1
|
Charlick JN, Bozadzhieva D, Butler AS, Wilkinson KA, Marrion NV. A single coiled-coil domain mutation in hIKCa channel subunits disrupts preferential formation of heteromeric hSK1:hIKCa channels. Eur J Neurosci 2024; 59:3-16. [PMID: 38018635 PMCID: PMC10952195 DOI: 10.1111/ejn.16189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Revised: 09/22/2023] [Accepted: 10/25/2023] [Indexed: 11/30/2023]
Abstract
The expression of IKCa (SK4) channel subunits overlaps with that of SK channel subunits, and it has been proposed that the two related subunits prefer to co-assemble to form heteromeric hSK1:hIKCa channels. This implicates hSK1:hIKCa heteromers in physiological roles that might have been attributed to activation of SK channels. We have used a mutation approach to confirm formation of heterometric hSK1:hIKCa channels. Introduction of residues within hSK1 that were predicted to impart sensitivity to the hIKCa current blocker TRAM-34 changed the pharmacology of functional heteromers. Heteromeric channels formed between wildtype hIKCa and mutant hSK1 subunits displayed a significantly higher sensitivity and maximum block to addition of TRAM-34 than heteromers formed between wildtype subunits. Heteromer formation was disrupted by a single point mutation within one COOH-terminal coiled-coil domain of the hIKCa channel subunit. This mutation only disrupted the formation of hSK1:hIKCa heteromeric channels, without affecting the formation of homomeric hIKCa channels. Finally, the Ca2+ gating sensitivity of heteromeric hSK1:hIKCa channels was found to be significantly lower than the Ca2+ gating sensitivity of homomeric hIKCa channels. These data confirmed the preferred formation of heteromeric channels that results from COOH-terminal interactions between subunits. The distinct sensitivity of the heteromer to activation by Ca2+ suggests that heteromeric channels fulfil a distinct function within those neurons that express both subunits.
Collapse
Affiliation(s)
- James N. Charlick
- School of Physiology, Pharmacology and NeuroscienceUniversity of BristolBristolUK
| | - Daniella Bozadzhieva
- School of Physiology, Pharmacology and NeuroscienceUniversity of BristolBristolUK
| | - Andrew S. Butler
- School of Physiology, Pharmacology and NeuroscienceUniversity of BristolBristolUK
| | - Kevin A. Wilkinson
- School of Physiology, Pharmacology and NeuroscienceUniversity of BristolBristolUK
| | - Neil V. Marrion
- School of Physiology, Pharmacology and NeuroscienceUniversity of BristolBristolUK
| |
Collapse
|
2
|
Kaffashi K, Dréau D, Nesmelova IV. Heterodimers Are an Integral Component of Chemokine Signaling Repertoire. Int J Mol Sci 2023; 24:11639. [PMID: 37511398 PMCID: PMC10380872 DOI: 10.3390/ijms241411639] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Revised: 07/10/2023] [Accepted: 07/11/2023] [Indexed: 07/30/2023] Open
Abstract
Chemokines are a family of signaling proteins that play a crucial role in cell-cell communication, cell migration, and cell trafficking, particularly leukocytes, under both normal and pathological conditions. The oligomerization state of chemokines influences their biological activity. The heterooligomerization occurs when multiple chemokines spatially and temporally co-localize, and it can significantly affect cellular responses. Recently, obligate heterodimers have emerged as tools to investigate the activities and molecular mechanisms of chemokine heterodimers, providing valuable insights into their functional roles. This review focuses on the latest progress in understanding the roles of chemokine heterodimers and their contribution to the functioning of the chemokine network.
Collapse
Affiliation(s)
- Kimia Kaffashi
- Department of Biological Sciences, University of North Carolina, Charlotte, NC 28223, USA
- Department of Physics and Optical Sciences, University of North Carolina, Charlotte, NC 28223, USA
| | - Didier Dréau
- Department of Biological Sciences, University of North Carolina, Charlotte, NC 28223, USA
| | - Irina V Nesmelova
- Department of Physics and Optical Sciences, University of North Carolina, Charlotte, NC 28223, USA
- School of Data Science, University of North Carolina, Charlotte, NC 28223, USA
| |
Collapse
|
3
|
Lillo J, García-Pérez I, Lillo A, Serrano-Marín J, Martínez-Pinilla E, Navarro G, Franco R. The olfactory Olfr-78/51E2 receptor interacts with the adenosine A 2A receptor. Effect of menthol and 1,8-cineole on A 2A receptor-mediated signaling. Front Pharmacol 2023; 14:1108617. [PMID: 37266149 PMCID: PMC10229766 DOI: 10.3389/fphar.2023.1108617] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2022] [Accepted: 04/27/2023] [Indexed: 06/03/2023] Open
Abstract
Heteromer formation is unknown for the olfactory family of G protein-coupled receptors (GPCRs). We here identified, in a heterologous system, heteromers formed by the adenosine A2A receptor (A2AR), which is a target for neuroprotection, and an olfactory receptor. A2AR interacts with the receptor family 51, subfamily E, member 2 (OR51E2), the human ortholog of the mouse Olfr-78, whose mRNA is differentially expressed in activated microglia treated with adenosine receptor ligands. Bioluminescence resonance energy transfer (BRET) assays were performed in HEK-293T cells expressing the human version of the receptors, OR51E2 and A2AR, fused, respectively, to Renilla luciferase (RLuc) and the yellow fluorescent protein (YFP). BRET data was consistent with a receptor-receptor interaction whose consequences at the functional level were measured by cAMP level determination in CHO cells. Results showed an olfactory receptor-mediated partial blockade of Gs coupling to the A2AR, i.e., the effect of the A2AR selective agonist on intracellular levels of cAMP was significantly reduced. Two odorants, menthol and 1,8-cineole, which failed to show Golf-mediated OR51E2 activation because they did not increase cytosolic cAMP levels, reduced the BRET readings in cells expressing A2AR-YFP and OR51E2-Rluc, most likely suggesting a conformational change of at least one receptor. These odorants led to an almost complete block of A2AR coupling to Gs.
Collapse
Affiliation(s)
- Jaume Lillo
- Department of Biochemistry and Physiology, School of Pharmacy and Food Science, Universitat de Barcelona, Barcelona, Spain
- CiberNed, Network Center for Neurodegenerative Diseases, National Spanish Health Institute Carlos III, Madrid, Spain
| | - Irene García-Pérez
- Molecular Neurobiology Laboratory, Department of Biochemistry and Molecular Biomedicine, Faculty of Biology, Universitat de Barcelona, Barcelona, Spain
| | - Alejandro Lillo
- Department of Biochemistry and Physiology, School of Pharmacy and Food Science, Universitat de Barcelona, Barcelona, Spain
- CiberNed, Network Center for Neurodegenerative Diseases, National Spanish Health Institute Carlos III, Madrid, Spain
| | - Joan Serrano-Marín
- Molecular Neurobiology Laboratory, Department of Biochemistry and Molecular Biomedicine, Faculty of Biology, Universitat de Barcelona, Barcelona, Spain
| | - Eva Martínez-Pinilla
- Department of Morphology and Cell Biology, Faculty of Medicine, University of Oviedo, Asturias, Spain
- Instituto de Neurociencias del Principado de Asturias (INEUROPA), Asturias, Spain
- Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), Asturias, Spain
| | - Gemma Navarro
- Department of Biochemistry and Physiology, School of Pharmacy and Food Science, Universitat de Barcelona, Barcelona, Spain
- CiberNed, Network Center for Neurodegenerative Diseases, National Spanish Health Institute Carlos III, Madrid, Spain
- Institut de Neurociències, Universitat de Barcelona, Barcelona, Spain
| | - Rafael Franco
- CiberNed, Network Center for Neurodegenerative Diseases, National Spanish Health Institute Carlos III, Madrid, Spain
- Molecular Neurobiology Laboratory, Department of Biochemistry and Molecular Biomedicine, Faculty of Biology, Universitat de Barcelona, Barcelona, Spain
- School of Chemistry, Universitat de Barcelona, Barcelona, Spain
| |
Collapse
|
4
|
Walker AR, Larsen CB, Kundu S, Stavrinidis C, Kim SH, Inoue A, Woodward DF, Lee YS, Migale R, MacIntyre DA, Terzidou V, Fanelli F, Khanjani S, Bennett PR, Hanyaloglu AC. Functional rewiring of G protein-coupled receptor signaling in human labor. Cell Rep 2022; 40:111318. [PMID: 36070698 PMCID: PMC9638024 DOI: 10.1016/j.celrep.2022.111318] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 06/21/2022] [Accepted: 08/16/2022] [Indexed: 11/23/2022] Open
Abstract
Current strategies to manage preterm labor center around inhibition of uterine myometrial contractions, yet do not improve neonatal outcomes as they do not address activation of inflammation. Here, we identify that during human labor, activated oxytocin receptor (OTR) reprograms the prostaglandin E2 receptor, EP2, in the pregnant myometrium to suppress relaxatory/Gαs-cAMP signaling and promote pro-labor/inflammatory responses via altered coupling of EP2 from Gαq/11 to Gαi/o. The ability of EP2 to signal via Gαi/o is recapitulated with in vitro OT and only following OTR activation, suggesting direct EP2-OTR crosstalk. Super-resolution imaging with computational modeling reveals OT-dependent reorganization of EP2-OTR complexes to favor conformations for Gαi over Gαs activation. A selective EP2 ligand, PGN9856i, activates the relaxatory/Gαs-cAMP pathway but not the pro-labor/inflammatory responses in term-pregnant myometrium, even following OT. Our study reveals a mechanism, and provides a potential therapeutic solution, whereby EP2-OTR functional associations could be exploited to delay preterm labor. EP2 activity is reprogrammed toward pro-inflammatory pathways during human labor Oxytocin downregulates EP2-Gαs signaling and switches EP2-Gαq/11 signaling to Gαi/o EP2/OTR heterotetramers are reorganized by oxytocin to conformations favoring Gαi EP2 agonist PGN9856i does not activate pro-labor signals even after oxytocin treatment
Collapse
Affiliation(s)
- Abigail R Walker
- Institute of Reproductive and Developmental Biology, Department Metabolism, Digestion and Reproduction, Imperial College London, London, UK
| | - Camilla B Larsen
- Institute of Reproductive and Developmental Biology, Department Metabolism, Digestion and Reproduction, Imperial College London, London, UK
| | - Samit Kundu
- Institute of Reproductive and Developmental Biology, Department Metabolism, Digestion and Reproduction, Imperial College London, London, UK; March of Dimes European Preterm Birth Research Centre, Imperial College London, London, UK
| | - Christina Stavrinidis
- Institute of Reproductive and Developmental Biology, Department Metabolism, Digestion and Reproduction, Imperial College London, London, UK
| | - Sung Hye Kim
- Institute of Reproductive and Developmental Biology, Department Metabolism, Digestion and Reproduction, Imperial College London, London, UK; March of Dimes European Preterm Birth Research Centre, Imperial College London, London, UK
| | - Asuka Inoue
- Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan
| | - David F Woodward
- Department of Bioengineering, Imperial College London, London, UK
| | - Yun S Lee
- Institute of Reproductive and Developmental Biology, Department Metabolism, Digestion and Reproduction, Imperial College London, London, UK; March of Dimes European Preterm Birth Research Centre, Imperial College London, London, UK
| | - Roberta Migale
- Institute of Reproductive and Developmental Biology, Department Metabolism, Digestion and Reproduction, Imperial College London, London, UK; Stem Cell Biology and Developmental Genetics Laboratory, The Francis Crick Institute, London, UK
| | - David A MacIntyre
- Institute of Reproductive and Developmental Biology, Department Metabolism, Digestion and Reproduction, Imperial College London, London, UK; March of Dimes European Preterm Birth Research Centre, Imperial College London, London, UK
| | - Vasso Terzidou
- Institute of Reproductive and Developmental Biology, Department Metabolism, Digestion and Reproduction, Imperial College London, London, UK; March of Dimes European Preterm Birth Research Centre, Imperial College London, London, UK
| | - Francesca Fanelli
- Department Life Sciences, University of Modena and Reggio Emilia, via Campi 103, 41125 Modena, Italy; Center for Neuroscience and Neurotechnology, University of Modena and Reggio Emilia, via Campi 287, 41125 Modena, Italy
| | - Shirin Khanjani
- Institute of Reproductive and Developmental Biology, Department Metabolism, Digestion and Reproduction, Imperial College London, London, UK; Reproductive Medicine Unit, University College London Hospital, London, UK
| | - Phillip R Bennett
- Institute of Reproductive and Developmental Biology, Department Metabolism, Digestion and Reproduction, Imperial College London, London, UK; March of Dimes European Preterm Birth Research Centre, Imperial College London, London, UK.
| | - Aylin C Hanyaloglu
- Institute of Reproductive and Developmental Biology, Department Metabolism, Digestion and Reproduction, Imperial College London, London, UK.
| |
Collapse
|
5
|
Dale NC, Johnstone EKM, Pfleger KDG. GPCR heteromers: An overview of their classification, function and physiological relevance. Front Endocrinol (Lausanne) 2022; 13:931573. [PMID: 36111299 PMCID: PMC9468249 DOI: 10.3389/fendo.2022.931573] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Accepted: 08/08/2022] [Indexed: 11/25/2022] Open
Abstract
G protein-coupled receptors (GPCRs) are capable of interacting to form higher order structures such as homomers and heteromers. Heteromerisation in particular has implications for receptor function, with research showing receptors can attain unique expression, ligand binding, signalling and intracellular trafficking upon heteromerisation. As such, GPCR heteromers represent novel drug targets with extensive therapeutic potential. Changes to ligand affinity, efficacy and G protein coupling have all been described, with alterations to these pharmacological aspects now well accepted as common traits for heteromeric complexes. Changes in internalisation and trafficking kinetics, as well as β-arrestin interactions are also becoming more apparent, however, few studies to date have explicitly looked at the implications these factors have upon the signalling profile of a heteromer. Development of ligands to target GPCR heteromers both experimentally and therapeutically has been mostly concentrated on bivalent ligands due to difficulties in identifying and developing heteromer-specific ligands. Improving our understanding of the pharmacology and physiology of GPCR heteromers will enable further development of heteromer-specific ligands with potential to provide therapeutics with increased efficacy and decreased side effects.
