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Comps-Agrar L, Kniazeff J, Nørskov-Lauritsen L, Maurel D, Gassmann M, Gregor N, Prézeau L, Bettler B, Durroux T, Trinquet E, Pin JP. The oligomeric state sets GABA(B) receptor signalling efficacy. EMBO J 2011; 30:2336-49. [PMID: 21552208 PMCID: PMC3116278 DOI: 10.1038/emboj.2011.143] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2011] [Accepted: 04/11/2011] [Indexed: 12/20/2022] Open
Abstract
G protein-coupled receptors (GPCRs) have key roles in cell-cell communication. Recent data suggest that these receptors can form large complexes, a possibility expected to expand the complexity of this regulatory system. Among the brain GPCRs, the heterodimeric GABA(B) receptor is one of the most abundant, being distributed in most brain regions, on either pre- or post-synaptic elements. Here, using specific antibodies labelled with time-resolved FRET compatible fluorophores, we provide evidence that the heterodimeric GABA(B) receptor can form higher-ordered oligomers in the brain, as suggested by the close proximity of the GABA(B1) subunits. Destabilizing the oligomers using a competitor or a GABA(B1) mutant revealed different G protein coupling efficiencies depending on the oligomeric state of the receptor. By examining, in heterologous system, the G protein coupling properties of such GABA(B) receptor oligomers composed of a wild-type and a non-functional mutant heterodimer, we provide evidence for a negative functional cooperativity between the GABA(B) heterodimers.
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Affiliation(s)
- Laëtitia Comps-Agrar
- CNRS, UMR5203, Institut de Génomique Fonctionnelle, Department of Molecular Pharmacology, Montpellier, France
- INSERM, U661, Montpellier, France
- Universités de Montpellier 1 and 2, UMR5203, Montpellier, France
- Cisbio, Parc Technologique Marcel Boiteux, Bagnols/Cèze Cedex, France
| | - Julie Kniazeff
- CNRS, UMR5203, Institut de Génomique Fonctionnelle, Department of Molecular Pharmacology, Montpellier, France
- INSERM, U661, Montpellier, France
- Universités de Montpellier 1 and 2, UMR5203, Montpellier, France
| | - Lenea Nørskov-Lauritsen
- CNRS, UMR5203, Institut de Génomique Fonctionnelle, Department of Molecular Pharmacology, Montpellier, France
- INSERM, U661, Montpellier, France
- Universités de Montpellier 1 and 2, UMR5203, Montpellier, France
| | - Damien Maurel
- CNRS, UMR5203, Institut de Génomique Fonctionnelle, Department of Molecular Pharmacology, Montpellier, France
- INSERM, U661, Montpellier, France
- Universités de Montpellier 1 and 2, UMR5203, Montpellier, France
- Cisbio, Parc Technologique Marcel Boiteux, Bagnols/Cèze Cedex, France
| | - Martin Gassmann
- Department of Biomedicine, Institute of Physiology, Pharmazentrum, University of Basel, Basel, Switzerland
| | - Nathalie Gregor
- Cisbio, Parc Technologique Marcel Boiteux, Bagnols/Cèze Cedex, France
| | - Laurent Prézeau
- CNRS, UMR5203, Institut de Génomique Fonctionnelle, Department of Molecular Pharmacology, Montpellier, France
- INSERM, U661, Montpellier, France
- Universités de Montpellier 1 and 2, UMR5203, Montpellier, France
| | - Bernhard Bettler
- Department of Biomedicine, Institute of Physiology, Pharmazentrum, University of Basel, Basel, Switzerland
| | - Thierry Durroux
- CNRS, UMR5203, Institut de Génomique Fonctionnelle, Department of Molecular Pharmacology, Montpellier, France
- INSERM, U661, Montpellier, France
- Universités de Montpellier 1 and 2, UMR5203, Montpellier, France
| | - Eric Trinquet
- Cisbio, Parc Technologique Marcel Boiteux, Bagnols/Cèze Cedex, France
| | - Jean-Philippe Pin
- CNRS, UMR5203, Institut de Génomique Fonctionnelle, Department of Molecular Pharmacology, Montpellier, France
- INSERM, U661, Montpellier, France
- Universités de Montpellier 1 and 2, UMR5203, Montpellier, France
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52
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Nakata H, Suzuki T, Namba K, Oyanagi K. Dimerization of G protein-coupled purinergic receptors: increasing the diversity of purinergic receptor signal responses and receptor functions. J Recept Signal Transduct Res 2011; 30:337-46. [PMID: 20843271 DOI: 10.3109/10799893.2010.509729] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
It is well accepted that G protein-coupled receptors (GPCRs) arrange into dimers or higher-order oligomers that may modify various functions of GPCRs. GPCR-type purinergic receptors (i.e. adenosine and P2Y receptors) tend to form heterodimers with GPCRs not only of the different families but also of the same purinergic receptor families, leading to alterations in functional properties. In the present review, we focus on current knowledge of the formation of heterodimers between metabotropic purinergic receptors that activate novel functions in response to extracellular nucleosides/nucleotides, revealing that the dimerization seems to be employed for 'fine-tuning' of purinergic signaling. Thus, the relationship between adenosine and adenosine triphosphate is likely to be more and more intimate than simply being a metabolite of the other.
