1
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Faivre N, Verollet C, Dumas F. The chemokine receptor CCR5: multi-faceted hook for HIV-1. Retrovirology 2024; 21:2. [PMID: 38263120 PMCID: PMC10807162 DOI: 10.1186/s12977-024-00634-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Accepted: 01/13/2024] [Indexed: 01/25/2024] Open
Abstract
Chemokines are cytokines whose primary role is cellular activation and stimulation of leukocyte migration. They perform their various functions by interacting with G protein-coupled cell surface receptors (GPCRs) and are involved in the regulation of many biological processes such as apoptosis, proliferation, angiogenesis, hematopoiesis or organogenesis. They contribute to the maintenance of the homeostasis of lymphocytes and coordinate the function of the immune system. However, chemokines and their receptors are sometimes hijacked by some pathogens to infect the host organism. For a given chemokine receptor, there is a wide structural, organizational and conformational diversity. In this review, we describe the evidence for structural variety reported for the chemokine receptor CCR5, how this variability can be exploited by HIV-1 to infect its target cells and what therapeutic solutions are currently being developed to overcome this problem.
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Affiliation(s)
- Natacha Faivre
- Institut de Pharmacologie et de Biologie Structurale (IPBS), Université de Toulouse, CNRS, Université Toulouse III - Paul Sabatier (UPS), Toulouse, France
- International Research Laboratory (IRP) CNRS "IM-TB/HIV", Toulouse, France
- International Research Laboratory (IRP) CNRS "IM-TB/HIV", Buenos Aires, Argentina
| | - Christel Verollet
- Institut de Pharmacologie et de Biologie Structurale (IPBS), Université de Toulouse, CNRS, Université Toulouse III - Paul Sabatier (UPS), Toulouse, France
- International Research Laboratory (IRP) CNRS "IM-TB/HIV", Toulouse, France
- International Research Laboratory (IRP) CNRS "IM-TB/HIV", Buenos Aires, Argentina
| | - Fabrice Dumas
- Institut de Pharmacologie et de Biologie Structurale (IPBS), Université de Toulouse, CNRS, Université Toulouse III - Paul Sabatier (UPS), Toulouse, France.
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2
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Li M, Qing R, Tao F, Xu P, Zhang S. Dynamic Dimerization of Chemokine Receptors and Potential Inhibitory Role of Their Truncated Isoforms Revealed through Combinatorial Prediction. Int J Mol Sci 2023; 24:16266. [PMID: 38003455 PMCID: PMC10671024 DOI: 10.3390/ijms242216266] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2023] [Revised: 11/03/2023] [Accepted: 11/08/2023] [Indexed: 11/26/2023] Open
Abstract
Chemokine receptors play crucial roles in fundamental biological processes. Their malfunction may result in many diseases, including cancer, autoimmune diseases, and HIV. The oligomerization of chemokine receptors holds significant functional implications that directly affect their signaling patterns and pharmacological responses. However, the oligomerization patterns of many chemokine receptors remain poorly understood. Furthermore, several chemokine receptors have highly truncated isoforms whose functional role is not yet clear. Here, we computationally show homo- and heterodimerization patterns of four human chemokine receptors, namely CXCR2, CXCR7, CCR2, and CCR7, along with their interaction patterns with their respective truncated isoforms. By combining the neural network-based AlphaFold2 and physics-based protein-protein docking tool ClusPro, we predicted 15 groups of complex structures and assessed the binding affinities in the context of atomistic molecular dynamics simulations. Our results are in agreement with previous experimental observations and support the dynamic and diverse nature of chemokine receptor dimerization, suggesting possible patterns of higher-order oligomerization. Additionally, we uncover the strong potential of truncated isoforms to block homo- and heterodimerization of chemokine receptors, also in a dynamic manner. Our study provides insights into the dimerization patterns of chemokine receptors and the functional significance of their truncated isoforms.
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Affiliation(s)
- Mengke Li
- Laboratory of Molecular Architecture, Media Lab, Massachusetts Institute of Technology, Cambridge, MA 02139, USA;
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China; (R.Q.); (F.T.); (P.X.)
| | - Rui Qing
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China; (R.Q.); (F.T.); (P.X.)
| | - Fei Tao
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China; (R.Q.); (F.T.); (P.X.)
| | - Ping Xu
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China; (R.Q.); (F.T.); (P.X.)
| | - Shuguang Zhang
- Laboratory of Molecular Architecture, Media Lab, Massachusetts Institute of Technology, Cambridge, MA 02139, USA;
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3
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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] [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.
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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
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4
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El Khamlichi C, Cobret L, Arrang JM, Morisset-Lopez S. BRET Analysis of GPCR Dimers in Neurons and Non-Neuronal Cells: Evidence for Inactive, Agonist, and Constitutive Conformations. Int J Mol Sci 2021; 22:ijms221910638. [PMID: 34638980 PMCID: PMC8508734 DOI: 10.3390/ijms221910638] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Revised: 09/24/2021] [Accepted: 09/27/2021] [Indexed: 11/29/2022] Open
Abstract
G-protein-coupled receptors (GPCRs) are dimeric proteins, but the functional consequences of the process are still debated. Active GPCR conformations are promoted either by agonists or constitutive activity. Inverse agonists decrease constitutive activity by promoting inactive conformations. The histamine H3 receptor (H3R) is the target of choice for the study of GPCRs because it displays high constitutive activity. Here, we study the dimerization of recombinant and brain H3R and explore the effects of H3R ligands of different intrinsic efficacy on dimerization. Co-immunoprecipitations and Western blots showed that H3R dimers co-exist with monomers in transfected HEK 293 cells and in rodent brains. Bioluminescence energy transfer (BRET) analysis confirmed the existence of spontaneous H3R dimers, not only in living HEK 293 cells but also in transfected cortical neurons. In both cells, agonists and constitutive activity of the H3R decreased BRET signals, whereas inverse agonists and GTPγS, which promote inactive conformations, increased BRET signals. These findings show the existence of spontaneous H3R dimers not only in heterologous systems but also in native tissues, which are able to adopt a number of allosteric conformations, from more inactive to more active states.
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Affiliation(s)
- Chayma El Khamlichi
- Centre de Biophysique Moléculaire, CNRS UPR 4301, Université d’Orléans, Rue Charles Sadron, CEDEX 2, 45071 Orléans, France; (C.E.K.); (L.C.)
| | - Laetitia Cobret
- Centre de Biophysique Moléculaire, CNRS UPR 4301, Université d’Orléans, Rue Charles Sadron, CEDEX 2, 45071 Orléans, France; (C.E.K.); (L.C.)
| | - Jean-Michel Arrang
- Centre de Psychiatrie et Neurosciences, 2 ter Rue d’Alésia, 75014 Paris, France;
- Institut de Psychiatrie et Neurosciences de Paris, UMR_S1266 INSERM, Université Paris Descartes, 102 Rue de la Santé, 75014 Paris, France
| | - Séverine Morisset-Lopez
- Centre de Biophysique Moléculaire, CNRS UPR 4301, Université d’Orléans, Rue Charles Sadron, CEDEX 2, 45071 Orléans, France; (C.E.K.); (L.C.)
- Institut de Psychiatrie et Neurosciences de Paris, UMR_S1266 INSERM, Université Paris Descartes, 102 Rue de la Santé, 75014 Paris, France
- Correspondence: ; Tel.: +33-238257858
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5
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Structural basis for chemokine recognition and receptor activation of chemokine receptor CCR5. Nat Commun 2021; 12:4151. [PMID: 34230484 PMCID: PMC8260604 DOI: 10.1038/s41467-021-24438-5] [Citation(s) in RCA: 47] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Accepted: 06/18/2021] [Indexed: 02/06/2023] Open
Abstract
The chemokine receptor CCR5 plays a vital role in immune surveillance and inflammation. However, molecular details that govern its endogenous chemokine recognition and receptor activation remain elusive. Here we report three cryo-electron microscopy structures of Gi1 protein-coupled CCR5 in a ligand-free state and in complex with the chemokine MIP-1α or RANTES, as well as the crystal structure of MIP-1α-bound CCR5. These structures reveal distinct binding modes of the two chemokines and a specific accommodate pattern of the chemokine for the distal N terminus of CCR5. Together with functional data, the structures demonstrate that chemokine-induced rearrangement of toggle switch and plasticity of the receptor extracellular region are critical for receptor activation, while a conserved tryptophan residue in helix II acts as a trigger of receptor constitutive activation.
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6
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Zamel IA, Palakkott A, Ashraf A, Iratni R, Ayoub MA. Interplay Between Angiotensin II Type 1 Receptor and Thrombin Receptor Revealed by Bioluminescence Resonance Energy Transfer Assay. Front Pharmacol 2020; 11:1283. [PMID: 32973514 PMCID: PMC7468457 DOI: 10.3389/fphar.2020.01283] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2020] [Accepted: 08/03/2020] [Indexed: 12/22/2022] Open
Abstract
The key hormone of the renin-angiotensin system (RAS), angiotensin II (AngII), and thrombin are known to play major roles in the vascular system and its related disorders. Previous studies reported connections between AngII and thrombin in both physiological and pathophysiological models. However, the molecular mechanisms controlling such interplay at the level of their receptors belonging to the family of G protein-coupled receptors (GPCRs) are not fully understood. In this study, we investigated the functional interaction between the AngII type 1 receptor (AT1R) and the thrombin receptor [or protease-activated receptor 1 (PAR1)] in human embryonic kidney 293 (HEK293) cells. For this, we used various bioluminescence resonance energy transfer (BRET) proximity-based assays to profile the coupling to the heterotrimeric Gαq protein, β-arrestin recruitment, and receptor internalization and trafficking in intact cells. The overall dose-response and real-time kinetic BRET data demonstrated the specific molecular proximity between AT1R and PAR1 resulting in their functional interaction. This was characterized by thrombin inducing BRET increase within AT1R/Gαq and AT1R/β-arrestin pairs and synergistic effects observed upon the concomitant activation of both receptors suggesting a positive allosteric interaction. The BRET data corroborated with the data on the downstream Gαq/inositol phosphate pathway. Moreover, the selective pharmacological blockade of the receptors revealed the implication of both AT1R and PAR1 protomers in such a synergistic interaction and the possible transactivation of AT1R by PAR1. Interestingly, the positive action of PAR1 on AT1R activation was contrasted with its apparent inhibition of AT1R internalization and its endosomal trafficking. Finally, BRET saturation and co-immunoprecipitation assays supported the physical AT1-PAR1 interaction in HEK293 cells. Our study reveals for the first time the functional interaction between AT1R and PAR1 in vitro characterized by a transactivation and positive allosteric modulation of AT1R and inhibition of its desensitization and internalization. This finding may constitute the molecular basis of the well-known interplay between RAS and thrombin. Thus, our data should lead to revising some findings on the implication of RAS and thrombin in vascular physiology and pathophysiology revealing the importance to consider the functional and pharmacological interaction between AT1R and thrombin receptors.