Collapse
Affiliation(s)
- Natasha C. Dale
- Molecular Endocrinology and Pharmacology, Harry Perkins Institute of Medical Research and Centre for Medical Research, The University of Western Australia, Nedlands, WA, Australia
- Australian Research Council Centre for Personalised Therapeutics Technologies, Perth, WA, Australia
| | - Elizabeth K. M. Johnstone
- Molecular Endocrinology and Pharmacology, Harry Perkins Institute of Medical Research and Centre for Medical Research, The University of Western Australia, Nedlands, WA, Australia
- Australian Research Council Centre for Personalised Therapeutics Technologies, Perth, WA, Australia
- School of Biomedical Sciences, The University of Western Australia, Nedlands, WA, Australia
- *Correspondence: Kevin D. G. Pfleger, ; Elizabeth K. M. Johnstone,
| | - Kevin D. G. Pfleger
- Molecular Endocrinology and Pharmacology, Harry Perkins Institute of Medical Research and Centre for Medical Research, The University of Western Australia, Nedlands, WA, Australia
- Australian Research Council Centre for Personalised Therapeutics Technologies, Perth, WA, Australia
- Dimerix Limited, Nedlands, Australia
- *Correspondence: Kevin D. G. Pfleger, ; Elizabeth K. M. Johnstone,
| |
Collapse
|
6
|
Johnstone EKM, Ayoub MA, Hertzman RJ, See HB, Abhayawardana RS, Seeber RM, Pfleger KDG. Novel Pharmacology Following Heteromerization of the Angiotensin II Type 2 Receptor and the Bradykinin Type 2 Receptor. Front Endocrinol (Lausanne) 2022; 13:848816. [PMID: 35721749 PMCID: PMC9204302 DOI: 10.3389/fendo.2022.848816] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Accepted: 03/21/2022] [Indexed: 01/18/2023] Open
Abstract
The angiotensin type 2 (AT2) receptor and the bradykinin type 2 (B2) receptor are G protein-coupled receptors (GPCRs) that have major roles in the cardiovascular system. The two receptors are known to functionally interact at various levels, and there is some evidence that the observed crosstalk may occur as a result of heteromerization. We investigated evidence for heteromerization of the AT2 receptor and the B2 receptor in HEK293FT cells using various bioluminescence resonance energy transfer (BRET)-proximity based assays, including the Receptor Heteromer Investigation Technology (Receptor-HIT) and the NanoBRET ligand-binding assay. The Receptor-HIT assay showed that Gαq, GRK2 and β-arrestin2 recruitment proximal to AT2 receptors only occurred upon B2 receptor coexpression and activation, all of which is indicative of AT2-B2 receptor heteromerization. Additionally, we also observed specific coupling of the B2 receptor with the Gαz protein, and this was found only in cells coexpressing both receptors and stimulated with bradykinin. The recruitment of Gαz, Gαq, GRK2 and β-arrestin2 was inhibited by B2 receptor but not AT2 receptor antagonism, indicating the importance of B2 receptor activation within AT2-B2 heteromers. The close proximity between the AT2 receptor and B2 receptor at the cell surface was also demonstrated with the NanoBRET ligand-binding assay. Together, our data demonstrate functional interaction between the AT2 receptor and B2 receptor in HEK293FT cells, resulting in novel pharmacology for both receptors with regard to Gαq/GRK2/β-arrestin2 recruitment (AT2 receptor) and Gαz protein coupling (B2 receptor). Our study has revealed a new mechanism for the enigmatic and poorly characterized AT2 receptor to be functionally active within cells, further illustrating the role of heteromerization in the diversity of GPCR pharmacology and signaling.
Collapse
Affiliation(s)
- Elizabeth K. M. Johnstone
- Harry Perkins Institute of Medical Research and Centre for Medical Research, The University of Western Australia, Nedlands, WA, Australia
- Australian Research Council Centre for Personalised Therapeutics Technologies, Perth, WA, Australia
- School of Biomedical Sciences, The University of Western Australia, Nedlands, WA, Australia
- *Correspondence: Elizabeth K. M. Johnstone, ; Kevin D. G. Pfleger,
| | - Mohammed Akli Ayoub
- Harry Perkins Institute of Medical Research and Centre for Medical Research, The University of Western Australia, Nedlands, WA, Australia
- Department of Biology, College of Science, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Rebecca J. Hertzman
- Harry Perkins Institute of Medical Research and Centre for Medical Research, The University of Western Australia, Nedlands, WA, Australia
- School of Biomedical Sciences, The University of Western Australia, Nedlands, WA, Australia
| | - Heng B. See
- Harry Perkins Institute of Medical Research and Centre for Medical Research, The University of Western Australia, Nedlands, WA, Australia
- Australian Research Council Centre for Personalised Therapeutics Technologies, Perth, WA, Australia
| | - Rekhati S. Abhayawardana
- Harry Perkins Institute of Medical Research and Centre for Medical Research, The University of Western Australia, Nedlands, WA, Australia
- Australian Research Council Centre for Personalised Therapeutics Technologies, Perth, WA, Australia
| | - Ruth M. Seeber
- Harry Perkins Institute of Medical Research and Centre for Medical Research, The University of Western Australia, Nedlands, WA, Australia
- Australian Research Council Centre for Personalised Therapeutics Technologies, Perth, WA, Australia
| | - Kevin D. G. Pfleger
- Harry Perkins Institute of Medical Research and Centre for Medical Research, The University of Western Australia, Nedlands, WA, Australia
- Australian Research Council Centre for Personalised Therapeutics Technologies, Perth, WA, Australia
- Dimerix Limited, Nedlands, WA, Australia
- *Correspondence: Elizabeth K. M. Johnstone, ; Kevin D. G. Pfleger,
| |
Collapse
|
7
|
Johnson GP, Jonas KC. Mechanistic insight into how gonadotropin hormone receptor complexes direct signaling†. Biol Reprod 2021; 102:773-783. [PMID: 31882999 DOI: 10.1093/biolre/ioz228] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Revised: 12/09/2019] [Accepted: 12/17/2019] [Indexed: 12/29/2022] Open
Abstract
Gonadotropin hormones and their receptors play a central role in the control of male and female reproduction. In recent years, there has been growing evidence surrounding the complexity of gonadotropin hormone/receptor signaling, with it increasingly apparent that the Gαs/cAMP/PKA pathway is not the sole signaling pathway that confers their biological actions. Here we review recent literature on the different receptor-receptor, receptor-scaffold, and receptor-signaling molecule complexes formed and how these modulate and direct gonadotropin hormone-dependent intracellular signal activation. We will touch upon the more controversial issue of extragonadal expression of FSHR and the differential signal pathways activated in these tissues, and lastly, highlight the open questions surrounding the role these gonadotropin hormone receptor complexes and how this will shape future research directions.
Collapse
Affiliation(s)
| | - Kim Carol Jonas
- Department of Women and Children's Health, School of Life Course Sciences, King's College London, London, UK
| |
Collapse
|
8
|
Casanovas M, Reyes-Resina I, Lillo A, Lillo J, López-Arnau R, Camarasa J, Escubedo E, Navarro G, Franco R. Methamphetamine Blocks Adenosine A 2A Receptor Activation via Sigma 1 and Cannabinoid CB 1 Receptors. Int J Mol Sci 2021; 22:2743. [PMID: 33803075 PMCID: PMC7963146 DOI: 10.3390/ijms22052743] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2021] [Accepted: 03/01/2021] [Indexed: 11/16/2022] Open
Abstract
Methamphetamine is, worldwide, one of the most consumed drugs of abuse. One important side effect is neurodegeneration leading to a decrease in life expectancy. The aim of this paper was to check whether the drug affects one of the receptors involved in neurodegeneration/neuroprotection events, namely the adenosine A2A receptor (A2AR). First, we noticed that methamphetamine does not affect A2A functionality if the receptor is expressed in a heterologous system. However, A2AR becomes sensitive to the drug upon complexes formation with the cannabinoid CB1 receptor (CB1R) and the sigma 1 receptor (σ1R). Signaling via both adenosine A2AR and cannabinoid CB1R was affected by methamphetamine in cells co-expressing the two receptors. In striatal primary cultures, the A2AR-CB1R heteromer complex was detected and methamphetamine not only altered its expression but completely blocked the A2AR- and the CB1R-mediated activation of the mitogen activated protein kinase (MAPK) pathway. In conclusion, methamphetamine, with the participation of σ1R, alters the expression and function of two interacting receptors, A2AR, which is a therapeutic target for neuroprotection, and CB1R, which is the most abundant G protein-coupled receptor (GPCR) in the brain.
Collapse
Affiliation(s)
- Mireia Casanovas
- Biology School, Department of Biochemistry and Molecular Biomedicine, University of Barcelona, 08028 Barcelona, Spain; (M.C.); (I.R.-R.); (J.L.)
- Centro de Investigación Biomédica en Red Enfermedades Neurodegenerativas (CiberNed), Instituto de Salud Carlos III, 28031 Madrid, Spain
| | - Irene Reyes-Resina
- Biology School, Department of Biochemistry and Molecular Biomedicine, University of Barcelona, 08028 Barcelona, Spain; (M.C.); (I.R.-R.); (J.L.)
| | - Alejandro Lillo
- Department of Biochemistry and Physiology, Faculty of Pharmacy and Food Sciences, University of Barcelona, 08028 Barcelona, Spain;
| | - Jaume Lillo
- Biology School, Department of Biochemistry and Molecular Biomedicine, University of Barcelona, 08028 Barcelona, Spain; (M.C.); (I.R.-R.); (J.L.)
- Centro de Investigación Biomédica en Red Enfermedades Neurodegenerativas (CiberNed), Instituto de Salud Carlos III, 28031 Madrid, Spain
| | - Raul López-Arnau
- Department of Pharmacology, Toxicology and Therapeutic Chemistry, Institute of Biomedicine (IBUB), University of Barcelona, 08028 Barcelona, Spain; (R.L.-A.); (J.C.); (E.E.)
| | - Jorge Camarasa
- Department of Pharmacology, Toxicology and Therapeutic Chemistry, Institute of Biomedicine (IBUB), University of Barcelona, 08028 Barcelona, Spain; (R.L.-A.); (J.C.); (E.E.)
| | - Elena Escubedo
- Department of Pharmacology, Toxicology and Therapeutic Chemistry, Institute of Biomedicine (IBUB), University of Barcelona, 08028 Barcelona, Spain; (R.L.-A.); (J.C.); (E.E.)
| | - Gemma Navarro
- Centro de Investigación Biomédica en Red Enfermedades Neurodegenerativas (CiberNed), Instituto de Salud Carlos III, 28031 Madrid, Spain
- Department of Biochemistry and Physiology, Faculty of Pharmacy and Food Sciences, University of Barcelona, 08028 Barcelona, Spain;
| | - Rafael Franco
- Centro de Investigación Biomédica en Red Enfermedades Neurodegenerativas (CiberNed), Instituto de Salud Carlos III, 28031 Madrid, Spain
- Chemistry School, Department of Biochemistry and Molecular Biomedicine, University of Barcelona, 08028 Barcelona, Spain
| |
Collapse
|
9
|
Franco R, Rivas‐Santisteban R, Reyes-Resina I, Navarro G. The Old and New Visions of Biased Agonism Through the Prism of Adenosine Receptor Signaling and Receptor/Receptor and Receptor/Protein Interactions. Front Pharmacol 2021; 11:628601. [PMID: 33584311 PMCID: PMC7878529 DOI: 10.3389/fphar.2020.628601] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Accepted: 12/21/2020] [Indexed: 12/18/2022] Open
Abstract
Biased signaling is a concept that has arisen in the G protein-coupled receptor (GCPR) research field, and holds promise for the development of new drug development strategies. It consists of different signaling outputs depending on the agonist's chemical structure. Here we review the most accepted mechanisms for explaining biased agonism, namely the induced fit hypothesis and the key/lock hypothesis, but we also consider how bias can be produced by a given agonist. In fact, different signaling outputs may originate at a given receptor when activated by, for instance, the endogenous agonist. We take advantage of results obtained with adenosine receptors to explain how such mechanism of functional selectivity depends on the context, being receptor-receptor interactions (heteromerization) one of the most relevant and most studied mechanisms for mammalian homeostasis. Considering all the possible mechanisms underlying functional selectivity is essential to optimize the selection of biased agonists in the design of drugs targeting GPCRs.
