimers. We anticipate that the approach outlined here could be extended to other GPCRs or membrane receptors to better understand specific receptor dimerization mechanisms.
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Affiliation(s)
- Dorothy Yanling Zhao
- Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Matthias Pöge
- Department of Molecular Structural Biology, Max-Planck Institute of Biochemistry, 82152 Martinsried, Germany
| | - Takefumi Morizumi
- Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Sahil Gulati
- Gavin Herbert Eye Institute and the Department of Ophthalmology, University of California, Irvine, California 92697
- Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio 44106
| | - Ned Van Eps
- Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Jianye Zhang
- Gavin Herbert Eye Institute and the Department of Ophthalmology, University of California, Irvine, California 92697
- Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio 44106
| | - Przemyslaw Miszta
- Faculty of Chemistry, Biological and Chemical Research Centre, University of Warsaw, Warsaw 02-093, Poland
| | - Slawomir Filipek
- Faculty of Chemistry, Biological and Chemical Research Centre, University of Warsaw, Warsaw 02-093, Poland
| | - Julia Mahamid
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany
| | - Jürgen M Plitzko
- Department of Molecular Structural Biology, Max-Planck Institute of Biochemistry, 82152 Martinsried, Germany
| | - Wolfgang Baumeister
- Department of Molecular Structural Biology, Max-Planck Institute of Biochemistry, 82152 Martinsried, Germany
| | - Oliver P Ernst
- Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Krzysztof Palczewski
- Gavin Herbert Eye Institute and the Department of Ophthalmology, University of California, Irvine, California 92697
- Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio 44106
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13
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GPCR homo-oligomerization. Curr Opin Cell Biol 2018; 57:40-47. [PMID: 30453145 PMCID: PMC7083226 DOI: 10.1016/j.ceb.2018.10.007] [Citation(s) in RCA: 83] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Revised: 10/22/2018] [Accepted: 10/23/2018] [Indexed: 12/21/2022]
Abstract
G protein-coupled receptors (GPCRs) are an extensive class of trans-plasma membrane proteins that function to regulate a wide range of physiological functions. Despite a general perception that GPCRs exist as monomers an extensive literature has examined whether GPCRs can also form dimers and even higher-order oligomers, and if such organization influences various aspects of GPCR function, including cellular trafficking, ligand binding, G protein coupling and signalling. Here we focus on recent studies that employ approaches ranging from computational methods to single molecule tracking and both quantal brightness and fluorescence fluctuation measurements to assess the organization, stability and potential functional significance of dimers and oligomers within the class A, rhodopsin-like GPCR family.
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14
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Burger WAC, Sexton PM, Christopoulos A, Thal DM. Toward an understanding of the structural basis of allostery in muscarinic acetylcholine receptors. J Gen Physiol 2018; 150:1360-1372. [PMID: 30190312 PMCID: PMC6168235 DOI: 10.1085/jgp.201711979] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Accepted: 08/14/2018] [Indexed: 01/16/2023] Open
Abstract
Burger et al. summarize our mechanistic understanding of allostery in the prototypical GPCR, the muscarinic acetylcholine receptor. Recent breakthroughs and developments in structural biology have led to a spate of crystal structures for G protein–coupled receptors (GPCRs). This is the case for the muscarinic acetylcholine receptors (mAChRs) where inactive-state structures for four of the five subtypes and two active-state structures for one subtype are available. These mAChR crystal structures have provided new insights into receptor mechanisms, dynamics, and allosteric modulation. This is highly relevant to the mAChRs given that these receptors are an exemplar model system for the study of GPCR allostery. Allosteric mechanisms of the mAChRs are predominantly consistent with a two-state model, albeit with some notable recent exceptions. Herein, we discuss the mechanisms for positive and negative allosteric modulation at the mAChRs and compare and contrast these to evidence offered by pharmacological, biochemical, and computational approaches. This analysis provides insight into the fundamental pharmacological properties exhibited by GPCR allosteric modulators, such as enhanced subtype selectivity, probe dependence, and biased modulation while highlighting the current challenges that remain. Though complex, enhanced molecular understanding of allosteric mechanisms will have considerable influence on our understanding of GPCR activation and signaling and development of therapeutic interventions.
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Affiliation(s)
- Wessel A C Burger
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
| | - Patrick M Sexton
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
| | - Arthur Christopoulos
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
| | - David M Thal
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
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15
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Li Y, Shivnaraine RV, Huang F, Wells JW, Gradinaru CC. Ligand-Induced Coupling between Oligomers of the M 2 Receptor and the G i1 Protein in Live Cells. Biophys J 2018; 115:881-895. [PMID: 30131171 DOI: 10.1016/j.bpj.2018.08.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Revised: 07/23/2018] [Accepted: 08/02/2018] [Indexed: 02/07/2023] Open
Abstract
Uncertainty over the mechanism of signaling via G protein-coupled receptors (GPCRs) relates in part to questions regarding their supramolecular structure. GPCRs and heterotrimeric G proteins are known to couple as monomers under various conditions. Many GPCRs form oligomers under many of the same conditions, however, and the biological role of those complexes is unclear. We have used dual-color fluorescence correlation spectroscopy to identify oligomers of the M2 muscarinic receptor and of Gi1 in purified preparations and live Chinese hamster ovary cells. Measurements on differently tagged receptors (i.e., eGFP-M2 and mCherry-M2) and G proteins (i.e., eGFP-Gαi1β1γ2 and mCherry-Gαi1β1γ2) detected significant cross-correlations between the two fluorophores in each case, both in detergent micelles and in live cells, indicating that both the receptor and Gi1 can exist as homo-oligomers. Oligomerization of differently tagged Gi1 decreased upon the activation of co-expressed wild-type M2 receptor by an agonist. Measurements on a tagged M2 receptor (M2-mCherry) and eGFP-Gαi1β1γ2 co-expressed in live cells detected cross-correlations only in the presence of an agonist, which therefore promoted coupling of the receptor and the G protein. The effect of the agonist was retained when a fluorophore-tagged receptor lacking the orthosteric site (i.e., M2(D103A)-mCherry) was co-expressed with the wild-type receptor and eGFP-Gαi1β1γ2, indicating that the ligand acted via an oligomeric receptor. Our results point to a model in which an agonist promotes transient coupling of otherwise independent oligomers of the M2 receptor on the one hand and of Gi1 on the other and that an activated complex leads to a reduction in the oligomeric size of the G protein. They suggest that GPCR-mediated signaling proceeds, at least in part, via oligomers.