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Affiliation(s)
- Isra Al Zamel
- Department of Biology, College of Science, The United Arab Emirates University (UAEU), Al Ain, United Arab Emirates
| | - Abdulrasheed Palakkott
- Department of Biology, College of Science, The United Arab Emirates University (UAEU), Al Ain, United Arab Emirates
| | - Arshida Ashraf
- Department of Biology, College of Science, The United Arab Emirates University (UAEU), Al Ain, United Arab Emirates
| | - Rabah Iratni
- Department of Biology, College of Science, The United Arab Emirates University (UAEU), Al Ain, United Arab Emirates
| | - Mohammed Akli Ayoub
- Department of Biology, College of Science, The United Arab Emirates University (UAEU), Al Ain, United Arab Emirates
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7
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Essential role of the C148–C227 disulphide bridge in the human 5-HT2A homodimeric receptor. Biochem Pharmacol 2020; 177:113985. [DOI: 10.1016/j.bcp.2020.113985] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Accepted: 04/15/2020] [Indexed: 01/12/2023]
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8
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D'Agostino G, García-Cuesta EM, Gomariz RP, Rodríguez-Frade JM, Mellado M. The multilayered complexity of the chemokine receptor system. Biochem Biophys Res Commun 2020; 528:347-358. [PMID: 32145914 DOI: 10.1016/j.bbrc.2020.02.120] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Revised: 02/17/2020] [Accepted: 02/20/2020] [Indexed: 01/08/2023]
Abstract
The chemokines receptor family are membrane-expressed class A-specific seven-transmembrane receptors linked to G proteins. Through interaction with the corresponding ligands, the chemokines, they induce a wide variety of cellular responses including cell polarization, movement, immune and inflammatory responses, as well as the prevention of HIV-1 infection. Like a Russian matryoshka doll, the chemokine receptor system is more complex than initially envisaged. This review focuses on the mechanisms that contribute to this dazzling complexity and how they modulate the signaling events triggered by chemokines. The chemokines and their receptors exist as monomers, dimers and oligomers, their expression pattern is highly regulated, and the ligands can bind distinct receptors with similar affinities. The use of novel imaging-based technologies, particularly real-time imaging modalities, has shed new light on the very dynamic conformations that chemokine receptors adopt depending on the cellular context, and that affect chemokine-mediated responses. This complex scenario presents both challenging and exciting opportunities for drug discovery.
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Affiliation(s)
- Gianluca D'Agostino
- Dept. Immunology and Oncology, Centro Nacional de Biotecnología/CSIC, Darwin 3, Campus Cantoblanco, E-28049, Madrid, Spain
| | - Eva M García-Cuesta
- Dept. Immunology and Oncology, Centro Nacional de Biotecnología/CSIC, Darwin 3, Campus Cantoblanco, E-28049, Madrid, Spain
| | - Rosa P Gomariz
- Dept. Cell Biology, Complutense University of Madrid, Research Institute Hospital 12 de Octubre (i+12), E-28041, Madrid, Spain
| | - José Miguel Rodríguez-Frade
- Dept. Immunology and Oncology, Centro Nacional de Biotecnología/CSIC, Darwin 3, Campus Cantoblanco, E-28049, Madrid, Spain
| | - Mario Mellado
- Dept. Immunology and Oncology, Centro Nacional de Biotecnología/CSIC, Darwin 3, Campus Cantoblanco, E-28049, Madrid, Spain.
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9
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CCR5: Established paradigms and new frontiers for a 'celebrity' chemokine receptor. Cytokine 2019; 109:81-93. [PMID: 29903576 DOI: 10.1016/j.cyto.2018.02.018] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Revised: 02/14/2018] [Accepted: 02/16/2018] [Indexed: 01/04/2023]
Abstract
Because of the level of attention it received due to its role as the principal HIV coreceptor, CCR5 has been described as a 'celebrity' chemokine receptor. Here we describe the development of CCR5 inhibitory strategies that have been developed for HIV therapy and which are now additionally being considered for use in HIV prevention and cure. The wealth of CCR5-related tools that have been developed during the intensive investigation of CCR5 as an HIV drug target can now be turned towards the study of CCR5 as a model chemokine receptor. We also summarize what is currently known about the cell biology and pharmacology of CCR5, providing an update on new areas of investigation that have emerged in recent research. Finally, we discuss the potential of CCR5 as a drug target for diseases other than HIV, discussing the evidence linking CCR5 and its natural chemokine ligands with inflammatory diseases, particularly neuroinflammation, and certain cancers. These pathologies may provide new uses for the strategies for CCR5 blockade originally developed to combat HIV/AIDS.
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10
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Sykes DA, Stoddart LA, Kilpatrick LE, Hill SJ. Binding kinetics of ligands acting at GPCRs. Mol Cell Endocrinol 2019; 485:9-19. [PMID: 30738950 PMCID: PMC6406023 DOI: 10.1016/j.mce.2019.01.018] [Citation(s) in RCA: 61] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Revised: 01/19/2019] [Accepted: 01/19/2019] [Indexed: 12/31/2022]
Abstract
The influence of drug-receptor binding kinetics has often been overlooked during the development of new therapeutics that target G protein-coupled receptors (GPCRs). Over the last decade there has been a growing understanding that an in-depth knowledge of binding kinetics at GPCRs is required to successfully target this class of proteins. Ligand binding to a GPCR is often not a simple single step process with ligand freely diffusing in solution. This review will discuss the experiments and equations that are commonly used to measure binding kinetics and how factors such as allosteric regulation, rebinding and ligand interaction with the plasma membrane may influence these measurements. We will then consider the molecular characteristics of a ligand and if these can be linked to association and dissociation rates.
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Affiliation(s)
- David A Sykes
- Cell Signalling and Pharmacology Research Group, Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham, UK; Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, Midlands, UK
| | - Leigh A Stoddart
- Cell Signalling and Pharmacology Research Group, Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham, UK; Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, Midlands, UK
| | - Laura E Kilpatrick
- Cell Signalling and Pharmacology Research Group, Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham, UK; Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, Midlands, UK
| | - Stephen J Hill
- Cell Signalling and Pharmacology Research Group, Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham, UK; Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, Midlands, UK.
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11
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Susec M, Sencanski M, Glisic S, Veljkovic N, Pedersen C, Drinovec L, Stojan J, Nøhr J, Vrecl M. Functional characterization of β 2-adrenergic and insulin receptor heteromers. Neuropharmacology 2019; 152:78-89. [PMID: 30707913 DOI: 10.1016/j.neuropharm.2019.01.025] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Revised: 01/01/2019] [Accepted: 01/23/2019] [Indexed: 01/06/2023]
Abstract
This study aimed to functionally characterize β2-adrenergic (β2AR) and insulin receptor (IR) heteromers in regard to β-arrestin 2 (βarr2) recruitment and cAMP signaling and to examine the involvement of the cytoplasmic portion of the IR β chain in heteromerization with β2AR. Evidence for β2AR:IR:βarr2 complex formation and the specificity of the IR:βarr2 interaction was first provided by bioinfomatics analysis. Receptor-heteromer investigation technology (HIT) then provided functional evidence of β2AR:IR heterodimerization by showing isoproterenol-induced but not insulin-induced GFP2-βarr2 recruitment to the β2AR:IR complex; the IR:βarr2 interaction was found to only be constitutive. The constitutive IR:βarr2 BRET signal (BRETconst) was significantly smaller in cells coexpressing IR-RLuc8 and a GFP2-βarr2 1-185 mutant lacking the proposed IR binding domain. β2AR:IR heteromerization also influenced the pharmacological phenotype of β2AR, i.e., its efficacy in recruiting βarr2 and activating cAMP signaling. Evidence suggesting involvement of the cytoplasmic portion of the IR β chain in the interaction with β2AR was provided by BRET2 saturation and HIT assays using an IR 1-1271 stop mutant lacking the IR C-terminal tail region. For the complex consisting of IR 1-1271-RLuc8:β2AR-GFP2, saturation was not reached, most likely reflecting random collisions between IR 1-1271 and β2AR. Furthermore, in the HIT assay, no substantial agonist-induced increase in the BRET2 signal was detected that would be indicative of βarr2 recruitment to the IR 1-1271:β2AR heteromer. Complementary 3D visualization of β2AR:IR provided supporting evidence for stability of the heterotetramer complex and identified amino acid residues involved in β2AR:IR heteromerization. This article is part of the Special Issue entitled 'Receptor heteromers and their allosteric receptor-receptor interactions'.
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Affiliation(s)
- Maja Susec
- Institute of Preclinical Sciences, Veterinary Faculty, University of Ljubljana, Slovenia
| | - Milan Sencanski
- Center for Multidisciplinary Research, Institute of Nuclear Sciences VINCA, University of Belgrade, Belgrade, Serbia
| | - Sanja Glisic
- Center for Multidisciplinary Research, Institute of Nuclear Sciences VINCA, University of Belgrade, Belgrade, Serbia
| | - Nevena Veljkovic
- Center for Multidisciplinary Research, Institute of Nuclear Sciences VINCA, University of Belgrade, Belgrade, Serbia
| | - Christina Pedersen
- Department of Incretin & Islet Biology, Novo Nordisk A/S, Måløv, Denmark
| | - Luka Drinovec
- Department of Condensed Matter Physics, Jožef Stefan Institute, Slovenia
| | - Jurij Stojan
- Institute of Biochemistry, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
| | - Jane Nøhr
- Department of Incretin & Islet Biology, Novo Nordisk A/S, Måløv, Denmark
| | - Milka Vrecl
- Institute of Preclinical Sciences, Veterinary Faculty, University of Ljubljana, Slovenia.
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12
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Colin P, Zhou Z, Staropoli I, Garcia-Perez J, Gasser R, Armani-Tourret M, Benureau Y, Gonzalez N, Jin J, Connell BJ, Raymond S, Delobel P, Izopet J, Lortat-Jacob H, Alcami J, Arenzana-Seisdedos F, Brelot A, Lagane B. CCR5 structural plasticity shapes HIV-1 phenotypic properties. PLoS Pathog 2018; 14:e1007432. [PMID: 30521629 PMCID: PMC6283471 DOI: 10.1371/journal.ppat.1007432] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Accepted: 10/24/2018] [Indexed: 01/20/2023] Open
Abstract
CCR5 plays immune functions and is the coreceptor for R5 HIV-1 strains. It exists in diverse conformations and oligomerization states. We interrogated the significance of the CCR5 structural diversity on HIV-1 infection. We show that envelope glycoproteins (gp120s) from different HIV-1 strains exhibit divergent binding levels to CCR5 on cell lines and primary cells, but not to CD4 or the CD4i monoclonal antibody E51. This owed to differential binding of the gp120s to different CCR5 populations, which exist in varying quantities at the cell surface and are differentially expressed between different cell types. Some, but not all, of these populations are antigenically distinct conformations of the coreceptor. The different binding levels of gp120s also correspond to differences in their capacity to bind CCR5 dimers/oligomers. Mutating the CCR5 dimerization interface changed conformation of the CCR5 homodimers and modulated differentially the binding of distinct gp120s. Env-pseudotyped viruses also use particular CCR5 conformations for entry, which may differ between different viruses and represent a subset of those binding gp120s. In particular, even if gp120s can bind both CCR5 monomers and oligomers, impairment of CCR5 oligomerization improved viral entry, suggesting that HIV-1 prefers monomers for entry. From a functional standpoint, we illustrate that the nature of the CCR5 molecules to which gp120/HIV-1 binds shapes sensitivity to inhibition by CCR5 ligands and cellular tropism. Differences exist in the CCR5 populations between T-cells and macrophages, and this is associated with differential capacity to bind gp120s and to support viral entry. In macrophages, CCR5 structural plasticity is critical for entry of blood-derived R5 isolates, which, in contrast to prototypical M-tropic strains from brain tissues, cannot benefit from enhanced affinity for CD4. Collectively, our results support a role for CCR5 heterogeneity in diversifying the phenotypic properties of HIV-1 isolates and provide new clues for development of CCR5-targeting drugs.