Collapse
Affiliation(s)
- Rafael Franco
- Department Biochemistry and Molecular Biomedicine, School of Biology, University of Barcelona, Barcelona, Spain
- Centro de Investigación en Red, Enfermedades Neurodegenerativas (CiberNed), Instituto de Salud Carlos iii, Madrid, Spain
| | - Rafael Rivas‐Santisteban
- Department Biochemistry and Molecular Biomedicine, School of Biology, University of Barcelona, Barcelona, Spain
- Centro de Investigación en Red, Enfermedades Neurodegenerativas (CiberNed), Instituto de Salud Carlos iii, Madrid, Spain
| | - Irene Reyes-Resina
- RG Neuroplasticity, Leibniz Institute for Neurobiology, Magdeburg, Germany
| | - Gemma Navarro
- Centro de Investigación en Red, Enfermedades Neurodegenerativas (CiberNed), Instituto de Salud Carlos iii, Madrid, Spain
- Department of Biochemistry and Physiology, School of Pharmacy, University of Barcelona, Barcelona, Spain
| |
Collapse
|
10
|
Johnstone EKM, See HB, Abhayawardana RS, Song A, Rosengren KJ, Hill SJ, Pfleger KDG. Investigation of Receptor Heteromers Using NanoBRET Ligand Binding. Int J Mol Sci 2021; 22:1082. [PMID: 33499147 PMCID: PMC7866079 DOI: 10.3390/ijms22031082] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Revised: 01/19/2021] [Accepted: 01/19/2021] [Indexed: 12/20/2022] Open
Abstract
Receptor heteromerization is the formation of a complex involving at least two different receptors with pharmacology that is distinct from that exhibited by its constituent receptor units. Detection of these complexes and monitoring their pharmacology is crucial for understanding how receptors function. The Receptor-Heteromer Investigation Technology (Receptor-HIT) utilizes ligand-dependent modulation of interactions between receptors and specific biomolecules for the detection and profiling of heteromer complexes. Previously, the interacting biomolecules used in Receptor-HIT assays have been intracellular proteins, however in this study we have for the first time used bioluminescence resonance energy transfer (BRET) with fluorescently-labeled ligands to investigate heteromerization of receptors on the cell surface. Using the Receptor-HIT ligand binding assay with NanoBRET, we have successfully investigated heteromers between the angiotensin II type 1 (AT1) receptor and the β2 adrenergic receptor (AT1-β2AR heteromer), as well as between the AT1 and angiotensin II type 2 receptor (AT1-AT2 heteromer).
Collapse
Affiliation(s)
- Elizabeth K. M. Johnstone
- Molecular Endocrinology and Pharmacology Group, Harry Perkins Institute of Medical Research, Nedlands, WA 6009, Australia; (H.B.S.); (R.S.A.); (S.J.H.)
- Centre for Medical Research, The University of Western Australia, Crawley, WA 6009, Australia
- Australian Research Council Centre for Personalised Therapeutics Technologies, Canberra, NSW 2609, Australia
| | - Heng B. See
- Molecular Endocrinology and Pharmacology Group, Harry Perkins Institute of Medical Research, Nedlands, WA 6009, Australia; (H.B.S.); (R.S.A.); (S.J.H.)
- Centre for Medical Research, The University of Western Australia, Crawley, WA 6009, Australia
- Australian Research Council Centre for Personalised Therapeutics Technologies, Canberra, NSW 2609, Australia
| | - Rekhati S. Abhayawardana
- Molecular Endocrinology and Pharmacology Group, Harry Perkins Institute of Medical Research, Nedlands, WA 6009, Australia; (H.B.S.); (R.S.A.); (S.J.H.)
- Centre for Medical Research, The University of Western Australia, Crawley, WA 6009, Australia
- Australian Research Council Centre for Personalised Therapeutics Technologies, Canberra, NSW 2609, Australia
| | - Angela Song
- School of Biomedical Sciences, Faculty of Medicine, The University of Queensland, St Lucia, QLD 4072, Australia; (A.S.); (K.J.R.)
| | - K. Johan Rosengren
- School of Biomedical Sciences, Faculty of Medicine, The University of Queensland, St Lucia, QLD 4072, Australia; (A.S.); (K.J.R.)
| | - Stephen J. Hill
- Molecular Endocrinology and Pharmacology Group, Harry Perkins Institute of Medical Research, Nedlands, WA 6009, Australia; (H.B.S.); (R.S.A.); (S.J.H.)
- Centre for Medical Research, The University of Western Australia, Crawley, WA 6009, Australia
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham Medical School, Nottingham NG7 2UH, UK
- Centre of Membrane Proteins and Receptors, University of Nottingham, Midlands NG7 2UH, UK
| | - Kevin D. G. Pfleger
- Molecular Endocrinology and Pharmacology Group, Harry Perkins Institute of Medical Research, Nedlands, WA 6009, Australia; (H.B.S.); (R.S.A.); (S.J.H.)
- Centre for Medical Research, The University of Western Australia, Crawley, WA 6009, Australia
- Australian Research Council Centre for Personalised Therapeutics Technologies, Canberra, NSW 2609, Australia
- Dimerix Limited, Nedlands, WA 6009, Australia
| |
Collapse
|
11
|
Naulin PA, Lozano B, Fuentes C, Liu Y, Schmidt C, Contreras JE, Barrera NP. Polydisperse molecular architecture of connexin 26/30 heteromeric hemichannels revealed by atomic force microscopy imaging. J Biol Chem 2020; 295:16499-16509. [PMID: 32887797 PMCID: PMC7864052 DOI: 10.1074/jbc.ra119.012128] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2019] [Revised: 08/31/2020] [Indexed: 11/06/2022] Open
Abstract
Connexin (Cx) protein forms hemichannels and gap junctional channels, which play diverse and profound roles in human physiology and diseases. Gap junctions are arrays of intercellular channels formed by the docking of two hemichannels from adjacent cells. Each hexameric hemichannel contains the same or different Cx isoform. Although homomeric Cxs forms have been largely described functionally and structurally, the stoichiometry and arrangement of heteromeric Cx channels remain unknown. The latter, however, are widely expressed in human tissues and variation might have important implications on channel function. Investigating properties of heteromeric Cx channels is challenging considering the high number of potential subunit arrangements and stoichiometries, even when only combining two Cx isoforms. To tackle this problem, we engineered an HA tag onto Cx26 or Cx30 subunits and imaged hemichannels that were liganded by Fab-epitope antibody fragments via atomic force microscopy. For Cx26-HA/Cx30 or Cx30-HA/Cx26 heteromeric channels, the Fab-HA binding distribution was binomial with a maximum of three Fab-HA bound. Furthermore, imaged Cx26/Cx30-HA triple liganded by Fab-HA showed multiple arrangements that can be derived from the law of total probabilities. Atomic force microscopy imaging of ringlike structures of Cx26/Cx30-HA hemichannels confirmed these findings and also detected a polydisperse distribution of stoichiometries. Our results indicate a dominant subunit stoichiometry of 3Cx26:3Cx30 with the most abundant subunit arrangement of Cx26-Cx26-Cx30-Cx26-Cx30-Cx30. To our knowledge, this is the first time that the molecular architecture of heteromeric Cx channels has been revealed, thus providing the basis to explore the functional effect of these channels in biology.
Collapse
Affiliation(s)
- Pamela A Naulin
- Department of Physiology, Faculty of Biological Sciences, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Benjamin Lozano
- Department of Physiology, Faculty of Biological Sciences, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Christian Fuentes
- Department of Physiology, Faculty of Biological Sciences, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Yu Liu
- Department of Pharmacology, Physiology and Neuroscience, New Jersey Medical School, Rutgers University, Newark, New Jersey, USA
| | - Carla Schmidt
- Department of Chemistry, University of Oxford, Oxford, United Kingdom
| | - Jorge E Contreras
- Department of Pharmacology, Physiology and Neuroscience, New Jersey Medical School, Rutgers University, Newark, New Jersey, USA
| | - Nelson P Barrera
- Department of Physiology, Faculty of Biological Sciences, Pontificia Universidad Católica de Chile, Santiago, Chile.
| |
Collapse
|
12
|
Fujita W. The Possible Role of MOPr-DOPr Heteromers and Its Regulatory Protein RTP4 at Sensory Neurons in Relation to Pain Perception. Front Cell Neurosci 2020; 14:609362. [PMID: 33304244 PMCID: PMC7693438 DOI: 10.3389/fncel.2020.609362] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Accepted: 10/28/2020] [Indexed: 12/25/2022] Open
Abstract
Heteromers between mu opioid receptor (MOPr) and delta opioid receptor (DOPr) (i.e., MOPr-DOPr heteromer) have been found to be expressed in different brain regions, in the spinal cord, and in dorsal root ganglia. Recent studies on this heteromer reveal its important pathophysiological function in pain regulation including neuropathic pain; this suggests a role as a novel therapeutic target in chronic pain management. In addition, receptor transporter protein 4 (RTP4) has been shown to be involved in the intracellular maturation of the MOPr-DOPr heteromers. RTP4 appears to have unique distribution in vivo being highly expressed in sensory neurons and also macrophages; the latter are effector cells of the innate immune system that phagocytose foreign substances and secrete both pro-inflammatory and antimicrobial mediators; this suggests a possible contribution of RTP4 to neuronal immune-related pathological conditions such as neuropathic pain. Although RTP4 could be considered as an important therapeutic target in the management of pain via MOPr-DOPr heteromer, a few reports have supported this. This review will summarize the possible role or functions of the MOPr-DOPr heteromer and its regulatory molecule RTP4 in pain modulation at sensory neurons.
Collapse
Affiliation(s)
- Wakako Fujita
- Department of Medical Pharmacology, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
| |
Collapse
|
13
|
Derouiche L, Pierre F, Doridot S, Ory S, Massotte D. Heteromerization of Endogenous Mu and Delta Opioid Receptors Induces Ligand-Selective Co-Targeting to Lysosomes. Molecules 2020; 25:molecules25194493. [PMID: 33007971 PMCID: PMC7583997 DOI: 10.3390/molecules25194493] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 09/23/2020] [Accepted: 09/29/2020] [Indexed: 12/12/2022] Open
Abstract
Increasing evidence indicates that native mu and delta opioid receptors can associate to form heteromers in discrete brain neuronal circuits. However, little is known about their signaling and trafficking. Using double-fluorescent knock-in mice, we investigated the impact of neuronal co-expression on the internalization profile of mu and delta opioid receptors in primary hippocampal cultures. We established ligand selective mu–delta co-internalization upon activation by 1-[[4-(acetylamino)phenyl]methyl]-4-(2-phenylethyl)-4-piperidinecarboxylic acid, ethyl ester (CYM51010), [d-Ala2, NMe-Phe4, Gly-ol5]enkephalin (DAMGO), and deltorphin II, but not (+)-4-[(αR)-α-((2S,5R)-4-Allyl-2,5-dimethyl-1-piperazinyl)-3-methoxybenzyl]-N,N-diethylbenzamide (SNC80), morphine, or methadone. Co-internalization was driven by the delta opioid receptor, required an active conformation of both receptors, and led to sorting to the lysosomal compartment. Altogether, our data indicate that mu–delta co-expression, likely through heteromerization, alters the intracellular fate of the mu opioid receptor, which provides a way to fine-tune mu opioid receptor signaling. It also represents an interesting emerging concept for the development of novel therapeutic drugs and strategies.
Collapse
MESH Headings
- Animals
- Cells, Cultured
- Endocytosis
- Hippocampus/cytology
- Ligands
- Lysosomes
- Mice, Inbred C57BL
- Neurons/metabolism
- Piperidines/pharmacology
- Protein Multimerization
- Receptors, Opioid, delta/antagonists & inhibitors
- Receptors, Opioid, delta/metabolism
- Receptors, Opioid, mu/antagonists & inhibitors
- Receptors, Opioid, mu/metabolism
Collapse
Affiliation(s)
- Lyes Derouiche
- French National Centre for Scientific Research, Institut des Neurosciences Cellulaires et Intégratives, University of Strasbourg, 67000 Strasbourg, France; (L.D.); (F.P.); (S.O.)
| | - Florian Pierre
- French National Centre for Scientific Research, Institut des Neurosciences Cellulaires et Intégratives, University of Strasbourg, 67000 Strasbourg, France; (L.D.); (F.P.); (S.O.)
| | - Stéphane Doridot
- French National Centre for Scientific Research, Chronobiotron, 67200 Strasbourg, France;
| | - Stéphane Ory
- French National Centre for Scientific Research, Institut des Neurosciences Cellulaires et Intégratives, University of Strasbourg, 67000 Strasbourg, France; (L.D.); (F.P.); (S.O.)
| | - Dominique Massotte
- French National Centre for Scientific Research, Institut des Neurosciences Cellulaires et Intégratives, University of Strasbourg, 67000 Strasbourg, France; (L.D.); (F.P.); (S.O.)
