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Mitroshina EV, Marasanova EA, Vedunova MV. Functional Dimerization of Serotonin Receptors: Role in Health and Depressive Disorders. Int J Mol Sci 2023; 24:16416. [PMID: 38003611 PMCID: PMC10671093 DOI: 10.3390/ijms242216416] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Revised: 11/11/2023] [Accepted: 11/13/2023] [Indexed: 11/26/2023] Open
Abstract
Understanding the neurobiological underpinnings of depressive disorder constitutes a pressing challenge in the fields of psychiatry and neurobiology. Depression represents one of the most prevalent forms of mental and behavioral disorders globally. Alterations in dimerization capacity can influence the functional characteristics of serotonin receptors and may constitute a contributing factor to the onset of depressive disorders. The objective of this review is to consolidate the current understanding of interactions within the 5-HT receptor family and between 5-HT receptors and members of other receptor families. Furthermore, it aims to elucidate the role of such complexes in depressive disorders and delineate the mechanisms through which antidepressants exert their effects.
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Affiliation(s)
- Elena V. Mitroshina
- Institute of Biology and Biomedicine, Lobachevsky State University of Nizhny Novgorod, 23 Gagarin Avenue, 603022 Nizhny Novgorod, Russia; (E.A.M.)
| | - Ekaterina A. Marasanova
- Institute of Biology and Biomedicine, Lobachevsky State University of Nizhny Novgorod, 23 Gagarin Avenue, 603022 Nizhny Novgorod, Russia; (E.A.M.)
| | - Maria V. Vedunova
- Institute of Biology and Biomedicine, Lobachevsky State University of Nizhny Novgorod, 23 Gagarin Avenue, 603022 Nizhny Novgorod, Russia; (E.A.M.)
- Faculty of Biology and Biotechnology, HSE University, St. Profsoyuznaya, 33, 117418 Moscow, Russia
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2
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Nguyen KDQ, Vigers M, Sefah E, Seppälä S, Hoover JP, Schonenbach NS, Mertz B, O'Malley MA, Han S. Homo-oligomerization of the human adenosine A 2A receptor is driven by the intrinsically disordered C-terminus. eLife 2021; 10:e66662. [PMID: 34269678 PMCID: PMC8328514 DOI: 10.7554/elife.66662] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Accepted: 07/15/2021] [Indexed: 11/27/2022] Open
Abstract
G protein-coupled receptors (GPCRs) have long been shown to exist as oligomers with functional properties distinct from those of the monomeric counterparts, but the driving factors of oligomerization remain relatively unexplored. Herein, we focus on the human adenosine A2A receptor (A2AR), a model GPCR that forms oligomers both in vitro and in vivo. Combining experimental and computational approaches, we discover that the intrinsically disordered C-terminus of A2AR drives receptor homo-oligomerization. The formation of A2AR oligomers declines progressively with the shortening of the C-terminus. Multiple interaction types are responsible for A2AR oligomerization, including disulfide linkages, hydrogen bonds, electrostatic interactions, and hydrophobic interactions. These interactions are enhanced by depletion interactions, giving rise to a tunable network of bonds that allow A2AR oligomers to adopt multiple interfaces. This study uncovers the disordered C-terminus as a prominent driving factor for the oligomerization of a GPCR, offering important insight into the effect of C-terminus modification on receptor oligomerization of A2AR and other GPCRs reconstituted in vitro for biophysical studies.
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Affiliation(s)
- Khanh Dinh Quoc Nguyen
- Department of Chemistry and Biochemistry, University of California, Santa BarbaraSanta BarbaraUnited States
| | - Michael Vigers
- Department of Chemical Engineering, University of California, Santa BarbaraSanta BarbaraUnited States
| | - Eric Sefah
- C. Eugene Bennett Department of Chemistry, West Virginia UniversityMorgantownUnited States
| | - Susanna Seppälä
- Department of Chemical Engineering, University of California, Santa BarbaraSanta BarbaraUnited States
| | - Jennifer Paige Hoover
- Department of Chemistry and Biochemistry, University of California, Santa BarbaraSanta BarbaraUnited States
| | - Nicole Star Schonenbach
- Department of Chemical Engineering, University of California, Santa BarbaraSanta BarbaraUnited States
| | - Blake Mertz
- C. Eugene Bennett Department of Chemistry, West Virginia UniversityMorgantownUnited States
| | - Michelle Ann O'Malley
- Department of Chemical Engineering, University of California, Santa BarbaraSanta BarbaraUnited States
| | - Songi Han
- Department of Chemistry and Biochemistry, University of California, Santa BarbaraSanta BarbaraUnited States
- Department of Chemical Engineering, University of California, Santa BarbaraSanta BarbaraUnited States
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3
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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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4
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El Khamlichi C, Reverchon-Assadi F, Hervouet-Coste N, Blot L, Reiter E, Morisset-Lopez S. Bioluminescence Resonance Energy Transfer as a Method to Study Protein-Protein Interactions: Application to G Protein Coupled Receptor Biology. Molecules 2019; 24:E537. [PMID: 30717191 PMCID: PMC6384791 DOI: 10.3390/molecules24030537] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Revised: 01/21/2019] [Accepted: 01/30/2019] [Indexed: 12/22/2022] Open
Abstract
The bioluminescence resonance energy transfer (BRET) approach involves resonance energy transfer between a light-emitting enzyme and fluorescent acceptors. The major advantage of this technique over biochemical methods is that protein-protein interactions (PPI) can be monitored without disrupting the natural environment, frequently altered by detergents and membrane preparations. Thus, it is considered as one of the most versatile technique for studying molecular interactions in living cells at "physiological" expression levels. BRET analysis has been applied to study many transmembrane receptor classes including G-protein coupled receptors (GPCR). It is well established that these receptors may function as dimeric/oligomeric forms and interact with multiple effectors to transduce the signal. Therefore, they are considered as attractive targets to identify PPI modulators. In this review, we present an overview of the different BRET systems developed up to now and their relevance to identify inhibitors/modulators of protein⁻protein interaction. Then, we introduce the different classes of agents that have been recently developed to target PPI, and provide some examples illustrating the use of BRET-based assays to identify and characterize innovative PPI modulators in the field of GPCRs biology. Finally, we discuss the main advantages and the limits of BRET approach to characterize PPI modulators.
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Affiliation(s)
- Chayma El Khamlichi
- Centre de Biophysique Moléculaire, CNRS, UPR 4301, University of Orléans and INSERM, 45071 Orléans, France.
- PRC, INRA, CNRS, Université François Rabelais-Tours, 37380 Nouzilly, France.
| | - Flora Reverchon-Assadi
- Centre de Biophysique Moléculaire, CNRS, UPR 4301, University of Orléans and INSERM, 45071 Orléans, France.
| | - Nadège Hervouet-Coste
- Centre de Biophysique Moléculaire, CNRS, UPR 4301, University of Orléans and INSERM, 45071 Orléans, France.
| | - Lauren Blot
- Centre de Biophysique Moléculaire, CNRS, UPR 4301, University of Orléans and INSERM, 45071 Orléans, France.
| | - Eric Reiter
- PRC, INRA, CNRS, Université François Rabelais-Tours, 37380 Nouzilly, France.
| | - Séverine Morisset-Lopez
- Centre de Biophysique Moléculaire, CNRS, UPR 4301, University of Orléans and INSERM, 45071 Orléans, France.
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5
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Maroteaux L, Béchade C, Roumier A. Dimers of serotonin receptors: Impact on ligand affinity and signaling. Biochimie 2019; 161:23-33. [PMID: 30685449 DOI: 10.1016/j.biochi.2019.01.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Accepted: 01/16/2019] [Indexed: 01/03/2023]
Abstract
Membrane receptors often form complexes with other membrane proteins that directly interact with different effectors of the signal transduction machinery. G-protein-coupled receptors (GPCRs) were for long time considered as single pharmacological entities. However, evidence for oligomerization appeared for various classes and subtypes of GPCRs. This review focuses on metabotropic serotonin (5-hydroxytryptamine, 5-HT) receptors, which belong to the rhodopsin-like class A of GPCRs, and will summarize the convergent evidence that homo- and hetero-dimers containing 5-HT receptors exist in transfected cells and in-vivo. We will show that complexes involving 5-HT receptors may acquire new signal transduction pathways and new physiological roles. In some cases, these complexes participate in disease-specific deregulations, that can be differentially affected by various drugs. Hence, selecting receptor complex-specific responses of these heterodimers may constitute an emerging strategy likely to improve beneficial therapeutic effects.