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Affiliation(s)
- Hiroyasu Nakata
- Department of Molecular Cell Signaling, Tokyo Metropolitan Institute for Neuroscience, Fuchu, Japan.
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Ollivier JF, Shahrezaei V, Swain PS. Scalable rule-based modelling of allosteric proteins and biochemical networks. PLoS Comput Biol 2010; 6:e1000975. [PMID: 21079669 PMCID: PMC2973810 DOI: 10.1371/journal.pcbi.1000975] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2010] [Accepted: 09/24/2010] [Indexed: 01/14/2023] Open
Abstract
Much of the complexity of biochemical networks comes from the information-processing abilities of allosteric proteins, be they receptors, ion-channels, signalling molecules or transcription factors. An allosteric protein can be uniquely regulated by each combination of input molecules that it binds. This “regulatory complexity” causes a combinatorial increase in the number of parameters required to fit experimental data as the number of protein interactions increases. It therefore challenges the creation, updating, and re-use of biochemical models. Here, we propose a rule-based modelling framework that exploits the intrinsic modularity of protein structure to address regulatory complexity. Rather than treating proteins as “black boxes”, we model their hierarchical structure and, as conformational changes, internal dynamics. By modelling the regulation of allosteric proteins through these conformational changes, we often decrease the number of parameters required to fit data, and so reduce over-fitting and improve the predictive power of a model. Our method is thermodynamically grounded, imposes detailed balance, and also includes molecular cross-talk and the background activity of enzymes. We use our Allosteric Network Compiler to examine how allostery can facilitate macromolecular assembly and how competitive ligands can change the observed cooperativity of an allosteric protein. We also develop a parsimonious model of G protein-coupled receptors that explains functional selectivity and can predict the rank order of potency of agonists acting through a receptor. Our methodology should provide a basis for scalable, modular and executable modelling of biochemical networks in systems and synthetic biology. The complexity of biochemical networks challenges our ability to create quantitative and predictive models of cellular responses to extracellular changes. In these networks, the regulation of allosteric receptors and proteins by multiple drugs or endogenous ligands introduces “regulatory complexity” because a large number of parameters is required to describe such interactions. Protein interactions also give rise to “combinatorial complexity” by generating large numbers of protein complexes and covalent modification states. To address these twin problems, we propose a modelling framework that combines a modular description of protein structure and function with a rule-based description of protein interactions. We define the input-output function of an allosteric protein through its thermodynamic properties and structural components. We show that our “biomolecule-centric” methodology, in contrast to ad hoc approaches that emphasize the regulatory logic of interactions, can reduce the number of parameters required to model experimental observations. We also demonstrate how the application of our framework gives insights into the assembly of macromolecular complexes and increases the predictive power of a standard model of G protein-coupled receptors. These benefits are possible in many systems, given the ubiquity of allostery in biochemical networks. Our research delineates a fundamental relationship between allostery, modularity, and complexity in biochemical networks.