- Correspondence:
| |
Collapse
|
14
|
Sutton MN, Lu Z, Li YC, Zhou Y, Huang T, Reger AS, Hurwitz AM, Palzkill T, Logsdon C, Liang X, Gray JW, Nan X, Hancock J, Wahl GM, Bast RC Jr. DIRAS3 (ARHI) Blocks RAS/MAPK Signaling by Binding Directly to RAS and Disrupting RAS Clusters. Cell Rep 2019; 29:3448-3459.e6. [PMID: 31825828 DOI: 10.1016/j.celrep.2019.11.045] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Revised: 08/06/2019] [Accepted: 11/11/2019] [Indexed: 12/21/2022] Open
Abstract
Oncogenic RAS mutations drive cancers at many sites. Recent reports suggest that RAS dimerization, multimerization, and clustering correlate strongly with activation of RAS signaling. We have found that re-expression of DIRAS3, a RAS-related small GTPase tumor suppressor that is downregulated in multiple cancers, inhibits RAS/mitogen-activated protein kinase (MAPK) signaling by interacting directly with RAS-forming heteromers, disrupting RAS clustering, inhibiting Raf kinase activation, and inhibiting transformation and growth of cancer cells and xenografts. Disruption of K-RAS cluster formation requires the N terminus of DIRAS3 and interaction of both DIRAS3 and K-RAS with the plasma membrane. Interaction of DIRAS3 with both K-RAS and H-RAS suggests a strategy for inhibiting oncogenic RAS function.
Collapse
|
15
|
Bagher AM, Young AP, Laprairie RB, Toguri JT, Kelly MEM, Denovan-Wright EM. Heteromer formation between cannabinoid type 1 and dopamine type 2 receptors is altered by combination cannabinoid and antipsychotic treatments. J Neurosci Res 2020; 98:2496-2509. [PMID: 32881145 DOI: 10.1002/jnr.24716] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 07/05/2020] [Accepted: 08/07/2020] [Indexed: 12/21/2022]
Abstract
The cannabinoid type 1 (CB1 ) receptor and the dopamine type 2 (D2 ) receptor are co-localized on medium spiny neuron terminals in the globus pallidus where they modulate neural circuits involved in voluntary movement. Physical interactions between the two receptors have been shown to alter receptor signaling in cell culture. The objectives of the current study were to identify the presence of CB1 /D2 heteromers in the globus pallidus of C57BL/6J male mice, define how CB1 /D2 heteromer levels are altered following treatment with cannabinoids and/or antipsychotics, and determine if fluctuating levels of CB1 /D2 heteromers have functional consequences. Using in situ proximity ligation assays, we observed CB1 /D2 heteromers in the globus pallidus of C57BL/6J mice. The abundance of the heteromers increased following treatment with the nonselective cannabinoid receptor agonist, CP55,940. In contrast, treatment with the typical antipsychotic haloperidol reduced the number of CB1 /D2 heteromers, whereas the atypical antipsychotic olanzapine treatment had no effect. Co-treatment with CP55,940 and haloperidol had similar effects to haloperidol alone, whereas co-treatment with CP55,940 and olanzapine had similar effects to CP55,940. The observed changes were found to have functional consequences as the differential effects of haloperidol and olanzapine also applied to γ-aminobutyric acid release in STHdhQ7/Q7 cells and motor function in C57BL/6J male mice. This work highlights the clinical relevance of co-exposure to cannabinoids and different antipsychotics over acute and prolonged time periods.
Collapse
Affiliation(s)
- Amina M Bagher
- Department of Pharmacology and Toxicology, King AbdulAziz University, Jeddah, Saudi Arabia.,Department of Pharmacology, Dalhousie University, Halifax, NS, Canada
| | - Alexander P Young
- Department of Pharmacology, Dalhousie University, Halifax, NS, Canada
| | - Robert B Laprairie
- College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, SK, Canada
| | - James T Toguri
- Department of Pharmacology, Dalhousie University, Halifax, NS, Canada
| | - Melanie E M Kelly
- Department of Pharmacology, Dalhousie University, Halifax, NS, Canada.,Department of Ophthalmology and Visual Sciences, Dalhousie University, Halifax, NS, Canada
| | | |
Collapse
|
16
|
Skarratt KK, Gu BJ, Lovelace MD, Milligan CJ, Stokes L, Glover R, Petrou S, Wiley JS, Fuller SJ. A P2RX7 single nucleotide polymorphism haplotype promotes exon 7 and 8 skipping and disrupts receptor function. FASEB J 2020; 34:3884-3901. [PMID: 32003498 DOI: 10.1096/fj.201901198rr] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Revised: 12/23/2019] [Accepted: 12/24/2019] [Indexed: 12/12/2022]
Abstract
P2X7 is an ATP-gated membrane ion channel that is expressed by multiple cell types. Brief exposure to ATP induces the opening of a nonselective cation channel; while repeated or prolonged exposure induces formation of a transmembrane pore. This process may be partially regulated by alternative splicing of full-length P2RX7A pre-mRNA, producing isoforms that delete or retain functional domains. Here, we report cloning and expression of a novel P2RX7 splice variant, P2RX7L, that is, characterized by skipping of exons 7 and 8. In HEK 293 cells, expression of P2RX7L produces a protein isoform, P2X7L, that forms a heteromer with P2X7A. A haplotype defined by six single nucleotide polymorphisms (SNPs) (rs208307, rs208306, rs36144485, rs208308, rs208309, and rs373655596) promotes allele-specific alternative splicing, increasing mRNA levels of P2RX7L and another isoform, P2RX7E, which in addition has a truncated C-terminus. Skipping of exons 7 and 8 is predicted to delete critical amino acids in the ATP-binding site. P2X7L-transfected HEK 293 cells have phagocytic but not channel, pore, or membrane-blebbing function, and double-transfected P2X7L and P2X7A cells have reduced pore function. Heteromeric receptor complexes of P2X7A and P2X7L are predicted to have reduced numbers of ATP-binding sites, which potentially alters receptor function compared to homomeric P2X7A complexes.
Collapse
Affiliation(s)
- Kristen K Skarratt
- Department of Medicine, Sydney Medical School Nepean, Faculty of Medicine and Health, The University of Sydney, Kingswood, NSW, Australia
| | - Ben J Gu
- Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Melbourne, VIC, Australia
| | - Michael D Lovelace
- Department of Medicine, Sydney Medical School Nepean, Faculty of Medicine and Health, The University of Sydney, Kingswood, NSW, Australia
| | - Carol J Milligan
- Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Melbourne, VIC, Australia
| | - Leanne Stokes
- Department of Medicine, Sydney Medical School Nepean, Faculty of Medicine and Health, The University of Sydney, Kingswood, NSW, Australia.,School of Pharmacy, University of East Anglia, Norwich Research Park, Norwich, UK
| | - Rachel Glover
- Department of Medicine, Sydney Medical School Nepean, Faculty of Medicine and Health, The University of Sydney, Kingswood, NSW, Australia
| | - Steven Petrou
- Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Melbourne, VIC, Australia
| | - James S Wiley
- Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Melbourne, VIC, Australia
| | - Stephen J Fuller
- Department of Medicine, Sydney Medical School Nepean, Faculty of Medicine and Health, The University of Sydney, Kingswood, NSW, Australia
| |
Collapse
|
17
|
Yarur HE, Andrés ME, Gysling K. Type 2β Corticotrophin Releasing Factor Receptor Forms a Heteromeric Complex With Dopamine D1 Receptor in Living Cells. Front Pharmacol 2020; 10:1501. [PMID: 31969820 PMCID: PMC6960402 DOI: 10.3389/fphar.2019.01501] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Accepted: 11/20/2019] [Indexed: 11/23/2022] Open
Abstract
Corticotrophin releasing factor (CRF) and its related peptides differentially bind to CRF receptors to modulate stress-related behaviors. CRF receptors comprise two G-protein coupled receptors (GPCR), type-1 CRF receptors (CRF1), and type-2 CRF receptors (CRF2). CRF2 encompasses three spliced variants in humans, alpha (CRF2α), beta (CRF2β), and gamma (CRF2γ), which differ in their N-terminal extracellular domains and expression patterns. Previously, we showed that CRF2α form a heteromeric protein complex with dopamine D1 receptors (D1R), leading to changes in the signaling of D1R. Based on the high sequence identity between CRF2α and CRF2β, we hypothesized that CRF2β also heteromerize with D1R. To test the hypothesis, we compared the expression and localization of both CRF2 isoforms and whether CRF2β form stable protein complexes with D1R in HEK293 and ATR75 cell lines. We observed that the immunoreactivity for CRF2β was similar to that of CRF2α in the endoplasmic compartment but significantly higher in the Golgi compartment. Immunoprecipitation analysis showed that CRF2β forms a heteromeric protein complex with D1R. Furthermore, the protein complex formed by CRF2β and D1R was stable enough to change the sub-cellular localization of CRF2β when it was co-expressed with a construct of D1R bearing a nuclear localization signal. Immunofluorescence in A7R5 cells, which endogenously express CRF2β and D1R, shows significant colocalization of CRF2β with D1R. In conclusion, our results show that CRF2β forms a stable heteromeric protein complex with D1R, a potential new therapeutic target in tissues where both receptors are co-expressed, such as the septum in the brain, and heart, kidney, and skeletal muscle in the periphery.
Collapse
Affiliation(s)
- Hector E. Yarur
- Department of Cellular and Molecular Biology, Faculty of Biological Sciences, Pontificia Universidad Católica de Chile, Santiago, Chile
| | | | - Katia Gysling
- Department of Cellular and Molecular Biology, Faculty of Biological Sciences, Pontificia Universidad Católica de Chile, Santiago, Chile
| |
Collapse
|
18
|
Franco R, Reyes-Resina I, Aguinaga D, Lillo A, Jiménez J, Raïch I, Borroto-Escuela DO, Ferreiro-Vera C, Canela EI, Sánchez de Medina V, Del Ser-Badia A, Fuxe K, Saura CA, Navarro G. Potentiation of cannabinoid signaling in microglia by adenosine A 2A receptor antagonists. Glia 2019; 67:2410-2423. [PMID: 31429130 DOI: 10.1002/glia.23694] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 07/18/2019] [Accepted: 07/22/2019] [Indexed: 12/15/2022]
Abstract
Neuroprotective M2-skewed microglia appear as promising to alter the course of neurodegenerative diseases and G protein-coupled receptors (GPCRs) are potential targets to achieve such microglial polarization. A common feature of adenosine A2A (A2A R) and cannabinoid CB2 (CB2 R) GPCRs in microglia is that their expression is upregulated in Alzheimer's disease (AD). On the one hand, CB2 R seems a target for neuroprotection, delaying neurodegenerative processes like those associated to AD or Parkinson's diseases. A2A R antagonists reduce amyloid burden and improve cognitive performance and memory in AD animal models. We here show a close interrelationship between these two receptors in microglia; they are able to physically interact and affect the signaling of each other, likely due to conformational changes within the A2A -CB2 receptor heteromer (A2A -CB2 Het). Particularly relevant is the upregulation of A2A -CB2 Het expression in samples from the APPSw ,Ind AD transgenic mice model. The most relevant finding, confirmed in both heterologous cells and in primary cultures of microglia, was that blockade of A2A receptors results in increased CB2 R-mediated signaling. This heteromer-specific feature suggests that A2A R antagonists would potentiate, via microglia, the neuroprotective action of endocannabinoids with implications for AD therapy.