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Affiliation(s)
- Luc Maroteaux
- INSERM UMR-S839, S1270, Paris, 75005, France; Sorbonne Université, Paris, 75005, France; Institut du Fer à Moulin, Paris, 75005, France.
| | - Catherine Béchade
- INSERM UMR-S839, S1270, Paris, 75005, France; Sorbonne Université, Paris, 75005, France; Institut du Fer à Moulin, Paris, 75005, France
| | - Anne Roumier
- INSERM UMR-S839, S1270, Paris, 75005, France; Sorbonne Université, Paris, 75005, France; Institut du Fer à Moulin, Paris, 75005, France
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6
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Borroto-Escuela DO, Narváez M, Ambrogini P, Ferraro L, Brito I, Romero-Fernandez W, Andrade-Talavera Y, Flores-Burgess A, Millon C, Gago B, Narvaez JA, Odagaki Y, Palkovits M, Diaz-Cabiale Z, Fuxe K. Receptor⁻Receptor Interactions in Multiple 5-HT1A Heteroreceptor Complexes in Raphe-Hippocampal 5-HT Transmission and Their Relevance for Depression and Its Treatment. Molecules 2018; 23:molecules23061341. [PMID: 29865267 PMCID: PMC6099659 DOI: 10.3390/molecules23061341] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2018] [Revised: 05/22/2018] [Accepted: 05/22/2018] [Indexed: 12/21/2022] Open
Abstract
Due to the binding to a number of proteins to the receptor protomers in receptor heteromers in the brain, the term "heteroreceptor complexes" was introduced. A number of serotonin 5-HT1A heteroreceptor complexes were recently found to be linked to the ascending 5-HT pathways known to have a significant role in depression. The 5-HT1A⁻FGFR1 heteroreceptor complexes were involved in synergistically enhancing neuroplasticity in the hippocampus and in the dorsal raphe 5-HT nerve cells. The 5-HT1A protomer significantly increased FGFR1 protomer signaling in wild-type rats. Disturbances in the 5-HT1A⁻FGFR1 heteroreceptor complexes in the raphe-hippocampal 5-HT system were found in a genetic rat model of depression (Flinders sensitive line (FSL) rats). Deficits in FSL rats were observed in the ability of combined FGFR1 and 5-HT1A agonist cotreatment to produce antidepressant-like effects. It may in part reflect a failure of FGFR1 treatment to uncouple the 5-HT1A postjunctional receptors and autoreceptors from the hippocampal and dorsal raphe GIRK channels, respectively. This may result in maintained inhibition of hippocampal pyramidal nerve cell and dorsal raphe 5-HT nerve cell firing. Also, 5-HT1A⁻5-HT2A isoreceptor complexes were recently demonstrated to exist in the hippocampus and limbic cortex. They may play a role in depression through an ability of 5-HT2A protomer signaling to inhibit the 5-HT1A protomer recognition and signaling. Finally, galanin (1⁻15) was reported to enhance the antidepressant effects of fluoxetine through the putative formation of GalR1⁻GalR2⁻5-HT1A heteroreceptor complexes. Taken together, these novel 5-HT1A receptor complexes offer new targets for treatment of depression.
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Affiliation(s)
- Dasiel O Borroto-Escuela
- Department of Neuroscience, Karolinska Institutet; Retzius väg 8, 17177 Stockholm, Sweden.
- Department of Biomolecular Sciences, University of Urbino Carlo Bo, 61029 Urbino, Italy.
- Observatorio Cubano de Neurociencias, Grupo Bohío-Estudio, Zaya 50, 62100 Yaguajay, Cuba.
| | - Manuel Narváez
- Instituto de Investigación Biomédica de Málaga, Facultad de Medicina, Universidad de Málaga, 29071 Málaga, Spain.
| | - Patrizia Ambrogini
- Department of Biomolecular Sciences, University of Urbino Carlo Bo, 61029 Urbino, Italy.
| | - Luca Ferraro
- Department of Life Sciences and Biotechnology (SVEB), University of Ferrara, 44121 Ferrara, Italy.
| | - Ismel Brito
- Department of Neuroscience, Karolinska Institutet; Retzius väg 8, 17177 Stockholm, Sweden.
- Observatorio Cubano de Neurociencias, Grupo Bohío-Estudio, Zaya 50, 62100 Yaguajay, Cuba.
| | | | - Yuniesky Andrade-Talavera
- Department of Neurobiology, Care Sciences and Society, Center for Alzheimer Research, Neuronal Oscillations Lab, Karolinska Institutet, 171 77 Stockholm, Sweden.
| | - Antonio Flores-Burgess
- Instituto de Investigación Biomédica de Málaga, Facultad de Medicina, Universidad de Málaga, 29071 Málaga, Spain.
| | - Carmelo Millon
- Instituto de Investigación Biomédica de Málaga, Facultad de Medicina, Universidad de Málaga, 29071 Málaga, Spain.
| | - Belen Gago
- Instituto de Investigación Biomédica de Málaga, Facultad de Medicina, Universidad de Málaga, 29071 Málaga, Spain.
| | - Jose Angel Narvaez
- Instituto de Investigación Biomédica de Málaga, Facultad de Medicina, Universidad de Málaga, 29071 Málaga, Spain.
| | - Yuji Odagaki
- Department of Psychiatry, Saitama Medical University, 3388570 Saitama, Japan.
| | - Miklos Palkovits
- Department of Anatomy, Histology and Embryology. Faculty of Medicine. Semmelweis University, H-1094 Budapest, Hungary.
| | - Zaida Diaz-Cabiale
- Instituto de Investigación Biomédica de Málaga, Facultad de Medicina, Universidad de Málaga, 29071 Málaga, Spain.
| | - Kjell Fuxe
- Department of Neuroscience, Karolinska Institutet; Retzius väg 8, 17177 Stockholm, Sweden.
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7
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Durdagi S, Erol I, Salmas RE, Aksoydan B, Kantarcioglu I. Oligomerization and cooperativity in GPCRs from the perspective of the angiotensin AT1 and dopamine D2 receptors. Neurosci Lett 2018; 700:30-37. [PMID: 29684528 DOI: 10.1016/j.neulet.2018.04.028] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2018] [Revised: 04/13/2018] [Accepted: 04/16/2018] [Indexed: 12/22/2022]
Abstract
G Protein-Coupled Receptors (GPCRs) can form homo- and heterodimers or constitute higher oligomeric clusters with other heptahelical GPCRs. In this article, multiscale molecular modeling approaches as well as experimental techniques which are used to study oligomerization of GPCRs are reviewed. In particular, the effect of dimerization/oligomerization to the ligand binding affinity of individual protomers and also on the efficacy of the oligomer are discussed by including diverse examples from the literature. In addition, possible allosteric effects that may emerge upon interaction of GPCRs with membrane components, like cholesterol, is also discussed. Investigation of these above-mentioned interactions may greatly contribute to the candidate molecule screening studies and development of novel therapeutics with fewer adverse effects.
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Affiliation(s)
- Serdar Durdagi
- Computational Biology and Molecular Simulations Laboratory, Department of Biophysics, School of Medicine, Bahcesehir University (BAU), Istanbul, Turkey; Neuroscience Program, Graduate School of Health Sciences, Bahcesehir University, Istanbul, Turkey.