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Affiliation(s)
- Yuchong Li
- Department of Physics, University of Toronto, Toronto, Ontario, Canada; Department of Chemical & Physical Sciences, University of Toronto Mississauga, Mississauga, Ontario, Canada
| | - Rabindra V Shivnaraine
- Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario, Canada
| | - Fei Huang
- Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario, Canada
| | - James W Wells
- Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario, Canada
| | - Claudiu C Gradinaru
- Department of Physics, University of Toronto, Toronto, Ontario, Canada; Department of Chemical & Physical Sciences, University of Toronto Mississauga, Mississauga, Ontario, Canada.
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16
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Marsango S, Ward RJ, Alvarez-Curto E, Milligan G. Muscarinic receptor oligomerization. Neuropharmacology 2018; 136:401-410. [PMID: 29146505 PMCID: PMC6078712 DOI: 10.1016/j.neuropharm.2017.11.023] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Revised: 11/01/2017] [Accepted: 11/13/2017] [Indexed: 12/30/2022]
Abstract
G protein-coupled receptors (GPCRs) have been classically described as monomeric entities that function by binding in a 1:1 stoichiometric ratio to both ligand and downstream signalling proteins. However, in recent years, a growing number of studies has supported the hypothesis that these receptors can interact to form dimers and higher order oligomers although the molecular basis for these interactions, the overall quaternary arrangements and the functional importance of GPCR oligomerization remain topics of intense speculation. Muscarinic acetylcholine receptors belong to class A of the GPCR family. Each muscarinic receptor subtype has its own particular distribution throughout the central and peripheral nervous systems. In the central nervous system, muscarinic receptors regulate several sensory, cognitive, and motor functions while, in the peripheral nervous system, they are involved in the regulation of heart rate, stimulation of glandular secretion and smooth muscle contraction. Muscarinic acetylcholine receptors have long been used as a model for the study of GPCR structure and function and to address aspects of GPCR dimerization using a broad range of approaches. In this review, the prevailing knowledge regarding the quaternary arrangement for the various muscarinic acetylcholine receptors has been summarized by discussing work ranging from initial results obtained using more traditional biochemical approaches to those generated with more modern biophysical techniques. This article is part of the Special Issue entitled 'Neuropharmacology on Muscarinic Receptors'.
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Affiliation(s)
- Sara Marsango
- Centre for Translational Pharmacology, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, Scotland, UK.
| | - Richard J Ward
- Centre for Translational Pharmacology, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, Scotland, UK.
| | - Elisa Alvarez-Curto
- Centre for Translational Pharmacology, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, Scotland, UK
| | - Graeme Milligan
- Centre for Translational Pharmacology, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, Scotland, UK
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17
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Gurevich VV, Gurevich EV. GPCRs and Signal Transducers: Interaction Stoichiometry. Trends Pharmacol Sci 2018; 39:672-684. [PMID: 29739625 DOI: 10.1016/j.tips.2018.04.002] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Revised: 04/11/2018] [Accepted: 04/13/2018] [Indexed: 12/12/2022]
Abstract
Until the late 1990s, class A G protein-coupled receptors (GPCRs) were believed to function as monomers. Indirect evidence that they might internalize or even signal as dimers has emerged, along with proof that class C GPCRs are obligatory dimers. Crystal structures of GPCRs and their much larger binding partners were consistent with the idea that two receptors might engage a single G protein, GRK, or arrestin. However, recent biophysical, biochemical, and structural evidence invariably suggests that a single GPCR binds G proteins, GRKs, and arrestins. Here we review existing evidence of the stoichiometry of GPCR interactions with signal transducers and discuss potential biological roles of class A GPCR oligomers, including proposed homo- and heterodimers.
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Affiliation(s)
- Vsevolod V Gurevich
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, USA.
| | - Eugenia V Gurevich
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, USA
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18
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Pediani JD, Ward RJ, Marsango S, Milligan G. Spatial Intensity Distribution Analysis: Studies of G Protein-Coupled Receptor Oligomerisation. Trends Pharmacol Sci 2017; 39:175-186. [PMID: 29032835 PMCID: PMC5783713 DOI: 10.1016/j.tips.2017.09.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Revised: 09/04/2017] [Accepted: 09/14/2017] [Indexed: 02/08/2023]
Abstract
Spatial intensity distribution analysis (SpIDA) is a recently developed approach for determining quaternary structure information on fluorophore-labelled proteins of interest in situ. It can be applied to live or fixed cells and native tissue. Using confocal images, SpIDA generates fluorescence intensity histograms that are analysed by super-Poissonian distribution functions to obtain density and quantal brightness values of the fluorophore-labelled protein of interest. This allows both expression level and oligomerisation state of the protein to be determined. We describe the application of SpIDA to investigate the oligomeric state of G protein-coupled receptors (GPCRs) at steady state and following cellular challenge, and consider how SpIDA may be used to explore GPCR quaternary organisation in pathophysiology and to stratify medicines. GPCRs may exist and function as monomers: however, abundant evidence suggests they can form dimers/oligomers. This concept has implications for drug discovery as it may offer opportunities to modulate the effects of known pharmaceuticals or identify new drug therapies. A variety of approaches have been applied to this issue from traditional biochemical techniques, via resonance energy transfer approaches to recently developed image analysis-based techniques such as SpIDA. This uses mathematical analysis of confocal microscopy images to generate quantal brightness and density information for a fluorophore-tagged receptor. SpIDA can be applied to live or fixed cells and native tissue. SpIDA has been applied to GPCRs from each of the major subfamilies to explore their oligomerisation status at steady state and their regulation by receptor density and ligand binding.
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Affiliation(s)
- John D Pediani
- Centre for Translational Pharmacology, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK
| | - Richard J Ward
- Centre for Translational Pharmacology, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK
| | - Sara Marsango
- Centre for Translational Pharmacology, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK
| | - Graeme Milligan
- Centre for Translational Pharmacology, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK.