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Affiliation(s)
- Julien F. Ollivier
- Centre for Nonlinear Dynamics, Department of Physiology, McGill University, Montreal, Québec, Canada
- Centre for Systems Biology at Edinburgh, University of Edinburgh, Edinburgh, United Kingdom
- * E-mail: (JFO); (PSS)
| | - Vahid Shahrezaei
- Department of Mathematics, Imperial College London, London, United Kingdom
| | - Peter S. Swain
- Centre for Systems Biology at Edinburgh, University of Edinburgh, Edinburgh, United Kingdom
- * E-mail: (JFO); (PSS)
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Tanaka T, Nomura W, Narumi T, Masuda A, Tamamura H. Bivalent ligands of CXCR4 with rigid linkers for elucidation of the dimerization state in cells. J Am Chem Soc 2010; 132:15899-901. [PMID: 20973474 DOI: 10.1021/ja107447w] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
To date, challenges in the design of bivalent ligands for G protein-coupled receptors (GPCRs) have revealed difficulties stemming from lack of knowledge of the state of oligomerization of the GPCR. The synthetic bivalent ligands with rigid linkers that are presented here can predict the dimer form of CXCR4 and be applied to molecular probes in cancerous cells. This "molecular ruler" approach would be useful in elucidating the details of CXCR4 oligomer formation.
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Affiliation(s)
- Tomohiro Tanaka
- Department of Medicinal Chemistry, Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, 2-3-10 Kandasurugadai, Chiyoda-ku, Tokyo 101-0062, Japan
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Dowie MJ, Scotter EL, Molinari E, Glass M. The therapeutic potential of G-protein coupled receptors in Huntington's disease. Pharmacol Ther 2010; 128:305-23. [PMID: 20708032 DOI: 10.1016/j.pharmthera.2010.07.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2010] [Accepted: 07/14/2010] [Indexed: 01/29/2023]
Abstract
Huntington's disease is a late-onset autosomal dominant inherited neurodegenerative disease characterised by increased symptom severity over time and ultimately premature death. An expanded CAG repeat sequence in the huntingtin gene leads to a polyglutamine expansion in the expressed protein, resulting in complex dysfunctions including cellular excitotoxicity and transcriptional dysregulation. Symptoms include cognitive deficits, psychiatric changes and a movement disorder often referred to as Huntington's chorea, which involves characteristic involuntary dance-like writhing movements. Neuropathologically Huntington's disease is characterised by neuronal dysfunction and death in the striatum and cortex with an overall decrease in cerebral volume (Ho et al., 2001). Neuronal dysfunction begins prior to symptom presentation, and cells of particular vulnerability include the striatal medium spiny neurons. Huntington's is a devastating disease for patients and their families and there is currently no cure, or even an effective therapy for disease symptoms. G-protein coupled receptors are the most abundant receptor type in the central nervous system and are linked to complex downstream pathways, manipulation of which may have therapeutic application in many neurological diseases. This review will highlight the potential of G-protein coupled receptor drug targets as emerging therapies for Huntington's disease.
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Affiliation(s)
- Megan J Dowie
- Centre for Brain Research, University of Auckland, Private Bag 92019 Auckland, New Zealand
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Abstract
The 21-amino-acid peptide ET-1 (endothelin-1) regulates a diverse array of physiological processes, including vasoconstriction, angiogenesis, nociception and cell proliferation. Most of the effects of ET-1 are associated with an increase in intracellular calcium concentration. The calcium influx and mobilization pathways activated by ET-1, however, vary immensely. The present review begins with the basics of calcium signalling and investigates the different ways intracellular calcium concentration can increase in response to a stimulus. The focus then shifts to ET-1, and discusses how ET receptors mobilize calcium. We also examine how disease alters calcium-dependent responses to ET-1 by discussing changes to ET-1-mediated calcium signalling in hypertension, as there is significant interest in the role of ET-1 in this important disease. A list of unanswered questions regarding ET-mediated calcium signals are also presented, as well as perspectives for future research of calcium mobilization by ET-1.
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Affiliation(s)
- Nathan R Tykocki
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI 48824, USA.
