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Hu L, An K, Zhang Y, Bai C. Exploring the Activation Mechanism of the GPR183 Receptor. J Phys Chem B 2024; 128:6071-6081. [PMID: 38877985 DOI: 10.1021/acs.jpcb.4c02812] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/28/2024]
Abstract
The G protein-coupled receptors (GPCRs) play a pivotal role in numerous biological processes as crucial cell membrane receptors. However, the dynamic mechanisms underlying the activation of GPR183, a specific GPCR, remain largely elusive. To address this, we employed computational simulation techniques to elucidate the activation process and key events associated with GPR183, including conformational changes from inactive to active state, binding interactions with the Gi protein complex, and GDP release. Our findings demonstrate that the association between GPR183 and the Gi protein involves the formation of receptor-specific conformations, the gradual proximity of the Gi protein to the binding pocket, and fine adjustments of the protein conformation, ultimately leading to a stable GPR183-Gi complex characterized by a high energy barrier. The presence of Gi protein partially promotes GPR183 activation, which is consistent with the observation of GPCR constitutive activity test experiments, thus illustrating the reliability of our calculations. Moreover, our study suggests the existence of a stable partially activated state preceding complete activation, providing novel avenues for future investigations. In addition, the relevance of GPR183 for various diseases, such as colitis, the response of eosinophils to Mycobacterium tuberculosis infection, antiviral properties, and pulmonary inflammation, has been emphasized, underscoring its therapeutic potential. Consequently, understanding the activation process of GPR183 through molecular dynamic simulations offers valuable kinetic insights that can aid in the development of targeted therapies.
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Affiliation(s)
- Linfeng Hu
- School of Life and Health Sciences, School of Medicine, The Chinese University of Hong Kong, Shenzhen, Guangdong 518172, PR China
- Warshel Institute for Computational Biology, Shenzhen, Guangdong 518172, PR China
| | - Ke An
- Chenzhu (MoMeD) Biotechnology Co., Ltd, Hangzhou, Zhejiang 310005, PR China
| | - Yue Zhang
- School of Life and Health Sciences, School of Medicine, The Chinese University of Hong Kong, Shenzhen, Guangdong 518172, PR China
- Warshel Institute for Computational Biology, Shenzhen, Guangdong 518172, PR China
| | - Chen Bai
- School of Life and Health Sciences, School of Medicine, The Chinese University of Hong Kong, Shenzhen, Guangdong 518172, PR China
- Warshel Institute for Computational Biology, Shenzhen, Guangdong 518172, PR China
- Chenzhu (MoMeD) Biotechnology Co., Ltd, Hangzhou, Zhejiang 310005, PR China
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2
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Kjær VMS, Stępniewski TM, Medel-Lacruz B, Reinmuth L, Ciba M, Rexen Ulven E, Bonomi M, Selent J, Rosenkilde MM. Ligand entry pathways control the chemical space recognized by GPR183. Chem Sci 2023; 14:10671-10683. [PMID: 37829039 PMCID: PMC10566501 DOI: 10.1039/d2sc05962b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Accepted: 08/26/2023] [Indexed: 10/14/2023] Open
Abstract
The G protein-coupled receptor GPR183 is a chemotactic receptor with an important function in the immune system and association with a variety of diseases. It recognizes ligands with diverse physicochemical properties as both the endogenous oxysterol ligand 7α,25-OHC and synthetic molecules can activate the G protein pathway of the receptor. To better understand the ligand promiscuity of GPR183, we utilized both molecular dynamics simulations and cell-based validation experiments. Our work reveals that the receptor possesses two ligand entry channels: one lateral between transmembrane helices 4 and 5 facing the membrane, and one facing the extracellular environment. Using enhanced sampling, we provide a detailed structural model of 7α,25-OHC entry through the lateral membrane channel. Importantly, the first ligand recognition point at the receptor surface has been captured in diverse experimentally solved structures of different GPCRs. The proposed ligand binding pathway is supported by in vitro data employing GPR183 mutants with a sterically blocked lateral entrance, which display diminished binding and signaling. In addition, computer simulations and experimental validation confirm the existence of a polar water channel which might serve as an alternative entrance gate for less lipophilic ligands from the extracellular milieu. Our study reveals knowledge to understand GPR183 functionality and ligand recognition with implications for the development of drugs for this receptor. Beyond, our work provides insights into a general mechanism GPCRs may use to respond to chemically diverse ligands.
