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The Heptahelical Domain of the Sweet Taste Receptor T1R2 Is a New Allosteric Binding Site for the Sweet Taste Modulator Amiloride That Modulates Sweet Taste in a Species-Dependent Manner. J Mol Neurosci 2018; 66:207-213. [PMID: 30120716 DOI: 10.1007/s12031-018-1156-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Accepted: 08/06/2018] [Indexed: 10/28/2022]
Abstract
The activity of sweet taste receptor (heterodimeric T1R2 and T1R3) can be modulated by sweet regulators. The compound amiloride can inhibit the sweet sensitivity of the human sweet taste receptor. This study describes the species-dependent regulation of the response of sweet taste receptors by this sweet inhibitor. Amiloride inhibited the sweet taste response of humans and mice but not that of squirrel monkeys. Using human/squirrel monkey/mouse chimeric T1R2 and T1R3 receptors as well as the agonist perillartine (which can activate the single heptahelical domain of T1R2), we found that the heptahelical domain of T1R2 is the molecular determinant that mediates the species-dependent sensitivity to this sweet regulator. Compared to the sweet inhibitor lactisole (which acts on T1R3), amiloride has a different allosteric binding site on the sweet receptor, which is important new information for the design of novel sweet taste modulators that act on T1R2.
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52
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Tora AS, Rovira X, Cao AM, Cabayé A, Olofsson L, Malhaire F, Scholler P, Baik H, Van Eeckhaut A, Smolders I, Rondard P, Margeat E, Acher F, Pin JP, Goudet C. Chloride ions stabilize the glutamate-induced active state of the metabotropic glutamate receptor 3. Neuropharmacology 2018; 140:275-286. [PMID: 30102917 DOI: 10.1016/j.neuropharm.2018.08.011] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Revised: 07/25/2018] [Accepted: 08/09/2018] [Indexed: 02/06/2023]
Abstract
Due to the essential roles of glutamate, detection and response to a large range of extracellular concentrations of this excitatory amino acid are necessary for the fine-tuning of brain functions. Metabotropic glutamate receptors (mGluRs) are implicated in shaping the activity of many synapses in the central nervous system. Among the eight mGluR subtypes, there is increasing interest in studying the mGlu3 receptor which has recently been linked to various diseases, including psychiatric disorders. This receptor displays striking functional properties, with a high and, often, full basal activity, making its study elusive in heterologous systems. Here, we demonstrate that Cl- ions exert strong positive allosteric modulation of glutamate on the mGlu3 receptor. We have also identified the molecular and structural determinants lying behind this allostery: a unique interactive "chloride-lock" network. Indeed, Cl- ions dramatically stabilize the glutamate-induced active state of the extracellular domain of the mGlu3 receptor. Thus, the mGlu3 receptors' large basal activity does not correspond to a constitutive activity in absence of agonist. Instead, it results mostly from a Cl-mediated amplified response to low ambient glutamate concentrations, such as those measured in cell media. This strong interaction between glutamate and Cl- ions allows the mGlu3 receptor to sense and efficiently react to sub-micromolar concentrations of glutamate, making it the most sensitive member of mGluR family.
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Affiliation(s)
- Amélie S Tora
- IGF, CNRS, INSERM, Univ. de Montpellier, Montpellier, F-34094, Montpellier, France
| | - Xavier Rovira
- IGF, CNRS, INSERM, Univ. de Montpellier, Montpellier, F-34094, Montpellier, France; Present Address: Molecular Photopharmacology Research Group, The Tissue Repair and Regeneration Laboratory, University of Vic - Central University of Catalonia, C. de La Laura,13, 08500, Vic, Spain
| | - Anne-Marinette Cao
- Centre de Biochimie Structurale (CBS), INSERM, CNRS, Université de Montpellier, F-34094, Montpellier, France
| | - Alexandre Cabayé
- Laboratoire de Chimie et Biochimie Pharmacologiques et Toxicologiques, CNRS UMR8601, Université Paris Descartes, Sorbonne Paris Cité, F-75270, Paris Cedex 6, France
| | - Linnéa Olofsson
- Centre de Biochimie Structurale (CBS), INSERM, CNRS, Université de Montpellier, F-34094, Montpellier, France
| | - Fanny Malhaire
- IGF, CNRS, INSERM, Univ. de Montpellier, Montpellier, F-34094, Montpellier, France
| | - Pauline Scholler
- IGF, CNRS, INSERM, Univ. de Montpellier, Montpellier, F-34094, Montpellier, France
| | - Hayeon Baik
- IGF, CNRS, INSERM, Univ. de Montpellier, Montpellier, F-34094, Montpellier, France
| | - Ann Van Eeckhaut
- Research Group Experimental Pharmacology (EFAR/FASC), Center for Neurosciences (C4N), Vrije Universiteit Brussel (VUB), 1090, Brussel, Belgium
| | - Ilse Smolders
- Research Group Experimental Pharmacology (EFAR/FASC), Center for Neurosciences (C4N), Vrije Universiteit Brussel (VUB), 1090, Brussel, Belgium
| | - Philippe Rondard
- IGF, CNRS, INSERM, Univ. de Montpellier, Montpellier, F-34094, Montpellier, France
| | - Emmanuel Margeat
- Centre de Biochimie Structurale (CBS), INSERM, CNRS, Université de Montpellier, F-34094, Montpellier, France
| | - Francine Acher
- Laboratoire de Chimie et Biochimie Pharmacologiques et Toxicologiques, CNRS UMR8601, Université Paris Descartes, Sorbonne Paris Cité, F-75270, Paris Cedex 6, France.
| | - Jean-Philippe Pin
- IGF, CNRS, INSERM, Univ. de Montpellier, Montpellier, F-34094, Montpellier, France.
| | - Cyril Goudet
- IGF, CNRS, INSERM, Univ. de Montpellier, Montpellier, F-34094, Montpellier, France.
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53
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Oligomerization of a G protein-coupled receptor in neurons controlled by its structural dynamics. Sci Rep 2018; 8:10414. [PMID: 29991736 PMCID: PMC6039492 DOI: 10.1038/s41598-018-28682-6] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Accepted: 06/26/2018] [Indexed: 12/16/2022] Open
Abstract
G protein coupled receptors (GPCRs) play essential roles in intercellular communication. Although reported two decades ago, the assembly of GPCRs into dimer and larger oligomers in their native environment is still a matter of intense debate. Here, using number and brightness analysis of fluorescently labeled receptors in cultured hippocampal neurons, we confirm that the metabotropic glutamate receptor type 2 (mGlu2) is a homodimer at expression levels in the physiological range, while heterodimeric GABAB receptors form larger complexes. Surprisingly, we observed the formation of larger mGlu2 oligomers upon both activation and inhibition of the receptor. Stabilizing the receptor in its inactive conformation using biochemical constraints also led to the observation of oligomers. Following our recent observation that mGlu receptors are in constant and rapid equilibrium between several states under basal conditions, we propose that this structural heterogeneity limits receptor oligomerization. Such assemblies are expected to stabilize either the active or the inactive state of the receptor.
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54
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Frangaj A, Fan QR. Structural biology of GABA B receptor. Neuropharmacology 2018; 136:68-79. [PMID: 29031577 PMCID: PMC5897222 DOI: 10.1016/j.neuropharm.2017.10.011] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2017] [Revised: 10/09/2017] [Accepted: 10/11/2017] [Indexed: 11/17/2022]
Abstract
Metabotropic GABAB receptor is a G protein-coupled receptor (GPCR) that mediates slow and prolonged inhibitory neurotransmission in the brain. It functions as a constitutive heterodimer composed of the GABAB1 and GABAB2 subunits. Each subunit contains three domains; the extracellular Venus flytrap module, seven-helix transmembrane region and cytoplasmic tail. In recent years, the three-dimensional structures of GABAB receptor extracellular and intracellular domains have been elucidated. These structures reveal the molecular basis of ligand recognition, receptor heterodimerization and receptor activation. Here we provide a brief review of the GABAB receptor structures, with an emphasis on describing the different ligand-bound states of the receptor. We will also compare these with the known structures of related GPCRs to shed light on the molecular mechanisms of activation and regulation in the GABAB system, as well as GPCR dimers in general. This article is part of the "Special Issue Dedicated to Norman G. Bowery".
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Affiliation(s)
- Aurel Frangaj
- Department of Pharmacology, Columbia University, New York, NY 10032, USA
| | - Qing R Fan
- Department of Pharmacology, Columbia University, New York, NY 10032, USA; Department of Pathology & Cell Biology, Columbia University, New York, NY 10032, USA.
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55
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Doornbos ML, Van der Linden I, Vereyken L, Tresadern G, IJzerman AP, Lavreysen H, Heitman LH. Constitutive activity of the metabotropic glutamate receptor 2 explored with a whole-cell label-free biosensor. Biochem Pharmacol 2018; 152:201-210. [DOI: 10.1016/j.bcp.2018.03.026] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Accepted: 03/27/2018] [Indexed: 12/14/2022]
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56
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Wang A, Feng J, Li Y, Zou P. Beyond Fluorescent Proteins: Hybrid and Bioluminescent Indicators for Imaging Neural Activities. ACS Chem Neurosci 2018; 9:639-650. [PMID: 29482322 DOI: 10.1021/acschemneuro.7b00455] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Optical biosensors have been invaluable tools in neuroscience research, as they provide the ability to directly visualize neural activity in real time, with high specificity, and with exceptional spatial and temporal resolution. Notably, a majority of these sensors are based on fluorescent protein scaffolds, which offer the ability to target specific cell types or even subcellular compartments. However, fluorescent proteins are intrinsically bulky tags, often insensitive to the environment, and always require excitation light illumination. To address these limitations, there has been a proliferation of alternative sensor scaffolds developed in recent years, including hybrid sensors that combine the advantages of synthetic fluorophores and genetically encoded protein tags, as well as bioluminescent probes. While still in their early stage of development as compared with fluorescent protein-based sensors, these novel probes have offered complementary solutions to interrogate various aspects of neuronal communication, including transmitter release, changes in membrane potential, and the production of second messengers. In this Review, we discuss these important new developments with a particular focus on design strategies.