| | - Ismail Erol
- Computational Biology and Molecular Simulations Laboratory, Department of Biophysics, School of Medicine, Bahcesehir University (BAU), Istanbul, Turkey; Department of Chemistry, Gebze Technical University, Kocaeli, Turkey
| | - Ramin Ekhteiari Salmas
- Computational Biology and Molecular Simulations Laboratory, Department of Biophysics, School of Medicine, Bahcesehir University (BAU), Istanbul, Turkey
| | - Busecan Aksoydan
- Computational Biology and Molecular Simulations Laboratory, Department of Biophysics, School of Medicine, Bahcesehir University (BAU), Istanbul, Turkey; Neuroscience Program, Graduate School of Health Sciences, Bahcesehir University, Istanbul, Turkey
| | - Isik Kantarcioglu
- Computational Biology and Molecular Simulations Laboratory, Department of Biophysics, School of Medicine, Bahcesehir University (BAU), Istanbul, Turkey; Bioengineering Program, Graduate School of Natural and Applied Sciences, Bahcesehir University, Istanbul, Turkey
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8
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Borroto-Escuela DO, Tarakanov AO, Brito I, Fuxe K. Glutamate heteroreceptor complexes in the brain. Pharmacol Rep 2018; 70:936-950. [PMID: 32002960 DOI: 10.1016/j.pharep.2018.04.002] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2018] [Revised: 03/26/2018] [Accepted: 04/09/2018] [Indexed: 10/17/2022]
Abstract
The existence of mGluR, NMDAR, AMPAR and putative KAR heteroreceptor complexes in synaptic and extrasynaptic regions of brain glutamate synapses represents a major integrative mechanism. Our aim in the current article is to analyze if the formation of the different types glutamate hetereceptor complexes involves the contribution of triplet amino acid homologies (protriplets) in a postulated receptor interface based on the triplet puzzle theory. Seven main sets (lists) of receptor pairs in databases were used containing various sets (lists) of human receptor heteromers and nonheteromers obtained from the available scientific publications including the publically available GPCR-hetnet database. Brain mGluR1-mGluR5 and mGluR2-mGluR4 isoreceptor complexes were demonstrated with a predominant extrasynaptic localization at a post- and prejunctional localization. The existence of putative mGluR4-mGluR7 heteroreceptor complexes in the basal ganglia is proposed. Metabotropic glutamate receptor subtypes also participated in the formation of a large number of heteroreceptor complexes like mGluR1-A1R, mGluR5-A2AR, mGluR5-D2R and D2R-A2AR-mGluR5, located in relation to glutamate synapses, especially in the basal ganglia. A putative mGluR1-GABAB1/2 heterocomplex may also exist. NMDAR heteroreceptor complexes were also demonstrated as a fundamental integrative mechanism in the glutamate synapse and its extrasynaptic membranes. It represented fundamental work on inter alia NMDAR-mGluR5, NMDAR-D1R and NMDAR-D2R heteroreceptor complexes involving both antagonistic and facilitatory allosteric receptor-receptor interactions. As to AMPA receptors, a heterocomplex was found for the interaction between IFNgR1 and the AMPAR mediated via the subunit GluA1 which may be of relevance for neuroinflammation. AMPAR-D2R heteroreceptor complexes were also demonstrated. Besides glutamate heteroreceptor complexes and their allosteric receptor-receptor interactions, a significant mechanism for the functional crosstalk can also be phosphorylation and/or reorganization of adapter proteins with dynamic binding to the two receptors modulating the allosteric receptor mechanism.
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Affiliation(s)
- Dasiel O Borroto-Escuela
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden.,Department of Biomolecular Science, Section of Physiology, University of Urbino, Campus Scientifico Enrico Mattei, Urbino, Italy.,Grupo Bohío-Estudio, Observatorio Cubano de Neurociencias, Yaguajay, Cuba
| | - Alexander O Tarakanov
- St. Petersburg Institute for Informatics and Automation, Russian Academy of Sciences, Saint Petersburg, Russia
| | - Ismel Brito
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden.,Grupo Bohío-Estudio, Observatorio Cubano de Neurociencias, Yaguajay, Cuba
| | - Kjell Fuxe
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden.
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9
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Drugs which influence serotonin transporter and serotonergic receptors: Pharmacological and clinical properties in the treatment of depression. Pharmacol Rep 2018; 70:37-46. [DOI: 10.1016/j.pharep.2017.07.011] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Revised: 05/17/2017] [Accepted: 07/12/2017] [Indexed: 12/25/2022]
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10
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Iglesias A, Cimadevila M, la Fuente RAD, Martí-Solano M, Cadavid MI, Castro M, Selent J, Loza MI, Brea J. Serotonin 2A receptor disulfide bridge integrity is crucial for ligand binding to different signalling states but not for its homodimerization. Eur J Pharmacol 2017; 815:138-146. [PMID: 28899696 DOI: 10.1016/j.ejphar.2017.09.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Revised: 08/28/2017] [Accepted: 09/08/2017] [Indexed: 02/06/2023]
Abstract
The serotonin 2A (5-HT2A) receptor is a G-protein coupled receptor (GPCR) with a conserved disulfide bridge formed by Cys148 (transmembrane helix 3, TM3) and Cys227 (extracellular loop 2, ECL-2). We hypothesized that disulfide bridges may determine serotonin 5-HT2A receptor functions such as receptor activation, functional selectivity and ligand recognition. We used the reducing agent dithiothreitol (DTT) to determine how the reduction of disulfide bridges affects radioligand binding, second messenger mobilization and receptor dimerization. A DTT-induced decrease in the number of binding sites (1190 ± 63.55 fmol/mg protein for control cells compared with 921.2 ± 60.84 fmol/mg protein for DTT-treated cells) as well as in the efficacy of both signalling pathways characterized was observed, although the affinity and potency were unchanged. Bioluminiscence resonance energy transfer (BRET) assays revealed the DTT treatment did not modify the homodimeric nature of serotonin 5-HT2A receptors. In molecular dynamic simulations, the ECL-2 of the receptor with a broken cysteine bond adopts a wider variety of conformations, some of which protrude deeper into the receptor orthosteric binding pocket leading to collapse of the pocket. A shrunken binding pocket would be incapable of accommodating lysergic acid diethylamide (LSD). Our findings suggest that the decrease of efficacy may be due to disruption of disulfide bridge between TM3 and ECL-2. This reveals the integrity of the ECL-2 epitope, which should be explored in the development of novel ligands acting as allosteric modulators of serotonin 5-HT2A receptors.
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Affiliation(s)
- Alba Iglesias
- BioFarma Research Group, Centro Singular de Investigación en Medicina Molecular y Enfermedades Crónicas (CIMUS), Universidade de Santiago de Compostela, Avenida de Barcelona 22, 15782 Santiago de Compostela, Spain
| | - Marta Cimadevila
- BioFarma Research Group, Centro Singular de Investigación en Medicina Molecular y Enfermedades Crónicas (CIMUS), Universidade de Santiago de Compostela, Avenida de Barcelona 22, 15782 Santiago de Compostela, Spain
| | - Rocío Ailim de la Fuente
- BioFarma Research Group, Centro Singular de Investigación en Medicina Molecular y Enfermedades Crónicas (CIMUS), Universidade de Santiago de Compostela, Avenida de Barcelona 22, 15782 Santiago de Compostela, Spain; Molecular Pharmacology of G Protein-coupled Receptors Laboratory, Centro Singular de Investigación en Medicina Molecular y Enfermedades Crónicas (CIMUS), Universidade de Santiago de Compostela, Avenida de Barcelona 22, 15782 Santiago de Compostela, Spain
| | - María Martí-Solano
- GPCR Drug Discovery Group, Research Programme on Biomedical Informatics (GRIB), Hospital del Mar Medical Research Institute (IMIM) - Department of Experimental and Health Sciences of Pompeu Fabra University (UPF), Barcelona, Spain
| | - María Isabel Cadavid
- BioFarma Research Group, Centro Singular de Investigación en Medicina Molecular y Enfermedades Crónicas (CIMUS), Universidade de Santiago de Compostela, Avenida de Barcelona 22, 15782 Santiago de Compostela, Spain
| | - Marián Castro
- BioFarma Research Group, Centro Singular de Investigación en Medicina Molecular y Enfermedades Crónicas (CIMUS), Universidade de Santiago de Compostela, Avenida de Barcelona 22, 15782 Santiago de Compostela, Spain; Molecular Pharmacology of G Protein-coupled Receptors Laboratory, Centro Singular de Investigación en Medicina Molecular y Enfermedades Crónicas (CIMUS), Universidade de Santiago de Compostela, Avenida de Barcelona 22, 15782 Santiago de Compostela, Spain
| | - Jana Selent
- GPCR Drug Discovery Group, Research Programme on Biomedical Informatics (GRIB), Hospital del Mar Medical Research Institute (IMIM) - Department of Experimental and Health Sciences of Pompeu Fabra University (UPF), Barcelona, Spain
| | - María Isabel Loza
- BioFarma Research Group, Centro Singular de Investigación en Medicina Molecular y Enfermedades Crónicas (CIMUS), Universidade de Santiago de Compostela, Avenida de Barcelona 22, 15782 Santiago de Compostela, Spain.
| | - José Brea
- BioFarma Research Group, Centro Singular de Investigación en Medicina Molecular y Enfermedades Crónicas (CIMUS), Universidade de Santiago de Compostela, Avenida de Barcelona 22, 15782 Santiago de Compostela, Spain.