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19
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Gendron L, Cahill CM, von Zastrow M, Schiller PW, Pineyro G. Molecular Pharmacology of δ-Opioid Receptors. Pharmacol Rev 2017; 68:631-700. [PMID: 27343248 DOI: 10.1124/pr.114.008979] [Citation(s) in RCA: 89] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Opioids are among the most effective analgesics available and are the first choice in the treatment of acute severe pain. However, partial efficacy, a tendency to produce tolerance, and a host of ill-tolerated side effects make clinically available opioids less effective in the management of chronic pain syndromes. Given that most therapeutic opioids produce their actions via µ-opioid receptors (MOPrs), other targets are constantly being explored, among which δ-opioid receptors (DOPrs) are being increasingly considered as promising alternatives. This review addresses DOPrs from the perspective of cellular and molecular determinants of their pharmacological diversity. Thus, DOPr ligands are examined in terms of structural and functional variety, DOPrs' capacity to engage a multiplicity of canonical and noncanonical G protein-dependent responses is surveyed, and evidence supporting ligand-specific signaling and regulation is analyzed. Pharmacological DOPr subtypes are examined in light of the ability of DOPr to organize into multimeric arrays and to adopt multiple active conformations as well as differences in ligand kinetics. Current knowledge on DOPr targeting to the membrane is examined as a means of understanding how these receptors are especially active in chronic pain management. Insight into cellular and molecular mechanisms of pharmacological diversity should guide the rational design of more effective, longer-lasting, and better-tolerated opioid analgesics for chronic pain management.
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Affiliation(s)
- Louis Gendron
- Département de Pharmacologie-Physiologie, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Centre de Recherche du CHU de Sherbrooke, Centre d'excellence en neurosciences de l'Univeristé de Sherbrooke, and Institut de Pharmacologie de Sherbrooke, Sherbrooke, Quebec, Canada (L.G.); Québec Pain Research Network, Sherbrooke, Quebec, Canada (L.G.); Departments of Anesthesiology and Perioperative Care and Pharmacology, University of California, Irvine, California (C.M.C.); Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, Canada (C.M.C.); Departments of Psychiatry and Cellular and Molecular Pharmacology, University of California, San Francisco, California (M.v.Z.); Laboratory of Chemical Biology and Peptide Research, Clinical Research Institute of Montréal, Montreal, Quebec, Canada (P.W.S.); and Departments of Psychiatry, Pharmacology, and Neurosciences, Faculty of Medicine, University of Montréal and Sainte-Justine Hospital Research Center, Montreal, Quebec, Canada (G.P.)
| | - Catherine M Cahill
- Département de Pharmacologie-Physiologie, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Centre de Recherche du CHU de Sherbrooke, Centre d'excellence en neurosciences de l'Univeristé de Sherbrooke, and Institut de Pharmacologie de Sherbrooke, Sherbrooke, Quebec, Canada (L.G.); Québec Pain Research Network, Sherbrooke, Quebec, Canada (L.G.); Departments of Anesthesiology and Perioperative Care and Pharmacology, University of California, Irvine, California (C.M.C.); Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, Canada (C.M.C.); Departments of Psychiatry and Cellular and Molecular Pharmacology, University of California, San Francisco, California (M.v.Z.); Laboratory of Chemical Biology and Peptide Research, Clinical Research Institute of Montréal, Montreal, Quebec, Canada (P.W.S.); and Departments of Psychiatry, Pharmacology, and Neurosciences, Faculty of Medicine, University of Montréal and Sainte-Justine Hospital Research Center, Montreal, Quebec, Canada (G.P.)
| | - Mark von Zastrow
- Département de Pharmacologie-Physiologie, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Centre de Recherche du CHU de Sherbrooke, Centre d'excellence en neurosciences de l'Univeristé de Sherbrooke, and Institut de Pharmacologie de Sherbrooke, Sherbrooke, Quebec, Canada (L.G.); Québec Pain Research Network, Sherbrooke, Quebec, Canada (L.G.); Departments of Anesthesiology and Perioperative Care and Pharmacology, University of California, Irvine, California (C.M.C.); Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, Canada (C.M.C.); Departments of Psychiatry and Cellular and Molecular Pharmacology, University of California, San Francisco, California (M.v.Z.); Laboratory of Chemical Biology and Peptide Research, Clinical Research Institute of Montréal, Montreal, Quebec, Canada (P.W.S.); and Departments of Psychiatry, Pharmacology, and Neurosciences, Faculty of Medicine, University of Montréal and Sainte-Justine Hospital Research Center, Montreal, Quebec, Canada (G.P.)
| | - Peter W Schiller
- Département de Pharmacologie-Physiologie, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Centre de Recherche du CHU de Sherbrooke, Centre d'excellence en neurosciences de l'Univeristé de Sherbrooke, and Institut de Pharmacologie de Sherbrooke, Sherbrooke, Quebec, Canada (L.G.); Québec Pain Research Network, Sherbrooke, Quebec, Canada (L.G.); Departments of Anesthesiology and Perioperative Care and Pharmacology, University of California, Irvine, California (C.M.C.); Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, Canada (C.M.C.); Departments of Psychiatry and Cellular and Molecular Pharmacology, University of California, San Francisco, California (M.v.Z.); Laboratory of Chemical Biology and Peptide Research, Clinical Research Institute of Montréal, Montreal, Quebec, Canada (P.W.S.); and Departments of Psychiatry, Pharmacology, and Neurosciences, Faculty of Medicine, University of Montréal and Sainte-Justine Hospital Research Center, Montreal, Quebec, Canada (G.P.)
| | - Graciela Pineyro
- Département de Pharmacologie-Physiologie, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Centre de Recherche du CHU de Sherbrooke, Centre d'excellence en neurosciences de l'Univeristé de Sherbrooke, and Institut de Pharmacologie de Sherbrooke, Sherbrooke, Quebec, Canada (L.G.); Québec Pain Research Network, Sherbrooke, Quebec, Canada (L.G.); Departments of Anesthesiology and Perioperative Care and Pharmacology, University of California, Irvine, California (C.M.C.); Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, Canada (C.M.C.); Departments of Psychiatry and Cellular and Molecular Pharmacology, University of California, San Francisco, California (M.v.Z.); Laboratory of Chemical Biology and Peptide Research, Clinical Research Institute of Montréal, Montreal, Quebec, Canada (P.W.S.); and Departments of Psychiatry, Pharmacology, and Neurosciences, Faculty of Medicine, University of Montréal and Sainte-Justine Hospital Research Center, Montreal, Quebec, Canada (G.P.)