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Affiliation(s)
- Anqi Wang
- College of Chemistry and Molecular Engineering, Synthetic and Functional Biomolecules Center, Beijing National Laboratory for Molecular Sciences, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, Peking University, Beijing 100871, China
- Peking-Tsinghua Center for Life Sciences, PKU-IDG/McGovern Institute for Brain Research, Peking University, Beijing 100871, China
| | - Jiesi Feng
- State Key Laboratory of Membrane Biology, School of Life Sciences, Peking University, Beijing 100871, China
- Peking-Tsinghua Center for Life Sciences, PKU-IDG/McGovern Institute for Brain Research, Peking University, Beijing 100871, China
| | - Yulong Li
- State Key Laboratory of Membrane Biology, School of Life Sciences, Peking University, Beijing 100871, China
- Peking-Tsinghua Center for Life Sciences, PKU-IDG/McGovern Institute for Brain Research, Peking University, Beijing 100871, China
| | - Peng Zou
- College of Chemistry and Molecular Engineering, Synthetic and Functional Biomolecules Center, Beijing National Laboratory for Molecular Sciences, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, Peking University, Beijing 100871, China
- Peking-Tsinghua Center for Life Sciences, PKU-IDG/McGovern Institute for Brain Research, Peking University, Beijing 100871, China
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57
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Nasrallah C, Rottier K, Marcellin R, Compan V, Font J, Llebaria A, Pin JP, Banères JL, Lebon G. Direct coupling of detergent purified human mGlu 5 receptor to the heterotrimeric G proteins Gq and Gs. Sci Rep 2018. [PMID: 29535347 PMCID: PMC5849714 DOI: 10.1038/s41598-018-22729-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
The metabotropic glutamate (mGlu) receptors are class C G protein-coupled receptors (GPCRs) that modulate synaptic activity and plasticity throughout the mammalian brain. Signal transduction is initiated by glutamate binding to the venus flytrap domains (VFT), which initiates a conformational change that is transmitted to the conserved heptahelical domains (7TM) and results ultimately in the activation of intracellular G proteins. While both mGlu1 and mGlu5 activate Gαq G-proteins, they also increase intracellular cAMP concentration through an unknown mechanism. To study directly the G protein coupling properties of the human mGlu5 receptor homodimer, we purified the full-length receptor, which required careful optimisation of the expression, N-glycosylation and purification. We successfully purified functional mGlu5 that activated the heterotrimeric G protein Gq. The high-affinity agonist-PAM VU0424465 also activated the purified receptor in the absence of an orthosteric agonist. In addition, it was found that purified mGlu5 was capable of activating the G protein Gs either upon stimulation with VU0424465 or glutamate, although the later induced a much weaker response. Our findings provide important mechanistic insights into mGlu5 G protein-dependent activity and selectivity.
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Affiliation(s)
- Chady Nasrallah
- Institut de Génomique Fonctionnelle, Centre National de la Recherche Scientifique (CNRS), Institut National de la Santé et de la Recherche Médicale (INSERM), Université de Montpellier, F-34000, Montpellier, France
| | - Karine Rottier
- Institut de Génomique Fonctionnelle, Centre National de la Recherche Scientifique (CNRS), Institut National de la Santé et de la Recherche Médicale (INSERM), Université de Montpellier, F-34000, Montpellier, France
| | - Romain Marcellin
- Institut de Génomique Fonctionnelle, Centre National de la Recherche Scientifique (CNRS), Institut National de la Santé et de la Recherche Médicale (INSERM), Université de Montpellier, F-34000, Montpellier, France
| | - Vincent Compan
- Institut de Génomique Fonctionnelle, Centre National de la Recherche Scientifique (CNRS), Institut National de la Santé et de la Recherche Médicale (INSERM), Université de Montpellier, F-34000, Montpellier, France
| | - Joan Font
- MCS, Laboratory of Medicinal Chemistry, Institute for Advanced Chemistry of Catalonia (IQAC-CSIC), Barcelona, Spain
| | - Amadeu Llebaria
- MCS, Laboratory of Medicinal Chemistry, Institute for Advanced Chemistry of Catalonia (IQAC-CSIC), Barcelona, Spain
| | - Jean-Philippe Pin
- Institut de Génomique Fonctionnelle, Centre National de la Recherche Scientifique (CNRS), Institut National de la Santé et de la Recherche Médicale (INSERM), Université de Montpellier, F-34000, Montpellier, France
| | - Jean-Louis Banères
- Institut des Biomolécules Max Mousseron (IBMM), CNRS, Univ. Montpellier, ENSCM, Montpellier, France
| | - Guillaume Lebon
- Institut de Génomique Fonctionnelle, Centre National de la Recherche Scientifique (CNRS), Institut National de la Santé et de la Recherche Médicale (INSERM), Université de Montpellier, F-34000, Montpellier, France.
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58
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Abstract
G protein-coupled receptors (GPCRs), which mediate processes as diverse as olfaction and maintenance of metabolic homeostasis, have become the single most effective class of therapeutic drug targets. As a result, understanding the molecular basis for their activity is of paramount importance. Recent technological advances have made GPCR structural biology increasingly tractable, offering views of these receptors in unprecedented atomic detail. Structural and biophysical data have shown that GPCRs function as complex allosteric machines, communicating ligand-binding events through conformational change. Changes in receptor conformation lead to activation of effector proteins, such as G proteins and arrestins, which are themselves conformational switches. Here, we review how structural biology has illuminated the agonist-induced cascade of conformational changes that culminate in a cellular response to GPCR activation.
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Affiliation(s)
- Sarah C Erlandson
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115, USA;
| | - Conor McMahon
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115, USA;
| | - Andrew C Kruse
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115, USA;
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59
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Goudet C, Rovira X, Llebaria A. Shedding light on metabotropic glutamate receptors using optogenetics and photopharmacology. Curr Opin Pharmacol 2018; 38:8-15. [DOI: 10.1016/j.coph.2018.01.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Accepted: 01/30/2018] [Indexed: 11/27/2022]
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60
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Scholler P, Nevoltris D, de Bundel D, Bossi S, Moreno-Delgado D, Rovira X, Møller TC, El Moustaine D, Mathieu M, Blanc E, McLean H, Dupuis E, Mathis G, Trinquet E, Daniel H, Valjent E, Baty D, Chames P, Rondard P, Pin JP. Allosteric nanobodies uncover a role of hippocampal mGlu2 receptor homodimers in contextual fear consolidation. Nat Commun 2017; 8:1967. [PMID: 29213077 PMCID: PMC5719040 DOI: 10.1038/s41467-017-01489-1] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Accepted: 09/15/2017] [Indexed: 11/09/2022] Open
Abstract
Antibodies have enormous therapeutic and biotechnology potential. G protein-coupled receptors (GPCRs), the main targets in drug development, are of major interest in antibody development programs. Metabotropic glutamate receptors are dimeric GPCRs that can control synaptic activity in a multitude of ways. Here we identify llama nanobodies that specifically recognize mGlu2 receptors, among the eight subtypes of mGluR subunits. Among these nanobodies, DN10 and 13 are positive allosteric modulators (PAM) on homodimeric mGlu2, while DN10 displays also a significant partial agonist activity. DN10 and DN13 have no effect on mGlu2-3 and mGlu2-4 heterodimers. These PAMs enhance the inhibitory action of the orthosteric mGlu2/mGlu3 agonist, DCG-IV, at mossy fiber terminals in the CA3 region of hippocampal slices. DN13 also impairs contextual fear memory when injected in the CA3 region of hippocampal region. These data highlight the potential of developing antibodies with allosteric actions on GPCRs to better define their roles in vivo.