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11
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Altwaijry NA, Baron M, Wright DW, Coveney PV, Townsend-Nicholson A. An Ensemble-Based Protocol for the Computational Prediction of Helix-Helix Interactions in G Protein-Coupled Receptors using Coarse-Grained Molecular Dynamics. J Chem Theory Comput 2017; 13:2254-2270. [PMID: 28383913 PMCID: PMC5557214 DOI: 10.1021/acs.jctc.6b01246] [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] [Indexed: 01/11/2023]
Abstract
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The
accurate identification of the specific points of interaction
between G protein-coupled receptor (GPCR) oligomers is essential for
the design of receptor ligands targeting oligomeric receptor targets.
A coarse-grained molecular dynamics computer simulation approach would
provide a compelling means of identifying these specific protein–protein
interactions and could be applied both for known oligomers of interest
and as a high-throughput screen to identify novel oligomeric targets.
However, to be effective, this in silico modeling must provide accurate,
precise, and reproducible information. This has been achieved recently
in numerous biological systems using an ensemble-based all-atom molecular
dynamics approach. In this study, we describe an equivalent methodology
for ensemble-based coarse-grained simulations. We report the performance
of this method when applied to four different GPCRs known to oligomerize
using error analysis to determine the ensemble size and individual
replica simulation time required. Our measurements of distance between
residues shown to be involved in oligomerization of the fifth transmembrane
domain from the adenosine A2A receptor are in very good
agreement with the existing biophysical data and provide information
about the nature of the contact interface that cannot be determined
experimentally. Calculations of distance between rhodopsin, CXCR4,
and β1AR transmembrane domains reported to form contact
points in homodimers correlate well with the corresponding measurements
obtained from experimental structural data, providing an ability to predict
contact interfaces computationally. Interestingly, error analysis
enables identification of noninteracting regions. Our results confirm
that GPCR interactions can be reliably predicted using this novel
methodology.
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Affiliation(s)
- Nojood A Altwaijry
- Institute of Structural and Molecular Biology, Research Department of Structural and Molecular Biology, Division of Biosciences, University College London , London, WC1E 6BT, United Kingdom.,King Saud University , Riyadh, Kingdom of Saudi Arabia
| | - Michael Baron
- Institute of Structural and Molecular Biology, Research Department of Structural and Molecular Biology, Division of Biosciences, University College London , London, WC1E 6BT, United Kingdom
| | - David W Wright
- Centre for Computational Science, Department of Chemistry, University College London , London WC1H 0AJ, United Kingdom
| | - Peter V Coveney
- Centre for Computational Science, Department of Chemistry, University College London , London WC1H 0AJ, United Kingdom
| | - Andrea Townsend-Nicholson
- Institute of Structural and Molecular Biology, Research Department of Structural and Molecular Biology, Division of Biosciences, University College London , London, WC1E 6BT, United Kingdom
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12
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Methods used to study the oligomeric structure of G-protein-coupled receptors. Biosci Rep 2017; 37:BSR20160547. [PMID: 28062602 PMCID: PMC5398257 DOI: 10.1042/bsr20160547] [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: 11/28/2016] [Revised: 01/05/2017] [Accepted: 01/06/2017] [Indexed: 02/02/2023] Open
Abstract
G-protein-coupled receptors (GPCRs), which constitute the largest family of cell surface receptors, were originally thought to function as monomers, but are now recognized as being able to act in a wide range of oligomeric states and indeed, it is known that the oligomerization state of a GPCR can modulate its pharmacology and function. A number of experimental techniques have been devised to study GPCR oligomerization including those based upon traditional biochemistry such as blue-native PAGE (BN-PAGE), co-immunoprecipitation (Co-IP) and protein-fragment complementation assays (PCAs), those based upon resonance energy transfer, FRET, time-resolved FRET (TR-FRET), FRET spectrometry and bioluminescence resonance energy transfer (BRET). Those based upon microscopy such as FRAP, total internal reflection fluorescence microscopy (TIRFM), spatial intensity distribution analysis (SpIDA) and various single molecule imaging techniques. Finally with the solution of a growing number of crystal structures, X-ray crystallography must be acknowledged as an important source of discovery in this field. A different, but in many ways complementary approach to the use of more traditional experimental techniques, are those involving computational methods that possess obvious merit in the study of the dynamics of oligomer formation and function. Here, we summarize the latest developments that have been made in the methods used to study GPCR oligomerization and give an overview of their application.
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13
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Bram Z, Louiset E, Ragazzon B, Renouf S, Wils J, Duparc C, Boutelet I, Rizk-Rabin M, Libé R, Young J, Carson D, Vantyghem MC, Szarek E, Martinez A, Stratakis CA, Bertherat J, Lefebvre H. PKA regulatory subunit 1A inactivating mutation induces serotonin signaling in primary pigmented nodular adrenal disease. JCI Insight 2016; 1:e87958. [PMID: 27699247 DOI: 10.1172/jci.insight.87958] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Primary pigmented nodular adrenocortical disease (PPNAD) is a rare cause of ACTH-independent hypercortisolism. The disease is primarily caused by germline mutations of the protein kinase A (PKA) regulatory subunit 1A (PRKAR1A) gene, which induces constitutive activation of PKA in adrenocortical cells. Hypercortisolism is thought to result from PKA hyperactivity, but PPNAD tissues exhibit features of neuroendocrine differentiation, which may lead to stimulation of steroidogenesis by abnormally expressed neurotransmitters. We hypothesized that serotonin (5-HT) may participate in the pathophysiology of PPNAD-associated hypercortisolism. We show that PPNAD tissues overexpress the 5-HT synthesizing enzyme tryptophan hydroxylase type 2 (Tph2) and the serotonin receptors types 4, 6, and 7, leading to formation of an illicit stimulatory serotonergic loop whose pharmacological inhibition in vitro decreases cortisol production. In the human PPNAD cell line CAR47, the PKA inhibitor H-89 decreases 5-HT4 and 5-HT7 receptor expression. Moreover, in the human adrenocortical cell line H295R, inhibition of PRKAR1A expression increases the expression of Tph2 and 5-HT4/6/7 receptors, an effect that is blocked by H-89. These findings show that the serotonergic process observed in PPNAD tissues results from PKA activation by PRKAR1A mutations. They also suggest that Tph inhibitors may represent efficient treatments of hypercortisolism in patients with PPNAD.
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Affiliation(s)
- Zakariae Bram
- Normandie University, UNIROUEN, INSERM, U982, Laboratoire Differenciation et Communication Neuronale et Neuroendocrine, 76000 Rouen, France
| | - Estelle Louiset
- Normandie University, UNIROUEN, INSERM, U982, Laboratoire Differenciation et Communication Neuronale et Neuroendocrine, 76000 Rouen, France
| | - Bruno Ragazzon
- INSERM, U1016, University Paris V, Cochin Institute, Paris, France
| | - Sylvie Renouf
- Normandie University, UNIROUEN, INSERM, U982, Laboratoire Differenciation et Communication Neuronale et Neuroendocrine, 76000 Rouen, France
| | - Julien Wils
- Normandie University, UNIROUEN, INSERM, U982, Laboratoire Differenciation et Communication Neuronale et Neuroendocrine, 76000 Rouen, France
| | - Céline Duparc
- Normandie University, UNIROUEN, INSERM, U982, Laboratoire Differenciation et Communication Neuronale et Neuroendocrine, 76000 Rouen, France
| | - Isabelle Boutelet
- Normandie University, UNIROUEN, INSERM, U982, Laboratoire Differenciation et Communication Neuronale et Neuroendocrine, 76000 Rouen, France
| | | | - Rossella Libé
- INSERM, U1016, University Paris V, Cochin Institute, Paris, France
| | - Jacques Young
- University Paris Sud, INSERM Unité 693, Le Kremlin-Bicêtre, France
| | - Dennis Carson
- Department of Paediatric Endocrinology, Royal Belfast Hospital for Sick Children, Belfast, United Kingdom
| | - Marie-Christine Vantyghem
- CHU Lille, Endocrinology Diabetology and Metabolism, Lille, France.,Univ. Lille, Inserm U1190 - EGID, Lille, France
| | - Eva Szarek
- Section of Endocrinology and Genetics, PDEGEN, NICHD, Bethesda, Maryland, USA
| | - Antoine Martinez
- CNRS UMR6247, INSERM U931, Gred, Clermont Université, Aubière, France
| | | | - Jérôme Bertherat
- INSERM, U1016, University Paris V, Cochin Institute, Paris, France
| | - Hervé Lefebvre
- Normandie University, UNIROUEN, INSERM, U982, Laboratoire Differenciation et Communication Neuronale et Neuroendocrine, 76000 Rouen, France.,Department of Endocrinology, CHU Rouen, Rouen, France
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14
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Fischer J, Kleinau G, Müller A, Kühnen P, Zwanziger D, Kinne A, Rehders M, Moeller LC, Führer D, Grüters A, Krude H, Brix K, Biebermann H. Modulation of monocarboxylate transporter 8 oligomerization by specific pathogenic mutations. J Mol Endocrinol 2015; 54:39-50. [PMID: 25527620 DOI: 10.1530/jme-14-0272] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The monocarboxylate transporter 8 (MCT8) is a member of the major facilitator superfamily (MFS). These membrane-spanning proteins facilitate translocation of a variety of substrates, MCT8 specifically transports iodothyronines. Mutations in MCT8 are the underlying cause of severe X-linked psychomotor retardation. At the molecular level, such mutations led to deficiencies in substrate translocation due to reduced cell-surface expression, impaired substrate binding, or decreased substrate translocation capabilities. However, the causal relationships between genotypes, molecular features of mutated MCT8, and patient characteristics have not yet been comprehensively deciphered. We investigated the relationship between pathogenic mutants of MCT8 and their capacity to form dimers (presumably oligomeric structures) as a potential regulatory parameter of the transport function of MCT8. Fourteen pathogenic variants of MCT8 were investigated in vitro with respect to their capacity to form oligomers. Particular mutations close to the substrate translocation channel (S194F, A224T, L434W, and R445C) were found to inhibit dimerization of MCT8. This finding is in contrast to those for other transporters or transmembrane proteins, in which substitutions predominantly at the outer-surface inhibit oligomerization. Moreover, specific mutations of MCT8 located in transmembrane helix 2 (del230F, V235M, and ins236V) increased the capacity of MCT8 variants to dimerize. We analyzed the localization of MCT8 dimers in a cellular context, demonstrating differences in MCT8 dimer formation and distribution. In summary, our results add a new link between the functions (substrate transport) and protein organization (dimerization) of MCT8, and might be of relevance for other members of the MFS. Finally, the findings are discussed in relationship to functional data combined with structural-mechanistical insights into MCT8.