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20
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Farran B. An update on the physiological and therapeutic relevance of GPCR oligomers. Pharmacol Res 2017; 117:303-327. [PMID: 28087443 DOI: 10.1016/j.phrs.2017.01.008] [Citation(s) in RCA: 78] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Revised: 01/06/2017] [Accepted: 01/09/2017] [Indexed: 01/17/2023]
Abstract
The traditional view on GPCRs held that they function as single monomeric units composed of identical subunits. This notion was overturned by the discovery that GPCRs can form homo- and hetero-oligomers, some of which are obligatory, and can further assemble into receptor mosaics consisting of three or more protomers. Oligomerisation exerts significant impacts on receptor function and physiology, offering a platform for the diversification of receptor signalling, pharmacology, regulation, crosstalk, internalization and trafficking. Given their involvement in the modulation of crucial physiological processes, heteromers could constitute important therapeutic targets for a wide range of diseases, including schizophrenia, Parkinson's disease, substance abuse or obesity. This review aims at depicting the current developments in GPCR oligomerisation research, documenting various class A, B and C GPCR heteromers detected in vitro and in vivo using biochemical and biophysical approaches, as well as recently identified higher-order oligomeric complexes. It explores the current understanding of dimerization dynamics and the possible interaction interfaces that drive oligomerisation. Most importantly, it provides an inventory of the wide range of physiological processes and pathophysiological conditions to which GPCR oligomers contribute, surveying some of the oligomers that constitute potential drug targets. Finally, it delineates the efforts to develop novel classes of ligands that specifically target and tether to receptor oligomers instead of a single monomeric entity, thus ameliorating their ability to modulate GPCR function.
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Affiliation(s)
- Batoul Farran
- Department of Structural and Molecular Biology, University College London, Gower Street, London, WC1E 6BT, United Kingdom.
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21
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Graded activation and free energy landscapes of a muscarinic G-protein-coupled receptor. Proc Natl Acad Sci U S A 2016; 113:12162-12167. [PMID: 27791003 DOI: 10.1073/pnas.1614538113] [Citation(s) in RCA: 109] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
G-protein-coupled receptors (GPCRs) recognize ligands of widely different efficacies, from inverse to partial and full agonists, which transduce cellular signals at differentiated levels. However, the mechanism of such graded activation remains unclear. Using the Gaussian accelerated molecular dynamics (GaMD) method that enables both unconstrained enhanced sampling and free energy calculation, we have performed extensive GaMD simulations (∼19 μs in total) to investigate structural dynamics of the M2 muscarinic GPCR that is bound by the full agonist iperoxo (IXO), the partial agonist arecoline (ARC), and the inverse agonist 3-quinuclidinyl-benzilate (QNB), in the presence or absence of the G-protein mimetic nanobody. In the receptor-nanobody complex, IXO binding leads to higher fluctuations in the protein-coupling interface than ARC, especially in the receptor transmembrane helix 5 (TM5), TM6, and TM7 intracellular domains that are essential elements for GPCR activation, but less flexibility in the receptor extracellular region due to stronger binding compared with ARC. Two different binding poses are revealed for ARC in the orthosteric pocket. Removal of the nanobody leads to GPCR deactivation that is characterized by inward movement of the TM6 intracellular end. Distinct low-energy intermediate conformational states are identified for the IXO- and ARC-bound M2 receptor. Both dissociation and binding of an orthosteric ligand are observed in a single all-atom GPCR simulation in the case of partial agonist ARC binding to the M2 receptor. This study demonstrates the applicability of GaMD for exploring free energy landscapes of large biomolecules and the simulations provide important insights into the GPCR functional mechanism.
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22
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Quaternary structures of opsin in live cells revealed by FRET spectrometry. Biochem J 2016; 473:3819-3836. [PMID: 27623775 DOI: 10.1042/bcj20160422] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2016] [Accepted: 09/12/2016] [Indexed: 02/06/2023]
Abstract
Rhodopsin is a prototypical G-protein-coupled receptor (GPCR) that initiates phototransduction in the retina. The receptor consists of the apoprotein opsin covalently linked to the inverse agonist 11-cis retinal. Rhodopsin and opsin have been shown to form oligomers within the outer segment disc membranes of rod photoreceptor cells. However, the physiological relevance of the observed oligomers has been questioned since observations were made on samples prepared from the retina at low temperatures. To investigate the oligomeric status of opsin in live cells at body temperatures, we utilized a novel approach called Förster resonance energy transfer spectrometry, which previously has allowed the determination of the stoichiometry and geometry (i.e. quaternary structure) of various GPCRs. In the current study, we have extended the method to additionally determine whether or not a mixture of oligomeric forms of opsin exists and in what proportion. The application of this improved method revealed that opsin expressed in live Chinese hamster ovary (CHO) cells at 37°C exists as oligomers of various sizes. At lower concentrations, opsin existed in an equilibrium of dimers and tetramers. The tetramers were in the shape of a near-rhombus. At higher concentrations of the receptor, higher-order oligomers began to form. Thus, a mixture of different oligomeric forms of opsin is present in the membrane of live CHO cells and oligomerization occurs in a concentration-dependent manner. The general principles underlying the concentration-dependent oligomerization of opsin may be universal and apply to other GPCRs as well.