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Affiliation(s)
- Viktoria Madeline Skovgaard Kjær
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences University of Copenhagen Blegdamsvej 3B 2200 København N Denmark
| | - Tomasz Maciej Stępniewski
- Research Programme on Biomedical Informatics (GRIB), Hospital del Mar Research Institute (IMIM) & Pompeu Fabra University (UPF) Dr Aiguader 88 E-8003 Barcelona Spain
- InterAx Biotech AG, PARK innovAARE 5234 Villigen Switzerland
- Biological and Chemical Research Centre, Faculty of Chemistry, University of Warsaw 02-089 Warsaw Poland
| | - Brian Medel-Lacruz
- Research Programme on Biomedical Informatics (GRIB), Hospital del Mar Research Institute (IMIM) & Pompeu Fabra University (UPF) Dr Aiguader 88 E-8003 Barcelona Spain
| | - Lisa Reinmuth
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences University of Copenhagen Blegdamsvej 3B 2200 København N Denmark
| | - Marija Ciba
- Department of Drug Design and Pharmacology, University of Copenhagen Jagtvej 160 2100 København Ø Denmark
| | - Elisabeth Rexen Ulven
- Department of Drug Design and Pharmacology, University of Copenhagen Jagtvej 160 2100 København Ø Denmark
| | - Massimiliano Bonomi
- Institut Pasteur, Université Paris Cité, CNRS UMR3528, Structural Bioinformatics Unit 75015 Paris France
| | - Jana Selent
- Research Programme on Biomedical Informatics (GRIB), Hospital del Mar Research Institute (IMIM) & Pompeu Fabra University (UPF) Dr Aiguader 88 E-8003 Barcelona Spain
| | - Mette Marie Rosenkilde
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences University of Copenhagen Blegdamsvej 3B 2200 København N Denmark
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Kjær VMS, Daugvilaite V, Stepniewski TM, Madsen CM, Jørgensen AS, Bhuskute KR, Inoue A, Ulven T, Benned-Jensen T, Hjorth SA, Hjortø GM, Moo EV, Selent J, Rosenkilde MM. Migration mediated by the oxysterol receptor GPR183 depends on arrestin coupling but not receptor internalization. Sci Signal 2023; 16:eabl4283. [PMID: 37014928 DOI: 10.1126/scisignal.abl4283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/06/2023]
Abstract
The chemotactic G protein-coupled receptor GPR183 and its most potent endogenous oxysterol ligand 7α,25-dihydroxycholesterol (7α,25-OHC) are important for immune cell positioning in secondary lymphoid tissues. This receptor-ligand pair is associated with various diseases, in some cases contributing favorably and in other cases adversely, making GPR183 an attractive target for therapeutic intervention. We investigated the mechanisms underlying GPR183 internalization and the role of internalization in the main biological function of the receptor, chemotaxis. We found that the C terminus of the receptor was important for ligand-induced internalization but less so for constitutive (ligand-independent) internalization. β-arrestin potentiated ligand-induced internalization but was not required for ligand-induced or constitutive internalization. Caveolin and dynamin were the main mediators of both constitutive and ligand-induced receptor internalization in a mechanism independent of G protein activation. Clathrin-mediated endocytosis also contributed to constitutive GPR183 internalization in a β-arrestin-independent manner, suggesting the existence of different pools of surface-localized GPR183. Chemotaxis mediated by GPR183 depended on receptor desensitization by β-arrestins but could be uncoupled from internalization, highlighting an important biological role for the recruitment of β-arrestin to GPR183. The role of distinct pathways in internalization and chemotaxis may aid in the development of GPR183-targeting drugs for specific disease contexts.