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Affiliation(s)
- Jana Fischer
- Institut für Experimentelle Pädiatrische EndokrinologieCharité-Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, GermanyLeibniz-Institut für Molekulare PharmakologieBerlin, GermanyUniversitätsklinikum EssenKlinik für Endokrinologie und Stoffwechselerkrankungen, Essen, GermanyJacobs University BremenBremen, Germany
| | - Gunnar Kleinau
- Institut für Experimentelle Pädiatrische EndokrinologieCharité-Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, GermanyLeibniz-Institut für Molekulare PharmakologieBerlin, GermanyUniversitätsklinikum EssenKlinik für Endokrinologie und Stoffwechselerkrankungen, Essen, GermanyJacobs University BremenBremen, Germany
| | - Anne Müller
- Institut für Experimentelle Pädiatrische EndokrinologieCharité-Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, GermanyLeibniz-Institut für Molekulare PharmakologieBerlin, GermanyUniversitätsklinikum EssenKlinik für Endokrinologie und Stoffwechselerkrankungen, Essen, GermanyJacobs University BremenBremen, Germany
| | - Peter Kühnen
- Institut für Experimentelle Pädiatrische EndokrinologieCharité-Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, GermanyLeibniz-Institut für Molekulare PharmakologieBerlin, GermanyUniversitätsklinikum EssenKlinik für Endokrinologie und Stoffwechselerkrankungen, Essen, GermanyJacobs University BremenBremen, Germany
| | - Denise Zwanziger
- Institut für Experimentelle Pädiatrische EndokrinologieCharité-Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, GermanyLeibniz-Institut für Molekulare PharmakologieBerlin, GermanyUniversitätsklinikum EssenKlinik für Endokrinologie und Stoffwechselerkrankungen, Essen, GermanyJacobs University BremenBremen, Germany
| | - Anita Kinne
- Institut für Experimentelle Pädiatrische EndokrinologieCharité-Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, GermanyLeibniz-Institut für Molekulare PharmakologieBerlin, GermanyUniversitätsklinikum EssenKlinik für Endokrinologie und Stoffwechselerkrankungen, Essen, GermanyJacobs University BremenBremen, Germany
| | - Maren Rehders
- Institut für Experimentelle Pädiatrische EndokrinologieCharité-Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, GermanyLeibniz-Institut für Molekulare PharmakologieBerlin, GermanyUniversitätsklinikum EssenKlinik für Endokrinologie und Stoffwechselerkrankungen, Essen, GermanyJacobs University BremenBremen, Germany
| | - Lars C Moeller
- Institut für Experimentelle Pädiatrische EndokrinologieCharité-Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, GermanyLeibniz-Institut für Molekulare PharmakologieBerlin, GermanyUniversitätsklinikum EssenKlinik für Endokrinologie und Stoffwechselerkrankungen, Essen, GermanyJacobs University BremenBremen, Germany
| | - Dagmar Führer
- Institut für Experimentelle Pädiatrische EndokrinologieCharité-Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, GermanyLeibniz-Institut für Molekulare PharmakologieBerlin, GermanyUniversitätsklinikum EssenKlinik für Endokrinologie und Stoffwechselerkrankungen, Essen, GermanyJacobs University BremenBremen, Germany
| | - Annette Grüters
- Institut für Experimentelle Pädiatrische EndokrinologieCharité-Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, GermanyLeibniz-Institut für Molekulare PharmakologieBerlin, GermanyUniversitätsklinikum EssenKlinik für Endokrinologie und Stoffwechselerkrankungen, Essen, GermanyJacobs University BremenBremen, Germany
| | - Heiko Krude
- Institut für Experimentelle Pädiatrische EndokrinologieCharité-Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, GermanyLeibniz-Institut für Molekulare PharmakologieBerlin, GermanyUniversitätsklinikum EssenKlinik für Endokrinologie und Stoffwechselerkrankungen, Essen, GermanyJacobs University BremenBremen, Germany
| | - Klaudia Brix
- Institut für Experimentelle Pädiatrische EndokrinologieCharité-Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, GermanyLeibniz-Institut für Molekulare PharmakologieBerlin, GermanyUniversitätsklinikum EssenKlinik für Endokrinologie und Stoffwechselerkrankungen, Essen, GermanyJacobs University BremenBremen, Germany
| | - Heike Biebermann
- Institut für Experimentelle Pädiatrische EndokrinologieCharité-Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, GermanyLeibniz-Institut für Molekulare PharmakologieBerlin, GermanyUniversitätsklinikum EssenKlinik für Endokrinologie und Stoffwechselerkrankungen, Essen, GermanyJacobs University BremenBremen, Germany
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15
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Functional significance of serotonin receptor dimerization. Exp Brain Res 2013; 230:375-86. [PMID: 23811735 DOI: 10.1007/s00221-013-3622-1] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2013] [Accepted: 06/10/2013] [Indexed: 01/01/2023]
Abstract
The original model of G-protein activation by a single G-protein-coupled receptor (GPCR) is giving way to a new model, wherein two protomers of a GPCR dimer interact with a single G-protein. This article will review the evidence suggesting that 5-HT receptors form dimers/oligomers and will compare the findings with the results obtained from the studies with other biogenic amine receptors. Topics to be covered include the origin or biogenesis of dimer formation, potential dimer interface(s), and oligomer size (dimer vs. tetramer or higher order). The functional significance will be discussed in terms of G-protein activation following ligand binding to one or two protomers in a dimeric structure, the formation of heterodimers, and the development of bivalent ligands.
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16
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Piechowski CL, Rediger A, Lagemann C, Mühlhaus J, Müller A, Pratzka J, Tarnow P, Grüters A, Krude H, Kleinau G, Biebermann H. Inhibition of melanocortin-4 receptor dimerization by substitutions in intracellular loop 2. J Mol Endocrinol 2013; 51:109-18. [PMID: 23674133 DOI: 10.1530/jme-13-0061] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Obesity is one of the most challenging global health problems. One key player in energy homeostasis is the melanocortin-4 receptor (MC4R), which is a family A G-protein-coupled receptor (GPCR). It has recently been shown that MC4R has the capacity to form homo- or heterodimers. Dimerization of GPCRs is of great importance for signaling regulation, with major pharmacological implications. Unfortunately, not enough is yet known about the detailed structural properties of MC4R dimers or the functional consequences of receptor dimerization. Our goal, therefore, was to explore specific properties related to MC4R dimerization. First, we aimed to induce the dissociation of dimers to monomers and to compare the functional parameters of wild-type and MC4R variants. To inhibit homodimerization, we designed MC4R chimeras with the cannabinoid-1 receptor, a receptor that does not interact with MC4R. Indeed, we identified several substitutions in the intracellular loop 2 (ICL2) and adjacent regions of transmembrane helix 3 (TMH3) and TMH4 that lead to partial dimer dissociation. Interestingly, the capacity for signaling activity was generally increased in these MC4R variants, although receptor expression remained unchanged. This increase in activity for dissociated receptors might indicate a link between receptor dimerization and signaling capacity. Moreover, dimer dissociation was also observed in a naturally occurring activating MC4R mutation in ICL2. Taken together, this study provides new information on the structural prerequisites for MC4R dimerization and identifies an approach to induce the dissociation of MC4R dimers. This might be useful for further investigation of pharmacological properties.