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Affiliation(s)
- Philippe Colin
- Viral Pathogenesis Unit, Department of Virology, Institut Pasteur, Paris, France
- INSERM Unit U1108, Institut Pasteur, Paris, France
- Paris Diderot University, Sorbonne Paris Cité, Cellule Pasteur, Rue du Docteur Roux, Paris, France
| | - Zhicheng Zhou
- Viral Pathogenesis Unit, Department of Virology, Institut Pasteur, Paris, France
- INSERM Unit U1108, Institut Pasteur, Paris, France
| | - Isabelle Staropoli
- Viral Pathogenesis Unit, Department of Virology, Institut Pasteur, Paris, France
- INSERM Unit U1108, Institut Pasteur, Paris, France
| | | | - Romain Gasser
- Centre de Physiopathologie Toulouse-Purpan (CPTP), Université de Toulouse, CNRS, Inserm, UPS, Toulouse, France
| | - Marie Armani-Tourret
- Centre de Physiopathologie Toulouse-Purpan (CPTP), Université de Toulouse, CNRS, Inserm, UPS, Toulouse, France
| | - Yann Benureau
- Viral Pathogenesis Unit, Department of Virology, Institut Pasteur, Paris, France
- INSERM Unit U1108, Institut Pasteur, Paris, France
| | - Nuria Gonzalez
- AIDS Immunopathogenesis Unit, Instituto de Salud Carlos III, Madrid, Spain
| | - Jun Jin
- Viral Pathogenesis Unit, Department of Virology, Institut Pasteur, Paris, France
- INSERM Unit U1108, Institut Pasteur, Paris, France
| | - Bridgette J. Connell
- Grenoble Alpes University, CNRS, CEA, Institut de Biologie Structurale (IBS), Grenoble, France
| | - Stéphanie Raymond
- Centre de Physiopathologie Toulouse-Purpan (CPTP), Université de Toulouse, CNRS, Inserm, UPS, Toulouse, France
- CHU de Toulouse, Laboratoire de Virologie, Toulouse, France
| | - Pierre Delobel
- Centre de Physiopathologie Toulouse-Purpan (CPTP), Université de Toulouse, CNRS, Inserm, UPS, Toulouse, France
- CHU de Toulouse, Service des Maladies Infectieuses et Tropicales, Toulouse, France
| | - Jacques Izopet
- Centre de Physiopathologie Toulouse-Purpan (CPTP), Université de Toulouse, CNRS, Inserm, UPS, Toulouse, France
- CHU de Toulouse, Laboratoire de Virologie, Toulouse, France
| | - Hugues Lortat-Jacob
- Grenoble Alpes University, CNRS, CEA, Institut de Biologie Structurale (IBS), Grenoble, France
| | - Jose Alcami
- AIDS Immunopathogenesis Unit, Instituto de Salud Carlos III, Madrid, Spain
| | - Fernando Arenzana-Seisdedos
- Viral Pathogenesis Unit, Department of Virology, Institut Pasteur, Paris, France
- INSERM Unit U1108, Institut Pasteur, Paris, France
| | - Anne Brelot
- Viral Pathogenesis Unit, Department of Virology, Institut Pasteur, Paris, France
- INSERM Unit U1108, Institut Pasteur, Paris, France
| | - Bernard Lagane
- Viral Pathogenesis Unit, Department of Virology, Institut Pasteur, Paris, France
- INSERM Unit U1108, Institut Pasteur, Paris, France
- Centre de Physiopathologie Toulouse-Purpan (CPTP), Université de Toulouse, CNRS, Inserm, UPS, Toulouse, France
- * E-mail:
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13
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CCR5 Revisited: How Mechanisms of HIV Entry Govern AIDS Pathogenesis. J Mol Biol 2018; 430:2557-2589. [PMID: 29932942 DOI: 10.1016/j.jmb.2018.06.027] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Revised: 06/10/2018] [Accepted: 06/13/2018] [Indexed: 01/01/2023]
Abstract
The chemokine receptor CCR5 has been the focus of intensive studies since its role as a coreceptor for HIV entry was discovered in 1996. These studies lead to the development of small molecular drugs targeting CCR5, with maraviroc becoming in 2007 the first clinically approved chemokine receptor inhibitor. More recently, the apparent HIV cure in a patient transplanted with hematopoietic stem cells devoid of functional CCR5 rekindled the interest for inactivating CCR5 through gene therapy and pharmacological approaches. Fundamental research on CCR5 has also been boosted by key advances in the field of G-protein coupled receptor research, with the realization that CCR5 adopts a variety of conformations, and that only a subset of these conformations may be targeted by chemokine ligands. In addition, recent genetic and pathogenesis studies have emphasized the central role of CCR5 expression levels in determining the risk of HIV and SIV acquisition and disease progression. In this article, we propose to review the key properties of CCR5 that account for its central role in HIV pathogenesis, with a focus on mechanisms that regulate CCR5 expression, conformation, and interaction with HIV envelope glycoproteins.
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14
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Jin J, Momboisse F, Boncompain G, Koensgen F, Zhou Z, Cordeiro N, Arenzana-Seisdedos F, Perez F, Lagane B, Kellenberger E, Brelot A. CCR5 adopts three homodimeric conformations that control cell surface delivery. Sci Signal 2018; 11:11/529/eaal2869. [DOI: 10.1126/scisignal.aal2869] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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15
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Martínez-Muñoz L, Villares R, Rodríguez-Fernández JL, Rodríguez-Frade JM, Mellado M. Remodeling our concept of chemokine receptor function: From monomers to oligomers. J Leukoc Biol 2018; 104:323-331. [PMID: 29719064 DOI: 10.1002/jlb.2mr1217-503r] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2017] [Revised: 03/12/2018] [Accepted: 04/05/2018] [Indexed: 01/14/2023] Open
Abstract
The chemokines direct leukocyte recruitment in both homeostatic and inflammatory conditions, and are therefore critical for immune reactions. By binding to members of the class A G protein-coupled receptors, the chemokines play an essential role in numerous physiological and pathological processes. In the last quarter century, the field has accumulated much information regarding the implications of these molecules in different immune processes, as well as mechanistic insight into the signaling events activated through their binding to their receptors. Here, we will focus on chemokine receptors and how new methodological approaches have underscored the role of their conformations in chemokine functions. Advances in biophysical-based techniques show that chemokines and their receptors act in very complex networks and therefore should not be considered isolated entities. In this regard, the chemokine receptors can form homo- and heterodimers as well as oligomers at the cell surface. These findings are changing our view as to how chemokines influence cell biology, identify partners that regulate chemokine function, and open new avenues for therapeutic intervention.
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Affiliation(s)
- Laura Martínez-Muñoz
- Department of Cell Signaling, Centro Andaluz de Biología Molecular y Medicina Regenerativa (CABIMER-CSIC), Seville, Spain
| | - Ricardo Villares
- Department of Immunology and Oncology, Centro Nacional de Biotecnología (CNB-CSIC), Madrid, Spain
| | - José Luis Rodríguez-Fernández
- Department of Molecular Microbiology and Infection Biology, Centro de Investigaciones Biológicas (CIB/CSIC), Madrid, Spain
| | | | - Mario Mellado
- Department of Immunology and Oncology, Centro Nacional de Biotecnología (CNB-CSIC), Madrid, Spain
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16
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Gahbauer S, Pluhackova K, Böckmann RA. Closely related, yet unique: Distinct homo- and heterodimerization patterns of G protein coupled chemokine receptors and their fine-tuning by cholesterol. PLoS Comput Biol 2018; 14:e1006062. [PMID: 29529028 PMCID: PMC5864085 DOI: 10.1371/journal.pcbi.1006062] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Revised: 03/22/2018] [Accepted: 02/28/2018] [Indexed: 12/21/2022] Open
Abstract
Chemokine receptors, a subclass of G protein coupled receptors (GPCRs), play essential roles in the human immune system, they are involved in cancer metastasis as well as in HIV-infection. A plethora of studies show that homo- and heterodimers or even higher order oligomers of the chemokine receptors CXCR4, CCR5, and CCR2 modulate receptor function. In addition, membrane cholesterol affects chemokine receptor activity. However, structural information about homo- and heterodimers formed by chemokine receptors and their interplay with cholesterol is limited. Here, we report homo- and heterodimer configurations of the chemokine receptors CXCR4, CCR5, and CCR2 at atomistic detail, as obtained from thousands of molecular dynamics simulations. The observed homodimerization patterns were similar for the closely related CC chemokine receptors, yet they differed significantly between the CC receptors and CXCR4. Despite their high sequence identity, cholesterol modulated the CC homodimer interfaces in a subtype-specific manner. Chemokine receptor heterodimers display distinct dimerization patterns for CXCR4/CCR5 and CXCR4/CCR2. Furthermore, associations between CXCR4 and CCR5 reveal an increased cholesterol-sensitivity as compared to CXCR4/CCR2 heterodimerization patterns. This work provides a first comprehensive structural overview over the complex interaction network between chemokine receptors and indicates how heterodimerization and the interaction with the membrane environment diversifies the function of closely related GPCRs.
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MESH Headings
- Animals
- Chemokines/metabolism
- Cholesterol/metabolism
- Computer Simulation
- Dimerization
- Humans
- Molecular Dynamics Simulation
- Receptors, CCR2/chemistry
- Receptors, CCR2/metabolism
- Receptors, CCR2/ultrastructure
- Receptors, CCR5/chemistry
- Receptors, CCR5/metabolism
- Receptors, CCR5/ultrastructure
- Receptors, CXCR4/chemistry
- Receptors, CXCR4/metabolism
- Receptors, CXCR4/ultrastructure
- Receptors, Chemokine/chemistry
- Receptors, Chemokine/genetics
- Receptors, G-Protein-Coupled/genetics
- Signal Transduction
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Affiliation(s)
- Stefan Gahbauer
- Computational Biology, Department of Biology, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Germany
| | - Kristyna Pluhackova
- Computational Biology, Department of Biology, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Germany
| | - Rainer A. Böckmann
- Computational Biology, Department of Biology, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Germany
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17
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Pediani JD, Ward RJ, Marsango S, Milligan G. Spatial Intensity Distribution Analysis: Studies of G Protein-Coupled Receptor Oligomerisation. Trends Pharmacol Sci 2017; 39:175-186. [PMID: 29032835 PMCID: PMC5783713 DOI: 10.1016/j.tips.2017.09.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Revised: 09/04/2017] [Accepted: 09/14/2017] [Indexed: 02/08/2023]
Abstract
Spatial intensity distribution analysis (SpIDA) is a recently developed approach for determining quaternary structure information on fluorophore-labelled proteins of interest in situ. It can be applied to live or fixed cells and native tissue. Using confocal images, SpIDA generates fluorescence intensity histograms that are analysed by super-Poissonian distribution functions to obtain density and quantal brightness values of the fluorophore-labelled protein of interest. This allows both expression level and oligomerisation state of the protein to be determined. We describe the application of SpIDA to investigate the oligomeric state of G protein-coupled receptors (GPCRs) at steady state and following cellular challenge, and consider how SpIDA may be used to explore GPCR quaternary organisation in pathophysiology and to stratify medicines. GPCRs may exist and function as monomers: however, abundant evidence suggests they can form dimers/oligomers. This concept has implications for drug discovery as it may offer opportunities to modulate the effects of known pharmaceuticals or identify new drug therapies. A variety of approaches have been applied to this issue from traditional biochemical techniques, via resonance energy transfer approaches to recently developed image analysis-based techniques such as SpIDA. This uses mathematical analysis of confocal microscopy images to generate quantal brightness and density information for a fluorophore-tagged receptor. SpIDA can be applied to live or fixed cells and native tissue. SpIDA has been applied to GPCRs from each of the major subfamilies to explore their oligomerisation status at steady state and their regulation by receptor density and ligand binding.