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Affiliation(s)
- Pauline Scholler
- Institut de Génomique Fonctionnelle, CNRS, INSERM, Univ. Montpellier, F-34094, Montpellier, France
- Cisbio Bioassays, F-30200, Codolet, France
| | - Damien Nevoltris
- Cisbio Bioassays, F-30200, Codolet, France
- Aix Marseille Univ, CNRS, INSERM, Institut Paoli-Calmettes, CRCM, F-13009, Marseille, France
| | - Dimitri de Bundel
- Institut de Génomique Fonctionnelle, CNRS, INSERM, Univ. Montpellier, F-34094, Montpellier, France
| | - Simon Bossi
- CNRS UMR9197, Université Paris-Sud, Institut des Neurosciences Paris-Saclay, F-91405, Orsay, France
| | - David Moreno-Delgado
- Institut de Génomique Fonctionnelle, CNRS, INSERM, Univ. Montpellier, F-34094, Montpellier, France
| | - Xavier Rovira
- Institut de Génomique Fonctionnelle, CNRS, INSERM, Univ. Montpellier, F-34094, Montpellier, France
| | - Thor C Møller
- Institut de Génomique Fonctionnelle, CNRS, INSERM, Univ. Montpellier, F-34094, Montpellier, France
| | - Driss El Moustaine
- Institut de Génomique Fonctionnelle, CNRS, INSERM, Univ. Montpellier, F-34094, Montpellier, France
| | - Michaël Mathieu
- Institut de Génomique Fonctionnelle, CNRS, INSERM, Univ. Montpellier, F-34094, Montpellier, France
| | - Emilie Blanc
- Institut de Génomique Fonctionnelle, CNRS, INSERM, Univ. Montpellier, F-34094, Montpellier, France
| | - Heather McLean
- CNRS UMR9197, Université Paris-Sud, Institut des Neurosciences Paris-Saclay, F-91405, Orsay, France
| | | | | | | | - Hervé Daniel
- CNRS UMR9197, Université Paris-Sud, Institut des Neurosciences Paris-Saclay, F-91405, Orsay, France
| | - Emmanuel Valjent
- Institut de Génomique Fonctionnelle, CNRS, INSERM, Univ. Montpellier, F-34094, Montpellier, France
| | - Daniel Baty
- Aix Marseille Univ, CNRS, INSERM, Institut Paoli-Calmettes, CRCM, F-13009, Marseille, France
| | - Patrick Chames
- Aix Marseille Univ, CNRS, INSERM, Institut Paoli-Calmettes, CRCM, F-13009, Marseille, France.
| | - Philippe Rondard
- Institut de Génomique Fonctionnelle, CNRS, INSERM, Univ. Montpellier, F-34094, Montpellier, France.
| | - Jean-Philippe Pin
- Institut de Génomique Fonctionnelle, CNRS, INSERM, Univ. Montpellier, F-34094, Montpellier, France.
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61
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Liu J, Zhang Z, Moreno-Delgado D, Dalton JA, Rovira X, Trapero A, Goudet C, Llebaria A, Giraldo J, Yuan Q, Rondard P, Huang S, Liu J, Pin JP. Allosteric control of an asymmetric transduction in a G protein-coupled receptor heterodimer. eLife 2017; 6:26985. [PMID: 28829739 PMCID: PMC5582870 DOI: 10.7554/elife.26985] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Accepted: 08/03/2017] [Indexed: 01/30/2023] Open
Abstract
GPCRs play critical roles in cell communication. Although GPCRs can form heteromers, their role in signaling remains elusive. Here we used rat metabotropic glutamate (mGlu) receptors as prototypical dimers to study the functional interaction between each subunit. mGluRs can form both constitutive homo- and heterodimers. Whereas both mGlu2 and mGlu4 couple to G proteins, G protein activation is mediated by mGlu4 heptahelical domain (HD) exclusively in mGlu2-4 heterodimers. Such asymmetric transduction results from the action of both the dimeric extracellular domain, and an allosteric activation by the partially-activated non-functional mGlu2 HD. G proteins activation by mGlu2 HD occurs if either the mGlu2 HD is occupied by a positive allosteric modulator or if mGlu4 HD is inhibited by a negative modulator. These data revealed an oriented asymmetry in mGlu heterodimers that can be controlled with allosteric modulators. They provide new insight on the allosteric interaction between subunits in a GPCR dimer.
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Affiliation(s)
- Junke Liu
- College of Life Science and Technology, Collaborative Innovation Center for Genetics and Development, and Key Laboratory of Molecular Biophysics of Ministry of Education, Huazhong University of Science and Technology, Wuhan, China
| | - Zongyong Zhang
- College of Life Science and Technology, Collaborative Innovation Center for Genetics and Development, and Key Laboratory of Molecular Biophysics of Ministry of Education, Huazhong University of Science and Technology, Wuhan, China
| | - David Moreno-Delgado
- Institut de Génomique Fonctionnelle, CNRS, INSERM, Université de Montpellier, Montpellier, France
| | - James Ar Dalton
- Institut de Neurociències and Unitat de Bioestadística, Universitat Autònoma de Barcelona, Barcelona, Spain.,Network Biomedical Research Center on Mental Health, Barcelona, Spain
| | - Xavier Rovira
- Institut de Génomique Fonctionnelle, CNRS, INSERM, Université de Montpellier, Montpellier, France
| | - Ana Trapero
- MCS, Laboratory of Medicinal Chemistry and Synthesis, Institute for Advanced Chemistry of Catalonia (IQAC-CSIC), Barcelona, Spain
| | - Cyril Goudet
- Institut de Génomique Fonctionnelle, CNRS, INSERM, Université de Montpellier, Montpellier, France
| | - Amadeu Llebaria
- MCS, Laboratory of Medicinal Chemistry and Synthesis, Institute for Advanced Chemistry of Catalonia (IQAC-CSIC), Barcelona, Spain
| | - Jesús Giraldo
- Institut de Neurociències and Unitat de Bioestadística, Universitat Autònoma de Barcelona, Barcelona, Spain.,Network Biomedical Research Center on Mental Health, Barcelona, Spain
| | - Qilin Yuan
- College of Life Science and Technology, Collaborative Innovation Center for Genetics and Development, and Key Laboratory of Molecular Biophysics of Ministry of Education, Huazhong University of Science and Technology, Wuhan, China
| | - Philippe Rondard
- Institut de Génomique Fonctionnelle, CNRS, INSERM, Université de Montpellier, Montpellier, France
| | - Siluo Huang
- College of Life Science and Technology, Collaborative Innovation Center for Genetics and Development, and Key Laboratory of Molecular Biophysics of Ministry of Education, Huazhong University of Science and Technology, Wuhan, China
| | - Jianfeng Liu
- College of Life Science and Technology, Collaborative Innovation Center for Genetics and Development, and Key Laboratory of Molecular Biophysics of Ministry of Education, Huazhong University of Science and Technology, Wuhan, China
| | - Jean-Philippe Pin
- Institut de Génomique Fonctionnelle, CNRS, INSERM, Université de Montpellier, Montpellier, France
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62
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Alvarado C, Nachtigal D, Slack JP, Green BG. Differential modulation of the lactisole 'Sweet Water Taste' by sweeteners. PLoS One 2017; 12:e0180787. [PMID: 28700634 PMCID: PMC5507258 DOI: 10.1371/journal.pone.0180787] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Accepted: 06/21/2017] [Indexed: 11/18/2022] Open
Abstract
Pre-exposure to taste stimuli and certain chemicals can cause water to have a taste. Here we studied further the 'sweet water taste' (SWT) perceived after exposure to the sweet taste inhibitor lactisole. Experiment 1 investigated an incidental observation that presenting lactisole in mixture with sucrose reduced the intensity of the SWT. The results confirmed this observation and also showed that rinsing with sucrose after lactisole could completely eliminate the SWT. The generalizability of these findings was investigated in experiment 2 by presenting 5 additional sweeteners before, during, or after exposure to lactisole. The results found with sucrose were replicated with fructose and cyclamate, but the 3 other sweeteners were less effective suppressors of the SWT, and the 2 sweeteners having the highest potency initially enhanced it. A third experiment investigated these interactions on the tongue tip and found that the lactisole SWT was perceived only when water was actively flowed across the tongue. The same experiment yielded evidence against the possibility that suppression of the SWT following exposure to sweeteners is an aftereffect of receptor activation while providing additional support for a role of sweetener potency. Collectively these results provide new evidence that complex inhibitory and excitatory interactions occur between lactisole and agonists of the sweet taste receptor TAS1R2-TAS1R3. Receptor mechanisms that may be responsible for these interactions are discussed in the context of the current model of the SWT and the possible contribution of allosteric modulation.
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Affiliation(s)
- Cynthia Alvarado
- The John B. Pierce Laboratory, New Haven, Connecticut, United States of America
| | - Danielle Nachtigal
- The John B. Pierce Laboratory, New Haven, Connecticut, United States of America
| | - Jay P. Slack
- Givaudan Flavors Corp, Department of Science + Technology, Cincinnati, Ohio, United States of America
| | - Barry G. Green
- The John B. Pierce Laboratory, New Haven, Connecticut, United States of America
- Department of Surgery (Otolaryngology), Yale School of Medicine, New Haven, Connecticut, United States of America
- * E-mail:
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63
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Abstract
G-protein-coupled receptors (GPCRs) constitute a large group of integral membrane proteins that transduce extracellular signals from a wide range of agonists into targeted intracellular responses. Although the responses can vary depending on the category of G-proteins activated by a particular receptor, responses were also found to be triggered by interactions of the receptor with β-arrestins. It was subsequently discovered that for the same receptor molecule (e.g., the β-adrenergic receptor), some agonists have a propensity to specifically favor responses by G-proteins, others by β-arrestins, as has now been extensively studied. This feature of the GPCR system is known as biased agonism and is subject to various interpretations, including agonist-induced conformational change versus selective stabilization of preexisting active conformations. Here, we explore a complete allosteric framework for biased agonism based on alternative preexisting conformations that bind more strongly, but nonexclusively, either G-proteins or β-arrestins. The framework incorporates reciprocal effects among all interacting molecules. As a result, G-proteins and β-arrestins are in steric competition for binding to the cytoplasmic surface of either the G-protein-favoring or β-arrestin-favoring GPCR conformation. Moreover, through linkage relations, the strength of the interactions of G-proteins or β-arrestins with the corresponding active conformation potentiates the apparent affinity for the agonist, effectively equating these two proteins to allosteric modulators. The balance between response alternatives can also be influenced by the physiological concentrations of either G-proteins or β-arrestins, as well as by phosphorylation or interactions with positive or negative allosteric modulators. The nature of the interactions in the simulations presented suggests novel experimental tests to distinguish more fully among alternative mechanisms.