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Affiliation(s)
- Carolin L Piechowski
- Institute of Experimental Pediatric Endocrinology, Charité-Universitätsmedizin Berlin, Humboldt-Universität zu Berlin, Augustenburger Platz 1, 13353 Berlin, Germany
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17
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18
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Jansen S, Perrakis A, Ulens C, Winkler C, Andries M, Joosten RP, Van Acker M, Luyten FP, Moolenaar WH, Bollen M. Structure of NPP1, an ectonucleotide pyrophosphatase/phosphodiesterase involved in tissue calcification. Structure 2012; 20:1948-59. [PMID: 23041369 DOI: 10.1016/j.str.2012.09.001] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2012] [Revised: 08/25/2012] [Accepted: 09/02/2012] [Indexed: 10/27/2022]
Abstract
Ectonucleotide pyrophosphatase/phosphodiesterase-1 (NPP1) converts extracellular nucleotides into inorganic pyrophosphate, whereas its close relative NPP2/autotaxin hydrolyzes lysophospholipids. NPP1 regulates calcification in mineralization-competent tissues, and a lack of NPP1 function underlies calcification disorders. Here, we show that NPP1 forms homodimers via intramembrane disulfide bonding, but is also processed intracellularly to a secreted monomer. The structure of secreted NPP1 reveals a characteristic bimetallic active site and a nucleotide-binding groove, but it lacks the lipid-binding pocket and open tunnel present in NPP2. A loop adjacent to the nucleotide-binding site, which is disordered in NPP2, is well ordered in NPP1 and might promote nucleotide binding. Remarkably, the N-terminal somatomedin B-like domains of NPP1, unlike those in NPP2, are flexible and do not contact the catalytic domain. Our results provide a structural basis for the nucleotide pyrophosphatase activity of NPP1 and help to understand how disease-causing mutations may affect NPP1 structure and function.
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Affiliation(s)
- Silvia Jansen
- Laboratory of Biosignaling and Therapeutics, Department of Cellular and Molecular Medicine, University of Leuven, 3000 Leuven, Belgium
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19
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Chen A, Kelley LD, Janušonis S. Effects of prenatal stress and monoaminergic perturbations on the expression of serotonin 5-HT4 and adrenergic β2 receptors in the embryonic mouse telencephalon. Brain Res 2012; 1459:27-34. [DOI: 10.1016/j.brainres.2012.04.019] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2011] [Revised: 03/21/2012] [Accepted: 04/11/2012] [Indexed: 12/13/2022]
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20
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Huot P, Fox SH, Brotchie JM. The serotonergic system in Parkinson's disease. Prog Neurobiol 2011; 95:163-212. [PMID: 21878363 DOI: 10.1016/j.pneurobio.2011.08.004] [Citation(s) in RCA: 135] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2011] [Revised: 08/05/2011] [Accepted: 08/15/2011] [Indexed: 01/23/2023]
Abstract
Although the cardinal manifestations of Parkinson's disease (PD) are attributed to a decline in dopamine levels in the striatum, a breadth of non-motor features and treatment-related complications in which the serotonergic system plays a pivotal role are increasingly recognised. Serotonin (5-HT)-mediated neurotransmission is altered in PD and the roles of the different 5-HT receptor subtypes in disease manifestations have been investigated. The aims of this article are to summarise and discuss all published preclinical and clinical studies that have investigated the serotonergic system in PD and related animal models, in order to recapitulate the state of the current knowledge and to identify areas that need further research and understanding.
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Affiliation(s)
- Philippe Huot
- Toronto Western Research Institute, MCL 11-419, Toronto Western Hospital, University Health Network, 399 Bathurst Street, Toronto, Ontario, Canada M5T 2S8
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21
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Janušonis S. Relationships among variables and their equilibrium values: caveats of time-less interpretation. Biol Rev Camb Philos Soc 2011; 87:275-89. [DOI: 10.1111/j.1469-185x.2011.00194.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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22
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Schiedel AC, Hinz S, Thimm D, Sherbiny F, Borrmann T, Maass A, Müller CE. The four cysteine residues in the second extracellular loop of the human adenosine A2B receptor: role in ligand binding and receptor function. Biochem Pharmacol 2011; 82:389-99. [PMID: 21620804 DOI: 10.1016/j.bcp.2011.05.008] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2011] [Revised: 05/09/2011] [Accepted: 05/11/2011] [Indexed: 11/17/2022]
Abstract
The adenosine A(2B) receptor is of considerable interest as a new drug target for the treatment of asthma, inflammatory diseases, pain, and cancer. In the present study we investigated the role of the cysteine residues in the extracellular loop 2 (ECL2) of the receptor, which is particularly cysteine-rich, by a combination of mutagenesis, molecular modeling, chemical and pharmacological experiments. Pretreatment of CHO cells recombinantly expressing the human A(2B) receptor with dithiothreitol led to a 74-fold increase in the EC(50) value of the agonist NECA in cyclic AMP accumulation. In the C78(3.25)S and the C171(45.50)S mutant high-affinity binding of the A(2B) antagonist radioligand [(3)H]PSB-603 was abolished and agonists were virtually inactive in cAMP assays. This indicates that the C3.25-C45.50 disulfide bond, which is highly conserved in GPCRs, is also important for binding and function of A(2B) receptors. In contrast, the C166(45.45)S and the C167(45.46)S mutant as well as the C166(45.45)S-C167(45.46)S double mutant behaved like the wild-type receptor, while in the C154(45.33)S mutant significant, although more subtle effects on cAMP accumulation were observed - decrease (BAY60-6583) or increase (NECA) - depending on the structure of the investigated agonist. In contrast to the X-ray structure of the closely related A(2A) receptor, which showed four disulfide bonds, the present data indicate that in the A(2B) receptor only the C3.25-C45.50 disulfide bond is essential for ligand binding and receptor activation. Thus, the cysteine residues in the ECL2 of the A(2B) receptor not involved in stabilization of the receptor structure may have other functions.
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Affiliation(s)
- Anke C Schiedel
- PharmaCenter Bonn, Pharmaceutical Institute, Pharmaceutical Chemistry I, University of Bonn, An der Immenburg 4, D-53121 Bonn, Germany.
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23
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Johnston JM, Aburi M, Provasi D, Bortolato A, Urizar E, Lambert NA, Javitch JA, Filizola M. Making structural sense of dimerization interfaces of delta opioid receptor homodimers. Biochemistry 2011; 50:1682-90. [PMID: 21261298 PMCID: PMC3050604 DOI: 10.1021/bi101474v] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
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Opioid receptors, like other members of the G protein-coupled receptor (GPCR) family, have been shown to associate to form dimers and/or oligomers at the plasma membrane. Whether this association is stable or transient is not known. Recent compelling evidence suggests that at least some GPCRs rapidly associate and dissociate. We have recently calculated binding affinities from free energy estimates to predict transient association between mouse delta opioid receptor (DOR) protomers at a symmetric interface involving the fourth transmembrane (TM4) helix (herein termed “4” dimer). Here we present disulfide cross-linking experiments with DOR constructs with cysteines substituted at the extracellular ends of TM4 or TM5 that confirm the formation of DOR complexes involving these helices. Our results are consistent with the involvement of TM4 and/or TM5 at the DOR homodimer interface, but possibly with differing association propensities. Coarse-grained (CG) well-tempered metadynamics simulations of two different dimeric arrangements of DOR involving TM4 alone or with TM5 (herein termed “4/5” dimer) in an explicit lipid−water environment confirmed the presence of two structurally and energetically similar configurations of the 4 dimer, as previously assessed by umbrella sampling calculations, and revealed a single energetic minimum of the 4/5 dimer. Additional CG umbrella sampling simulations of the 4/5 dimer indicated that the strength of association between DOR protomers varies depending on the protein region at the interface, with the 4 dimer being more stable than the 4/5 dimer.