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23
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Shivnaraine RV, Fernandes DD, Ji H, Li Y, Kelly B, Zhang Z, Han YR, Huang F, Sankar KS, Dubins DN, Rocheleau JV, Wells JW, Gradinaru CC. Single-Molecule Analysis of the Supramolecular Organization of the M2 Muscarinic Receptor and the Gαi1 Protein. J Am Chem Soc 2016; 138:11583-98. [DOI: 10.1021/jacs.6b04032] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Rabindra V. Shivnaraine
- Department
of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario M5S 3M2, Canada
| | - Dennis D. Fernandes
- Department
of Physics, University of Toronto, Toronto, Ontario M5S 1A7, Canada
- Department of Chemical & Physical Sciences, University of Toronto Mississauga, Mississauga, Ontario L5L 1C6, Canada
| | - Huiqiao Ji
- Department
of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario M5S 3M2, Canada
| | - Yuchong Li
- Department
of Physics, University of Toronto, Toronto, Ontario M5S 1A7, Canada
- Department of Chemical & Physical Sciences, University of Toronto Mississauga, Mississauga, Ontario L5L 1C6, Canada
| | - Brendan Kelly
- Department
of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario M5S 3M2, Canada
- Krembil Research
Institute, University Health Network, Toronto, Ontario M5T 2S8, Canada
| | - Zhenfu Zhang
- Department
of Physics, University of Toronto, Toronto, Ontario M5S 1A7, Canada
- Department of Chemical & Physical Sciences, University of Toronto Mississauga, Mississauga, Ontario L5L 1C6, Canada
| | - Yi Rang Han
- Department
of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario M5S 3M2, Canada
| | - Fei Huang
- Department
of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario M5S 3M2, Canada
| | - Krishana S. Sankar
- Department
of Physiology, University of Toronto, Toronto, Ontario M5G 1L7, Canada
| | - David N. Dubins
- Department
of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario M5S 3M2, Canada
| | - Jonathan V. Rocheleau
- Department
of Physiology, University of Toronto, Toronto, Ontario M5G 1L7, Canada
- Institute
of Biomedical and Biomaterial Engineering, University of Toronto, Toronto, Ontario M5S 3G9, Canada
| | - James W. Wells
- Department
of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario M5S 3M2, Canada
| | - Claudiu C. Gradinaru
- Department
of Physics, University of Toronto, Toronto, Ontario M5S 1A7, Canada
- Department of Chemical & Physical Sciences, University of Toronto Mississauga, Mississauga, Ontario L5L 1C6, Canada
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24
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Shivnaraine RV, Kelly B, Sankar KS, Redka DS, Han YR, Huang F, Elmslie G, Pinto D, Li Y, Rocheleau JV, Gradinaru CC, Ellis J, Wells JW. Allosteric modulation in monomers and oligomers of a G protein-coupled receptor. eLife 2016; 5. [PMID: 27151542 PMCID: PMC4900804 DOI: 10.7554/elife.11685] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2015] [Accepted: 04/30/2016] [Indexed: 12/03/2022] Open
Abstract
The M2 muscarinic receptor is the prototypic model of allostery in GPCRs, yet the molecular and the supramolecular determinants of such effects are unknown. Monomers and oligomers of the M2 muscarinic receptor therefore have been compared to identify those allosteric properties that are gained in oligomers. Allosteric interactions were monitored by means of a FRET-based sensor of conformation at the allosteric site and in pharmacological assays involving mutants engineered to preclude intramolecular effects. Electrostatic, steric, and conformational determinants of allostery at the atomic level were examined in molecular dynamics simulations. Allosteric effects in monomers were exclusively negative and derived primarily from intramolecular electrostatic repulsion between the allosteric and orthosteric ligands. Allosteric effects in oligomers could be positive or negative, depending upon the allosteric-orthosteric pair, and they arose from interactions within and between the constituent protomers. The complex behavior of oligomers is characteristic of muscarinic receptors in myocardial preparations. DOI:http://dx.doi.org/10.7554/eLife.11685.001 Proteins called G protein-coupled receptors (GPCRs) are found on the surface of cells throughout the body. Hormones or other signal molecules – collectively known as ligands – from outside the cell can bind to the receptors to activate them. This causes a change in the structure of the receptor, which triggers a signal inside the cell to alter the cell’s behavior. GPCRs are known to form clusters of two or more receptor units, but it is not known if these clusters have unique properties or what role they play in cells. Many drugs can bind to GPCRs and most of them block the activity of the receptors by taking the place of the natural ligand. Another way to alter the activity of a GPCR is with so-called 'allosteric' drugs. These bind to different sites on the receptor than the natural ligands do and can inhibit or enhance binding of the ligands by altering the shape of the receptor. Shivnaraine et al. investigated how a type of GPCR called muscarinic cholinergic receptors interact within clusters. This involved developing a method to track the receptor in mammalian cells using a fluorescent sensor that detects changes in the allosteric site. The experiments show that two or more GPCRs need to interact for the receptors to respond to allosteric drugs in a manner that reflects the normal effect of the drugs on the body. This result is unexpected in light of the assumption that individual receptor molecules act independently. Shivnaraine et al.’s findings indicate that the clusters may play a role in the normal behavior of GPCRs in cells. A future challenge is to understand exactly how the GPCRs interact with each other. DOI:http://dx.doi.org/10.7554/eLife.11685.002
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Affiliation(s)
- Rabindra V Shivnaraine
- Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Canada
| | - Brendan Kelly
- Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Canada
| | | | - Dar'ya S Redka
- Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Canada
| | - Yi Rang Han
- Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Canada
| | - Fei Huang
- Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Canada
| | - Gwendolynne Elmslie
- Departments of Psychiatry and Pharmacology, Hershey Medical Center, Hershey, United States
| | - Daniel Pinto
- Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Canada
| | - Yuchong Li
- Department of Physics, University of Toronto, Toronto, Canada
| | | | | | - John Ellis
- Departments of Psychiatry and Pharmacology, Hershey Medical Center, Hershey, United States
| | - James W Wells
- Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Canada
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Pediani JD, Ward RJ, Godin AG, Marsango S, Milligan G. Dynamic Regulation of Quaternary Organization of the M1 Muscarinic Receptor by Subtype-selective Antagonist Drugs. J Biol Chem 2016; 291:13132-46. [PMID: 27080256 PMCID: PMC4933229 DOI: 10.1074/jbc.m115.712562] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Indexed: 12/14/2022] Open
Abstract
Although rhodopsin-like G protein-coupled receptors can exist as both monomers and non-covalently associated dimers/oligomers, the steady-state proportion of each form and whether this is regulated by receptor ligands are unknown. Herein we address these topics for the M1 muscarinic acetylcholine receptor, a key molecular target for novel cognition enhancers, by using spatial intensity distribution analysis. This method can measure fluorescent particle concentration and assess oligomerization states of proteins within defined regions of living cells. Imaging and analysis of the basolateral surface of cells expressing some 50 molecules·μm−2 human muscarinic M1 receptor identified a ∼75:25 mixture of receptor monomers and dimers/oligomers. Both sustained and shorter term treatment with the selective M1 antagonist pirenzepine resulted in a large shift in the distribution of receptor species to favor the dimeric/oligomeric state. Although sustained treatment with pirenzepine also resulted in marked up-regulation of the receptor, simple mass action effects were not the basis for ligand-induced stabilization of receptor dimers/oligomers. The related antagonist telenzepine also produced stabilization and enrichment of the M1 receptor dimer population, but the receptor subtype non-selective antagonists atropine and N-methylscopolamine did not. In contrast, neither pirenzepine nor telenzepine altered the quaternary organization of the related M3 muscarinic receptor. These data provide unique insights into the selective capacity of receptor ligands to promote and/or stabilize receptor dimers/oligomers and demonstrate that the dynamics of ligand regulation of the quaternary organization of G protein-coupled receptors is markedly more complex than previously appreciated. This may have major implications for receptor function and behavior.