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64
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Moreno Delgado D, Møller TC, Ster J, Giraldo J, Maurel D, Rovira X, Scholler P, Zwier JM, Perroy J, Durroux T, Trinquet E, Prezeau L, Rondard P, Pin JP. Pharmacological evidence for a metabotropic glutamate receptor heterodimer in neuronal cells. eLife 2017; 6. [PMID: 28661401 PMCID: PMC5540479 DOI: 10.7554/elife.25233] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Accepted: 06/26/2017] [Indexed: 12/25/2022] Open
Abstract
Metabotropic glutamate receptors (mGluRs) are mandatory dimers playing important roles in regulating CNS function. Although assumed to form exclusive homodimers, 16 possible heterodimeric mGluRs have been proposed but their existence in native cells remains elusive. Here, we set up two assays to specifically identify the pharmacological properties of rat mGlu heterodimers composed of mGlu2 and 4 subunits. We used either a heterodimer-specific conformational LRET-based biosensor or a system that guarantees the cell surface targeting of the heterodimer only. We identified mGlu2-4 specific pharmacological fingerprints that were also observed in a neuronal cell line and in lateral perforant path terminals naturally expressing mGlu2 and mGlu4. These results bring strong evidence for the existence of mGlu2-4 heterodimers in native cells. In addition to reporting a general approach to characterize heterodimeric mGluRs, our study opens new avenues to understanding the pathophysiological roles of mGlu heterodimers. DOI:http://dx.doi.org/10.7554/eLife.25233.001
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Affiliation(s)
- David Moreno Delgado
- Institut de Génomique Fonctionnelle (IGF), CNRS, INSERM, Univ. Montpellier, Montpellier, France
| | - Thor C Møller
- Institut de Génomique Fonctionnelle (IGF), CNRS, INSERM, Univ. Montpellier, Montpellier, France
| | - Jeanne Ster
- Institut de Génomique Fonctionnelle (IGF), CNRS, INSERM, Univ. Montpellier, Montpellier, France
| | - Jesús Giraldo
- Laboratory of Molecular Neuropharmacology and Bioinformatics, Institut de Neurociències and Unitat de Bioestadística, Universitat Autònoma de Barcelona, Bellaterra, Spain.,Network Biomedical Research Center on Mental Health, Madrid, Spain
| | - Damien Maurel
- Institut de Génomique Fonctionnelle (IGF), CNRS, INSERM, Univ. Montpellier, Montpellier, France
| | - Xavier Rovira
- Institut de Génomique Fonctionnelle (IGF), CNRS, INSERM, Univ. Montpellier, Montpellier, France
| | - Pauline Scholler
- Institut de Génomique Fonctionnelle (IGF), CNRS, INSERM, Univ. Montpellier, Montpellier, France
| | | | - Julie Perroy
- Institut de Génomique Fonctionnelle (IGF), CNRS, INSERM, Univ. Montpellier, Montpellier, France
| | - Thierry Durroux
- Institut de Génomique Fonctionnelle (IGF), CNRS, INSERM, Univ. Montpellier, Montpellier, France
| | | | - Laurent Prezeau
- Institut de Génomique Fonctionnelle (IGF), CNRS, INSERM, Univ. Montpellier, Montpellier, France
| | - Philippe Rondard
- Institut de Génomique Fonctionnelle (IGF), CNRS, INSERM, Univ. Montpellier, Montpellier, France
| | - Jean-Philippe Pin
- Institut de Génomique Fonctionnelle (IGF), CNRS, INSERM, Univ. Montpellier, Montpellier, France
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65
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Investigating the molecular mechanism of positive and negative allosteric modulators in the calcium-sensing receptor dimer. Sci Rep 2017; 7:46355. [PMID: 28417952 PMCID: PMC5394417 DOI: 10.1038/srep46355] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Accepted: 03/20/2017] [Indexed: 11/09/2022] Open
Abstract
Allosteric modulators that are targeting the calcium-sensing receptor (CaSR) hold great therapeutic potential, and elucidating the molecular basis for modulation would thus benefit the development of novel therapeutics. In the present study, we aimed at investigating the mechanism of allosteric modulation in CaSR by testing dimers carrying mutations in the allosteric site of one or both of the subunits. To ensure measurements on a well-defined dimer composition, we applied a trans-activation system in which only the specific heterodimer of two loss-of-function mutants responded to agonist. Although one of these mutants was potentiated by a positive allosteric modulator, we showed that receptor activity was further potentiated in a trans-activation heterodimer containing a single allosteric site, however only when the allosteric site was located in the subunit responsible for G protein coupling. On the contrary, preventing activation in both subunits was necessary for obtaining full inhibition by a negative allosteric modulator. These findings correlate with the proposed activation mechanism of the metabotropic glutamate receptors (mGluRs), in which only a single transmembrane domain is activated at a time. CaSR and mGluRs belong to the class C G protein-coupled receptors, and our findings thus suggest that the activation mechanism is common to this subfamily.
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66
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Lecat-Guillet N, Monnier C, Rovira X, Kniazeff J, Lamarque L, Zwier JM, Trinquet E, Pin JP, Rondard P. FRET-Based Sensors Unravel Activation and Allosteric Modulation of the GABA B Receptor. Cell Chem Biol 2017; 24:360-370. [PMID: 28286129 DOI: 10.1016/j.chembiol.2017.02.011] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Revised: 11/21/2016] [Accepted: 02/10/2017] [Indexed: 01/11/2023]
Abstract
The main inhibitory neurotransmitter, γ-aminobutyric acid (GABA), modulates many synapses by activating the G protein-coupled receptor GABAB, which is a target for various therapeutic applications. It is an obligatory heterodimer made of GB1 and GB2 that can be regulated by positive allosteric modulators (PAMs). The molecular mechanism of activation of the GABAB receptor remains poorly understood. Here, we have developed FRET-based conformational GABAB sensors compatible with high-throughput screening. We identified conformational changes occurring within the extracellular and transmembrane domains upon receptor activation, which are smaller than those observed in the related metabotropic glutamate receptors. These sensors also allow discrimination between agonists of different efficacies and between PAMs that have different modes of action, which has not always been possible using conventional functional assays. Our study brings important new information on the activation mechanism of the GABAB receptor and should facilitate the screening and identification of new chemicals targeting this receptor.
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Affiliation(s)
- Nathalie Lecat-Guillet
- Institut de Génomique Fonctionnelle (IGF), CNRS, INSERM, University of Montpellier, 141 rue de la Cardonille, 34094 Montpellier, France
| | - Carine Monnier
- Institut de Génomique Fonctionnelle (IGF), CNRS, INSERM, University of Montpellier, 141 rue de la Cardonille, 34094 Montpellier, France
| | - Xavier Rovira
- Institut de Génomique Fonctionnelle (IGF), CNRS, INSERM, University of Montpellier, 141 rue de la Cardonille, 34094 Montpellier, France
| | - Julie Kniazeff
- Institut de Génomique Fonctionnelle (IGF), CNRS, INSERM, University of Montpellier, 141 rue de la Cardonille, 34094 Montpellier, France
| | | | | | | | - Jean-Philippe Pin
- Institut de Génomique Fonctionnelle (IGF), CNRS, INSERM, University of Montpellier, 141 rue de la Cardonille, 34094 Montpellier, France
| | - Philippe Rondard
- Institut de Génomique Fonctionnelle (IGF), CNRS, INSERM, University of Montpellier, 141 rue de la Cardonille, 34094 Montpellier, France.
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67
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Class C G protein-coupled receptors: reviving old couples with new partners. BIOPHYSICS REPORTS 2017; 3:57-63. [PMID: 29238742 PMCID: PMC5719802 DOI: 10.1007/s41048-017-0036-9] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Accepted: 01/11/2017] [Indexed: 02/02/2023] Open
Abstract
G protein-coupled receptors (GPCRs) are key players in cell communication and are encoded by the largest family in our genome. As such, GPCRs represent the main targets in drug development programs. Sequence analysis revealed several classes of GPCRs: the class A rhodopsin-like receptors represent the majority, the class B includes the secretin-like and adhesion GPCRs, the class F includes the frizzled receptors, and the class C includes receptors for the main neurotransmitters, glutamate and GABA, and those for sweet and umami taste and calcium receptors. Class C receptors are far more complex than other GPCRs, being mandatory dimers, with each subunit being composed of several domains. In this review, we summarize our actual knowledge regarding the activation mechanism and subunit organization of class C GPCRs, and how this brings information for many other GPCRs.
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68
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Activation mechanism of the G protein-coupled sweet receptor heterodimer with sweeteners and allosteric agonists. Proc Natl Acad Sci U S A 2017; 114:2568-2573. [PMID: 28228527 DOI: 10.1073/pnas.1700001114] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The sweet taste in humans is mediated by the TAS1R2/TAS1R3 G protein-coupled receptor (GPCR), which belongs to the class C family that also includes the metabotropic glutamate and γ-aminobutyric acid receptors. We report here the predicted 3D structure of the full-length TAS1R2/TAS1R3 heterodimer, including the Venus Flytrap Domains (VFDs) [in the closed-open (co) active conformation], the cysteine-rich domains (CRDs), and the transmembrane domains (TMDs) at the TM56/TM56 interface. We observe that binding of agonists to VFD2 of TAS1R2 leads to major conformational changes to form a TM6/TM6 interface between TMDs of TAS1R2 and TAS1R3, which is consistent with the activation process observed biophysically on the metabotropic glutamate receptor 2 homodimer. We find that the initial effect of the agonist is to pull the bottom part of VFD3/TAS1R3 toward the bottom part of VFD2/TAS1R2 by ∼6 Å and that these changes get transmitted from VFD2 of TAS1R2 (where agonists bind) through the VFD3 and the CRD3 to the TMD3 of TAS1R3 (which couples to the G protein). These structural transformations provide a detailed atomistic mechanism for the activation process in GPCR, providing insights and structural details that can now be validated through mutation experiments.