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57
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Alvarez-Curto E, Pediani JD, Milligan G. Applications of fluorescence and bioluminescence resonance energy transfer to drug discovery at G protein coupled receptors. Anal Bioanal Chem 2010; 398:167-80. [DOI: 10.1007/s00216-010-3823-4] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2010] [Revised: 05/03/2010] [Accepted: 05/03/2010] [Indexed: 10/19/2022]
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Khelashvili G, Dorff K, Shan J, Camacho-Artacho M, Skrabanek L, Vroling B, Bouvier M, Devi LA, George SR, Javitch JA, Lohse MJ, Milligan G, Neubig RR, Palczewski K, Parmentier M, Pin JP, Vriend G, Campagne F, Filizola M. GPCR-OKB: the G Protein Coupled Receptor Oligomer Knowledge Base. ACTA ACUST UNITED AC 2010; 26:1804-5. [PMID: 20501551 DOI: 10.1093/bioinformatics/btq264] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
SUMMARY Rapid expansion of available data about G Protein Coupled Receptor (GPCR) dimers/oligomers over the past few years requires an effective system to organize this information electronically. Based on an ontology derived from a community dialog involving colleagues using experimental and computational methodologies, we developed the GPCR-Oligomerization Knowledge Base (GPCR-OKB). GPCR-OKB is a system that supports browsing and searching for GPCR oligomer data. Such data were manually derived from the literature. While focused on GPCR oligomers, GPCR-OKB is seamlessly connected to GPCRDB, facilitating the correlation of information about GPCR protomers and oligomers. AVAILABILITY AND IMPLEMENTATION The GPCR-OKB web application is freely available at http://www.gpcr-okb.org
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Affiliation(s)
- George Khelashvili
- Department of Physiology & Biophysics, Weill Medical College of Cornell University, New York, NY, USA
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Manolios N, Ali M, Bender V. T-cell antigen receptor (TCR) transmembrane peptides: A new paradigm for the treatment of autoimmune diseases. Cell Adh Migr 2010; 4:273-83. [PMID: 20431344 DOI: 10.4161/cam.4.2.11909] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Cell surface membranes are generally considered as inert and hydrophobic providing a stable physical barrier that anchor proteins and maintain cellular homeostasis between the intra- and the extra-cellular environment. The integral proteins that transverse membranes do so once or multiple times and can function alone or as part of a larger complex. Far from being inert, there is a multiplicity of biophysical factors that drive protein-protein and protein-lipid interactions within membranes that are being increasingly recognised as very important for cellular function. Unravelling these "hot-spots" on the contact surface of transmembrane (TM) proteins and targeting peptides to these sites to interrupt the cohesive interaction between the proteins provides both an enormous challenge and a huge therapeutic potential that as yet remains unrecognized. Indeed, with biopharmaceutical research on the rise, TM peptides may prove a useful innovation. Using the T-cell antigen receptor (TCR) as a model system of multi-subunits interacting at the TM via electrostatic charges the potential for peptides as therapeutic agents to interfere with normal immune responses is discussed. The principles of such can be extended to other similar receptor systems including those involved in cancer or infection.
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Affiliation(s)
- Nicholas Manolios
- Department of Rheumatology, Westmead Hospital, Westmead, NSW, Australia.
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Bortolato A, Mobarec JC, Provasi D, Filizola M. Progress in elucidating the structural and dynamic character of G Protein-Coupled Receptor oligomers for use in drug discovery. Curr Pharm Des 2010; 15:4017-25. [PMID: 20028319 DOI: 10.2174/138161209789824768] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
G Protein-Coupled Receptors (GPCRs) are the most targeted group of proteins for the development of therapeutic drugs. Until the last decade, structural information about this family of membrane proteins was relatively scarce, and their mechanisms of ligand binding and signal transduction were modeled on the assumption that GPCRs existed and functioned as monomeric entities. New crystal structures of native and engineered GPCRs, together with important biochemical and biophysical data that reveal structural details of the activation mechanism(s) of this receptor family, provide a valuable framework to improve dynamic molecular models of GPCRs with the ultimate goal of elucidating their allostery and functional selectivity. Since the dynamic movements of single GPCR protomers are likely to be affected by the presence of neighboring interacting subunits, oligomeric arrangements should be taken into account to improve the predictive ability of computer-assisted structural models of GPCRs for effective use in drug design.