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Affiliation(s)
- John D Pediani
- Centre for Translational Pharmacology, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK
| | - Richard J Ward
- Centre for Translational Pharmacology, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK
| | - Sara Marsango
- Centre for Translational Pharmacology, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK
| | - Graeme Milligan
- Centre for Translational Pharmacology, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK.
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18
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CXCR4 targeted dendrimer for anti-cancer drug delivery and breast cancer cell migration inhibition. Eur J Pharm Biopharm 2017; 119:310-321. [PMID: 28694161 DOI: 10.1016/j.ejpb.2017.07.003] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Revised: 06/10/2017] [Accepted: 07/06/2017] [Indexed: 12/26/2022]
Abstract
CXCR4 and its ligand CXCL12 play a critical role in the metastasis of various types of cancer including breast cancer. Breast tumors preferentially metastasize to the lung, bones and distant lymph nodes, secreting high levels of CXCL12. We hypothesized that targeted inhibition of CXCR4 in breast cancer cells should suppress CXCR4-positive tumor cells toward secondary metastatic sites. In the present study, the efficacy of CXCR4 targeted dendrimers carrying DOX (LFC131-DOX-D4) on cellular binding, cytotoxicity, and migration of BT-549-Luc and T47D breast cancer cells was investigated. PAMAM dendrimers encapsulating DOX was surface functionalized with LFC131 peptide which recognized CXCR4 expressed on the surface of breast cancer cells. The LFC131-DOX-D4 bound to breast cancer cells resulting in significantly enhanced in vitro cellular toxicity as compared with non-targeted dendrimers. The LFC131-D4 exhibited remarkable reduced migration of BT-549-Luc breast cancer cells toward chemoattractant. This report demonstrated the potential utility of LFC131-dendrimer conjugates for breast cancer therapy and metastasis.
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19
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Kufareva I, Gustavsson M, Zheng Y, Stephens BS, Handel TM. What Do Structures Tell Us About Chemokine Receptor Function and Antagonism? Annu Rev Biophys 2017; 46:175-198. [PMID: 28532213 PMCID: PMC5764094 DOI: 10.1146/annurev-biophys-051013-022942] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Chemokines and their cell surface G protein-coupled receptors are critical for cell migration, not only in many fundamental biological processes but also in inflammatory diseases and cancer. Recent X-ray structures of two chemokines complexed with full-length receptors provided unprecedented insight into the atomic details of chemokine recognition and receptor activation, and computational modeling informed by new experiments leverages these insights to gain understanding of many more receptor:chemokine pairs. In parallel, chemokine receptor structures with small molecules reveal the complicated and diverse structural foundations of small molecule antagonism and allostery, highlight the inherent physicochemical challenges of receptor:chemokine interfaces, and suggest novel epitopes that can be exploited to overcome these challenges. The structures and models promote unique understanding of chemokine receptor biology, including the interpretation of two decades of experimental studies, and will undoubtedly assist future drug discovery endeavors.
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Affiliation(s)
- Irina Kufareva
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, California 92093; ,
| | - Martin Gustavsson
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, California 92093; ,
| | - Yi Zheng
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, California 92093; ,
| | - Bryan S Stephens
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, California 92093; ,
| | - Tracy M Handel
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, California 92093; ,
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20
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Yan X, Dai X, He L, Ling X, Shao M, Zhang C, Wang Y, Xiao J, Cai L, Li X, Tan Y. A Novel CXCR4 antagonist enhances angiogenesis via modifying the ischaemic tissue environment. J Cell Mol Med 2017; 21:2298-2307. [PMID: 28374486 PMCID: PMC5618675 DOI: 10.1111/jcmm.13150] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2016] [Accepted: 02/07/2017] [Indexed: 01/01/2023] Open
Abstract
Endothelial progenitor cells (EPCs) play a capital role in angiogenesis via directly participating in neo-vessel formation and secreting pro-angiogenic factors. Stromal cell-derived factor 1 (SDF-1) and its receptor CXCR4 play a critical role in the retention and quiescence of EPCs within its niche in the bone marrow. Disturbing the interaction between SDF-1 and CXCR4 is an effective strategy for EPC mobilization. We developed a novel CXCR4 antagonist P2G, a mutant protein of SDF-1β with high antagonistic activity against CXCR4 and high potency in enhancing ischaemic angiogenesis and blood perfusion. However, its direct effects on ischaemic tissue remain largely unknown. In this study, P2G was found to possess a robust capability to promote EPC infiltration and incorporation in neo-vessels, enhance the expression and function of pro-angiogenic factors, such as SDF-1, vascular endothelial growth factor and matrix metalloprotein-9, and activate cell signals involved in angiogenesis, such as proliferating cell nuclear antigen, protein kinase B (Akt), extracellular regulated protein kinases and mammalian target of rapamycin, in ischaemic tissue. Moreover, P2G can attenuate fibrotic remodelling to facilitate the recovery of ischaemic tissue. The capability of P2G in direct augmenting ischaemic environment for angiogenesis suggests that it is a potential candidate for the therapy of ischaemia diseases.
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Affiliation(s)
- Xiaoqing Yan
- Chinese-American Research Institute for Diabetic Complications, Wenzhou Medical University, Chashan University-town, Wenzhou, Zhejiang, China.,Pediatric Research Institute, Department of Pediatrics, University of Louisville, Louisville, KY, USA.,Chinese-American Pediatric Research Institute at the First Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Xiaozhen Dai
- Pediatric Research Institute, Department of Pediatrics, University of Louisville, Louisville, KY, USA.,School of Biomedicine, Chengdu Medical College, Chengdu, Sichuan, China
| | - Luqing He
- Chinese-American Research Institute for Diabetic Complications, Wenzhou Medical University, Chashan University-town, Wenzhou, Zhejiang, China
| | - Xiao Ling
- Chinese-American Research Institute for Diabetic Complications, Wenzhou Medical University, Chashan University-town, Wenzhou, Zhejiang, China
| | - Minglong Shao
- Chinese-American Research Institute for Diabetic Complications, Wenzhou Medical University, Chashan University-town, Wenzhou, Zhejiang, China
| | - Chi Zhang
- Chinese-American Research Institute for Diabetic Complications, Wenzhou Medical University, Chashan University-town, Wenzhou, Zhejiang, China
| | - Yuehui Wang
- Department of Geriatric Medicine, the first hospital of Jilin university, Changchun, Jilin, China
| | - Jian Xiao
- Chinese-American Research Institute for Diabetic Complications, Wenzhou Medical University, Chashan University-town, Wenzhou, Zhejiang, China
| | - Lu Cai
- Chinese-American Research Institute for Diabetic Complications, Wenzhou Medical University, Chashan University-town, Wenzhou, Zhejiang, China.,Pediatric Research Institute, Department of Pediatrics, University of Louisville, Louisville, KY, USA.,Chinese-American Pediatric Research Institute at the First Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Xiaokun Li
- Chinese-American Research Institute for Diabetic Complications, Wenzhou Medical University, Chashan University-town, Wenzhou, Zhejiang, China
| | - Yi Tan
- Chinese-American Research Institute for Diabetic Complications, Wenzhou Medical University, Chashan University-town, Wenzhou, Zhejiang, China.,Pediatric Research Institute, Department of Pediatrics, University of Louisville, Louisville, KY, USA.,Chinese-American Pediatric Research Institute at the First Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China
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21
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Vauquelin G. Cell membranes… and how long drugs may exert beneficial pharmacological activity in vivo. Br J Clin Pharmacol 2016; 82:673-82. [PMID: 27135195 PMCID: PMC5338106 DOI: 10.1111/bcp.12996] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Revised: 04/28/2016] [Accepted: 04/28/2016] [Indexed: 12/14/2022] Open
Abstract
The time course of the beneficial pharmacological effect of a drug has long been considered to depend merely on the temporal fluctuation of its free concentration. Only in the last decade has it become widely accepted that target-binding kinetics can also affect in vivo pharmacological activity. Although current reviews still essentially focus on genuine dissociation rates, evidence is accumulating that additional micro-pharmacokinetic (PK) and -pharmacodynamic (PD) mechanisms, in which the cell membrane plays a central role, may also increase the residence time of a drug on its target. The present review provides a compilation of otherwise widely dispersed information on this topic. The cell membrane can intervene in drug binding via the following three major mechanisms: (i) by acting as a sink/repository for the drug; (ii) by modulating the conformation of the drug and even by participating in the binding process; and (iii) by facilitating the approach (and rebinding) of the drug to the target. To highlight these mechanisms, we focus on drugs that are currently used in clinical therapy, such as the antihypertensive angiotensin II type 1 receptor antagonist candesartan, the atypical antipsychotic agent clozapine and the bronchodilator salmeterol. Although the role of cell membranes in PK-PD modelling is gaining increasing interest, many issues remain unresolved. It is likely that novel biophysical and computational approaches will provide improved insights in the near future.
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Affiliation(s)
- Georges Vauquelin
- Department Molecular and Biochemical PharmacologyVrije Universiteit BrusselBrusselsBelgium
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22
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Kleist AB, Getschman AE, Ziarek JJ, Nevins AM, Gauthier PA, Chevigné A, Szpakowska M, Volkman BF. New paradigms in chemokine receptor signal transduction: Moving beyond the two-site model. Biochem Pharmacol 2016; 114:53-68. [PMID: 27106080 DOI: 10.1016/j.bcp.2016.04.007] [Citation(s) in RCA: 88] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Accepted: 04/13/2016] [Indexed: 10/21/2022]
Abstract
Chemokine receptor (CKR) signaling forms the basis of essential immune cellular functions, and dysregulated CKR signaling underpins numerous disease processes of the immune system and beyond. CKRs, which belong to the seven transmembrane domain receptor (7TMR) superfamily, initiate signaling upon binding of endogenous, secreted chemokine ligands. Chemokine-CKR interactions are traditionally described by a two-step/two-site mechanism, in which the CKR N-terminus recognizes the chemokine globular core (i.e. site 1 interaction), followed by activation when the unstructured chemokine N-terminus is inserted into the receptor TM bundle (i.e. site 2 interaction). Several recent studies challenge the structural independence of sites 1 and 2 by demonstrating physical and allosteric links between these supposedly separate sites. Others contest the functional independence of these sites, identifying nuanced roles for site 1 and other interactions in CKR activation. These developments emerge within a rapidly changing landscape in which CKR signaling is influenced by receptor PTMs, chemokine and CKR dimerization, and endogenous non-chemokine ligands. Simultaneous advances in the structural and functional characterization of 7TMR biased signaling have altered how we understand promiscuous chemokine-CKR interactions. In this review, we explore new paradigms in CKR signal transduction by considering studies that depict a more intricate architecture governing the consequences of chemokine-CKR interactions.
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Affiliation(s)
- Andrew B Kleist
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI 53226, USA.
| | - Anthony E Getschman
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI 53226, USA.
| | - Joshua J Ziarek
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, 240 Longwood Ave, Boston, MA 02115, USA.
| | - Amanda M Nevins
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI 53226, USA.
| | - Pierre-Arnaud Gauthier
- Department of Infection and Immunity, Luxembourg Institute of Health, L-4354 Esch-sur-Alzette, Luxembourg.
| | - Andy Chevigné
- Department of Infection and Immunity, Luxembourg Institute of Health, L-4354 Esch-sur-Alzette, Luxembourg.
| | - Martyna Szpakowska
- Department of Infection and Immunity, Luxembourg Institute of Health, L-4354 Esch-sur-Alzette, Luxembourg.
| | - Brian F Volkman
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI 53226, USA.