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69
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70
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Scholler P, Moreno-Delgado D, Lecat-Guillet N, Doumazane E, Monnier C, Charrier-Savournin F, Fabre L, Chouvet C, Soldevila S, Lamarque L, Donsimoni G, Roux T, Zwier JM, Trinquet E, Rondard P, Pin JP. HTS-compatible FRET-based conformational sensors clarify membrane receptor activation. Nat Chem Biol 2017; 13:372-380. [DOI: 10.1038/nchembio.2286] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Accepted: 11/18/2016] [Indexed: 12/26/2022]
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71
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Pin JP, Bettler B. Organization and functions of mGlu and GABAB receptor complexes. Nature 2016; 540:60-68. [DOI: 10.1038/nature20566] [Citation(s) in RCA: 155] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Accepted: 10/21/2016] [Indexed: 02/08/2023]
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72
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Tateyama M, Kubo Y. Stabilizing effects of G protein on the active conformation of adenosine A 1 receptor differ depending on G protein type. Eur J Pharmacol 2016; 788:122-131. [DOI: 10.1016/j.ejphar.2016.06.025] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Revised: 06/15/2016] [Accepted: 06/15/2016] [Indexed: 01/07/2023]
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73
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Mechanism of Assembly and Cooperativity of Homomeric and Heteromeric Metabotropic Glutamate Receptors. Neuron 2016; 92:143-159. [PMID: 27641494 DOI: 10.1016/j.neuron.2016.08.036] [Citation(s) in RCA: 122] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Revised: 07/19/2016] [Accepted: 08/19/2016] [Indexed: 11/23/2022]
Abstract
G protein-coupled receptors (GPCRs) mediate cellular responses to a wide variety of extracellular stimuli. GPCR dimerization may expand signaling diversity and tune functionality, but little is known about the mechanisms of subunit assembly and interaction or the signaling properties of heteromers. Using single-molecule subunit counting on class C metabotropic glutamate receptors (mGluRs), we map dimerization determinants and define a heterodimerization profile. Intersubunit fluorescence resonance energy transfer measurements reveal that interactions between ligand-binding domains control the conformational rearrangements underlying receptor activation. Selective liganding with photoswitchable tethered agonists conjugated to one or both subunits of covalently linked mGluR2 homodimers reveals that receptor activation is highly cooperative. Strikingly, this cooperativity is asymmetric in mGluR2/mGluR3 heterodimers. Our results lead to a model of cooperative activation of mGluRs that provides a framework for understanding how class C GPCRs couple extracellular binding to dimer reorganization and G protein activation.
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74
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Taste substance binding elicits conformational change of taste receptor T1r heterodimer extracellular domains. Sci Rep 2016; 6:25745. [PMID: 27160511 PMCID: PMC4861910 DOI: 10.1038/srep25745] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2015] [Accepted: 04/22/2016] [Indexed: 11/09/2022] Open
Abstract
Sweet and umami tastes are perceived by T1r taste receptors in oral cavity. T1rs are class C G-protein coupled receptors (GPCRs), and the extracellular ligand binding domains (LBDs) of T1r1/T1r3 and T1r2/T1r3 heterodimers are responsible for binding of chemical substances eliciting umami or sweet taste. However, molecular analyses of T1r have been hampered due to the difficulties in recombinant expression and protein purification, and thus little is known about mechanisms for taste perception. Here we show the first molecular view of reception of a taste substance by a taste receptor, where the binding of the taste substance elicits a different conformational state of T1r2/T1r3 LBD heterodimer. Electron microscopy has showed a characteristic dimeric structure. Förster resonance energy transfer and X-ray solution scattering have revealed the transition of the dimerization manner of the ligand binding domains, from a widely spread to compactly organized state upon taste substance binding, which may correspond to distinct receptor functional states.
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75
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Litim N, Morissette M, Di Paolo T. Metabotropic glutamate receptors as therapeutic targets in Parkinson's disease: An update from the last 5 years of research. Neuropharmacology 2016; 115:166-179. [PMID: 27055772 DOI: 10.1016/j.neuropharm.2016.03.036] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2015] [Revised: 03/21/2016] [Accepted: 03/22/2016] [Indexed: 12/21/2022]
Abstract
Disturbance of glutamate neurotransmission in Parkinson's disease (PD) and l-DOPA induced dyskinesia (LID) is well documented. This review focuses on advances during the past five years on pharmacological modulation of metabotropic glutamate (mGlu) receptors in relation to anti-parkinsonian activity, LID attenuation, and neuroprotection. Drug design and characterization have led to the development of orthosteric agonists binding the same site as glutamate and Positive and Negative Allosteric modulators (PAMs and NAMs) binding sites different from the orthosteric site and offering subtype selectivity. Inhibition of group I (mGlu1 and mGlu5) receptors with NAMs and activation of group II (mGlu2 and 3 receptors) and group III (mGlu 4, 7 and 8 receptors) with PAMs and orthosteric agonists have shown their potential to inhibit glutamate release and attenuate excitotoxicity. Earlier and recent studies have led to the development of mGlu5 receptors NAMs to reduce LID and for neuroprotection, mGlu3 receptor agonists for neuroprotection while mGlu4 receptor PAMs and agonists for antiparkinsonian effects and neuroprotection. Furthermore, homo- and heterodimers of mGlu receptors are documented and highlight the complexity of the functioning of these receptors. Research on partial allosteric modulators and biased mGlu receptor allosteric modulators offer new glutamatergic drugs with better therapeutic effects and less off target adverse activity. Thus these various mGlu receptor targets will enable the development of novel drugs with improved clinical effects for normalization of glutamate transmission, treat PD and LID relief. This article is part of the Special Issue entitled 'Metabotropic Glutamate Receptors, 5 years on'.
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Affiliation(s)
- Nadhir Litim
- Neuroscience Research Unit, Centre Hospitalier Universitaire de Québec, CHUL, Quebec City, Canada; Faculty of Pharmacy, Laval University, Quebec City, Canada
| | - Marc Morissette
- Neuroscience Research Unit, Centre Hospitalier Universitaire de Québec, CHUL, Quebec City, Canada
| | - Thérèse Di Paolo
- Neuroscience Research Unit, Centre Hospitalier Universitaire de Québec, CHUL, Quebec City, Canada; Faculty of Pharmacy, Laval University, Quebec City, Canada.
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76
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Investigation of allosteric modulation mechanism of metabotropic glutamate receptor 1 by molecular dynamics simulations, free energy and weak interaction analysis. Sci Rep 2016; 6:21763. [PMID: 26887338 PMCID: PMC4757871 DOI: 10.1038/srep21763] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Accepted: 01/18/2016] [Indexed: 12/18/2022] Open
Abstract
Metabotropic glutamate receptor 1 (mGlu1), which belongs to class C G protein-coupled receptors (GPCRs), can be coupled with G protein to transfer extracellular signal by dimerization and allosteric regulation. Unraveling the dimer packing and allosteric mechanism can be of great help for understanding specific regulatory mechanism and designing more potential negative allosteric modulator (NAM). Here, we report molecular dynamics simulation studies of the modulation mechanism of FITM on the wild type, T815M and Y805A mutants of mGlu1 through weak interaction analysis and free energy calculation. The weak interaction analysis demonstrates that van der Waals (vdW) and hydrogen bonding play an important role on the dimer packing between six cholesterol molecules and mGlu1 as well as the interaction between allosteric sites T815, Y805 and FITM in wild type, T815M and Y805A mutants of mGlu1. Besides, the results of free energy calculations indicate that secondary binding pocket is mainly formed by the residues Thr748, Cys746, Lys811 and Ser735 except for FITM-bound pocket in crystal structure. Our results can not only reveal the dimer packing and allosteric regulation mechanism, but also can supply useful information for the design of potential NAM of mGlu1.
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77
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Huynh THV, Erichsen MN, Tora AS, Goudet C, Sagot E, Assaf Z, Thomsen C, Brodbeck R, Stensbøl TB, Bjørn-Yoshimoto WE, Nielsen B, Pin JP, Gefflaut T, Bunch L. New 4-Functionalized Glutamate Analogues Are Selective Agonists at Metabotropic Glutamate Receptor Subtype 2 or Selective Agonists at Metabotropic Glutamate Receptor Group III. J Med Chem 2016; 59:914-24. [PMID: 26814576 DOI: 10.1021/acs.jmedchem.5b01333] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The metabotropic glutamate (Glu) receptors (mGluRs) play key roles in modulating excitatory neurotransmission in the brain. In all, eight subtypes have been identified and divided into three groups, group I (mGlu1,5), group II (mGlu2,3), and group III (mGlu4,6-8). In this article, we present a L-2,4-syn-substituted Glu analogue, 1d, which displays selective agonist activity at mGlu2 over the remaining mGluR subtypes. A modeling study and redesign of the core scaffold led to the stereoselective synthesis of four new conformationally restricted Glu analogues, 2a-d. Most interestingly, 2a retained a selective agonist activity profile at mGlu2 (EC50 in the micromolar range), whereas 2c/2d were both selective agonists at group III, subtypes mGlu4,6,8. In general, 2d was 20-fold more potent than 2c and potently activated mGlu4,6,8 in the low-mid nanomolar range.