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Affiliation(s)
- Viktoria M S Kjær
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Viktorija Daugvilaite
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Tomasz M Stepniewski
- Research Programme on Biomedical Informatics (GRIB), Hospital del Mar Medical Research Institute (IMIM)-Pompeu Fabra University (UPF), Barcelona 08003, Spain
- InterAx Biotech AG, Villigen 5234, Switzerland
- Faculty of Chemistry, Biological and Chemical Research Centre, University of Warsaw, Warsaw 02-089, Poland
| | - Christian M Madsen
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Astrid S Jørgensen
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Kaustubh R Bhuskute
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Asuka Inoue
- Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai 980-8578, Japan
| | - Trond Ulven
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Tau Benned-Jensen
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Siv A Hjorth
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Gertrud M Hjortø
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Ee Von Moo
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jana Selent
- Research Programme on Biomedical Informatics (GRIB), Hospital del Mar Medical Research Institute (IMIM)-Pompeu Fabra University (UPF), Barcelona 08003, Spain
| | - Mette M Rosenkilde
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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4
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Reinmuth L, Hsiao CC, Hamann J, Rosenkilde M, Mackrill J. Multiple Targets for Oxysterols in Their Regulation of the Immune System. Cells 2021; 10:cells10082078. [PMID: 34440846 PMCID: PMC8391951 DOI: 10.3390/cells10082078] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 08/05/2021] [Accepted: 08/11/2021] [Indexed: 02/07/2023] Open
Abstract
Oxysterols, or cholesterol oxidation products, are naturally occurring lipids which regulate the physiology of cells, including those of the immune system. In contrast to effects that are mediated through nuclear receptors or by epigenetic mechanism, which take tens of minutes to occur, changes in the activities of cell-surface receptors caused by oxysterols can be extremely rapid, often taking place within subsecond timescales. Such cell-surface receptor effects of oxysterols allow for the regulation of fast cellular processes, such as motility, secretion and endocytosis. These cellular processes play critical roles in both the innate and adaptive immune systems. This review will survey the two broad classes of cell-surface receptors for oxysterols (G-protein coupled receptors (GPCRs) and ion channels), the mechanisms by which cholesterol oxidation products act on them, and their presence and functions in the different cell types of the immune system. Overall, this review will highlight the potential of oxysterols, synthetic derivatives and their receptors for physiological and therapeutic modulation of the immune system.
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Affiliation(s)
- Lisa Reinmuth
- Laboratory for Molecular Pharmacology, Department of Biomedical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark;
| | - Cheng-Chih Hsiao
- Department of Experimental Immunology, Amsterdam Institute for Infection and Immunity, Amsterdam University Medical Centers, Meibergdreef 9, 1105AZ Amsterdam, The Netherlands; (C.-C.H.); (J.H.)
- Neuroimmunology Research Group, The Netherlands Institute for Neuroscience, 1105BA Amsterdam, The Netherlands
| | - Jörg Hamann
- Department of Experimental Immunology, Amsterdam Institute for Infection and Immunity, Amsterdam University Medical Centers, Meibergdreef 9, 1105AZ Amsterdam, The Netherlands; (C.-C.H.); (J.H.)
- Neuroimmunology Research Group, The Netherlands Institute for Neuroscience, 1105BA Amsterdam, The Netherlands
| | - Mette Rosenkilde
- Laboratory for Molecular Pharmacology, Department of Biomedical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark;
- Correspondence: (M.R.); (J.M.); Tel.: +353-(0)21-490-1400 (J.M.)
| | - John Mackrill
- Department of Physiology, School of Medicine, BioSciences Institute, University College Cork, College Road, Cork T12 YT20, Ireland
- Correspondence: (M.R.); (J.M.); Tel.: +353-(0)21-490-1400 (J.M.)
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5
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Bartlett S, Gemiarto AT, Ngo MD, Sajiir H, Hailu S, Sinha R, Foo CX, Kleynhans L, Tshivhula H, Webber T, Bielefeldt-Ohmann H, West NP, Hiemstra AM, MacDonald CE, Christensen LVV, Schlesinger LS, Walzl G, Rosenkilde MM, Mandrup-Poulsen T, Ronacher K. GPR183 Regulates Interferons, Autophagy, and Bacterial Growth During Mycobacterium tuberculosis Infection and Is Associated With TB Disease Severity. Front Immunol 2020; 11:601534. [PMID: 33240287 PMCID: PMC7677584 DOI: 10.3389/fimmu.2020.601534] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Accepted: 10/14/2020] [Indexed: 12/15/2022] Open
Abstract
Oxidized cholesterols have emerged as important signaling molecules of immune function, but little is known about the role of these oxysterols during mycobacterial infections. We found that expression of the oxysterol-receptor GPR183 was reduced in blood from patients with tuberculosis (TB) and type 2 diabetes (T2D) compared to TB patients without T2D and was associated with TB disease severity on chest x-ray. GPR183 activation by 7α,25-dihydroxycholesterol (7α,25-OHC) reduced growth of Mycobacterium tuberculosis (Mtb) and Mycobacterium bovis BCG in primary human monocytes, an effect abrogated by the GPR183 antagonist GSK682753. Growth inhibition was associated with reduced IFN-β and IL-10 expression and enhanced autophagy. Mice lacking GPR183 had significantly increased lung Mtb burden and dysregulated IFNs during early infection. Together, our data demonstrate that GPR183 is an important regulator of intracellular mycobacterial growth and interferons during mycobacterial infection.