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23
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Coke CJ, Scarlett KA, Chetram MA, Jones KJ, Sandifer BJ, Davis AS, Marcus AI, Hinton CV. Simultaneous Activation of Induced Heterodimerization between CXCR4 Chemokine Receptor and Cannabinoid Receptor 2 (CB2) Reveals a Mechanism for Regulation of Tumor Progression. J Biol Chem 2016; 291:9991-10005. [PMID: 26841863 DOI: 10.1074/jbc.m115.712661] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Indexed: 12/19/2022] Open
Abstract
The G-protein-coupled chemokine receptor CXCR4 generates signals that lead to cell migration, cell proliferation, and other survival mechanisms that result in the metastatic spread of primary tumor cells to distal organs. Numerous studies have demonstrated that CXCR4 can form homodimers or can heterodimerize with other G-protein-coupled receptors to form receptor complexes that can amplify or decrease the signaling capacity of each individual receptor. Using biophysical and biochemical approaches, we found that CXCR4 can form an induced heterodimer with cannabinoid receptor 2 (CB2) in human breast and prostate cancer cells. Simultaneous, agonist-dependent activation of CXCR4 and CB2 resulted in reduced CXCR4-mediated expression of phosphorylated ERK1/2 and ultimately reduced cancer cell functions such as calcium mobilization and cellular chemotaxis. Given that treatment with cannabinoids has been shown to reduce invasiveness of cancer cells as well as CXCR4-mediated migration of immune cells, it is plausible that CXCR4 signaling can be silenced through a physical heterodimeric association with CB2, thereby inhibiting subsequent functions of CXCR4. Taken together, the data illustrate a mechanism by which the cannabinoid system can negatively modulate CXCR4 receptor function and perhaps tumor progression.
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Affiliation(s)
- Christopher J Coke
- From the Department of Biological Sciences and the Center for Cancer Research and Therapeutic Development, Clark Atlanta University, Atlanta, Georgia 30314
| | - Kisha A Scarlett
- From the Department of Biological Sciences and the Center for Cancer Research and Therapeutic Development, Clark Atlanta University, Atlanta, Georgia 30314
| | - Mahandranauth A Chetram
- Molecular Oncology Program, Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, D. C. 20057, and
| | - Kia J Jones
- From the Department of Biological Sciences and the Center for Cancer Research and Therapeutic Development, Clark Atlanta University, Atlanta, Georgia 30314
| | - Brittney J Sandifer
- From the Department of Biological Sciences and the Center for Cancer Research and Therapeutic Development, Clark Atlanta University, Atlanta, Georgia 30314
| | - Ahriea S Davis
- From the Department of Biological Sciences and the Center for Cancer Research and Therapeutic Development, Clark Atlanta University, Atlanta, Georgia 30314
| | - Adam I Marcus
- Department of Hematology and Medical Oncology, Emory University, Atlanta, Georgia 30322
| | - Cimona V Hinton
- From the Department of Biological Sciences and the Center for Cancer Research and Therapeutic Development, Clark Atlanta University, Atlanta, Georgia 30314,
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24
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Abstract
Chemokine receptors are involved in various pathologies such as inflammatory diseases, cancer, and HIV infection. Small molecule and antibody-based antagonists have been developed to inhibit chemokine-induced receptor activity. Currently two small molecule inhibitors targeting CXCR4 and CCR5 are on the market for stem cell mobilization and the treatment of HIV infection, respectively. Antibody fragments (e.g., nanobodies) targeting chemokine receptors are primarily orthosteric ligands, competing for the chemokine binding site. This is opposed by most small molecules, which act as allosteric modulators and bind to the receptor at a topographically distinct site as compared to chemokines. Allosteric modulators can be distinguished from orthosteric ligands by unique features, such as a saturable effect and probe dependency. For successful drug development, it is essential to determine pharmacological parameters (i.e., affinity, potency, and efficacy) and the mode of action of potential drugs during early stages of research in order to predict the biological effect of chemokine receptor targeting drugs in the clinic. This chapter explains how the pharmacological profile of chemokine receptor targeting ligands can be determined and quantified using binding and functional experiments.
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25
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Vischer HF, Castro M, Pin JP. G Protein-Coupled Receptor Multimers: A Question Still Open Despite the Use of Novel Approaches. Mol Pharmacol 2015; 88:561-71. [PMID: 26138074 DOI: 10.1124/mol.115.099440] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2015] [Accepted: 07/02/2015] [Indexed: 12/11/2022] Open
Abstract
Heteromerization of G protein-coupled receptors (GPCRs) can significantly change the functional properties of involved receptors. Various biochemical and biophysical methodologies have been developed in the last two decades to identify and functionally evaluate GPCR heteromers in heterologous cells, with recent approaches focusing on GPCR complex stoichiometry and stability. Yet validation of these observations in native tissues is still lagging behind for the majority of GPCR heteromers. Remarkably, recent studies, particularly some involving advanced fluorescence microscopy techniques, are contributing to our current knowledge of aspects that were not well known until now, such as GPCR complex stoichiometry and stability. In parallel, a growing effort is being applied to move the field forward into native systems. This short review will highlight recent developments to study the stoichiometry and stability of GPCR complexes and methodologies to detect native GPCR dimers.
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Affiliation(s)
- Henry F Vischer
- Amsterdam Institute for Molecules, Medicines and Systems, Division of Medicinal Chemistry, Faculty of Sciences, VU University Amsterdam, Amsterdam, The Netherlands (H.F.V.); Molecular Pharmacology Laboratory, Biofarma Research Group (GI-1685), University of Santiago de Compostela, Center for Research in Molecular Medicine and Chronic Diseases, Santiago de Compostela, Spain (M.C.); and Centre National de la Recherche Scientifique, Institut de Génomique Fonctionnelle, Université de Montpellier, Montpellier, France (J.-P.P.)
| | - Marián Castro
- Amsterdam Institute for Molecules, Medicines and Systems, Division of Medicinal Chemistry, Faculty of Sciences, VU University Amsterdam, Amsterdam, The Netherlands (H.F.V.); Molecular Pharmacology Laboratory, Biofarma Research Group (GI-1685), University of Santiago de Compostela, Center for Research in Molecular Medicine and Chronic Diseases, Santiago de Compostela, Spain (M.C.); and Centre National de la Recherche Scientifique, Institut de Génomique Fonctionnelle, Université de Montpellier, Montpellier, France (J.-P.P.)
| | - Jean-Philippe Pin
- Amsterdam Institute for Molecules, Medicines and Systems, Division of Medicinal Chemistry, Faculty of Sciences, VU University Amsterdam, Amsterdam, The Netherlands (H.F.V.); Molecular Pharmacology Laboratory, Biofarma Research Group (GI-1685), University of Santiago de Compostela, Center for Research in Molecular Medicine and Chronic Diseases, Santiago de Compostela, Spain (M.C.); and Centre National de la Recherche Scientifique, Institut de Génomique Fonctionnelle, Université de Montpellier, Montpellier, France (J.-P.P.)
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Vauquelin G, Hall D, Charlton SJ. 'Partial' competition of heterobivalent ligand binding may be mistaken for allosteric interactions: a comparison of different target interaction models. Br J Pharmacol 2015; 172:2300-15. [PMID: 25537684 DOI: 10.1111/bph.13053] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2013] [Revised: 10/25/2014] [Accepted: 12/14/2014] [Indexed: 01/15/2023] Open
Abstract
BACKGROUND AND PURPOSE Non-competitive drugs that confer allosteric modulation of orthosteric ligand binding are of increasing interest as therapeutic agents. Sought-after advantages include a ceiling level to drug effect and greater receptor-subtype selectivity. It is thus important to determine the mode of interaction of newly identified receptor ligands early in the drug discovery process and binding studies with labelled orthosteric ligands constitute a traditional approach for this. According to the general allosteric ternary complex model, allosteric ligands that exhibit negative cooperativity may generate distinctive 'competition' curves: they will not reach baseline levels and their nadir will increase in par with the orthosteric ligand concentration. This behaviour is often considered a key hallmark of allosteric interactions. EXPERIMENTAL APPROACH The present study is based on differential equation-based simulations. KEY RESULTS The differential equation-based simulations revealed that the same 'competition binding' pattern was also obtained when a monovalent ligand binds to one of the target sites of a heterobivalent ligand, even if this process is exempt of allosteric interactions. This pattern was not strictly reciprocal when the binding of each of the ligands was recorded. The prominence of this phenomenon may vary from one heterobivalent ligand to another and we suggest that this phenomenon may take place with ligands that have been proposed to bind according to 'two-domain' and 'charnière' models. CONCLUSIONS AND IMPLICATIONS The present findings indicate a familiar experimental situation where bivalency may give rise to observations that could inadvertently be interpreted as allosteric binding. Yet, both mechanisms could be differentiated based on alternative experiments and structural considerations.
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Affiliation(s)
- Georges Vauquelin
- Department Molecular and Biochemical Pharmacology, Vrije Universiteit Brussel, Brussels, Belgium
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27
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Hill SJ, May LT, Kellam B, Woolard J. Allosteric interactions at adenosine A(1) and A(3) receptors: new insights into the role of small molecules and receptor dimerization. Br J Pharmacol 2014; 171:1102-13. [PMID: 24024783 DOI: 10.1111/bph.12345] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2013] [Revised: 07/09/2013] [Accepted: 07/12/2013] [Indexed: 12/22/2022] Open
Abstract
The purine nucleoside adenosine is present in all cells in tightly regulated concentrations. It is released under a variety of physiological and pathophysiological conditions to facilitate protection and regeneration of tissues. Adenosine acts via specific GPCRs to either stimulate cyclic AMP formation, as exemplified by Gs -protein-coupled adenosine receptors (A2A and A2B ), or inhibit AC activity, in the case of Gi/o -coupled adenosine receptors (A1 and A3 ). Recent advances in our understanding of GPCR structure have provided insights into the conformational changes that occur during receptor activation following binding of agonists to orthosteric (i.e. at the same binding site as an endogenous modulator) and allosteric regulators to allosteric sites (i.e. at a site that is topographically distinct from the endogenous modulator). Binding of drugs to allosteric sites may lead to changes in affinity or efficacy, and affords considerable potential for increased selectivity in new drug development. Herein, we provide an overview of the properties of selective allosteric regulators of the adenosine A1 and A3 receptors, focusing on the impact of receptor dimerization, mechanistic approaches to single-cell ligand-binding kinetics and the effects of A1 - and A3 -receptor allosteric modulators on in vivo pharmacology.