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Affiliation(s)
- Jennifer M Johnston
- Department of Structural and Chemical Biology, Mount Sinai School of Medicine, New York, New York 10029, United States
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Ciruela F, Vallano A, Arnau JM, Sánchez S, Borroto-Escuela DO, Agnati LF, Fuxe K, Fernández-Dueñas V. G protein-coupled receptor oligomerization for what? J Recept Signal Transduct Res 2011; 30:322-30. [PMID: 20718634 DOI: 10.3109/10799893.2010.508166] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Although the G protein-coupled receptor (GPCR) oligomerization has been questioned during the last decade, under some premises the existence of a supramolecular organization of these receptors begins now to be widely accepted by the scientific community. Indeed, GPCR oligomers may enhance the diversity and performance by which extracellular signals are transferred to the G proteins in the process of receptor transduction, although the mechanism that underlie this phenomenon remains still unexplained. Recently, a trans-conformational switching model has been proposed as a mechanism allowing direct inhibition of receptor activation. Thus, heterotropic receptor-receptor allosteric regulations are behind the GPCR oligomeric function. Accordingly, we revise here how GPCR oligomerization impinge in several important receptor functions like biosynthesis, plasma membrane diffusion or velocity, pharmacology and signaling. Overall, the rationale of receptor oligomerization might lie in the cellular need of sensing complex extracellular signals and to translate into a simple computational mode.
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Affiliation(s)
- Francisco Ciruela
- Unitat de Farmacologia, Departament de Patologia i Terapèutica Experimental, Facultat de Medicina, IDIBELL-Universitat de Barcelona, 08907 Barcelona, Spain.
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Provasi D, Johnston JM, Filizola M. Lessons from free energy simulations of delta-opioid receptor homodimers involving the fourth transmembrane helix. Biochemistry 2010; 49:6771-6. [PMID: 20617813 PMCID: PMC2914489 DOI: 10.1021/bi100686t] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Several G protein-coupled receptors (GPCRs), including opioid receptors deltaOR, muOR, and kappaOR, have been reported to form stable dimers or oligomers in lipid bilayers and cell membranes. This notion has been recently challenged by imaging data supporting a transient nature of GPCR association. Here we use umbrella sampling reconstructed free energies of deltaOR homodimers involving the fourth transmembrane helix to predict their association constant. The results of these simulations, combined with estimates of diffusion-limited association rates, suggest a short lifetime for deltaOR homodimers in the membrane, in agreement with recent trends.
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Affiliation(s)
- Davide Provasi
- Department of Structural and Chemical Biology, Mount Sinai School of Medicine, New York, New York 10029, USA
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Kosel D, Heiker JT, Juhl C, Wottawah CM, Blüher M, Mörl K, Beck-Sickinger AG. Dimerization of adiponectin receptor 1 is inhibited by adiponectin. J Cell Sci 2010; 123:1320-8. [PMID: 20332107 DOI: 10.1242/jcs.057919] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
AdipoR1 and AdipoR2 are newly discovered members of the huge family of seven-transmembrane receptors, but both receptors are structurally and functionally different from G-protein-coupled receptors. Little is known about the oligomerization of the AdipoRs. Here, we show the presence of endogenous AdipoR1 dimers in various cell lines and human muscle tissue. To directly follow and localize the dimerization, we applied bimolecular fluorescence complementation (BiFC) in combination with flow cytometry. We visualized and quantified AdipoR1 homodimers in HEK293 cells. Moreover, we identified a GxxxG dimerization motif in the fifth transmembrane domain of the AdipoR1. By mutating both glycine residues to phenylalanine or glutamic acid, we were able to modulate the dimerization of AdipoR1, implicating a role for the GxxxG motif in AdipoR1 dimerization. Furthermore, we tested whether the AdipoR1 ligand adiponectin had any influence on receptor dimerization. Interestingly, we found that adiponectin decreases the receptor dimerization in a concentration-dependent manner. This effect is mainly mediated by segments of the collagen-like domain of full-length adiponectin. Accordingly, this is the first direct read-out signal of adiponectin at the AdipoR1 receptor, which revealed the involvement of specific amino acids of both the receptor and the ligand to modulate the quaternary structure of the AdipoR1.
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Affiliation(s)
- David Kosel
- Faculty of Biosciences, Institute of Biochemistry, Leipzig University, Brüderstr 34, 04103 Leipzig, Germany
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Bruno A, Guadix AE, Costantino G. Molecular dynamics simulation of the heterodimeric mGluR2/5HT(2A) complex. An atomistic resolution study of a potential new target in psychiatric conditions. J Chem Inf Model 2009; 49:1602-16. [PMID: 19422244 DOI: 10.1021/ci900067g] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Homo- and heterodimerization is becoming an assessed concept in G-protein coupled receptor (GPCR) pharmacology, and the notion that GPCRs may dimerize or oligomerize is allowing for a reinterpretation of some inconsistencies or anomalies and is providing medicinal chemists with potentially relevant novel molecular targets for a variety of therapeutic conditions. Recently, it has been reported that two unrelated GPCRs, namely class C metabotropic glutamate receptor type-2 (mGluR2) and class A 5HT(2A) serotoninergic receptor, can heterodimerize at the transmembrane domain level. We performed a 40 ns molecular dynamics simulation of the mGluR2/5HT(2A) heterocomplex constructed around a TM4/TM5 interface and embedded in an explicit phospholipidic bilayer surrounded by water molecules. In a separate experiment, the monomeric 5HT(2A) receptor was simulated for additional 40 ns under the same conditions. The analysis and the comparison of the two simulations allowed us to clearly identify a cross-talk between the two protomers and to put forward an effect of the heterodimerization on the shape of the binding pocket of 5HT(2A). This result provides the first molecular explanation for the reported allosteric effect of mGluR2 on 5HT(2A)-mediated response and suggests that the heterocomplex can be a more suitable target for in silico screening than the monomeric protomers.
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Affiliation(s)
- Agostino Bruno
- Dipartimento Farmaceutico, Via G. P. Usberti 27/A- Campus Universitario, Universita degli Studi di Parma, 43124 Parma, Italy
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Parker MS, Sah R, Balasubramaniam A, Sallee FR, Sweatman T, Park EA, Parker SL. Dimers of the neuropeptide Y (NPY) Y2 receptor show asymmetry in agonist affinity and association with G proteins. J Recept Signal Transduct Res 2009; 28:437-51. [PMID: 18946765 DOI: 10.1080/10799890802447423] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
In conditions precluding activation of G proteins, the binding of agonists to dimers of the neuropeptide Y (NPY) Y2 receptor shows two components of similar size, but differing in affinity. The dimers of all NPY receptors are solubilized as approximately 180-kDa complexes containing one G protein alpha beta gamma trimer. These heteropentamers are stable to excess agonists, chelators, and alkylators. However, dispersion in the weak surfactant cholate releases approximately 300-kDa complexes. These findings indicate that both protomers in the Y2 dimer are associated with G protein heterotrimers, but the extent of interaction depends on affinity for the agonist peptide. The G protein in contact with the first-liganded, higher-affinity protomer should have a stronger interaction with the receptor and a larger probability of activation.
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Affiliation(s)
- M S Parker
- Department of Molecular Cell Sciences, University of Memphis, Memphis, Tennessee, USA.
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Increasingly accurate dynamic molecular models of G-protein coupled receptor oligomers: Panacea or Pandora's box for novel drug discovery? Life Sci 2009; 86:590-7. [PMID: 19465029 DOI: 10.1016/j.lfs.2009.05.004] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2008] [Revised: 05/07/2009] [Accepted: 05/14/2009] [Indexed: 01/06/2023]
Abstract
For years, conventional drug design at G-protein coupled receptors (GPCRs) has mainly focused on the inhibition of a single receptor at a usually well-defined ligand-binding site. The recent discovery of more and more physiologically relevant GPCR dimers/oligomers suggests that selectively targeting these complexes or designing small molecules that inhibit receptor-receptor interactions might provide new opportunities for novel drug discovery. To uncover the fundamental mechanisms and dynamics governing GPCR dimerization/oligomerization, it is crucial to understand the dynamic process of receptor-receptor association, and to identify regions that are suitable for selective drug binding. This minireview highlights current progress in the development of increasingly accurate dynamic molecular models of GPCR oligomers based on structural, biochemical, and biophysical information that has recently appeared in the literature. In view of this new information, there has never been a more exciting time for computational research into GPCRs than at present. Information-driven modern molecular models of GPCR complexes are expected to efficiently guide the rational design of GPCR oligomer-specific drugs, possibly allowing researchers to reach for the high-hanging fruits in GPCR drug discovery, i.e. more potent and selective drugs for efficient therapeutic interventions.