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Affiliation(s)
- Tri H V Huynh
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen , 2100 Copenhagen, Denmark
| | - Mette N Erichsen
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen , 2100 Copenhagen, Denmark
| | - Amélie S Tora
- Institute of Functional Genomics, CNRS, UMR5203, University of Montpellier , 34094 Montpellier, France.,INSERM, U1191 , 34094 Montpellier, France
| | - Cyril Goudet
- Institute of Functional Genomics, CNRS, UMR5203, University of Montpellier , 34094 Montpellier, France.,INSERM, U1191 , 34094 Montpellier, France
| | - Emmanuelle Sagot
- Institut de Chimie de Clermont-Ferrand, Clermont Université, Université Blaise Pascal, BP 10448 , 63000 Clermont-Ferrand, France.,CNRS, UMR6296, ICCF, BP 80026 , 63177 Aubière, France
| | - Zeinab Assaf
- Institut de Chimie de Clermont-Ferrand, Clermont Université, Université Blaise Pascal, BP 10448 , 63000 Clermont-Ferrand, France.,CNRS, UMR6296, ICCF, BP 80026 , 63177 Aubière, France
| | | | | | | | - Walden E Bjørn-Yoshimoto
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen , 2100 Copenhagen, Denmark
| | - Birgitte Nielsen
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen , 2100 Copenhagen, Denmark
| | - Jean-Philippe Pin
- Institute of Functional Genomics, CNRS, UMR5203, University of Montpellier , 34094 Montpellier, France.,INSERM, U1191 , 34094 Montpellier, France
| | - Thierry Gefflaut
- Institut de Chimie de Clermont-Ferrand, Clermont Université, Université Blaise Pascal, BP 10448 , 63000 Clermont-Ferrand, France.,CNRS, UMR6296, ICCF, BP 80026 , 63177 Aubière, France
| | - Lennart Bunch
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen , 2100 Copenhagen, Denmark
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78
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Abstract
Since their discovery, G protein-coupled receptors (GPCRs) constitute one of the most studied proteins leading to important discoveries and perspectives in terms of their biology and implication in physiology and pathophysiology. This is mostly linked to the remarkable advances in the development and application of the biophysical resonance energy transfer (RET)-based approaches, including bioluminescence and fluorescence resonance energy transfer (BRET and FRET, respectively). Indeed, BRET and FRET have been extensively applied to study different aspects of GPCR functioning such as their activation and regulation either statically or dynamically, in real-time and intact cells. Consequently, our view on GPCRs has considerably changed opening new challenges for the study of GPCRs in their native tissues in the aim to get more knowledge on how these receptors control the biological responses. Moreover, the technological aspect of this field of research promises further developments for robust and reliable new RET-based assays that may be compatible with high-throughput screening as well as drug discovery programs.
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Affiliation(s)
- Mohammed Akli Ayoub
- Biologie et Bioinformatique des Systèmes de Signalisation, Institut National de la Recherche Agronomique, UMR85, Unité Physiologie de la Reproduction et des Comportements; CNRS, UMR7247, Nouzilly, France; LE STUDIUM(®) Loire Valley Institute for Advanced Studies, Orléans, France.
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79
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Broichhagen J, Damijonaitis A, Levitz J, Sokol KR, Leippe P, Konrad D, Isacoff EY, Trauner D. Orthogonal Optical Control of a G Protein-Coupled Receptor with a SNAP-Tethered Photochromic Ligand. ACS CENTRAL SCIENCE 2015; 1:383-393. [PMID: 27162996 PMCID: PMC4827557 DOI: 10.1021/acscentsci.5b00260] [Citation(s) in RCA: 84] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2015] [Indexed: 05/30/2023]
Abstract
The covalent attachment of synthetic photoswitches is a general approach to impart light sensitivity onto native receptors. It mimics the logic of natural photoreceptors and significantly expands the reach of optogenetics. Here we describe a novel photoswitch design-the photoswitchable orthogonal remotely tethered ligand (PORTL)-that combines the genetically encoded SNAP-tag with photochromic ligands connected to a benzylguanine via a long flexible linker. We use the method to convert the G protein-coupled receptor mGluR2, a metabotropic glutamate receptor, into a photoreceptor (SNAG-mGluR2) that provides efficient optical control over the neuronal functions of mGluR2: presynaptic inhibition and control of excitability. The PORTL approach enables multiplexed optical control of different native receptors using distinct bioconjugation methods. It should be broadly applicable since SNAP-tags have proven to be reliable, many SNAP-tagged receptors are already available, and photochromic ligands on a long leash are readily designed and synthesized.
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Affiliation(s)
- Johannes Broichhagen
- Department
of Chemistry, Ludwig-Maximilians-Universität
München, Butenandtstrasse
5-13, 81377 München, Germany
- Munich Center for Integrated Protein Science, Butenandtstrasse 5-13, 81377 München, Germany
| | - Arunas Damijonaitis
- Department
of Chemistry, Ludwig-Maximilians-Universität
München, Butenandtstrasse
5-13, 81377 München, Germany
- Munich Center for Integrated Protein Science, Butenandtstrasse 5-13, 81377 München, Germany
| | - Joshua Levitz
- Department
of Molecular and Cell Biology, University
of California, Berkeley, California 94720, United States
| | - Kevin R. Sokol
- Department
of Chemistry, Ludwig-Maximilians-Universität
München, Butenandtstrasse
5-13, 81377 München, Germany
- Munich Center for Integrated Protein Science, Butenandtstrasse 5-13, 81377 München, Germany
| | - Philipp Leippe
- Department
of Chemistry, Ludwig-Maximilians-Universität
München, Butenandtstrasse
5-13, 81377 München, Germany
- Munich Center for Integrated Protein Science, Butenandtstrasse 5-13, 81377 München, Germany
| | - David Konrad
- Department
of Chemistry, Ludwig-Maximilians-Universität
München, Butenandtstrasse
5-13, 81377 München, Germany
- Munich Center for Integrated Protein Science, Butenandtstrasse 5-13, 81377 München, Germany
| | - Ehud Y. Isacoff
- Department
of Molecular and Cell Biology, University
of California, Berkeley, California 94720, United States
- Helen
Wills Neuroscience Institute, University
of California, Berkeley, California 94720, United States
- Physical
Bioscience Division, Lawrence Berkeley National
Laboratory, Berkeley, California 94720, United States
| | - Dirk Trauner
- Department
of Chemistry, Ludwig-Maximilians-Universität
München, Butenandtstrasse
5-13, 81377 München, Germany
- Munich Center for Integrated Protein Science, Butenandtstrasse 5-13, 81377 München, Germany
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80
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Conformational dynamics of a class C G-protein-coupled receptor. Nature 2015; 524:497-501. [PMID: 26258295 PMCID: PMC4597782 DOI: 10.1038/nature14679] [Citation(s) in RCA: 133] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Accepted: 06/19/2015] [Indexed: 12/12/2022]
Abstract
G protein-coupled receptors (GPCRs) constitute the largest family of membrane receptors in eukaryotes. Crystal structures have provided insight into GPCR interaction with ligands and G-proteins1,2, but our understanding of the conformational dynamics of activation is incomplete. Metabotropic glutamate receptors (mGluRs) are dimeric class C GPCRs that modulate neuronal excitability, synaptic plasticity, and serve as drug targets for neurological disorders3,4. A “clamshell” ligand-binding domain (LBD), which contains the ligand binding site, is coupled to the transmembrane domain (TMD) via a cysteine rich domain, and LBD closure appears to be the first step in activation5,6. Crystal structures of isolated mGluR LBD dimers led to the suggestion that activation also involves a reorientation of the dimer interface from a “relaxed” to an “active” state7,8, but the relationship between ligand binding, LBD closure and dimer interface rearrangement in activation remains unclear. We used single-molecule fluorescence resonance energy transfer (smFRET) to probe the activation mechanism of full-length mammalian group II mGluRs. We find that the LBDs interconvert between three conformations: resting, activated and a short-lived intermediate state. Orthosteric agonists induce transitions between these conformational states with efficacy determined by occupancy of the active conformation. Unlike mGluR2, mGluR3 displays basal dynamics, which are Ca2+ dependent and lead to basal protein activation. Our results support a general mechanism for the activation of mGluRs in which agonist binding induces closure of the LBDs followed by dimer interface reorientation. Our experimental strategy should be widely applicable to study conformational dynamics in GPCRs and other membrane proteins.