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Affiliation(s)
- John D Pediani
- From the Molecular Pharmacology Group, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, Scotland, United Kingdom and
| | - Richard J Ward
- From the Molecular Pharmacology Group, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, Scotland, United Kingdom and
| | - Antoine G Godin
- Institut d'Optique and CNRS, Laboratoire Photonique, Numérique et Nanosciences (LP2N) and Université de Bordeaux, LP2N, F-33405, UMR 5298, 33405 Talence Cedex, France
| | - Sara Marsango
- From the Molecular Pharmacology Group, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, Scotland, United Kingdom and
| | - Graeme Milligan
- From the Molecular Pharmacology Group, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, Scotland, United Kingdom and
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26
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Lyukmanova EN, Shenkarev ZO, Shulepko MA, Paramonov AS, Chugunov AO, Janickova H, Dolejsi E, Dolezal V, Utkin YN, Tsetlin VI, Arseniev AS, Efremov RG, Dolgikh DA, Kirpichnikov MP. Structural Insight into Specificity of Interactions between Nonconventional Three-finger Weak Toxin from Naja kaouthia (WTX) and Muscarinic Acetylcholine Receptors. J Biol Chem 2015; 290:23616-30. [PMID: 26242733 PMCID: PMC4583006 DOI: 10.1074/jbc.m115.656595] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2015] [Revised: 07/29/2015] [Indexed: 11/06/2022] Open
Abstract
Weak toxin from Naja kaouthia (WTX) belongs to the group of nonconventional "three-finger" snake neurotoxins. It irreversibly inhibits nicotinic acetylcholine receptors and allosterically interacts with muscarinic acetylcholine receptors (mAChRs). Using site-directed mutagenesis, NMR spectroscopy, and computer modeling, we investigated the recombinant mutant WTX analogue (rWTX) which, compared with the native toxin, has an additional N-terminal methionine residue. In comparison with the wild-type toxin, rWTX demonstrated an altered pharmacological profile, decreased binding of orthosteric antagonist N-methylscopolamine to human M1- and M2-mAChRs, and increased antagonist binding to M3-mAChR. Positively charged arginine residues located in the flexible loop II were found to be crucial for rWTX interactions with all types of mAChR. Computer modeling suggested that the rWTX loop II protrudes to the M1-mAChR allosteric ligand-binding site blocking the entrance to the orthosteric site. In contrast, toxin interacts with M3-mAChR by loop II without penetration into the allosteric site. Data obtained provide new structural insight into the target-specific allosteric regulation of mAChRs by "three-finger" snake neurotoxins.
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Affiliation(s)
- Ekaterina N Lyukmanova
- From the Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 16/10 Miklukho-Maklaya Street, 117997 Moscow, Russia, the Lomonosov Moscow State University, 119991 Moscow, Russia,
| | - Zakhar O Shenkarev
- From the Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 16/10 Miklukho-Maklaya Street, 117997 Moscow, Russia, the Lomonosov Moscow State University, 119991 Moscow, Russia, the Moscow Institute of Physics and Technology, Institutskiy Pereulok 9, Dolgoprudny, Moscow Region 141700, Russian
| | - Mikhail A Shulepko
- From the Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 16/10 Miklukho-Maklaya Street, 117997 Moscow, Russia, the Lomonosov Moscow State University, 119991 Moscow, Russia
| | - Alexander S Paramonov
- From the Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 16/10 Miklukho-Maklaya Street, 117997 Moscow, Russia, the Lomonosov Moscow State University, 119991 Moscow, Russia
| | - Anton O Chugunov
- From the Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 16/10 Miklukho-Maklaya Street, 117997 Moscow, Russia, the Lomonosov Moscow State University, 119991 Moscow, Russia
| | - Helena Janickova
- the Institute of Physiology, Academy of Sciences of the Czech Republic (Public Research Institution), 14220 Prague, Czech Republic, and
| | - Eva Dolejsi
- the Institute of Physiology, Academy of Sciences of the Czech Republic (Public Research Institution), 14220 Prague, Czech Republic, and
| | - Vladimir Dolezal
- the Institute of Physiology, Academy of Sciences of the Czech Republic (Public Research Institution), 14220 Prague, Czech Republic, and
| | - Yuri N Utkin
- From the Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 16/10 Miklukho-Maklaya Street, 117997 Moscow, Russia
| | - Victor I Tsetlin
- From the Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 16/10 Miklukho-Maklaya Street, 117997 Moscow, Russia
| | - Alexander S Arseniev
- From the Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 16/10 Miklukho-Maklaya Street, 117997 Moscow, Russia, the Moscow Institute of Physics and Technology, Institutskiy Pereulok 9, Dolgoprudny, Moscow Region 141700, Russian
| | - Roman G Efremov
- From the Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 16/10 Miklukho-Maklaya Street, 117997 Moscow, Russia, the Moscow Institute of Physics and Technology, Institutskiy Pereulok 9, Dolgoprudny, Moscow Region 141700, Russian
| | - Dmitry A Dolgikh
- From the Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 16/10 Miklukho-Maklaya Street, 117997 Moscow, Russia, the Lomonosov Moscow State University, 119991 Moscow, Russia
| | - Mikhail P Kirpichnikov
- From the Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 16/10 Miklukho-Maklaya Street, 117997 Moscow, Russia, the Lomonosov Moscow State University, 119991 Moscow, Russia
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27
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Chidiac P, Hébert TE. GPCR Retreat 2014: a good view leads to many discoveries! J Recept Signal Transduct Res 2015; 35:208-12. [PMID: 26366680 DOI: 10.3109/10799893.2015.1072977] [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: 11/13/2022]
Abstract
The GPCR gods smiled on us last year as the 15th Annual GPCR Retreat was held last October 2nd-4th in Bromont, Québec. The fall colors were at their peak and the meeting attendees were also in fine form. The program was one of the best we have seen at any GPCR-related meeting in years and there was a great deal of excitement about new methodological approaches to understanding receptor biology, new concepts in GPCR signaling and a continued emphasis on translation of these discoveries. This year was also the first year we opened the meeting with a short course on biased agonism and how to measure and analyze it.