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Affiliation(s)
- A Bortolato
- Department of Structural and Chemical Biology, Mount Sinai School of Medicine, New York, NY 10029-6574, USA
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Hudson BD, Hébert TE, M. Kelly ME. Ligand- and Heterodimer-Directed Signaling of the CB1 Cannabinoid Receptor. Mol Pharmacol 2009; 77:1-9. [DOI: 10.1124/mol.109.060251] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
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Bruno A, Guadix AE, Costantino G. Molecular dynamics simulation of the heterodimeric mGluR2/5HT(2A) complex. An atomistic resolution study of a potential new target in psychiatric conditions. J Chem Inf Model 2009; 49:1602-16. [PMID: 19422244 DOI: 10.1021/ci900067g] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Homo- and heterodimerization is becoming an assessed concept in G-protein coupled receptor (GPCR) pharmacology, and the notion that GPCRs may dimerize or oligomerize is allowing for a reinterpretation of some inconsistencies or anomalies and is providing medicinal chemists with potentially relevant novel molecular targets for a variety of therapeutic conditions. Recently, it has been reported that two unrelated GPCRs, namely class C metabotropic glutamate receptor type-2 (mGluR2) and class A 5HT(2A) serotoninergic receptor, can heterodimerize at the transmembrane domain level. We performed a 40 ns molecular dynamics simulation of the mGluR2/5HT(2A) heterocomplex constructed around a TM4/TM5 interface and embedded in an explicit phospholipidic bilayer surrounded by water molecules. In a separate experiment, the monomeric 5HT(2A) receptor was simulated for additional 40 ns under the same conditions. The analysis and the comparison of the two simulations allowed us to clearly identify a cross-talk between the two protomers and to put forward an effect of the heterodimerization on the shape of the binding pocket of 5HT(2A). This result provides the first molecular explanation for the reported allosteric effect of mGluR2 on 5HT(2A)-mediated response and suggests that the heterocomplex can be a more suitable target for in silico screening than the monomeric protomers.
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Affiliation(s)
- Agostino Bruno
- Dipartimento Farmaceutico, Via G. P. Usberti 27/A- Campus Universitario, Universita degli Studi di Parma, 43124 Parma, Italy
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63
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Schellekens H, Dinan TG, Cryan JF. Lean mean fat reducing "ghrelin" machine: hypothalamic ghrelin and ghrelin receptors as therapeutic targets in obesity. Neuropharmacology 2009; 58:2-16. [PMID: 19573543 DOI: 10.1016/j.neuropharm.2009.06.024] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2009] [Revised: 06/18/2009] [Accepted: 06/19/2009] [Indexed: 12/13/2022]
Abstract
Obesity has reached epidemic proportions not only in Western societies but also in the developing world. Current pharmacological treatments for obesity are either lacking in efficacy and/or are burdened with adverse side effects. Thus, novel strategies are required. A better understanding of the intricate molecular pathways controlling energy homeostasis may lead to novel therapeutic intervention. The circulating hormone, ghrelin represents a major target in the molecular signalling regulating food intake, appetite and energy expenditure and its circulating levels often display aberrant signalling in obesity. Ghrelin exerts its central orexigenic action mainly in the hypothalamus and in particular in the arcuate nucleus via activation of specific G-protein coupled receptors (GHS-R). In this review we describe current pharmacological models of how ghrelin regulates food intake and how manipulating ghrelin signalling may give novel insight into developing better and more selective anti-obesity drugs. Accumulating data suggests multiple ghrelin variants and additional receptors exist to play a role in energy metabolism and these may well play an important role in obesity. In addition, the recent findings of hypothalamic GHS-R crosstalk and heterodimerization may add to the understanding of the complexity of bodyweight regulation.
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Increasingly accurate dynamic molecular models of G-protein coupled receptor oligomers: Panacea or Pandora's box for novel drug discovery? Life Sci 2009; 86:590-7. [PMID: 19465029 DOI: 10.1016/j.lfs.2009.05.004] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2008] [Revised: 05/07/2009] [Accepted: 05/14/2009] [Indexed: 01/06/2023]
Abstract
For years, conventional drug design at G-protein coupled receptors (GPCRs) has mainly focused on the inhibition of a single receptor at a usually well-defined ligand-binding site. The recent discovery of more and more physiologically relevant GPCR dimers/oligomers suggests that selectively targeting these complexes or designing small molecules that inhibit receptor-receptor interactions might provide new opportunities for novel drug discovery. To uncover the fundamental mechanisms and dynamics governing GPCR dimerization/oligomerization, it is crucial to understand the dynamic process of receptor-receptor association, and to identify regions that are suitable for selective drug binding. This minireview highlights current progress in the development of increasingly accurate dynamic molecular models of GPCR oligomers based on structural, biochemical, and biophysical information that has recently appeared in the literature. In view of this new information, there has never been a more exciting time for computational research into GPCRs than at present. Information-driven modern molecular models of GPCR complexes are expected to efficiently guide the rational design of GPCR oligomer-specific drugs, possibly allowing researchers to reach for the high-hanging fruits in GPCR drug discovery, i.e. more potent and selective drugs for efficient therapeutic interventions.
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