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Liu X, Kai M, Jin L, Wang R. Computational study of the heterodimerization between mu and delta receptors. J Comput Aided Mol Des 2009; 23:321-32. [PMID: 19214754 DOI: 10.1007/s10822-009-9262-7] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2008] [Accepted: 01/18/2009] [Indexed: 11/27/2022]
Abstract
A growing body of evidence indicated that the G protein coupled receptors exist as homo- or hetero-dimers in the living cell. The heterodimerization between mu and delta opioid receptors has attracted researchers' particular interests, it is reported to display novel pharmacological and signalling regulation properties. In this study, we construct the full-length 3D-model of mu and delta opioid receptors using the homology modelling method. Threading program was used to predict the possible templates for the N- and C-terminus domains. Then, a 30 ns molecular dynamics simulations was performed with each receptor embedded in an explicit membrane-water environment to refine and explore the conformational space. Based on the structures extracted from the molecular dynamics, the likely interface of mu-delta heterodimer was investigated through the analysis of protein-protein docking, cluster, shape complementary and interaction energy. The computational modelling works revealed that the most likely interface of heterodimer was formed between the transmembrane1,7 (TM1,7) domains of mu receptor and the TM(4,5) domains of delta receptor, with emphasis on mu-TM1 and delta-TM4, the next likely interface was mu(TM6,7)-delta(TM4,5), with emphasis on mu-TM6 and delta-TM4. Our results were consistent with previous reports.
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Affiliation(s)
- Xin Liu
- Institute of Biochemistry and Molecular Biology, School of Basic Medical Science, State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou, China
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31
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Łukasiewicz S, Faron-Górecka A, Dobrucki J, Polit A, Dziedzicka-Wasylewska M. Studies on the role of the receptor protein motifs possibly involved in electrostatic interactions on the dopamine D1 and D2 receptor oligomerization. FEBS J 2009; 276:760-75. [PMID: 19143836 DOI: 10.1111/j.1742-4658.2008.06822.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We investigated the influence of an epitope from the third intracellular loop (ic3) of the dopamine D(2) receptor, which contains adjacent arginine residues (217RRRRKR222), and an acidic epitope from the C-terminus of the dopamine D(1) receptor (404EE405) on the receptors' localization and their interaction. We studied receptor dimer formation using fluorescence resonance energy transfer. Receptor proteins were tagged with fluorescence proteins and expressed in HEK293 cells. The degree of D(1)-D(2) receptor heterodimerization strongly depended on the number of Arg residues replaced by Ala in the ic3 of D(2)R, which may suggest that the indicated region of ic3 in D(2)R might be involved in interactions between two dopamine receptors. In addition, the subcellular localization of these receptors in cells expressing both receptors D(1)-cyan fluorescent protein, D(2)-yellow fluorescent protein, and various mutants was examined by confocal microscopy. Genetic manipulations of the Arg-rich epitope induced alterations in the localization of the resulting receptor proteins, leading to the conclusion that this epitope is responsible for the cellular localization of the receptor. The lack of energy transfer between the genetic variants of yellow fluorescent protein-tagged D(2)R and cyan fluorescent protein-tagged D(1)R may result from differing localization of these proteins in the cell rather than from the possible role of the D(2)R basic domain in the mechanism of D(1)-D(2) receptor heterodimerization. However, we find that the acidic epitope from the C-terminus of the dopamine D(1) receptor is engaged in the heterodimerization process.
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Affiliation(s)
- Sylwia Łukasiewicz
- Department of Physical Biochemistry, Jagiellonian University, Kraków, Poland
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32
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Affiliation(s)
- David E Nichols
- Department of Medicinal Chemistry and Molecular Pharmacology, School of Pharmacy and Pharmaceutical Sciences, Purdue University, West Lafayette, Indiana 47906-2091, USA.
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Milligan G. A day in the life of a G protein-coupled receptor: the contribution to function of G protein-coupled receptor dimerization. Br J Pharmacol 2008; 153 Suppl 1:S216-29. [PMID: 17965750 PMCID: PMC2268067 DOI: 10.1038/sj.bjp.0707490] [Citation(s) in RCA: 93] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2007] [Revised: 08/21/2007] [Accepted: 09/06/2007] [Indexed: 02/07/2023] Open
Abstract
G protein-coupled receptors are one of the most actively studied families of proteins. However, despite the ubiquity of protein dimerization and oligomerization as a structural and functional motif in biology, until the last decade they were generally considered as monomeric, non-interacting polypeptides. For the metabotropic glutamate-like group of G protein-coupled receptors, it is now firmly established that they exist and function as dimers or, potentially, even within higher-order structures. Despite some evidence continuing to support the view that rhodopsin-like G protein-coupled receptors are predominantly monomers, many recent studies are consistent with the dimerization/oligomerization of such receptors. Key roles suggested for dimerization of G protein-coupled receptors include control of protein maturation and cell surface delivery and providing the correct framework for interactions with both hetero-trimeric G proteins and arrestins to allow signal generation and its termination. As G protein-coupled receptors are the most targeted group of proteins for the development of therapeutic small molecule medicines, recent indications that hetero-dimerization between co-expressed G protein-coupled receptors may be a common process offers the potential for the development of more selective and tissue restricted medicines. However, many of the key experiments have, so far, been limited to model cell systems. Priorities for the future include the generation of tools and reagents able to identify unequivocally potential G protein-coupled receptor hetero-dimers in native tissues and detailed analyses of the influence of hetero-dimerization on receptor function and pharmacology.
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Affiliation(s)
- G Milligan
- Molecular Pharmacology Group, Division of Biochemistry and Molecular Biology, Institute of Biomedical and Life Sciences, University of Glasgow, Glasgow, Scotland, UK.
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Gurevich VV, Gurevich EV. GPCR monomers and oligomers: it takes all kinds. Trends Neurosci 2008; 31:74-81. [PMID: 18199492 DOI: 10.1016/j.tins.2007.11.007] [Citation(s) in RCA: 160] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2007] [Revised: 11/20/2007] [Accepted: 11/21/2007] [Indexed: 02/01/2023]
Abstract
Accumulating evidence of G-protein-coupled receptor (GPCR) oligomerization on the one hand and perfect functionality of monomeric receptors on the other creates an impression of controversy. However, the GPCR superfamily is extremely diverse, both structurally and functionally. The life cycle of each receptor includes many stages: synthesis, quality control in the endoplasmic reticulum, maturation in the Golgi, delivery to the plasma membrane (where it can be in the inactive or active state, in complex with cognate G protein, G-protein-coupled receptor kinase or arrestin), endocytosis and subsequent sorting in endosomes. Different GPCR subtypes, and even the same receptor at different stages of its life cycle, most likely exist in different oligomerization states, from monomers to dimers and possibly higher-order oligomers.
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Affiliation(s)
- Vsevolod V Gurevich
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN 37232, USA.
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Russo O, Berthouze M, Giner M, Soulier JL, Rivail L, Sicsic S, Lezoualc'h F, Jockers R, Berque-Bestel I. Synthesis of specific bivalent probes that functionally interact with 5-HT(4) receptor dimers. J Med Chem 2007; 50:4482-92. [PMID: 17676726 DOI: 10.1021/jm070552t] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
G-protein-coupled receptor dimerization directs the design of new drugs that specifically bind to receptor dimers. Here, we generated a targeted series of homobivalent ligands for serotonin 5-HT(4) receptor (5-HT(4)R) dimers composed of two 5-HT(4)R-specific ML10302 units linked by a spacer. The design of spacers was assisted by molecular modeling using our previously described 5-HT(4)R dimer model. Their syntheses were based on Sonogashira-Linstrumelle coupling methods. All compounds retained high-affinity binding to 5-HT(4)R but lost the agonistic character of the monomeric ML10302 compound. Direct evidence for the functional interaction of both pharmacophores of bivalent ligands with the 5-HT(4)R was obtained using a bioluminescence resonance energy transfer (BRET) based assay that monitors conformational changes within 5-HT(4) dimers. Whereas the monovalent ML10302 was inactive in this assay, several bivalent derivatives dose-dependently increased the BRET signal, indicating that both pharmacophores functionally interact with the 5-HT(4) dimer. These bivalent ligands may serve as a new basis for the synthesis of potential drugs for 5-HT(4)-associated disorders.
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Affiliation(s)
- Olivier Russo
- Université Paris-Sud, Faculté de Pharmacie, IFR141, UMR-S769, Châtenay-Malabry, F-92296, Inserm, U567, France
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