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Affiliation(s)
- Peter Chidiac
- a Department of Physiology and Pharmacology , Schulich School of Medicine & Dentistry, University of Western Ontario , London , Ontario , Canada and
| | - Terence E Hébert
- b Department of Pharmacology and Therapeutics , McGill University , Montréal, Québec , Canada
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28
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Marsango S, Caltabiano G, Pou C, Varela Liste MJ, Milligan G. Analysis of Human Dopamine D3 Receptor Quaternary Structure. J Biol Chem 2015; 290:15146-62. [PMID: 25931118 PMCID: PMC4463457 DOI: 10.1074/jbc.m114.630681] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2014] [Revised: 04/23/2015] [Indexed: 01/11/2023] Open
Abstract
The dopamine D3 receptor is a class A, rhodopsin-like G protein-coupled receptor that can form dimers and/or higher order oligomers. However, the molecular basis for production of these complexes is not well defined. Using combinations of molecular modeling, site-directed mutagenesis, and homogenous time-resolved FRET, the interfaces that allow dopamine D3 receptor monomers to interact were defined and used to describe likely quaternary arrangements of the receptor. These were then compared with published crystal structures of dimeric β1-adrenoreceptor, μ-opioid, and CXCR4 receptors. The data indicate important contributions of residues from within each of transmembrane domains I, II, IV, V, VI, and VII as well as the intracellular helix VIII in the formation of D3-D3 receptor interfaces within homo-oligomers and are consistent with the D3 receptor adopting a β1-adrenoreceptor-like quaternary arrangement. Specifically, results suggest that D3 protomers can interact with each other via at least two distinct interfaces: the first one comprising residues from transmembrane domains I and II along with those from helix VIII and a second one involving transmembrane domains IV and V. Moreover, rather than existing only as distinct dimeric species, the results are consistent with the D3 receptor also assuming a quaternary structure in which two transmembrane domain I-II-helix VIII dimers interact to form a "rhombic" tetramer via an interface involving residues from transmembrane domains VI and VII. In addition, the results also provide insights into the potential contribution of molecules of cholesterol to the overall organization and potential stability of the D3 receptor and possibly other GPCR quaternary structures.
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Affiliation(s)
- Sara Marsango
- From the Molecular Pharmacology Group, Institute of Molecular, Cell, and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, Scotland, United Kingdom and
| | - Gianluigi Caltabiano
- Laboratori de Medicina Computacional, Unitat de Bioestadística, Facultat de Medicina, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain
| | - Chantevy Pou
- From the Molecular Pharmacology Group, Institute of Molecular, Cell, and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, Scotland, United Kingdom and
| | - María José Varela Liste
- From the Molecular Pharmacology Group, Institute of Molecular, Cell, and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, Scotland, United Kingdom and
| | - Graeme Milligan
- From the Molecular Pharmacology Group, Institute of Molecular, Cell, and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, Scotland, United Kingdom and
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29
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Aslanoglou D, Alvarez-Curto E, Marsango S, Milligan G. Distinct Agonist Regulation of Muscarinic Acetylcholine M2-M3 Heteromers and Their Corresponding Homomers. J Biol Chem 2015; 290:14785-96. [PMID: 25918156 PMCID: PMC4505543 DOI: 10.1074/jbc.m115.649079] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Indexed: 01/01/2023] Open
Abstract
Each subtype of the muscarinic receptor family of G protein-coupled receptors is activated by similar concentrations of the neurotransmitter acetylcholine or closely related synthetic analogs such as carbachol. However, pharmacological selectivity can be generated by the introduction of a pair of mutations to produce Receptor Activated Solely by Synthetic Ligand (RASSL) forms of muscarinic receptors. These display loss of potency for acetylcholine/carbachol alongside a concurrent gain in potency for the ligand clozapine N-oxide. Co-expression of a form of wild type human M2 and a RASSL variant of the human M3 receptor resulted in concurrent detection of each of M2-M2 and M3-M3 homomers alongside M2-M3 heteromers at the surface of stably transfected Flp-InTM T-RExTM 293 cells. In this setting occupancy of the receptors with a muscarinic antagonist was without detectable effect on any of the muscarinic oligomers. However, selective agonist occupancy of the M2 receptor resulted in enhanced M2-M2 homomer interactions but decreased M2-M3 heteromer interactions. By contrast, selective activation of the M3 RASSL receptor did not significantly alter either M3-M3 homomer or M2-M3 heteromer interactions. Selectively targeting closely related receptor oligomers may provide novel therapeutic opportunities.