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Affiliation(s)
- Stephen J Hill
- Cell Signalling Research Group, School of Biomedical Sciences, Medical School, Queen's Medical Centre, University of Nottingham, Nottingham, UK
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Role of 3D Structures in Understanding, Predicting, and Designing Molecular Interactions in the Chemokine Receptor Family. ACTA ACUST UNITED AC 2014. [DOI: 10.1007/7355_2014_77] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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29
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A new mechanism of allostery in a G protein-coupled receptor dimer. Nat Chem Biol 2014; 10:745-52. [PMID: 25108820 PMCID: PMC4138267 DOI: 10.1038/nchembio.1593] [Citation(s) in RCA: 98] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2014] [Accepted: 06/26/2014] [Indexed: 01/11/2023]
Abstract
SB269652 (1) is the first drug-like allosteric modulator of the
dopamine D2 receptor (D2R), but contains structural features
associated with orthosteric D2R antagonists. Using a functional complementation
system to control the identity of individual protomers within a dimeric D2R
complex, we converted the pharmacology of the interaction between SB269652 and dopamine
from allosteric to competitive by impairing ligand binding to one of the protomers,
indicating that the allostery requires D2R dimers. Additional experiments
identified a “bitopic” pose for SB269652 extending from the orthosteric
site into a secondary pocket at the extracellular end of the transmembrane (TM) domain,
involving TM2 and TM7. Engagement of this secondary pocket was a requirement for the
allosteric pharmacology of SB269652. This suggests a novel mechanism whereby a bitopic
ligand binds in an extended pose on one G protein-coupled receptor protomer to
allosterically modulate the binding of a ligand to the orthosteric site of a second
protomer.
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30
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Stephens B, Handel TM. Chemokine receptor oligomerization and allostery. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2014; 115:375-420. [PMID: 23415099 DOI: 10.1016/b978-0-12-394587-7.00009-9] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Oligomerization of chemokine receptors has been reported to influence many aspects of receptor function through allosteric communication between receptor protomers. Allosteric interactions within chemokine receptor hetero-oligomers have been shown to cause negative cooperativity in the binding of chemokines and to inhibit receptor activation in the case of some receptor pairs. Other receptor pairs can cause enhanced signaling and even activate entirely new, hetero-oligomer-specific signaling complexes and responses downstream of receptor activation. Many mechanisms contribute to these effects including direct allosteric coupling between the receptors, G protein-mediated allostery, G protein stealing, ligand sequestration, and recruitment of new intracellular proteins by exposing unique binding interfaces on the oligomerized receptors. These effects present both challenges as well as exciting opportunities for drug discovery. One of the most difficult challenges will involve determining if and when hetero-oligomers versus homomeric receptors are involved in specific disease states.
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Affiliation(s)
- Bryan Stephens
- Skaggs School of Pharmacy and Pharmaceutical Science, University of California, San Diego, La Jolla, California, USA
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31
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Ford LB, Cerovic V, Milling SWF, Graham GJ, Hansell CAH, Nibbs RJB. Characterization of conventional and atypical receptors for the chemokine CCL2 on mouse leukocytes. THE JOURNAL OF IMMUNOLOGY 2014; 193:400-11. [PMID: 24890717 DOI: 10.4049/jimmunol.1303236] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Chemokine-directed leukocyte migration is crucial for effective immune and inflammatory responses. Conventional chemokine receptors (cCKRs) directly control cell movement; atypical chemokine receptors (ACKRs) regulate coexpressed cCKRs; and both cCKRs and ACKRs internalize chemokines to limit their abundance in vivo, a process referred to as scavenging. A leukocyte's migratory and chemokine-scavenging potential is determined by which cCKRs and ACKRs it expresses, and by the ligand specificity, signaling properties, and chemokine internalization capacity of these receptors. Most chemokines can bind at least one cCKR and one ACKR. CCL2 can bind to CCR2 (a cCKR) and two ACKRs (ACKR1 and ACKR2). In this study, by using fluorescent CCL2 uptake to label cells bearing functional CCL2 receptors, we have defined the expression profile, scavenging activity, and ligand specificity of CCL2 receptors on mouse leukocytes. We show that qualitative and quantitative differences in the expression of CCR2 and ACKR2 endow individual leukocyte subsets with distinctive CCL2 receptor profiles and CCL2-scavenging capacities. We reveal that some cells, including plasmacytoid dendritic cells, can express both CCR2 and ACKR2; that Ly6C(high) monocytes have particularly strong CCL2-scavenging potential in vitro and in vivo; and that CCR2 is a much more effective CCL2 scavenger than ACKR2. We confirm the unique, overlapping, ligand specificities of CCR2 and ACKR2 and, unexpectedly, find that cell context influences the interaction of CCL7 and CCL12 with CCR2. Fluorescent chemokine uptake assays were instrumental in providing these novel insights into CCL2 receptor biology, and the sensitivity, specificity, and versatility of these assays are discussed.
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Affiliation(s)
- Laura B Ford
- Centre for Immunobiology, Institute for Infection, Immunity, and Inflammation, College of Medical, Veterinary, and Life Sciences, University of Glasgow, Glasgow G12 8TA, Scotland, United Kingdom
| | - Vuk Cerovic
- Centre for Immunobiology, Institute for Infection, Immunity, and Inflammation, College of Medical, Veterinary, and Life Sciences, University of Glasgow, Glasgow G12 8TA, Scotland, United Kingdom
| | - Simon W F Milling
- Centre for Immunobiology, Institute for Infection, Immunity, and Inflammation, College of Medical, Veterinary, and Life Sciences, University of Glasgow, Glasgow G12 8TA, Scotland, United Kingdom
| | - Gerard J Graham
- Centre for Immunobiology, Institute for Infection, Immunity, and Inflammation, College of Medical, Veterinary, and Life Sciences, University of Glasgow, Glasgow G12 8TA, Scotland, United Kingdom
| | - Chris A H Hansell
- Centre for Immunobiology, Institute for Infection, Immunity, and Inflammation, College of Medical, Veterinary, and Life Sciences, University of Glasgow, Glasgow G12 8TA, Scotland, United Kingdom
| | - Robert J B Nibbs
- Centre for Immunobiology, Institute for Infection, Immunity, and Inflammation, College of Medical, Veterinary, and Life Sciences, University of Glasgow, Glasgow G12 8TA, Scotland, United Kingdom
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Modeling the allosteric modulation of CCR5 function by Maraviroc. DRUG DISCOVERY TODAY. TECHNOLOGIES 2014; 10:e297-305. [PMID: 24050281 DOI: 10.1016/j.ddtec.2012.07.011] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Maraviroc is a non-peptidic, low molecular weight CC chemokine receptor 5 (CCR5) ligand that has recently been marketed for the treatment of HIV infected individuals. This review discusses recent molecular modeling studies of CCR5 by homology to CXC chemokine receptor 4, their contribution to the understanding of the allosteric mode of action of the inhibitor and their potential for the development of future drugs with improved efficiency and preservation of CCR5 biological functions.
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33
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Bias in chemokine receptor signalling. Trends Immunol 2014; 35:243-52. [PMID: 24679437 DOI: 10.1016/j.it.2014.02.004] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2014] [Revised: 02/12/2014] [Accepted: 02/14/2014] [Indexed: 01/14/2023]
Abstract
Chemokine receptors are widely expressed on a variety of immune cells and play a crucial role in normal physiology as well as in inflammatory and infectious diseases. The existence of 23 chemokine receptors and 48 chemokine ligands guarantees a tight control and fine-tuning of the immune system. Here, we discuss the multiple regulatory mechanisms of chemokine signalling at a systemic, cellular, and molecular level. In particular, we focus on the impact of biased signalling at the receptor level; an emerging concept in molecular pharmacology. An improved understanding of these mechanisms may provide a framework for more effective drug discovery and development at a target class that is so relevant for immune function.
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Flegler AJ, Cianci GC, Hope TJ. CCR5 conformations are dynamic and modulated by localization, trafficking and G protein association. PLoS One 2014; 9:e89056. [PMID: 24586501 PMCID: PMC3938464 DOI: 10.1371/journal.pone.0089056] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2013] [Accepted: 01/15/2014] [Indexed: 11/19/2022] Open
Abstract
CCR5 acts as the principal coreceptor during HIV-1 transmission and early stages of infection. Efficient HIV-1 entry requires a series of processes, many dependent on the conformational state of both viral envelope protein and cellular receptor. Monoclonal antibodies (MAbs) are able to identify different CCR5 conformations, allowing for their use as probes to distinguish CCR5 populations. Not all CCR5 MAbs are able to reduce HIV-1 infection, suggesting the use of select CCR5 populations for entry. In the U87.CD4.CCR5-GFP cell line, we used such HIV-1-restricting MAbs to probe the relation between localization, trafficking and G protein association for individual CCR5 conformations. We find that CCR5 conformations not only exhibit different localization and abundance patterns throughout the cell, but that they also display distinct sensitivities to endocytosis inhibition. Using chemokine analogs that vary in their HIV-1 inhibitory mechanisms, we also illustrate that responses to ligand engagement are conformation-specific. Additionally, we provide supporting evidence for the select sensitivity of conformations to G protein association. Characterizing the link between the function and dynamics of CCR5 populations has implications for understanding their selective targeting by HIV-1 and for the development of inhibitors that will block CCR5 utilization by the virus.
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Affiliation(s)
- Ayanna J. Flegler
- Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States of America
| | - Gianguido C. Cianci
- Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States of America
| | - Thomas J. Hope
- Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States of America
- * E-mail:
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35
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Ferré S, Casadó V, Devi LA, Filizola M, Jockers R, Lohse MJ, Milligan G, Pin JP, Guitart X. G protein-coupled receptor oligomerization revisited: functional and pharmacological perspectives. Pharmacol Rev 2014; 66:413-34. [PMID: 24515647 DOI: 10.1124/pr.113.008052] [Citation(s) in RCA: 427] [Impact Index Per Article: 42.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Most evidence indicates that, as for family C G protein-coupled receptors (GPCRs), family A GPCRs form homo- and heteromers. Homodimers seem to be a predominant species, with potential dynamic formation of higher-order oligomers, particularly tetramers. Although monomeric GPCRs can activate G proteins, the pentameric structure constituted by one GPCR homodimer and one heterotrimeric G protein may provide a main functional unit, and oligomeric entities can be viewed as multiples of dimers. It still needs to be resolved if GPCR heteromers are preferentially heterodimers or if they are mostly constituted by heteromers of homodimers. Allosteric mechanisms determine a multiplicity of possible unique pharmacological properties of GPCR homomers and heteromers. Some general mechanisms seem to apply, particularly at the level of ligand-binding properties. In the frame of the dimer-cooperativity model, the two-state dimer model provides the most practical method to analyze ligand-GPCR interactions when considering receptor homomers. In addition to ligand-binding properties, unique properties for each GPCR oligomer emerge in relation to different intrinsic efficacy of ligands for different signaling pathways (functional selectivity). This gives a rationale for the use of GPCR oligomers, and particularly heteromers, as novel targets for drug development. Herein, we review the functional and pharmacological properties of GPCR oligomers and provide some guidelines for the application of discrete direct screening and high-throughput screening approaches to the discovery of receptor-heteromer selective compounds.
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Affiliation(s)
- Sergi Ferré
- Integrative Neurobiology Section, National Institute on Drug Abuse, Intramural Research Program, National Institutes on Drug Abuse, Department of Health and Human Services, 333 Cassell Drive, Baltimore, Maryland 21224.