Collapse
Affiliation(s)
- Rafael Franco
- Molecular Neurobiology Laboratory, Department of Biochemistry and Molecular Biomedicine, Universitat de Barcelona, Barcelona, Spain.,Centro de Investigación en Red, Enfermedades Neurodegenerativas (CiberNed), Instituto de Salud Carlos III, Madrid, Spain
| | - Irene Reyes-Resina
- Molecular Neurobiology Laboratory, Department of Biochemistry and Molecular Biomedicine, Universitat de Barcelona, Barcelona, Spain.,Centro de Investigación en Red, Enfermedades Neurodegenerativas (CiberNed), Instituto de Salud Carlos III, Madrid, Spain
| | - David Aguinaga
- Molecular Neurobiology Laboratory, Department of Biochemistry and Molecular Biomedicine, Universitat de Barcelona, Barcelona, Spain.,Centro de Investigación en Red, Enfermedades Neurodegenerativas (CiberNed), Instituto de Salud Carlos III, Madrid, Spain
| | - Alejandro Lillo
- Molecular Neurobiology Laboratory, Department of Biochemistry and Molecular Biomedicine, Universitat de Barcelona, Barcelona, Spain
| | - Jasmina Jiménez
- Molecular Neurobiology Laboratory, Department of Biochemistry and Molecular Biomedicine, Universitat de Barcelona, Barcelona, Spain.,Centro de Investigación en Red, Enfermedades Neurodegenerativas (CiberNed), Instituto de Salud Carlos III, Madrid, Spain
| | - Iu Raïch
- Molecular Neurobiology Laboratory, Department of Biochemistry and Molecular Biomedicine, Universitat de Barcelona, Barcelona, Spain
| | | | | | - Enric I Canela
- Molecular Neurobiology Laboratory, Department of Biochemistry and Molecular Biomedicine, Universitat de Barcelona, Barcelona, Spain.,Centro de Investigación en Red, Enfermedades Neurodegenerativas (CiberNed), Instituto de Salud Carlos III, Madrid, Spain
| | | | - Anna Del Ser-Badia
- Centro de Investigación en Red, Enfermedades Neurodegenerativas (CiberNed), Instituto de Salud Carlos III, Madrid, Spain.,Department de Bioquímica i Biologia Molecular, Institut de Neurociències, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Kjell Fuxe
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Carlos A Saura
- Centro de Investigación en Red, Enfermedades Neurodegenerativas (CiberNed), Instituto de Salud Carlos III, Madrid, Spain.,Department de Bioquímica i Biologia Molecular, Institut de Neurociències, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Gemma Navarro
- Centro de Investigación en Red, Enfermedades Neurodegenerativas (CiberNed), Instituto de Salud Carlos III, Madrid, Spain.,Department of Biochemistry and Physiology, Faculty of Pharmacy and Food Sciences, Universitat de Barcelona, Barcelona, Spain
| |
Collapse
|
19
|
Sierra S, Gupta A, Gomes I, Fowkes M, Ram A, Bobeck EN, Devi LA. Targeting Cannabinoid 1 and Delta Opioid Receptor Heteromers Alleviates Chemotherapy-Induced Neuropathic Pain. ACS Pharmacol Transl Sci 2019; 2:219-229. [PMID: 31565698 DOI: 10.1021/acsptsci.9b00008] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Cannabinoid 1 (CB1R) and delta opioid receptors (DOR) associate to form heteromers that exhibit distinct pharmacological properties. Not much is known about CB1R-DOR heteromer location or signaling along the pain circuit in either animal models or patients with chemotherapy-induced peripheral neuropathy (CIPN). Here, we use paclitaxel to induce CIPN in mice and confirm the development of mechanical allodynia. Under these conditions, we find significant increases in CB1R-DOR heteromers in the dorsal spinal cord of mice with CIPN as well as in postmortem spinal cords from human subjects with CIPN compared to controls. Next, we investigated receptor signaling in spinal cords of mice with CIPN and found that treatment with a combination of low signaling doses of CB1R and DOR ligands leads to significant enhancement in G-protein activity that could be selectively blocked by the CB1R-DOR antibody. Consistent with this, administration of subthreshold doses of a combination of ligands (CB1R agonist, Hu-210, and DOR agonist, SNC80) leads to significant attenuation of allodynia in mice with CIPN that is not seen with the administration of individual ligands, and this could be blocked by the CB1R-DOR antibody. Together, these results imply that CB1R-DOR heteromers upregulated during CIPN-associated mechanical allodynia could serve as a potential target for treatment of neuropathic pain including CIPN.
Collapse
Affiliation(s)
- Salvador Sierra
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, New York 10029, United States
| | - Achla Gupta
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, New York 10029, United States
| | - Ivone Gomes
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, New York 10029, United States
| | - Mary Fowkes
- Department of Pathology, Icahn School of Medicine at Mount Sinai, New York, New York 10029, United States
| | - Akila Ram
- Department of Biology, Utah State University, Logan, Utah 84322, United States
| | - Erin N Bobeck
- Department of Biology, Utah State University, Logan, Utah 84322, United States
| | - Lakshmi A Devi
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, New York 10029, United States
| |
Collapse
|
20
|
Abstract
INTRODUCTION Pain relief remains a major public health challenge. The most efficient available painkillers are opioids targeting the mu opioid receptor (MOR). MORs are expressed in the areas of the brain [including pain and respiratory centers] that are important for processing reward and aversion. Thus, MOR activation efficiently alleviates severe pain, but the concomitant reward and respiratory depressant effects pose a threat; patients taking opioids potentially develop opioid addiction and high risk for overdose. Areas covered: Ongoing efforts to generate safer opioid analgesics are reviewed here. The design of biased compounds that trigger MOR induced G protein over β-arrestin signaling, peripheral opioids, drugs targeting MORs in heteromers and drugs enhancing endogenous opioid activity are discussed. Expert opinion: There is evidence that throttling MOR signaling may lead to an era of opioids that are truly efficient painkillers with lower side effects and risk of overdose. However, few of the drugs derived from the advanced approaches outlined here, are getting approval by regulatory committees for use in clinical settings. Thus, there is an urgent need to (i) better clarify mechanisms underlying the hazardous physiological effects of MOR activation, and (ii) fully validate the safety of these new MOR-based therapies.
Collapse
Affiliation(s)
- Aliza T Ehrlich
- a Department of Psychiatry , McGill University, Douglas Hospital Research Center , Montréal , QC , Canada
| | - Brigitte L Kieffer
- a Department of Psychiatry , McGill University, Douglas Hospital Research Center , Montréal , QC , Canada
| | - Emmanuel Darcq
- a Department of Psychiatry , McGill University, Douglas Hospital Research Center , Montréal , QC , Canada
| |
Collapse
|
21
|
Ugur M, Derouiche L, Massotte D. Heteromerization Modulates mu Opioid Receptor Functional Properties in vivo. Front Pharmacol 2018; 9:1240. [PMID: 30483121 PMCID: PMC6244869 DOI: 10.3389/fphar.2018.01240] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Accepted: 10/11/2018] [Indexed: 01/28/2023] Open
Abstract
Mu opioid receptors modulate a large number of physiological functions. They are in particular involved in the control of pain perception and reward properties. They are also the primary molecular target of opioid drugs and mediate their beneficial analgesic effects, euphoric properties as well as negative side effects such as tolerance and physical dependence. Importantly, mu opioid receptors can physically associate with another receptor to form a novel entity called heteromer that exhibits specific ligand binding, signaling, and trafficking properties. As reviewed here, in vivo physical proximity has now been evidenced for several receptor pairs, subsequent impact of heteromerization on native mu opioid receptor signaling and trafficking identified and a link to behavioral changes established. Selective targeting of heteromers as a tool to modulate mu opioid receptor activity is therefore attracting growing interest and raises hopes for innovative therapeutic strategies.
Collapse
Affiliation(s)
- Muzeyyen Ugur
- Centre de la Recherche Nationale Scientifique, Institut des Neurosciences Cellulaires et Intégratives, Université de Strasbourg, Strasbourg, France
| | - Lyes Derouiche
- Centre de la Recherche Nationale Scientifique, Institut des Neurosciences Cellulaires et Intégratives, Université de Strasbourg, Strasbourg, France
| | - Dominique Massotte
- Centre de la Recherche Nationale Scientifique, Institut des Neurosciences Cellulaires et Intégratives, Université de Strasbourg, Strasbourg, France
| |
Collapse
|
22
|
Damian M, Pons V, Renault P, M'Kadmi C, Delort B, Hartmann L, Kaya AI, Louet M, Gagne D, Ben Haj Salah K, Denoyelle S, Ferry G, Boutin JA, Wagner R, Fehrentz JA, Martinez J, Marie J, Floquet N, Galès C, Mary S, Hamm HE, Banères JL. GHSR-D2R heteromerization modulates dopamine signaling through an effect on G protein conformation. Proc Natl Acad Sci U S A 2018; 115:4501-6. [PMID: 29632174 DOI: 10.1073/pnas.1712725115] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The growth hormone secretagogue receptor (GHSR) and dopamine receptor (D2R) have been shown to oligomerize in hypothalamic neurons with a significant effect on dopamine signaling, but the molecular processes underlying this effect are still obscure. We used here the purified GHSR and D2R to establish that these two receptors assemble in a lipid environment as a tetrameric complex composed of two each of the receptors. This complex further recruits G proteins to give rise to an assembly with only two G protein trimers bound to a receptor tetramer. We further demonstrate that receptor heteromerization directly impacts on dopamine-mediated Gi protein activation by modulating the conformation of its α-subunit. Indeed, association to the purified GHSR:D2R heteromer triggers a different active conformation of Gαi that is linked to a higher rate of GTP binding and a faster dissociation from the heteromeric receptor. This is an additional mechanism to expand the repertoire of GPCR signaling modulation that could have implications for the control of dopamine signaling in normal and physiopathological conditions.
Collapse
|
23
|
Navarro G, Morales P, Rodríguez-Cueto C, Fernández-Ruiz J, Jagerovic N, Franco R. Targeting Cannabinoid CB2 Receptors in the Central Nervous System. Medicinal Chemistry Approaches with Focus on Neurodegenerative Disorders. Front Neurosci 2016; 10:406. [PMID: 27679556 PMCID: PMC5020102 DOI: 10.3389/fnins.2016.00406] [Citation(s) in RCA: 90] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Accepted: 08/22/2016] [Indexed: 12/04/2022] Open
Abstract
Endocannabinoids activate two types of specific G-protein-coupled receptors (GPCRs), namely cannabinoid CB1 and CB2. Contrary to the psychotropic actions of agonists of CB1 receptors, and serious side effects of the selective antagonists of this receptor, drugs acting on CB2 receptors appear as promising drugs to combat CNS diseases (Parkinson's disease, Huntington's chorea, cerebellar ataxia, amyotrohic lateral sclerosis). Differential localization of CB2 receptors in neural cell types and upregulation in neuroinflammation are keys to understand the therapeutic potential in inter alia diseases that imply progressive neurodegeneration. Medicinal chemistry approaches are now engaged to develop imaging tools to map receptors in the living human brain, to develop more efficacious agonists, and to investigate the possibility to develop allosteric modulators.
Collapse
Affiliation(s)
- Gemma Navarro
- Department of Biochemistry and Molecular Biomedicine, University of BarcelonaBarcelona, Spain; Centro de Investigación en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Instituto de Salud Carlos IIIMadrid, Spain; Cell and Molecular Neuropharmacology, Institut de Biomedicina (IBUB), Universitat de BarcelonaBarcelona, Spain
| | - Paula Morales
- Instituto de Química Médica, Consejo Superior de Investigaciones CientíficasMadrid, Spain; Center for Drug Discovery, University of North Carolina at GreensboroGreensboro, NC, USA
| | - Carmen Rodríguez-Cueto
- Centro de Investigación en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Instituto de Salud Carlos IIIMadrid, Spain; Departamento de Bioquímica, Facultad de Medicina, Instituto Universitario de Investigación en Neuroquímica, Universidad ComplutenseMadrid, Spain; Instituto Ramón y Cajal de Investigación SanitariaMadrid, Spain
| | - Javier Fernández-Ruiz
- Centro de Investigación en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Instituto de Salud Carlos IIIMadrid, Spain; Departamento de Bioquímica, Facultad de Medicina, Instituto Universitario de Investigación en Neuroquímica, Universidad ComplutenseMadrid, Spain; Instituto Ramón y Cajal de Investigación SanitariaMadrid, Spain
| | - Nadine Jagerovic
- Instituto de Química Médica, Consejo Superior de Investigaciones Científicas Madrid, Spain
| | - Rafael Franco
- Department of Biochemistry and Molecular Biomedicine, University of BarcelonaBarcelona, Spain; Centro de Investigación en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Instituto de Salud Carlos IIIMadrid, Spain; Cell and Molecular Neuropharmacology, Institut de Biomedicina (IBUB), Universitat de BarcelonaBarcelona, Spain
| |
Collapse
|
24
|
Abstract
The interaction of biological macromolecules is a fundamental attribute of cellular life. Proteins, in particular, often form stable complexes with one another. Although the importance of protein complexes is widely recognized, we still have only a very limited understanding of the mechanisms underlying their assembly within cells. In this article, we review the available evidence for one such mechanism, namely the coupling of protein complex assembly to translation at the polysome. We discuss research showing that co-translational assembly can occur in both prokaryotic and eukaryotic organisms and can have important implications for the correct functioning of the complexes that result. Co-translational assembly can occur for both homomeric and heteromeric protein complexes and for both proteins that are translated directly into the cytoplasm and those that are translated into or across membranes. Finally, we discuss the properties of proteins that are most likely to be associated with co-translational assembly.