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81
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Tora AS, Rovira X, Dione I, Bertrand H, Brabet I, De Koninck Y, Doyon N, Pin J, Acher F, Goudet C. Allosteric modulation of metabotropic glutamate receptors by chloride ions. FASEB J 2015; 29:4174-88. [DOI: 10.1096/fj.14-269746] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2015] [Accepted: 06/15/2015] [Indexed: 11/11/2022]
Affiliation(s)
- Amélie S. Tora
- Institut de Génomique Fonctionnelle, CNRS, UMR 5203, Université de MontpellierMontpellierFrance
- INSERM U1191MontpellierFrance
| | - Xavier Rovira
- Institut de Génomique Fonctionnelle, CNRS, UMR 5203, Université de MontpellierMontpellierFrance
- INSERM U1191MontpellierFrance
| | - Ibrahima Dione
- Centre de Recherche de l'Institut Universitaire en Santé Mentale du Québec and Université LavalQuébecCanada
| | | | - Isabelle Brabet
- Institut de Génomique Fonctionnelle, CNRS, UMR 5203, Université de MontpellierMontpellierFrance
- INSERM U1191MontpellierFrance
| | - Yves De Koninck
- Centre de Recherche de l'Institut Universitaire en Santé Mentale du Québec and Université LavalQuébecCanada
| | - Nicolas Doyon
- Centre de Recherche de l'Institut Universitaire en Santé Mentale du Québec and Université LavalQuébecCanada
| | - Jean‐Philippe Pin
- Institut de Génomique Fonctionnelle, CNRS, UMR 5203, Université de MontpellierMontpellierFrance
- INSERM U1191MontpellierFrance
| | - Francine Acher
- Laboratoire de Chimie et Biochimie Pharmacologiques et ToxicologiquesCNRS, UMR 8601, Université Paris Descartes, Sorbonne Paris CitéParisFrance
| | - Cyril Goudet
- Institut de Génomique Fonctionnelle, CNRS, UMR 5203, Université de MontpellierMontpellierFrance
- INSERM U1191MontpellierFrance
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82
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Xue L, Rovira X, Scholler P, Zhao H, Liu J, Pin JP, Rondard P. Major ligand-induced rearrangement of the heptahelical domain interface in a GPCR dimer. Nat Chem Biol 2015; 11:134-40. [PMID: 25503927 DOI: 10.1038/nchembio.1711] [Citation(s) in RCA: 151] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2014] [Accepted: 10/14/2014] [Indexed: 12/30/2022]
Abstract
G protein-coupled receptors (GPCRs) are major players in cell communication. Although they form functional monomers, increasing evidence indicates that GPCR dimerization has a critical role in cooperative phenomena that are important for cell signal integration. However, the structural bases of these phenomena remain elusive. Here, using well-characterized receptor dimers, the metabotropic glutamate receptors (mGluRs), we show that structural changes at the dimer interface are linked to receptor activation. We demonstrate that the main dimer interface is formed by transmembrane α helix 4 (TM4) and TM5 in the inactive state and by TM6 in the active state. This major change in the dimer interface is required for receptor activity because locking the TM4-TM5 interface prevents activation by agonist, whereas locking the TM6 interface leads to a constitutively active receptor. These data provide important information on the activation mechanism of mGluRs and improve our understanding of the structural basis of the negative cooperativity observed in these GPCR dimers.
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MESH Headings
- Alanine/genetics
- Animals
- COS Cells
- Chlorocebus aethiops
- Cysteine/genetics
- HEK293 Cells
- Humans
- Ligands
- Models, Molecular
- Mutagenesis, Site-Directed
- Protein Binding
- Protein Multimerization
- Protein Structure, Tertiary
- Protein Subunits
- Rats
- Receptor, Metabotropic Glutamate 5/agonists
- Receptor, Metabotropic Glutamate 5/chemistry
- Receptor, Metabotropic Glutamate 5/genetics
- Receptors, GABA-B/chemistry
- Receptors, GABA-B/genetics
- Receptors, GABA-B/metabolism
- Receptors, Metabotropic Glutamate/agonists
- Receptors, Metabotropic Glutamate/chemistry
- Receptors, Metabotropic Glutamate/genetics
- Transcriptional Activation
- Transfection
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Affiliation(s)
- Li Xue
- 1] Cellular Signaling Laboratory, Key Laboratory of Molecular Biophysics of Ministry of Education, School of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China. [2] CNRS, UMR5203, Institut de Génomique Fonctionnelle, Montpellier, France. [3] INSERM, U661, Montpellier, France. [4] Université Montpellier 1 &2, Montpellier, France
| | - Xavier Rovira
- 1] CNRS, UMR5203, Institut de Génomique Fonctionnelle, Montpellier, France. [2] INSERM, U661, Montpellier, France. [3] Université Montpellier 1 &2, Montpellier, France
| | - Pauline Scholler
- 1] CNRS, UMR5203, Institut de Génomique Fonctionnelle, Montpellier, France. [2] INSERM, U661, Montpellier, France. [3] Université Montpellier 1 &2, Montpellier, France
| | - Han Zhao
- Cellular Signaling Laboratory, Key Laboratory of Molecular Biophysics of Ministry of Education, School of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
| | - Jianfeng Liu
- Cellular Signaling Laboratory, Key Laboratory of Molecular Biophysics of Ministry of Education, School of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
| | - Jean-Philippe Pin
- 1] CNRS, UMR5203, Institut de Génomique Fonctionnelle, Montpellier, France. [2] INSERM, U661, Montpellier, France. [3] Université Montpellier 1 &2, Montpellier, France
| | - Philippe Rondard
- 1] CNRS, UMR5203, Institut de Génomique Fonctionnelle, Montpellier, France. [2] INSERM, U661, Montpellier, France. [3] Université Montpellier 1 &2, Montpellier, France
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83
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Rondard P, Pin JP. Dynamics and modulation of metabotropic glutamate receptors. Curr Opin Pharmacol 2015; 20:95-101. [DOI: 10.1016/j.coph.2014.12.001] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2014] [Revised: 11/29/2014] [Accepted: 12/01/2014] [Indexed: 11/28/2022]
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84
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Kang HJ, Wilkins AD, Lichtarge O, Wensel TG. Determinants of endogenous ligand specificity divergence among metabotropic glutamate receptors. J Biol Chem 2014; 290:2870-8. [PMID: 25519912 DOI: 10.1074/jbc.m114.622233] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
To determine the structural origins of diverse ligand response specificities among metabotropic glutamate receptors (mGluRs), we combined computational approaches with mutagenesis and ligand response assays to identify specificity-determining residues in the group I receptor, mGluR1, and the group III receptors, mGluR4 and mGluR7. Among these, mGluR1 responds to L-glutamate effectively, whereas it binds weakly to another endogenous ligand, L-serine-O-phosphate (L-SOP), which antagonizes the effects of L-glutamate. In contrast, mGluR4 has in common with other group III mGluR that it is activated with higher potency and efficacy by L-SOP. mGluR7 differs from mGluR4 and other group III mGluR in that L-glutamate and L-SOP activate it with low potency and efficacy. Enhanced versions of the evolutionary trace (ET) algorithm were used to identify residues that when swapped between mGluR1 and mGluR4 increased the potency of L-SOP inhibition relative to the potency of L-glutamate activation in mGluR1 mutants and others that diminished the potency/efficacy of L-SOP for mGluR4 mutants. In addition, combining ET identified swaps from mGluR4 with one identified by computational docking produced mGluR7 mutants that respond with dramatically enhanced potency/efficacy to L-SOP. These results reveal that an early functional divergence between group I/II and group III involved variation at positions primarily at allosteric sites located outside of binding pockets, whereas a later divergence within group III occurred through sequence variation both at the ligand-binding pocket and at loops near the dimerization interface and interlobe hinge region. They also demonstrate the power of ET for identifying allosteric determinants of evolutionary importance.
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Affiliation(s)
- Hye Jin Kang
- From the Graduate Program in Structural and Computational Biology and Molecular Biophysics
| | | | - Olivier Lichtarge
- From the Graduate Program in Structural and Computational Biology and Molecular Biophysics, the Department of Molecular and Human Genetics, and the Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas 77030
| | - Theodore G Wensel
- From the Graduate Program in Structural and Computational Biology and Molecular Biophysics, the Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas 77030
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85
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Schonenbach NS, Hussain S, O'Malley MA. Structure and function of G protein‐coupled receptor oligomers: implications for drug discovery. WILEY INTERDISCIPLINARY REVIEWS-NANOMEDICINE AND NANOBIOTECHNOLOGY 2014; 7:408-27. [DOI: 10.1002/wnan.1319] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2014] [Revised: 09/26/2014] [Accepted: 10/11/2014] [Indexed: 12/21/2022]
Affiliation(s)
- Nicole S. Schonenbach
- Department of Chemical EngineeringUniversity of California Santa BarbaraSanta BarbaraCAUSA
| | - Sunyia Hussain
- Department of Chemical EngineeringUniversity of California Santa BarbaraSanta BarbaraCAUSA
| | - Michelle A. O'Malley
- Department of Chemical EngineeringUniversity of California Santa BarbaraSanta BarbaraCAUSA
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86
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Rovira X, Malhaire F, Scholler P, Rodrigo J, Gonzalez-Bulnes P, Llebaria A, Pin JP, Giraldo J, Goudet C. Overlapping binding sites drive allosteric agonism and positive cooperativity in type 4 metabotropic glutamate receptors. FASEB J 2014; 29:116-30. [PMID: 25342125 DOI: 10.1096/fj.14-257287] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Type 4 metabotropic glutamate (mGlu4) receptors are emerging targets for the treatment of various disorders. Accordingly, numerous mGlu4-positive allosteric modulators (PAMs) have been identified, some of which also display agonist activity. To identify the structural bases for their allosteric action, we explored the relationship between the binding pockets of mGlu4 PAMs with different chemical scaffolds and their functional properties. By use of innovative mGlu4 biosensors and second-messenger assays, we show that all PAMs enhance agonist action on the receptor through different degrees of allosteric agonism and positive cooperativity. For example, whereas VU0155041 and VU0415374 display equivalent efficacies [log(τ(B)) = 1.15 ± 0.38 and 1.25 ± 0.44, respectively], they increase the ability of L-AP4 to stabilize the active conformation of the receptor by 4 and 39 times, respectively. Modeling and docking studies identify 2 overlapping binding pockets as follows: a first site homologous to the pocket of natural agonists of class A GPCRs linked to allosteric agonism and a second one pointing toward a site topographically homologous to the Na(+) binding pocket of class A GPCRs, occupied by PAMs exhibiting the strongest cooperativity. These results reveal that intrinsic efficacy and cooperativity of mGlu4 PAMs are correlated with their binding mode, and vice versa, integrating structural and functional knowledge from different GPCR classes.