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36
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Watts AO, van Lipzig MMH, Jaeger WC, Seeber RM, van Zwam M, Vinet J, van der Lee MMC, Siderius M, Zaman GJR, Boddeke HWGM, Smit MJ, Pfleger KDG, Leurs R, Vischer HF. Identification and profiling of CXCR3-CXCR4 chemokine receptor heteromer complexes. Br J Pharmacol 2013; 168:1662-74. [PMID: 23170857 DOI: 10.1111/bph.12064] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2012] [Revised: 09/29/2012] [Accepted: 10/29/2012] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND AND PURPOSE The C-X-C chemokine receptors 3 (CXCR3) and C-X-C chemokine receptors 4 (CXCR4) are involved in various autoimmune diseases and cancers. Small antagonists have previously been shown to cross-inhibit chemokine binding to CXCR4, CC chemokine receptors 2 (CCR2) and 5 (CCR5) heteromers. We investigated whether CXCR3 and CXCR4 can form heteromeric complexes and the binding characteristics of chemokines and small ligand compounds to these chemokine receptor heteromers. EXPERIMENTAL APPROACH CXCR3-CXCR4 heteromers were identified in HEK293T cells using co-immunoprecipitation, time-resolved fluorescence resonance energy transfer, saturation BRET and the GPCR-heteromer identification technology (HIT) approach. Equilibrium competition binding and dissociation experiments were performed to detect negative binding cooperativity. KEY RESULTS We provide evidence that chemokine receptors CXCR3 and CXCR4 form heteromeric complexes in HEK293T cells. Chemokine binding was mutually exclusive on membranes co-expressing CXCR3 and CXCR4 as revealed by equilibrium competition binding and dissociation experiments. The small CXCR3 agonist VUF10661 impaired binding of CXCL12 to CXCR4, whereas small antagonists were unable to cross-inhibit chemokine binding to the other chemokine receptor. In contrast, negative binding cooperativity between CXCR3 and CXCR4 chemokines was not observed in intact cells. However, using the GPCR-HIT approach, we have evidence for specific β-arrestin2 recruitment to CXCR3-CXCR4 heteromers in response to agonist stimulation. CONCLUSIONS AND IMPLICATIONS This study indicates that heteromeric CXCR3-CXCR4 complexes may act as functional units in living cells, which potentially open up novel therapeutic opportunities.
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Affiliation(s)
- A O Watts
- Leiden/Amsterdam Center for Drug Research, Division of Medicinal Chemistry, Faculty of Science, VU University Amsterdam, Amsterdam, The Netherlands
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Vinet J, van Zwam M, Dijkstra IM, Brouwer N, van Weering HRJ, Watts A, Meijer M, Fokkens MR, Kannan V, Verzijl D, Vischer HF, Smit MJ, Leurs R, Biber K, Boddeke HWGM. Inhibition of CXCR3-mediated chemotaxis by the human chemokine receptor-like protein CCX-CKR. Br J Pharmacol 2013; 168:1375-87. [PMID: 23121557 DOI: 10.1111/bph.12042] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2012] [Revised: 09/28/2012] [Accepted: 10/01/2012] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND AND PURPOSE Induction of cellular migration is the primary effect of chemokine receptor activation. However, several chemokine receptor-like proteins bind chemokines without subsequent induction of intracellular signalling and chemotaxis. It has been suggested that they act as chemokine scavengers, which may control local chemokine levels and contribute to the function of chemokines during inflammation. This has been verified for the chemokine-like receptor proteins D6 and DARC as well as CCX-CKR. Here, we provide evidence for an additional biological function of human (h)CCX-CKR. EXPERIMENTAL APPROACH We used transfection strategies in HEK293 and human T cells. KEY RESULTS Co-expression of hCCX-CKR completely inhibits hCXCR3-induced chemotaxis. We found that hCCX-CKR forms complexes with hCXCR3, suggesting a relationship between CCX-CKR heteromerization and inhibition of chemotaxis. Moreover, negative binding cooperativity induced by ligands both for hCXCR3 and hCCX-CKR was observed in cells expressing both receptors. This negative cooperativity may also explain the hCCX-CKR-induced inhibition of chemotaxis. CONCLUSIONS AND IMPLICATIONS These findings suggest that hCCX-CKR prevents hCXCR3-induced chemotaxis by heteromerization thus representing a novel mechanism of regulation of immune cell migration.
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Affiliation(s)
- J Vinet
- Department of Neuroscience, Section Medical Physiology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
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Zweemer AJM, Nederpelt I, Vrieling H, Hafith S, Doornbos MLJ, de Vries H, Abt J, Gross R, Stamos D, Saunders J, Smit MJ, IJzerman AP, Heitman LH. Multiple Binding Sites for Small-Molecule Antagonists at the CC Chemokine Receptor 2. Mol Pharmacol 2013; 84:551-61. [DOI: 10.1124/mol.113.086850] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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Hiller C, Kühhorn J, Gmeiner P. Class A G-Protein-Coupled Receptor (GPCR) Dimers and Bivalent Ligands. J Med Chem 2013; 56:6542-59. [DOI: 10.1021/jm4004335] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Christine Hiller
- Department of Chemistry and Pharmacy,
Emil Fischer
Center, Friedrich Alexander University,
Schuhstraße 19, 91052 Erlangen, Germany
| | - Julia Kühhorn
- Department of Chemistry and Pharmacy,
Emil Fischer
Center, Friedrich Alexander University,
Schuhstraße 19, 91052 Erlangen, Germany
| | - Peter Gmeiner
- Department of Chemistry and Pharmacy,
Emil Fischer
Center, Friedrich Alexander University,
Schuhstraße 19, 91052 Erlangen, Germany
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HIV-1 exploits CCR5 conformational heterogeneity to escape inhibition by chemokines. Proc Natl Acad Sci U S A 2013; 110:9475-80. [PMID: 23696662 DOI: 10.1073/pnas.1222205110] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
CC chemokine receptor 5 (CCR5) is a receptor for chemokines and the coreceptor for R5 HIV-1 entry into CD4(+) T lymphocytes. Chemokines exert anti-HIV-1 activity in vitro, both by displacing the viral envelope glycoprotein gp120 from binding to CCR5 and by promoting CCR5 endocytosis, suggesting that they play a protective role in HIV infection. However, we showed here that different CCR5 conformations at the cell surface are differentially engaged by chemokines and gp120, making chemokines weaker inhibitors of HIV infection than would be expected from their binding affinity constants for CCR5. These distinct CCR5 conformations rely on CCR5 coupling to nucleotide-free G proteins ((NF)G proteins). Whereas native CCR5 chemokines bind with subnanomolar affinity to (NF)G protein-coupled CCR5, gp120/HIV-1 does not discriminate between (NF)G protein-coupled and uncoupled CCR5. Interestingly, the antiviral activity of chemokines is G protein independent, suggesting that "low-chemokine affinity" (NF)G protein-uncoupled conformations of CCR5 represent a portal for viral entry. Furthermore, chemokines are weak inducers of CCR5 endocytosis, as is revealed by EC50 values for chemokine-mediated endocytosis reflecting their low-affinity constant value for (NF)G protein-uncoupled CCR5. Abolishing CCR5 interaction with (NF)G proteins eliminates high-affinity binding of CCR5 chemokines but preserves receptor endocytosis, indicating that chemokines preferentially endocytose low-affinity receptors. Finally, we evidenced that chemokine analogs achieve highly potent HIV-1 inhibition due to high-affinity interactions with internalizing and/or gp120-binding receptors. These data are consistent with HIV-1 evading chemokine inhibition by exploiting CCR5 conformational heterogeneity, shed light into the inhibitory mechanisms of anti-HIV-1 chemokine analogs, and provide insights for the development of unique anti-HIV molecules.
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de Poorter C, Baertsoen K, Lannoy V, Parmentier M, Springael JY. Consequences of ChemR23 heteromerization with the chemokine receptors CXCR4 and CCR7. PLoS One 2013; 8:e58075. [PMID: 23469143 PMCID: PMC3585228 DOI: 10.1371/journal.pone.0058075] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2012] [Accepted: 01/30/2013] [Indexed: 02/05/2023] Open
Abstract
Recent studies have shown that heteromerization of the chemokine receptors CCR2, CCR5 and CXCR4 is associated to negative binding cooperativity. In the present study, we build on these previous results, and investigate the consequences of chemokine receptor heteromerization with ChemR23, the receptor of chemerin, a leukocyte chemoattractant protein structurally unrelated to chemokines. We show, using BRET and HTRF assays, that ChemR23 forms homomers, and provide data suggesting that ChemR23 also forms heteromers with the chemokine receptors CCR7 and CXCR4. As previously described for other chemokine receptor heteromers, negative binding cooperativity was detected between ChemR23 and chemokine receptors, i.e. the ligands of one receptor competed for the binding of a specific tracer of the other. We also showed, using mouse bone marrow-derived dendritic cells prepared from wild-type and ChemR23 knockout mice, that ChemR23-specific ligands cross-inhibited CXCL12 binding on CXCR4 in a ChemR23-dependent manner, supporting the relevance of the ChemR23/CXCR4 interaction in native leukocytes. Finally, and in contrast to the situation encountered for other previously characterized CXCR4 heteromers, we showed that the CXCR4-specific antagonist AMD3100 did not cross-inhibit chemerin binding in cells co-expressing ChemR23 and CXCR4, demonstrating that cross-regulation by AMD3100 depends on the nature of receptor partners with which CXCR4 is co-expressed.
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Affiliation(s)
- Cédric de Poorter
- Institut de Recherche Interdisciplinaire en Biologie Humaine et Moléculaire (IRIBHM) Université Libre de Bruxelles (U.L.B.), Campus Erasme, Brussels, Belgium
| | - Kevin Baertsoen
- Institut de Recherche Interdisciplinaire en Biologie Humaine et Moléculaire (IRIBHM) Université Libre de Bruxelles (U.L.B.), Campus Erasme, Brussels, Belgium
| | | | - Marc Parmentier
- Institut de Recherche Interdisciplinaire en Biologie Humaine et Moléculaire (IRIBHM) Université Libre de Bruxelles (U.L.B.), Campus Erasme, Brussels, Belgium
- * E-mail:
| | - Jean-Yves Springael
- Institut de Recherche Interdisciplinaire en Biologie Humaine et Moléculaire (IRIBHM) Université Libre de Bruxelles (U.L.B.), Campus Erasme, Brussels, Belgium
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Jalbert E, Shikuma CM, Ndhlovu LC, Barbour JD. Sequential staining improves detection of CCR2 and CX3CR1 on monocytes when simultaneously evaluating CCR5 by multicolor flow cytometry. Cytometry A 2013; 83:280-6. [PMID: 23426986 DOI: 10.1002/cyto.a.22257] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2012] [Revised: 12/04/2012] [Accepted: 12/23/2012] [Indexed: 01/24/2023]
Abstract
Chemokines and their receptors play an essential role within the immune system by dictating cellular migration. In vivo, receptor-ligand interactions rarely occur in isolation as cellular recruitment and migration are complex and highly coordinated processes often involving networks of multiple chemokines and multiple receptors. Simultaneous detection of multiple chemokine receptors on the single cell level is necessary to allow immunophenotyping studies that will help understand the intricacies of these networks. Chemokine receptors undergo a basal level of ongoing internalization, intracellular trafficking, and recycling back to the cell surface, even in the absence of the ligand. In the presence of ligand, receptor-ligand interactions enhance receptor internalization, reducing the cell surface receptor concentration, making precise determination of intrinsic levels challenging. Using multicolor flow cytometry, we sought to evaluate and optimize the simultaneous detection of cell surface expression levels of CCR2, CX3CR1, and CCR5 in primary human monocytes using a single antibody panel. We observed that staining for CCR2 alone or for CX3CR1 alone showed greater expression levels than when the cells were stained with the full panel of antibodies. Fluorescent-minus-one (FMO) controls revealed that ligation of the CCR5 monoclonal antibody to the receptor interfered with detection of CX3CR1 and CCR2. Sequential addition of antibodies during the staining procedure was sufficient to restore the detection levels, suggesting close proximity and possible functional interactions between CCR2/CCR5 and CX3CR1/CCR5 in monocytes. This study highlights the importance of optimizing staining procedures and using proper controls when simultaneously evaluating expression levels of multiple chemokine receptors by flow cytometry. Concurrent assessment of multiple receptors will provide insight and greater understanding of the complex interactions involved in cellular migration.