Collapse
|
25
|
Franco R, Martínez-Pinilla E, Lanciego JL, Navarro G. Basic Pharmacological and Structural Evidence for Class A G-Protein-Coupled Receptor Heteromerization. Front Pharmacol 2016; 7:76. [PMID: 27065866 PMCID: PMC4815248 DOI: 10.3389/fphar.2016.00076] [Citation(s) in RCA: 84] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Accepted: 03/11/2016] [Indexed: 12/25/2022] Open
Abstract
Cell membrane receptors rarely work on isolation, often they form oligomeric complexes with other receptor molecules and they may directly interact with different proteins of the signal transduction machinery. For a variety of reasons, rhodopsin-like class A G-protein-coupled receptors (GPCRs) seem an exception to the general rule of receptor-receptor direct interaction. In fact, controversy surrounds their potential to form homo- hetero-dimers/oligomers with other class A GPCRs; in a sense, the field is going backward instead of forward. This review focuses on the convergent, complementary and telling evidence showing that homo- and heteromers of class A GPCRs exist in transfected cells and, more importantly, in natural sources. It is time to decide between questioning the occurrence of heteromers or, alternatively, facing the vast scientific and technical challenges that class A receptor-dimer/oligomer existence pose to Pharmacology and to Drug Discovery.
Collapse
Affiliation(s)
- Rafael Franco
- Departament de Bioquímica i Biomedicina Molecular, Facultat de Biología, Universitat de BarcelonaBarcelona, Spain; Centro de Investigación Biomédica en Red: Enfermedades Neurodegenerativas (CIBERNED), Instituto de Salud Carlos IIIMadrid, Spain; Institute of Biomedicine, University of BarcelonaBarcelona, Spain
| | - Eva Martínez-Pinilla
- Instituto de Neurociencias del Principado de Asturias, Departamento de Morfología y Biología Celular, Facultad de Medicina, Universidad de OviedoAsturias, Spain; Neurosciences Division, Centre for Applied Medical Research, University of NavarraPamplona, Spain; Instituto de Investigaciones Sanitarias de NavarraPamplona, Spain
| | - José L Lanciego
- Centro de Investigación Biomédica en Red: Enfermedades Neurodegenerativas (CIBERNED), Instituto de Salud Carlos IIIMadrid, Spain; Neurosciences Division, Centre for Applied Medical Research, University of NavarraPamplona, Spain; Instituto de Investigaciones Sanitarias de NavarraPamplona, Spain
| | - Gemma Navarro
- Departament de Bioquímica i Biomedicina Molecular, Facultat de Biología, Universitat de BarcelonaBarcelona, Spain; Centro de Investigación Biomédica en Red: Enfermedades Neurodegenerativas (CIBERNED), Instituto de Salud Carlos IIIMadrid, Spain
| |
Collapse
|
26
|
Glass M, Govindpani K, Furkert DP, Hurst DP, Reggio PH, Flanagan JU. One for the Price of Two…Are Bivalent Ligands Targeting Cannabinoid Receptor Dimers Capable of Simultaneously Binding to both Receptors? Trends Pharmacol Sci 2016; 37:353-363. [PMID: 26917061 DOI: 10.1016/j.tips.2016.01.010] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2015] [Revised: 01/27/2016] [Accepted: 01/29/2016] [Indexed: 10/22/2022]
Abstract
Bivalent ligands bridging two G-protein-coupled receptors (GPCRs) provide valuable pharmacological tools to target oligomers. The success of therapeutically targeting the cannabinoid CB1 receptor has been limited, in part due to its widespread neuronal distribution. Therefore, CB1 ligands targeting oligomers that exhibit restricted distribution or altered pharmacology are highly desirable, and several bivalent ligands containing a CB1 pharmacophore have been reported. Bivalent ligand action presumes that the ligand simultaneously binds to both receptors within the dimeric complex. However, based on the current understanding of CB1 ligand binding, existing bivalent ligands are too short to bind both receptors simultaneously. However, ligands with longer linkers may not be the solution, because evidence suggests that ligands enter CB1 through the lipid bilayer and, thus, linkers are unlikely to exit the receptor through its external face. Thus, the entire premise of designing bivalent ligands targeting CB1 must be revisited.
Collapse
Affiliation(s)
- Michelle Glass
- Department of Pharmacology, School of Medical Sciences, University of Auckland, Private Bag 92019, Auckland, New Zealand.
| | - Karan Govindpani
- Department of Pharmacology, School of Medical Sciences, University of Auckland, Private Bag 92019, Auckland, New Zealand
| | - Daniel P Furkert
- School of Chemical Sciences, University of Auckland, Private Bag 92019, Auckland, New Zealand
| | - Dow P Hurst
- Center for Drug Design, University of North Carolina Greensboro, Greensboro, NC 27402, USA
| | - Patricia H Reggio
- Center for Drug Design, University of North Carolina Greensboro, Greensboro, NC 27402, USA
| | - Jack U Flanagan
- Department of Pharmacology, School of Medical Sciences, University of Auckland, Private Bag 92019, Auckland, New Zealand; Auckland Cancer Society Research Centre and Maurice Wilkens Centre for Molecular Biodiscovery, University of Auckland, Private Bag 92019, Auckland, New Zealand
| |
Collapse
|
27
|
Beaudry H, Gendron L, Morón JA. Implication of delta opioid receptor subtype 2 but not delta opioid receptor subtype 1 in the development of morphine analgesic tolerance in a rat model of chronic inflammatory pain. Eur J Neurosci 2015; 41:901--7. [PMID: 25639561 DOI: 10.1111/ejn.12829] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Revised: 11/11/2014] [Accepted: 12/10/2014] [Indexed: 12/20/2022]
Abstract
Opioids are well known for their robust analgesic effects. Chronic activation of mu opioid receptors (MOPs) is, however, accompanied by various unwanted effects such as analgesic tolerance. Among other mechanisms, interactions between MOPs and delta opioid receptors (DOPs) are thought to play an important role in morphine-induced behavioral adaptations. Interestingly, certain conditions such as inflammation enhance the function of the DOP through a MOP-dependent mechanism. Here, we investigated the role of DOPs during the development of morphine tolerance in an animal model of chronic inflammatory pain. Using behavioral approaches, we first established that repeated systemic morphine treatment induced morphine analgesic tolerance in rats coping with chronic inflammatory pain. We then observed that blockade of DOPs with subcutaneous naltrindole (NTI), a selective DOP antagonist, significantly attenuated the development of morphine tolerance in a dose-dependent manner. We confirmed that this effect was DOP mediated by showing that an acute injection of NTI had no effect on morphine-induced analgesia in naive animals. Previous pharmacological characterizations revealed the existence of DOP subtype 1 and DOP subtype 2. As opposed to NTI, 7-benzylidenenaltrexone and naltriben were reported to be selective DOP subtype 1 and DOP subtype 2 antagonists, respectively. Interestingly, naltriben but not 7-benzylidenenaltrexone was able to attenuate the development of morphine analgesic tolerance in inflamed rats. Altogether, our results suggest that targeting of DOP subtype 2 with antagonists provides a valuable strategy to attenuate the analgesic tolerance that develops after repeated morphine administration in the setting of chronic inflammatory pain.
Collapse
Affiliation(s)
- H Beaudry
- Department of Anesthesiology, College of Physicians and Surgeons, Columbia University Medical Center, Columbia University, P&S Box 46, 630 West 168th Street, New York, NY, 10032, USA; Department of Physiology and Biophysics, Faculty of Medicine and Health Sciences, Université de Sherbrooke, 3001, 12th Avenue North, Sherbrooke, QC, J1H 5N4, Canada
| | | | | |
Collapse
|
28
|
Abstract
G-protein-coupled receptors (GPCRs) are classified into A to F subfamilies in which only families A, B, and C are present in mammals. Some of these GPCRs were found to form higher ordered structures such as oligomers with the discovery of interacting receptors in the form of homomers or heteromers. The importance of these oligomers on regulating receptor functions has recently been an intense research focus. It has been proposed that receptor oligomer formation has impact on its physiological importance on receptor trafficking, signaling, ligand-related regulation, and also is related to certain diseases. The present body of knowledge, however, comprises mainly intra-family oligomers formation and their consequences. Inter-family oligomers are recognized but there is limited information. This article aims to provide a current view regarding inter-family GPCR oligomerization in the subfamilies A, B, and C found in mammals.
Collapse
Affiliation(s)
- Hans K. H. Ng
- Department of Endocrinology, School of Biological Sciences, The University of Hong Kong, Hong Kong, China
| | - Billy K. C. Chow
- Department of Endocrinology, School of Biological Sciences, The University of Hong Kong, Hong Kong, China
- *Correspondence: Billy K. C. Chow, Endocrinology, School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong, China e-mail:
| |
Collapse
|
29
|
Abstract
The assembly of individual proteins into functional complexes is fundamental to nearly all biological processes. In recent decades, many thousands of homomeric and heteromeric protein complex structures have been determined, greatly improving our understanding of the fundamental principles that control symmetric and asymmetric quaternary structure organization. Furthermore, our conception of protein complexes has moved beyond static representations to include dynamic aspects of quaternary structure, including conformational changes upon binding, multistep ordered assembly pathways, and structural fluctuations occurring within fully assembled complexes. Finally, major advances have been made in our understanding of protein complex evolution, both in reconstructing evolutionary histories of specific complexes and in elucidating general mechanisms that explain how quaternary structure tends to evolve. The evolution of quaternary structure occurs via changes in self-assembly state or through the gain or loss of protein subunits, and these processes can be driven by both adaptive and nonadaptive influences.
Collapse
Affiliation(s)
- Joseph A Marsh
- Medical Research Council Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Western General Hospital, Edinburgh EH4 2XU, United Kingdom;
| | | |
Collapse
|
30
|
Schuster DJ, Metcalf MD, Kitto KF, Messing RO, Fairbanks CA, Wilcox GL. Ligand requirements for involvement of PKCε in synergistic analgesic interactions between spinal μ and δ opioid receptors. Br J Pharmacol 2014; 172:642-53. [PMID: 24827408 DOI: 10.1111/bph.12774] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2013] [Revised: 04/29/2014] [Accepted: 05/01/2014] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND AND PURPOSE We recently found that PKCε was required for spinal analgesic synergy between two GPCRs, δ opioid receptors and α2 A adrenoceptors, co-located in the same cellular subpopulation. We sought to determine if co-delivery of μ and δ opioid receptor agonists would similarly result in synergy requiring PKCε. EXPERIMENTAL APPROACH Combinations of μ and δ opioid receptor agonists were co-administered intrathecally by direct lumbar puncture to PKCε-wild-type (PKCε-WT) and -knockout (PKCε-KO) mice. Antinociception was assessed using the hot-water tail-flick assay. Drug interactions were evaluated by isobolographic analysis. KEY RESULTS All agonists produced comparable antinociception in both PKCε-WT and PKCε-KO mice. Of 19 agonist combinations that produced analgesic synergy, only 3 required PKCε for a synergistic interaction. In these three combinations, one of the agonists was morphine, although not all combinations involving morphine required PKCε. Morphine + deltorphin II and morphine + deltorphin I required PKCε for synergy, whereas a similar combination, morphine + deltorphin, did not. Additionally, morphine + oxymorphindole required PKCε for synergy, whereas a similar combination, morphine + oxycodindole, did not. CONCLUSIONS AND IMPLICATIONS We discovered biased agonism for a specific signalling pathway at the level of spinally co-delivered opioid agonists. As the bias is only revealed by an appropriate ligand combination and cannot be accounted for by a single drug, it is likely that the receptors these agonists act on are interacting with each other. Our results support the existence of μ and δ opioid receptor heteromers at the spinal level in vivo. LINKED ARTICLES This article is part of a themed section on Opioids: New Pathways to Functional Selectivity. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2015.172.issue-2.
Collapse
Affiliation(s)
- D J Schuster
- Department of Neuroscience, Medical School, University of Minnesota, Minneapolis, MN, USA
| | | | | | | | | | | |
Collapse
|
31
|
Affiliation(s)
- Javier González-Maeso
- Departments of Psychiatry and Neurology, Friedman Brain Institute, Icahn School of Medicine at Mount Sinai New York, NY, USA
| |
Collapse
|
32
|
Fujita W, Gomes I, Devi LA. Heteromers of μ-δ opioid receptors: new pharmacology and novel therapeutic possibilities. Br J Pharmacol 2014; 172:375-87. [PMID: 24571499 DOI: 10.1111/bph.12663] [Citation(s) in RCA: 75] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2013] [Revised: 02/05/2014] [Accepted: 02/17/2014] [Indexed: 12/22/2022] Open
Abstract
UNLABELLED Several studies suggest that heteromerization between μ (MOP) and δ (DOP) opioid receptors modulates the signalling properties of the individual receptors. For example, whereas activation of MOP receptors by an agonist induces G protein-mediated signalling, the same agonist induces β-arrestin-mediated signalling in the context of the MOP-DOP receptor heteromer. Moreover, heteromer-mediated signalling is allosterically modulated by a combination of MOP and DOP receptor ligands. This has implications in analgesia given that morphine-induced antinociception can be potentiated by DOP receptor ligands. Recently reagents selectively targeting the MOP-DOP receptor heteromer such as bivalent ligands, antibodies or membrane permeable peptides have been generated; these reagents are enabling studies to elucidate the contribution of endogenously expressed heteromers to analgesia as well as to the development of side-effects associated with chronic opioid use. Recent advances in drug screening technology have led to the identification of a MOP-DOP receptor heteromer-biased agonist that activates both G protein-mediated and β-arrestin-mediated signalling. Moreover, this heteromer-biased agonist exhibits potent antinociceptive activity but with reduced side-effects, suggesting that ligands targeting the MOP-DOP receptor heteromer form a basis for the development of novel therapeutics for the treatment of pain. In this review, we summarize findings regarding the biological and functional characteristics of the MOP-DOP receptor heteromer and the in vitro and in vivo properties of heteromer-selective ligands. LINKED ARTICLES This article is part of a themed section on Opioids: New Pathways to Functional Selectivity. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2015.172.issue-2.