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Affiliation(s)
- Despoina Aslanoglou
- From the Molecular Pharmacology Group, Institute of Molecular, Cell, and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, Scotland, United Kingdom
| | - Elisa Alvarez-Curto
- From the Molecular Pharmacology Group, Institute of Molecular, Cell, and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, Scotland, United Kingdom
| | - Sara Marsango
- From the Molecular Pharmacology Group, Institute of Molecular, Cell, and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, Scotland, United Kingdom
| | - Graeme Milligan
- From the Molecular Pharmacology Group, Institute of Molecular, Cell, and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, Scotland, United Kingdom
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30
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Liste MJV, Caltabiano G, Ward RJ, Alvarez-Curto E, Marsango S, Milligan G. The molecular basis of oligomeric organization of the human M3 muscarinic acetylcholine receptor. Mol Pharmacol 2015; 87:936-53. [PMID: 25769304 DOI: 10.1124/mol.114.096925] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Accepted: 03/13/2015] [Indexed: 11/22/2022] Open
Abstract
G protein-coupled receptors, including the M3 muscarinic acetylcholine receptor, can form homo-oligomers. However, the basis of these interactions and the overall organizational structure of such oligomers are poorly understood. Combinations of site-directed mutagenesis and homogenous time-resolved fluorescence resonance energy transfer studies that assessed interactions between receptor protomers at the surface of transfected cells indicated important contributions of regions of transmembrane domains I, IV, V, VI, and VII as well as intracellular helix VIII to the overall organization. Molecular modeling studies based on both these results and an X-ray structure of the inactive state of the M3 receptor bound by the antagonist/inverse agonist tiotropium were then employed. The results could be accommodated fully by models in which a proportion of the cell surface M3 receptor population is a tetramer with rhombic, but not linear, orientation. This is consistent with previous studies based on spectrally resolved, multiphoton fluorescence resonance energy transfer. Modeling studies furthermore suggest an important role for molecules of cholesterol at the dimer + dimer interface of the tetramer, which is consistent with the presence of cholesterol at key locations in many G protein-coupled receptor crystal structures. Mutants that displayed disrupted quaternary organization were often poorly expressed and showed immature N-glycosylation. Sustained treatment of cells expressing such mutants with the muscarinic receptor inverse agonist atropine increased cellular levels and restored both cell surface delivery and quaternary organization to many of the mutants. These observations suggest that organization as a tetramer may occur before plasma membrane delivery and may be a key step in cellular quality control assessment.
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Affiliation(s)
- María José Varela Liste
- Molecular Pharmacology Group, Institute of Molecular, Cell, and Systems Biology, College of Medical, Veterinary, and Life Sciences, University of Glasgow, Glasgow, Scotland, United Kingdom (M.J.V.L., G.C., R.J.W., E.A.-C., S.M., G.M.), and Laboratori de Medicina Computacional, Unitat de Bioestadística, Facultat de Medicina, Universitat Autònoma de Barcelona, Bellaterra, Spain (G.C.)
| | - Gianluigi Caltabiano
- Molecular Pharmacology Group, Institute of Molecular, Cell, and Systems Biology, College of Medical, Veterinary, and Life Sciences, University of Glasgow, Glasgow, Scotland, United Kingdom (M.J.V.L., G.C., R.J.W., E.A.-C., S.M., G.M.), and Laboratori de Medicina Computacional, Unitat de Bioestadística, Facultat de Medicina, Universitat Autònoma de Barcelona, Bellaterra, Spain (G.C.)
| | - Richard J Ward
- Molecular Pharmacology Group, Institute of Molecular, Cell, and Systems Biology, College of Medical, Veterinary, and Life Sciences, University of Glasgow, Glasgow, Scotland, United Kingdom (M.J.V.L., G.C., R.J.W., E.A.-C., S.M., G.M.), and Laboratori de Medicina Computacional, Unitat de Bioestadística, Facultat de Medicina, Universitat Autònoma de Barcelona, Bellaterra, Spain (G.C.)
| | - Elisa Alvarez-Curto
- Molecular Pharmacology Group, Institute of Molecular, Cell, and Systems Biology, College of Medical, Veterinary, and Life Sciences, University of Glasgow, Glasgow, Scotland, United Kingdom (M.J.V.L., G.C., R.J.W., E.A.-C., S.M., G.M.), and Laboratori de Medicina Computacional, Unitat de Bioestadística, Facultat de Medicina, Universitat Autònoma de Barcelona, Bellaterra, Spain (G.C.)
| | - Sara Marsango
- Molecular Pharmacology Group, Institute of Molecular, Cell, and Systems Biology, College of Medical, Veterinary, and Life Sciences, University of Glasgow, Glasgow, Scotland, United Kingdom (M.J.V.L., G.C., R.J.W., E.A.-C., S.M., G.M.), and Laboratori de Medicina Computacional, Unitat de Bioestadística, Facultat de Medicina, Universitat Autònoma de Barcelona, Bellaterra, Spain (G.C.)
| | - Graeme Milligan
- Molecular Pharmacology Group, Institute of Molecular, Cell, and Systems Biology, College of Medical, Veterinary, and Life Sciences, University of Glasgow, Glasgow, Scotland, United Kingdom (M.J.V.L., G.C., R.J.W., E.A.-C., S.M., G.M.), and Laboratori de Medicina Computacional, Unitat de Bioestadística, Facultat de Medicina, Universitat Autònoma de Barcelona, Bellaterra, Spain (G.C.)
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31
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Ferré S. The GPCR heterotetramer: challenging classical pharmacology. Trends Pharmacol Sci 2015; 36:145-52. [PMID: 25704194 PMCID: PMC4357316 DOI: 10.1016/j.tips.2015.01.002] [Citation(s) in RCA: 83] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Revised: 01/15/2015] [Accepted: 01/20/2015] [Indexed: 01/09/2023]
Abstract
Two concepts are gaining increasing acceptance in G protein-coupled receptor (GPCR) pharmacology: (i) pre-coupling of GPCRs with their preferred signaling molecules, and (ii) GPCR oligomerization. This is begging for the introduction of new models such as GPCR oligomer-containing signaling complexes with GPCR homodimers as functional building blocks. This model favors the formation of GPCR heterotetramers - heteromers of homodimers coupled to their cognate G protein. The GPCR heterotetramer offers an optimal framework for a canonical antagonistic interaction between activated Gs and Gi proteins, which can simultaneously bind to their respective preferred receptors and to adenylyl cyclase (AC) catalytic units. This review addresses the current evidence for pre-coupling of the various specific components that provide the very elaborate signaling machinery exemplified by the Gs-Gi-AC-coupled GPCR heterotetramer.
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Affiliation(s)
- Sergi Ferré
- Integrative Neurobiology Section, National Institute on Drug Abuse, Intramural Research Program, National Institutes of Health (NIH), Triad Technology Building, 333 Cassell Drive, Baltimore, MD 21224, USA.
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