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Affiliation(s)
- Emilie Jalbert
- Hawaii Center for HIV/AIDS, University of Hawaii Manoa, Honolulu, Hawaii 96813, USA.
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Serotonin-glutamate and serotonin-dopamine reciprocal interactions as putative molecular targets for novel antipsychotic treatments: from receptor heterodimers to postsynaptic scaffolding and effector proteins. Psychopharmacology (Berl) 2013. [PMID: 23179966 DOI: 10.1007/s00213-012-2921-8] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The physical and functional interactions between serotonin-glutamate and serotonin-dopamine signaling have been suggested to be involved in psychosis pathophysiology and are supposed to be relevant for antipsychotic treatment. Type II metabotropic glutamate receptors (mGluRs) and serotonin 5-HT(2A) receptors have been reported to form heterodimers that modulate G-protein-mediated intracellular signaling differentially compared to mGluR2 and 5-HT(2A) homomers. Additionally, direct evidence has been provided that D(2) and 5-HT(2A) receptors form physical heterocomplexes which exert a functional cross-talk, as demonstrated by studies on hallucinogen-induced signaling. Moving from receptors to postsynaptic density (PSD) scenario, the scaffolding protein PSD-95 is known to interact with N-methyl-D-aspartate (NMDA), D(2) and 5-HT(2) receptors, regulating their activation state. Homer1a, the inducible member of the Homer family of PSD proteins that is implicated in glutamatergic signal transduction, is induced in striatum by antipsychotics with high dopamine receptor affinity and in the cortex by antipsychotics with mixed serotonergic/dopaminergic profile. Signaling molecules, such as Akt and glycogen-synthase-kinase-3 (GSK-3), could be involved in the mechanism of action of antipsychotics, targeting dopamine, serotonin, and glutamate neurotransmission. Altogether, these proteins stand at the crossroad of glutamate-dopamine-serotonin signaling pathways and may be considered as valuable molecular targets for current and new antipsychotics. The aim of this review is to provide a critical appraisal on serotonin-glutamate and serotonin-dopamine interplay to support the idea that next generation schizophrenia pharmacotherapy should not exclusively rely on receptor targeting strategies.
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Maggio R, Rocchi C, Scarselli M. Experimental strategies for studying G protein-coupled receptor homo- and heteromerization with radioligand binding and signal transduction methods. Methods Enzymol 2013; 521:295-310. [PMID: 23351746 DOI: 10.1016/b978-0-12-391862-8.00016-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Before the molecular biology era, functional experiments on isolated organs and radioligand binding and biochemical experiments on animal tissues were widely used to characterize G protein-coupled receptors (GPCRs). The introduction of recombinant cell lines expressing a single GPCR type has been a big step forward for studying both drug-receptor interactions and signal transduction. Before the introduction of the concept of receptor oligomerization, all data generated were attributed to the interaction of drugs with receptor monomers. Now, considerable data must be reinterpreted in light of receptor homo- and heteromerization. In this chapter, we will review some of the methods used to study radioligand binding and signal transduction modifications induced by GPCR homo- and heteromerization.
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Affiliation(s)
- Roberto Maggio
- Department of Biotechnological and Applied Clinical Sciences, University of L'Aquila, L'Aquila, Italy.
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45
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On the segregation of protein ionic residues by charge type. Amino Acids 2012; 43:2231-47. [PMID: 23081700 DOI: 10.1007/s00726-012-1418-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2012] [Accepted: 10/06/2012] [Indexed: 10/27/2022]
Abstract
Based on ubiquitous presence of large ionic motifs and clusters in proteins involved in gene transcription and protein synthesis, we analyzed the distribution of ionizable sidechains in a broad selection of proteins with regulatory, metabolic, structural and adhesive functions, in agonist, antagonist, toxin and antimicrobial peptides, and in self-excising inteins and intron-derived proteins and sequence constructs. All tested groups, regardless of taxa or sequence size, show considerable segregation of ionizable sidechains into same type charge (homoionic) tracts. These segments in most cases exceed half of the sequence length and comprise more than two-thirds of all ionizable sidechains. This distribution of ionic residues apparently reflects a fundamental advantage of sorted electrostatic contacts in association of sequence elements within and between polypeptides, as well as in interaction with polynucleotides. While large ionic densities are encountered in highly interactive proteins, the average ionic density in most sets does not change appreciably with size of the homoionic segments, which supports the segregation as a modular feature favoring association.
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Muñoz LM, Holgado BL, Martínez-A C, Rodríguez-Frade JM, Mellado M. Chemokine receptor oligomerization: a further step toward chemokine function. Immunol Lett 2012; 145:23-9. [PMID: 22698180 DOI: 10.1016/j.imlet.2012.04.012] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2011] [Accepted: 04/13/2012] [Indexed: 12/14/2022]
Abstract
A broad array of biological responses including cell polarization, movement, immune and inflammatory responses, as well as prevention of HIV-1 infection, are triggered by the chemokines, a family of secreted and structurally related chemoattractant proteins that bind to class A-specific seven-transmembrane receptors linked to G proteins. Chemokines and their receptors should not be considered isolated entities, as they act in complex networks. Chemokines bind as oligomers, or oligomerize after binding to glycosaminoglycans on endothelial cells, and are then presented to their receptors on target cells, facilitating the generation of chemoattractant gradients. The chemokine receptors form homo- and heterodimers, as well as higher order structures at the cell surface. These structures are dynamic and are regulated by receptor expression and ligand levels. Complexity is even greater, as in addition to regulation by cytokines and decoy receptors, chemokine and receptor levels are affected by proteolytic cleavage and other protein modifications. This complex scenario should be considered when analyzing chemokine biology and the ability of their antagonists to act in vivo. Strategies based on blocking or stabilizing ligand and receptor dimers could be alternative approaches that might have broad therapeutic potential.
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Affiliation(s)
- Laura Martínez Muñoz
- Department of Immunology and Oncology, Centro Nacional de Biotecnología/CSIC, Darwin 3, Campus de Cantoblanco, Madrid E-28049, Spain
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47
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Functional and physical interactions among Saccharomyces cerevisiae α-factor receptors. EUKARYOTIC CELL 2012; 11:1276-88. [PMID: 22923047 DOI: 10.1128/ec.00172-12] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The α-factor receptor Ste2p is a G protein-coupled receptor (GPCR) expressed on the surface of MATa haploid cells of the yeast Saccharomyces cerevisiae. Binding of α-factor to Ste2p results in activation of a heterotrimeric G protein and of the pheromone response pathway. Functional interactions between α-factor receptors, such as dominant-negative effects and recessive behavior of constitutive and hypersensitive mutant receptors, have been reported previously. We show here that dominant-negative effects of mutant receptors persist over a wide range of ratios of the abundances of G protein to receptor and that such effects are not blocked by covalent fusion of G protein α subunits to normal receptors. In addition, we detected dominant effects of mutant C-terminally truncated receptors, which had not been previously reported to act in a dominant manner. Furthermore, coexpression of C-terminally truncated receptors with constitutively active mutant receptors results in enhancement of constitutive signaling. Together with previous evidence for oligomerization of Ste2p receptors, these results are consistent with the idea that functional interactions between coexpressed receptors arise from physical interactions between them rather than from competition for limiting downstream components, such as G proteins.
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48
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Johnstone EKM, Pfleger KDG. Receptor-Heteromer Investigation Technology and its application using BRET. Front Endocrinol (Lausanne) 2012; 3:101. [PMID: 22936924 PMCID: PMC3424490 DOI: 10.3389/fendo.2012.00101] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2012] [Accepted: 08/04/2012] [Indexed: 01/08/2023] Open
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.
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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
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Scholten DJ, Canals M, Maussang D, Roumen L, Smit MJ, Wijtmans M, de Graaf C, Vischer HF, Leurs R. Pharmacological modulation of chemokine receptor function. Br J Pharmacol 2012; 165:1617-1643. [PMID: 21699506 DOI: 10.1111/j.1476-5381.2011.01551.x] [Citation(s) in RCA: 181] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
G protein-coupled chemokine receptors and their peptidergic ligands are interesting therapeutic targets due to their involvement in various immune-related diseases, including rheumatoid arthritis, multiple sclerosis, inflammatory bowel disease, chronic obstructive pulmonary disease, HIV-1 infection and cancer. To tackle these diseases, a lot of effort has been focused on discovery and development of small-molecule chemokine receptor antagonists. This has been rewarded by the market approval of two novel chemokine receptor inhibitors, AMD3100 (CXCR4) and Maraviroc (CCR5) for stem cell mobilization and treatment of HIV-1 infection respectively. The recent GPCR crystal structures together with mutagenesis and pharmacological studies have aided in understanding how small-molecule ligands interact with chemokine receptors. Many of these ligands display behaviour deviating from simple competition and do not interact with the chemokine binding site, providing evidence for an allosteric mode of action. This review aims to give an overview of the evidence supporting modulation of this intriguing receptor family by a range of ligands, including small molecules, peptides and antibodies. Moreover, the computer-assisted modelling of chemokine receptor-ligand interactions is discussed in view of GPCR crystal structures. Finally, the implications of concepts such as functional selectivity and chemokine receptor dimerization are considered.
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Affiliation(s)
- D J Scholten
- Leiden/Amsterdam Center for Drug Research, Division of Medicinal Chemistry, Faculty of Science, VU University Amsterdam, Amsterdam, the Netherlands
| | - M Canals
- Leiden/Amsterdam Center for Drug Research, Division of Medicinal Chemistry, Faculty of Science, VU University Amsterdam, Amsterdam, the Netherlands
| | - D Maussang
- Leiden/Amsterdam Center for Drug Research, Division of Medicinal Chemistry, Faculty of Science, VU University Amsterdam, Amsterdam, the Netherlands
| | - L Roumen
- Leiden/Amsterdam Center for Drug Research, Division of Medicinal Chemistry, Faculty of Science, VU University Amsterdam, Amsterdam, the Netherlands
| | - M J Smit
- Leiden/Amsterdam Center for Drug Research, Division of Medicinal Chemistry, Faculty of Science, VU University Amsterdam, Amsterdam, the Netherlands
| | - M Wijtmans
- Leiden/Amsterdam Center for Drug Research, Division of Medicinal Chemistry, Faculty of Science, VU University Amsterdam, Amsterdam, the Netherlands
| | - C de Graaf
- Leiden/Amsterdam Center for Drug Research, Division of Medicinal Chemistry, Faculty of Science, VU University Amsterdam, Amsterdam, the Netherlands
| | - H F Vischer
- Leiden/Amsterdam Center for Drug Research, Division of Medicinal Chemistry, Faculty of Science, VU University Amsterdam, Amsterdam, the Netherlands
| | - R Leurs
- Leiden/Amsterdam Center for Drug Research, Division of Medicinal Chemistry, Faculty of Science, VU University Amsterdam, Amsterdam, the Netherlands
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50
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Vauquelin G, Van Liefde I. Radioligand dissociation measurements: potential interference of rebinding and allosteric mechanisms and physiological relevance of the biological model systems. Expert Opin Drug Discov 2012; 7:583-95. [DOI: 10.1517/17460441.2012.687720] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
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