Collapse
Affiliation(s)
- Wakako Fujita
- Department of Pharmacology and Systems Therapeutics, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | | | | |
Collapse
|
33
|
Massotte D. In vivo opioid receptor heteromerization: where do we stand? Br J Pharmacol 2014; 172:420-34. [PMID: 24666391 DOI: 10.1111/bph.12702] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2013] [Revised: 03/17/2014] [Accepted: 03/19/2014] [Indexed: 12/22/2022] Open
Abstract
UNLABELLED Opioid receptors are highly homologous GPCRs that modulate brain function at all levels of neural integration, including autonomous, sensory, emotional and cognitive processing. Opioid receptors functionally interact in vivo, but the underlying mechanisms involving direct receptor-receptor interactions, affecting signalling pathways or engaging different neuronal circuits, remain unsolved. Heteromer formation through direct physical interaction between two opioid receptors or between an opioid receptor and a non-opioid one has been postulated and can be characterized by specific ligand binding, receptor signalling and trafficking properties. However, despite numerous studies in heterologous systems, evidence for physical proximity in vivo is only available for a limited number of opioid heteromers, and their physiopathological implication remains largely unknown mostly due to the lack of appropriate tools. Nonetheless, data collected so far using endogenous receptors point to a crucial role for opioid heteromers as a molecular entity that could underlie human pathologies such as alcoholism, acute or chronic pain as well as psychiatric disorders. Opioid heteromers therefore stand as new therapeutic targets for the drug discovery field. LINKED ARTICLES This article is part of a themed section on Opioids: New Pathways to Functional Selectivity. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2015.172.issue-2.
Collapse
Affiliation(s)
- D Massotte
- Institut des Neurosciences Cellulaires et Intégratives, INCI, Strasbourg, France
| |
Collapse
|
34
|
Abstract
Transient receptor potential (TRP) ion channels play a key role in sensing environmental and endogenous stimuli. Among sensory neurons, different TRP channels are widely expressed, and their expression profiles overlap. Although many TRP channels are homotetramers, we have shown that a functional tetrameric TRP channel can contain two types of monomers.
Collapse
Affiliation(s)
- Michael Jm Fischer
- Institute of Physiology and Pathophysiology; University of Erlangen-Nuremberg; Erlangen, Germany
| | | |
Collapse
|
35
|
Abstract
Guanine nucleotide binding protein (G protein)-coupled receptors (GPCRs) function in complexes with a range of molecules and proteins including ligands, G proteins, arrestins, ubiquitin, and other receptors. Elements of these complexes may interact constitutively or dynamically, dependent upon factors such as ligand binding, phosphorylation, and dephosphorylation. They may also be allosterically modulated by other proteins in a manner that changes temporally and spatially within the cell. Elucidating how these complexes function has been greatly enhanced by biophysical technologies that are able to monitor proximity and/or binding, often in real time and in live cells. These include resonance energy transfer approaches such as bioluminescence resonance energy transfer (BRET) and fluorescence resonance energy transfer (FRET). Furthermore, the use of fluorescent ligands has enabled novel insights into allosteric interactions between GPCRs. Consequently, biophysical approaches are helping to unlock the amazing diversity and bias in G protein-coupled receptor signaling.
Collapse
Affiliation(s)
- Werner C. Jaeger
- Molecular Endocrinology and Pharmacology, Harry Perkins Institute of Medical Research and Centre for Medical Research, The University of Western Australia, Perth, WA, Australia
| | - Stephen P. Armstrong
- Molecular Endocrinology and Pharmacology, Harry Perkins Institute of Medical Research and Centre for Medical Research, The University of Western Australia, Perth, WA, Australia
| | - Stephen J. Hill
- Cell Signalling Research Group, School of Life Sciences, Queen’s Medical Centre, University of Nottingham Medical School, Nottingham, UK
| | - Kevin D. G. Pfleger
- Molecular Endocrinology and Pharmacology, Harry Perkins Institute of Medical Research and Centre for Medical Research, The University of Western Australia, Perth, WA, Australia
- Dimerix Bioscience Pty Ltd, Perth, WA, Australia
- *Correspondence: Kevin D. G. Pfleger, Molecular Endocrinology and Pharmacology, Harry Perkins Institute of Medical Research and Centre for Medical Research, The University of Western Australia, QEII Medical Centre, QQ Block, 6 Verdun Street, Nedlands, Perth, WA 6009, Australia e-mail:
| |
Collapse
|
36
|
Abstract
Transcripts and/or proteins of P2X receptor (P2XR) subunits have been found in virtually all mammalian tissues. Generally more than one of the seven known P2X subunits have been identified in a given cell type. Six of the seven cloned P2X subunits can efficiently form functional homotrimeric ion channels in recombinant expression systems. This is in contrast to other ligand-gated ion channel families, such as the Cys-loop or glutamate receptors, where homomeric assemblies seem to represent the exception rather than the rule. P2XR mediated responses recorded from native tissues rarely match exactly the biophysical and pharmacological properties of heterologously expressed homomeric P2XRs. Heterotrimerization of P2X subunits is likely to account for this observed diversity. While the existence of heterotrimeric P2X2/3Rs and their role in physiological processes is well established, the composition of most other P2XR heteromers and/or the interplay between distinct trimeric receptor complexes in native tissues is not clear. After a description of P2XR assembly and the structure of the intersubunit ATP-binding site, this review summarizes the distribution of P2XR subunits in selected mammalian cell types and the biochemically and/or functionally characterized heteromeric P2XRs that have been observed upon heterologous co-expression of P2XR subunits. We further provide examples where the postulated heteromeric P2XRs have been suggested to occur in native tissues and an overview of the currently available pharmacological tools that have been used to discriminate between homo- and heteromeric P2XRs.
Collapse
Affiliation(s)
- Anika Saul
- Department of Molecular Biology of Neuronal Signals, Max Planck Institute for Experimental Medicine Göttingen, Germany
| | - Ralf Hausmann
- Molecular Pharmacology, RWTH Aachen University Aachen, Germany
| | - Achim Kless
- Department of Discovery Informatics, Grünenthal GmbH, Global Drug Discovery Aachen, Germany
| | - Annette Nicke
- Department of Molecular Biology of Neuronal Signals, Max Planck Institute for Experimental Medicine Göttingen, Germany
| |
Collapse
|
37
|
Navarro G, McCormick PJ, Mallol J, Lluís C, Franco R, Cortés A, Casadó V, Canela EI, Ferré S. Detection of receptor heteromers involving dopamine receptors by the sequential BRET-FRET technology. Methods Mol Biol 2013; 964:95-105. [PMID: 23296780 PMCID: PMC9386282 DOI: 10.1007/978-1-62703-251-3_7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Abstract
Until very recently, dopamine receptors, like other G-protein-coupled receptors, were believed to function as individual units on the cell surface. Now it has been described by several groups including ours that dopamine receptors not only function as homomers but also form heteromers with other receptors at the membrane level. Bioluminescence and fluorescence resonance energy transfer (BRET and FRET) based techniques have been very useful to determine the interaction between two receptors, but to demonstrate the existence of higher-order complexes involving more than two molecules requires more sophisticated techniques. Combining BRET and FRET in the Sequential BRET-FRET (SRET) technique permits heteromers formed by three different proteins to be identified. In SRET experiments, the oxidation of a Renilla Luciferase substrate triggers acceptor excitation by BRET and subsequent energy transfer to a FRET acceptor. Using this methodology here we describe the heteromerization between adenosine A(2A), dopamine D(2), and cannabinoids CB(1) receptors in living cells.
Collapse
Affiliation(s)
- Gemma Navarro
- CIBERNED, Department of Biochemistry and Molecular Biology, Faculty of Biology, University of Barcelona, Barcelona, Spain
| | - Peter J. McCormick
- CIBERNED, Department of Biochemistry and Molecular Biology, Faculty of Biology, University of Barcelona, Barcelona, Spain
| | - Josefa Mallol
- CIBERNED, Department of Biochemistry and Molecular Biology, Faculty of Biology, University of Barcelona, Barcelona, Spain
| | - Carme Lluís
- CIBERNED, Department of Biochemistry and Molecular Biology, Faculty of Biology, University of Barcelona, Barcelona, Spain
| | - Rafael Franco
- CIBERNED, Department of Biochemistry and Molecular Biology, Faculty of Biology, University of Barcelona, Barcelona, Spain,CIMA Neurociencias, Avda Pio XII 55, Pamplona, Spain
| | - Antoni Cortés
- CIBERNED, Department of Biochemistry and Molecular Biology, Faculty of Biology, University of Barcelona, Barcelona, Spain
| | - Vicent Casadó
- CIBERNED, Department of Biochemistry and Molecular Biology, Faculty of Biology, University of Barcelona, Barcelona, Spain
| | - Enric I. Canela
- CIBERNED, Department of Biochemistry and Molecular Biology, Faculty of Biology, University of Barcelona, Barcelona, Spain
| | - Sergi Ferré
- National Institute on Drug Abuse, IRP, NIH, DHHS, Baltimore, Maryland, USA,Correspondence to: Sergi Ferré, National Institute on Drug Abuse, IRP, NIH, DHHS, 251 Bayview Blvd, Baltimore, MD21224, USA. Tel.: +1 443 740 2647; Fax: +1 443 740 2816;
| |
Collapse
|
38
|
Abstract
Receptor heteromerization has the potential to alter every facet of receptor functioning, leading to new pharmacological profiles with increased signaling diversity and regulation from that of the monomeric receptor, or indeed receptor homomer. An understanding of the molecular consequences of receptor heteromerization will provide new insights into the physiology and pathology mediated by receptors, expanding the possibilities for pharmacological discovery. Particularly advantageous approaches to investigate novel heteromer pharmacology utilize cell-based assay technologies that assess ligand-dependent functional responses specific to the receptor heteromer. Importantly, this allows for differentiation of heteromer-specific pharmacology from pharmacology associated with the co-expressed receptor monomers and homomers. The Receptor-Heteromer Investigation Technology (Receptor-HIT) successfully employs a proximity-based reporter system, such as bioluminescence resonance energy transfer (BRET), in a configuration that enables determination of such heteromer-specific pharmacology. Therefore, Receptor-HIT provides a simple, robust and versatile approach for investigating the elusive "biochemical fingerprint" of receptor heteromers.
Collapse
Affiliation(s)
- Elizabeth K. M. Johnstone
- Laboratory for Molecular Endocrinology – GPCRs, Western Australian Institute for Medical Research and Centre for Medical Research, The University of Western AustraliaPerth, WA, Australia
| | - Kevin D. G. Pfleger
- Laboratory for Molecular Endocrinology – GPCRs, Western Australian Institute for Medical Research and Centre for Medical Research, The University of Western AustraliaPerth, WA, Australia
- Dimerix Bioscience Pty LtdPerth, WA, Australia
| |
Collapse
|
39
|
Brown RM, Mustafa S, Ayoub MA, Dodd PR, Pfleger KDG, Lawrence AJ. mGlu5 Receptor Functional Interactions and Addiction. Front Pharmacol 2012; 3:84. [PMID: 22586398 PMCID: PMC3345582 DOI: 10.3389/fphar.2012.00084] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2011] [Accepted: 04/16/2012] [Indexed: 12/22/2022] Open
Abstract
The idea of “receptor mosaics” is that proteins may form complex and dynamic networks with respect to time and composition. These have the potential to markedly expand the diversity and specificity of G protein-coupled receptors (GPCR) signaling, particularly in neural cells, where a few key receptors have been implicated in many neurological and psychiatric disorders, including addiction. Metabotropic glutamate type 5 receptors (mGlu5) can form complexes with other GPCRs, including adenosine A2A and dopamine D2 receptors. mGlu5-containing complexes have been reported in the striatum, a brain region critical for mediating the rewarding and incentive motivational properties of drugs of abuse. mGlu5-containing complexes and/or downstream interactions between divergent receptors may play roles in addiction–relevant behaviors. Interactions between mGlu5 receptors and other GPCRs can regulate the rewarding and conditioned effects of drugs as well as drug-seeking behaviors. mGlu5 complexes may influence striatal function, including GABAergic output of striatopallidal neurons and glutamatergic input from corticostriatal afferents. Given their discrete localization, mGlu5-[non-mGlu5] receptor interactions and/or mGlu5-containing complexes may minimize off-target effects and thus provide a novel avenue for drug discovery. The therapeutic targeting of receptor–receptor functional interactions and/or receptor mosaics in a tissue specific or temporal manner (for example, a sub-population of receptors in a “pathological state”) might reduce detrimental side effects that may otherwise impair vital brain functions.