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Affiliation(s)
- Xavier Rovira
- Institut de Génomique Fonctionnelle, CNRS UMR 5203, Université de Montpellier, Montpellier, France; INSERM, U661, Montpellier, France
| | - Fanny Malhaire
- Institut de Génomique Fonctionnelle, CNRS UMR 5203, Université de Montpellier, Montpellier, France; INSERM, U661, Montpellier, France
| | - Pauline Scholler
- Institut de Génomique Fonctionnelle, CNRS UMR 5203, Université de Montpellier, Montpellier, France; INSERM, U661, Montpellier, France
| | - Jordi Rodrigo
- Laboratoire de Chimie Thérapeutique, BioCIS UMR-CNRS 8076, LabEx LERMIT, Faculté de Pharmacie, Université Paris-Sud, Châtenay-Malabry, Paris, France
| | - Patricia Gonzalez-Bulnes
- Laboratory of Medicinal Chemistry, Departament of Biomedicinal Chemistry, Institute of Advanced Chemistry of Catalonia IQAC-CSIC, Barcelona, Spain; and
| | - Amadeu Llebaria
- Laboratory of Medicinal Chemistry, Departament of Biomedicinal Chemistry, Institute of Advanced Chemistry of Catalonia IQAC-CSIC, Barcelona, Spain; and
| | - Jean-Philippe Pin
- Institut de Génomique Fonctionnelle, CNRS UMR 5203, Université de Montpellier, Montpellier, France; INSERM, U661, Montpellier, France
| | - Jesús Giraldo
- Laboratory of Molecular Neuropharmacology and Bioinformatics, Institut de Neurociències and Unitat de Bioestadística, Universitat Autònoma de Barcelona, Bellaterra, Spain
| | - Cyril Goudet
- Institut de Génomique Fonctionnelle, CNRS UMR 5203, Université de Montpellier, Montpellier, France; INSERM, U661, Montpellier, France;
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87
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Fine tuning of sub-millisecond conformational dynamics controls metabotropic glutamate receptors agonist efficacy. Nat Commun 2014; 5:5206. [DOI: 10.1038/ncomms6206] [Citation(s) in RCA: 76] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2014] [Accepted: 09/09/2014] [Indexed: 11/08/2022] Open
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88
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Zakrys L, Ward RJ, Pediani JD, Godin AG, Graham GJ, Milligan G. Roundabout 1 exists predominantly as a basal dimeric complex and this is unaffected by binding of the ligand Slit2. Biochem J 2014; 461:61-73. [PMID: 24673457 DOI: 10.1042/bj20140190] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Robo (Roundabout) receptors and their Slit polypeptide ligands are known to play key roles in neuronal development and have been implicated in both angiogenesis and cancer. Like the other family members, Robo1 is a large single transmembrane domain polypeptide containing a series of well-defined extracellular elements. However, the intracellular domain lacks structural definition and little is known about the quaternary structure of Robo receptors or how binding of a Slit might affect this. To address these questions combinations of both autofluorescent protein-based FRET imaging and time-resolved FRET were employed. Both approaches identified oligomeric organization of Robo1 that did not require the presence of the intracellular domain. SpIDA (spatial intensity distribution analysis) of eGFP-tagged forms of Robo1 indicated that for a C-terminally deleted version approximately two-thirds of the receptor was present as a dimer and one-third as a monomer. By contrast, full-length Robo1 was present almost exclusively as a dimer. In each case this was unaffected by the addition of Slit2, although parallel studies demonstrated the biological activity of Slit2 and its interaction with Robo1. Deletion of both the immunoglobulin and fibronectin type III extracellular repeats prevented dimer formation, with the immunoglobulin repeats providing the bulk of the protein-protein interaction affinity.
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Affiliation(s)
| | - Richard J Ward
- *Molecular Pharmacology Group, Institute of Molecular, Cell and Systems Biology, University of Glasgow, Glasgow G12 8QQ, Scotland, U.K
| | - John D Pediani
- *Molecular Pharmacology Group, Institute of Molecular, Cell and Systems Biology, University of Glasgow, Glasgow G12 8QQ, Scotland, U.K
| | - Antoine G Godin
- ‡Laboratoire Photonique, Numérique et Nanosciences (LP2N) Institut d'Optique Graduate School, CNRS and Université Bordeaux, 351 cours de la libération, 33405 Talence Cedex, France
| | - Gerard J Graham
- †Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, Scotland, U.K
| | - Graeme Milligan
- *Molecular Pharmacology Group, Institute of Molecular, Cell and Systems Biology, University of Glasgow, Glasgow G12 8QQ, Scotland, U.K
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89
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Wu H, Wang C, Gregory KJ, Han GW, Cho HP, Xia Y, Niswender CM, Katritch V, Meiler J, Cherezov V, Conn PJ, Stevens RC. Structure of a class C GPCR metabotropic glutamate receptor 1 bound to an allosteric modulator. Science 2014; 344:58-64. [PMID: 24603153 DOI: 10.1126/science.1249489] [Citation(s) in RCA: 400] [Impact Index Per Article: 40.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The excitatory neurotransmitter glutamate induces modulatory actions via the metabotropic glutamate receptors (mGlus), which are class C G protein-coupled receptors (GPCRs). We determined the structure of the human mGlu1 receptor seven-transmembrane (7TM) domain bound to a negative allosteric modulator, FITM, at a resolution of 2.8 angstroms. The modulator binding site partially overlaps with the orthosteric binding sites of class A GPCRs but is more restricted than most other GPCRs. We observed a parallel 7TM dimer mediated by cholesterols, which suggests that signaling initiated by glutamate's interaction with the extracellular domain might be mediated via 7TM interactions within the full-length receptor dimer. A combination of crystallography, structure-activity relationships, mutagenesis, and full-length dimer modeling provides insights about the allosteric modulation and activation mechanism of class C GPCRs.
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Affiliation(s)
- Huixian Wu
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
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90
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Mølck C, Harpsøe K, Gloriam DE, Mathiesen JM, Nielsen SM, Bräuner-Osborne H. mGluR5: Exploration of Orthosteric and Allosteric Ligand Binding Pockets and Their Applications to Drug Discovery. Neurochem Res 2014; 39:1862-75. [DOI: 10.1007/s11064-014-1248-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2013] [Revised: 01/14/2014] [Accepted: 01/21/2014] [Indexed: 10/25/2022]
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91
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Zwier JM, Bazin H, Lamarque L, Mathis G. Luminescent lanthanide cryptates: from the bench to the bedside. Inorg Chem 2014; 53:1854-66. [PMID: 24392868 DOI: 10.1021/ic402234k] [Citation(s) in RCA: 84] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The design and application of luminescent lanthanide cryptates for sensing biological interactions is highlighted through the review of the work performed in our laboratory and with academic collaborations. The path from the initial applications probing biochemical interaction in vitro to "state-of-the-art" cellular assays toward clinical applications using homogeneous time-resolved fluorescence technology is described. An overview of the luminescent lanthanide macrocyclic compounds developed at Cisbio in the recent past is given with an emphasis on specific constraints required by specific applications. Recent assays for drug-discovery and diagnostic purposes using both antibody-based and suicide-enzyme-based technology are illustrated. New perspectives in the field of molecular medicine and time-resolved microscopy are discussed.
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Affiliation(s)
- Jurriaan M Zwier
- Cisbio Bioassays , Parc Marcel Boiteux, BP 84175, Codolet, France
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92
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Bautista-Barrufet A, Izquierdo-Serra M, Gorostiza P. Photoswitchable Ion Channels and Receptors. NOVEL APPROACHES FOR SINGLE MOLECULE ACTIVATION AND DETECTION 2014. [DOI: 10.1007/978-3-662-43367-6_9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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93
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Lakkaraju SK, Xue F, Faden AI, MacKerell AD. Estimation of ligand efficacies of metabotropic glutamate receptors from conformational forces obtained from molecular dynamics simulations. J Chem Inf Model 2013; 53:1337-49. [PMID: 23688150 DOI: 10.1021/ci400160x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Group 1 metabotropic glutamate receptors (mGluR) are G-protein coupled receptors with a large bilobate extracellular ligand binding region (LBR) that resembles a Venus fly trap. Closing of this LBR in the presence of a ligand is associated with the activation of the receptor. From conformational sampling of the LBR-ligand complexes using all-atom molecular dynamics (MD) simulations, we characterized the conformational minima related to the hinge like motion associated with the LBR closing/opening in the presence of known agonists and antagonists. By applying a harmonic restraint on the LBR, we also determined the conformational forces generated by the different ligands. The change in the location of the minima and the conformational forces were used to quantify the efficacies of the ligands. This analysis shows that efficacies can be estimated from the forces of a single conformation of the receptor, indicating the potential of MD simulations as an efficient and useful technique to quantify efficacies, thereby facilitating the rational design of mGluR agonists and antagonists.
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Affiliation(s)
- Sirish Kaushik Lakkaraju
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, 20 Penn St, Baltimore, Maryland 21201, USA
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94
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Sensing conformational changes in metabotropic glutamate receptors. Proc Natl Acad Sci U S A 2013; 110:5742-3. [PMID: 23542381 DOI: 10.1073/pnas.1303736110] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
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