Collapse
Affiliation(s)
- Robyn M Brown
- Addiction Neuroscience, Behavioural Neuroscience, Florey Neuroscience Institutes, University of Melbourne Parkville, VIC, Australia
| | | | | | | | | | | |
Collapse
|
40
|
Mustafa S, See HB, Seeber RM, Armstrong SP, White CW, Ventura S, Ayoub MA, Pfleger KDG. Identification and profiling of novel α1A-adrenoceptor-CXC chemokine receptor 2 heteromer. J Biol Chem 2012; 287:12952-65. [PMID: 22371491 PMCID: PMC3340001 DOI: 10.1074/jbc.m111.322834] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2011] [Revised: 02/20/2012] [Indexed: 01/14/2023] Open
Abstract
We have provided the first evidence for specific heteromerization between the α(1A)-adrenoceptor (α(1A)AR) and CXC chemokine receptor 2 (CXCR2) in live cells. α(1A)AR and CXCR2 are both expressed in areas such as the stromal smooth muscle layer of the prostate. By utilizing the G protein-coupled receptor (GPCR) heteromer identification technology on the live cell-based bioluminescence resonance energy transfer (BRET) assay platform, our studies in human embryonic kidney 293 cells have identified norepinephrine-dependent β-arrestin recruitment that was in turn dependent upon co-expression of α(1A)AR with CXCR2. These findings have been supported by co-localization observed using confocal microscopy. This norepinephrine-dependent β-arrestin recruitment was inhibited not only by the α(1)AR antagonist Terazosin but also by the CXCR2-specific allosteric inverse agonist SB265610. Furthermore, Labetalol, which is marketed for hypertension as a nonselective β-adrenoceptor antagonist with α(1)AR antagonist properties, was identified as a heteromer-specific-biased agonist exhibiting partial agonism for inositol phosphate production but essentially full agonism for β-arrestin recruitment at the α(1A)AR-CXCR2 heteromer. Finally, bioluminescence resonance energy transfer studies with both receptors tagged suggest that α(1A)AR-CXCR2 heteromerization occurs constitutively and is not modulated by ligand. These findings support the concept of GPCR heteromer complexes exhibiting distinct pharmacology, thereby providing additional mechanisms through which GPCRs can potentially achieve their diverse biological functions. This has important implications for the use and future development of pharmaceuticals targeting these receptors.
Collapse
MESH Headings
- Adrenergic alpha-1 Receptor Antagonists/pharmacology
- Adrenergic alpha-Agonists/pharmacology
- Allosteric Regulation/physiology
- Animals
- Arrestins/metabolism
- CHO Cells
- Chemokines/metabolism
- Cricetinae
- HEK293 Cells
- Humans
- Inositol Phosphates/metabolism
- Labetalol/pharmacology
- Male
- Mice
- Mice, Inbred C57BL
- Norepinephrine/pharmacology
- Prazosin/analogs & derivatives
- Prazosin/pharmacology
- Prostate/metabolism
- Protein Structure, Quaternary
- Receptors, Adrenergic, alpha-1/chemistry
- Receptors, Adrenergic, alpha-1/metabolism
- Receptors, G-Protein-Coupled/chemistry
- Receptors, G-Protein-Coupled/metabolism
- Receptors, Interleukin-8B/chemistry
- Receptors, Interleukin-8B/metabolism
- beta-Arrestins
Collapse
Affiliation(s)
- Sanam Mustafa
- From the Laboratory for Molecular Endocrinology-G Protein-Coupled Receptors, Western Australian Institute for Medical Research and Centre for Medical Research, The University of Western Australia, Nedlands, Perth, Western Australia 6009
| | - Heng B. See
- From the Laboratory for Molecular Endocrinology-G Protein-Coupled Receptors, Western Australian Institute for Medical Research and Centre for Medical Research, The University of Western Australia, Nedlands, Perth, Western Australia 6009
| | - Ruth M. Seeber
- From the Laboratory for Molecular Endocrinology-G Protein-Coupled Receptors, Western Australian Institute for Medical Research and Centre for Medical Research, The University of Western Australia, Nedlands, Perth, Western Australia 6009
| | - Stephen P. Armstrong
- From the Laboratory for Molecular Endocrinology-G Protein-Coupled Receptors, Western Australian Institute for Medical Research and Centre for Medical Research, The University of Western Australia, Nedlands, Perth, Western Australia 6009
| | - Carl W. White
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria 3052 and
| | - Sabatino Ventura
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria 3052 and
| | - Mohammed Akli Ayoub
- From the Laboratory for Molecular Endocrinology-G Protein-Coupled Receptors, Western Australian Institute for Medical Research and Centre for Medical Research, The University of Western Australia, Nedlands, Perth, Western Australia 6009
| | - Kevin D. G. Pfleger
- From the Laboratory for Molecular Endocrinology-G Protein-Coupled Receptors, Western Australian Institute for Medical Research and Centre for Medical Research, The University of Western Australia, Nedlands, Perth, Western Australia 6009
- Dimerix Bioscience Pty Ltd, Nedlands, Perth, Western Australia 6009, Australia
| |
Collapse
|
41
|
Koschatzky S, Tschammer N, Gmeiner P. Cross-receptor interactions between dopamine D2L and neurotensin NTS1 receptors modulate binding affinities of dopaminergics. ACS Chem Neurosci 2011; 2:308-16. [PMID: 22778874 DOI: 10.1021/cn200020y] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2011] [Accepted: 04/11/2011] [Indexed: 11/30/2022] Open
Abstract
Dopaminergic systems have been described to functionally interact with the neuromodulatory peptide neurotensin. Employing fluorescence detected coimmunoprecipitation and radioligand binding experiments, we herein demonstrate that coexpression of dopamine D(2L) receptor and the neurotensin receptor subtype NTS(1) leads to physical interaction and the formation of heteromers in transfected human embryonic kidney 293 cells. In this in vitro system, a trans-inhibitory effect on the agonist binding affinity of D(2) was observed in presence of neurotensin. To correlate between the functional properties of dopaminergic agents and the magnitude of neurotensin-induced modulation of D(2L) binding affinities in cells coexpressing D(2L) and NTS(1), a structurally diverse set of dopamine receptor agonists, partial agonists, and antagonists was tested. Ligand specific profiles indicating substantial bias between ligand efficacy and transmodulation were discovered, suggesting a heteromerization-based functional selectivity. In the presence of neurotensin, the novel D(2) agonist FAUC 326 displayed a 34-fold decrease of binding affinity in cells coexpressing D(2L) and NTS(1).
Collapse
Affiliation(s)
- Susanne Koschatzky
- Department of Chemistry and Pharmacy, Emil Fischer Center, Friedrich-Alexander University, Schuhstrasse 19, D- 91052 Erlangen, Germany
| | - Nuska Tschammer
- Department of Chemistry and Pharmacy, Emil Fischer Center, Friedrich-Alexander University, Schuhstrasse 19, D- 91052 Erlangen, Germany
| | - Peter Gmeiner
- Department of Chemistry and Pharmacy, Emil Fischer Center, Friedrich-Alexander University, Schuhstrasse 19, D- 91052 Erlangen, Germany
| |
Collapse
|
42
|
Bobanovic LK, Royle SJ, Murrell-Lagnado RD. P2X receptor trafficking in neurons is subunit specific. J Neurosci 2002; 22:4814-24. [PMID: 12077178 PMCID: PMC6757758] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/25/2023] Open
Abstract
P2X receptors within the CNS mediate excitatory synaptic transmission and also act presynaptically to modulate neurotransmitter release. We have studied the targeting and trafficking of P2X4 and P2X2 receptors heterologously expressed in cultured olfactory bulb neurons. Homomeric P2X4 receptors had a punctate distribution, and many of the puncta colocalized with early endosomes. In contrast, P2X2 receptors were primarily localized at the plasma membrane. By antibody-labeling of surface receptors in living neurons, we showed that P2X4 receptors undergo rapid constitutive internalization and subsequent reinsertion into the plasma membrane, whereas P2X2 receptors were not regulated in such a way. The internalization of P2X4 receptors was dynamin-dependent, and the binding of ATP enhanced the basal rate of retrieval in a Ca2+-independent manner. The presence of the P2X4 subunit in a P2X4/6 heteromer governed the trafficking properties of the receptor. P2X receptors acted presynaptically to enhance the release of glutamate, suggesting that the regulated cycling of P2X4-containing receptors might provide a mechanism for modulation of synaptic transmission.
Collapse
Affiliation(s)
- Laura K Bobanovic
- Department of Pharmacology, University of Cambridge, Cambridge CB2 1PD, United Kingdom
| | | | | |
Collapse
|
43
|
King BF, Townsend-Nicholson A, Wildman SS, Thomas T, Spyer KM, Burnstock G. Coexpression of rat P2X2 and P2X6 subunits in Xenopus oocytes. J Neurosci 2000; 20:4871-7. [PMID: 10864944 PMCID: PMC6772291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023] Open
Abstract
Transcripts for P2X(2) and P2X(6) subunits are present in rat CNS and frequently colocalize in the same brainstem nuclei. When rat P2X(2) (rP2X(2)) and rat P2X(6) (rP2X(6)) receptors were expressed individually in Xenopus oocytes and studied under voltage-clamp conditions, only homomeric rP2X(2) receptors were fully functional and gave rise to large inward currents (2-3 microA) to extracellular ATP. Coexpression of rP2X(2) and rP2X(6) subunits in Xenopus oocytes resulted in a heteromeric rP2X(2/6) receptor, which showed a significantly different phenotype from the wild-type rP2X(2) receptor. Differences included reduction in agonist potencies and, in some cases (e.g., Ap(4)A), significant loss of agonist activity. ATP-evoked inward currents were biphasic at the heteromeric rP2X(2/6) receptor, particularly when Zn(2+) ions were present or extracellular pH was lowered. The pH range was narrower for H(+) enhancement of ATP responses at the heteromeric rP2X(2/6) receptor. Also, H(+) ions inhibited ATP responses at low pH levels (<pH 6.3). The pH-dependent blocking activity of suramin was changed at this heteromeric receptor, although the potentiating effect of Zn(2+) on ATP responses was unchanged. Thus, the rP2X(2/6) receptor is a functionally modified P2X(2)-like receptor with a distinct pattern of pH modulation of ATP activation and suramin blockade. Although homomeric P2X(6) receptors function poorly, the P2X(6) subunit can contribute to functional heteromeric P2X channels and may influence the phenotype of native P2X receptors in those cells in which it is expressed.
Collapse
Affiliation(s)
- B F King
- Autonomic Neuroscience Institute, Royal Free and University College Medical School, Royal Free Campus, Hampstead, London NW3 2PF, United Kingdom.
| | | | | | | | | | | |
Collapse
|
44
|
Logan SM, Rivera FE, Leonard JP. Protein kinase C modulation of recombinant NMDA receptor currents: roles for the C-terminal C1 exon and calcium ions. J Neurosci 1999; 19:974-86. [PMID: 9920661 PMCID: PMC6782132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2023] Open
Abstract
Protein kinase C (PKC) positively modulates NMDA receptor (NMDAR) currents. In contrast to previous reports, this study determines the importance of individual exons in the mechanism underlying the potentiation process by examining the complete set of eight naturally occurring splice variants expressed in Xenopus oocytes both as homomers and as heteromeric NR1/NR2A or NR1/NR2B complexes. After PKC stimulation, homomeric currents demonstrated a high level of potentiation ( approximately 500% of untreated baseline currents) that reduced to a lower level ( approximately 300% of baseline) in variants containing the first C-terminal exon (C1). An ANOVA showed that only C1 and no other exon or interaction of exons determined the degree of NMDAR current modulation by PKC. When recordings were performed in solutions in which barium replaces calcium, only the lower form of potentiation was observed, regardless of the splice variant exon composition. This suggested an important role for calcium in the PKC modulation of homomeric NMDA splice variant currents in which the C1 exon also participates. The effectiveness of the C1 exon to reduce the higher form of potentiation is modulated by heteromeric assemblies with NR2A heteromers yielding smaller levels of potentiation and a larger C1 exon effect compared with NR2B heteromers. The heteromers demonstrated the higher form of potentiation even in the absence of calcium. Furthermore, calcium had different effects in the potentiation of the heteromers depending on the NR2 subunit. This study refines the region of the NR1 subunit involved in a modulation crucial to the function of NMDA receptors and provides evidence that the NR2A and NR2B subunits realize this modulation differentially.
Collapse
Affiliation(s)
- S M Logan
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, Illinois 60607-7056, USA
| | | | | |
Collapse
|