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MESH Headings
- Animals
- Autophagy
- Bacterial Load
- Case-Control Studies
- Diabetes Mellitus, Type 2/immunology
- Diabetes Mellitus, Type 2/metabolism
- Disease Models, Animal
- Female
- Host-Pathogen Interactions
- Humans
- Interferons/metabolism
- Leukocytes, Mononuclear/immunology
- Leukocytes, Mononuclear/metabolism
- Leukocytes, Mononuclear/microbiology
- Lung/immunology
- Lung/metabolism
- Lung/microbiology
- Male
- Mice, Inbred C57BL
- Mice, Knockout
- Mycobacterium bovis/growth & development
- Mycobacterium bovis/immunology
- Mycobacterium bovis/pathogenicity
- Mycobacterium tuberculosis/growth & development
- Mycobacterium tuberculosis/immunology
- Mycobacterium tuberculosis/pathogenicity
- Receptors, G-Protein-Coupled/genetics
- Receptors, G-Protein-Coupled/metabolism
- Severity of Illness Index
- Signal Transduction
- THP-1 Cells
- Tuberculosis, Pulmonary/immunology
- Tuberculosis, Pulmonary/metabolism
- Tuberculosis, Pulmonary/microbiology
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Affiliation(s)
- Stacey Bartlett
- Translational Research Institute–Mater Research Institute, The University of Queensland, Brisbane, QLD, Australia
| | - Adrian Tandhyka Gemiarto
- Translational Research Institute–Mater Research Institute, The University of Queensland, Brisbane, QLD, Australia
| | - Minh Dao Ngo
- Translational Research Institute–Mater Research Institute, The University of Queensland, Brisbane, QLD, Australia
| | - Haressh Sajiir
- Translational Research Institute–Mater Research Institute, The University of Queensland, Brisbane, QLD, Australia
| | - Semira Hailu
- Translational Research Institute–Mater Research Institute, The University of Queensland, Brisbane, QLD, Australia
| | - Roma Sinha
- Translational Research Institute–Mater Research Institute, The University of Queensland, Brisbane, QLD, Australia
| | - Cheng Xiang Foo
- Translational Research Institute–Mater Research Institute, The University of Queensland, Brisbane, QLD, Australia
| | - Léanie Kleynhans
- DSI-NRF Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Happy Tshivhula
- DSI-NRF Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Tariq Webber
- DSI-NRF Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Helle Bielefeldt-Ohmann
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, QLD, Australia
- Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, QLD, Australia
| | - Nicholas P. West
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, QLD, Australia
- Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, QLD, Australia
| | - Andriette M. Hiemstra
- DSI-NRF Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Candice E. MacDonald
- DSI-NRF Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | | | - Larry S. Schlesinger
- Host-Pathogens Interactions Program, Texas Biomedical Research Institute, San Antonio, TX, United States
| | - Gerhard Walzl
- DSI-NRF Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | | | | | - Katharina Ronacher
- Translational Research Institute–Mater Research Institute, The University of Queensland, Brisbane, QLD, Australia
- DSI-NRF Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
- Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, QLD, Australia
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6
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Effect of Intracoronary and Intravenous Melatonin on Myocardial Salvage Index in Patients with ST-Elevation Myocardial Infarction: a Randomized Placebo Controlled Trial. J Cardiovasc Transl Res 2017; 10:470-479. [PMID: 29027116 DOI: 10.1007/s12265-017-9768-7] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Accepted: 09/27/2017] [Indexed: 01/23/2023]
Abstract
Melatonin has attenuated myocardial ischemia reperfusion injury in experimental studies. We hypothesized that the administration of melatonin during acute myocardial reperfusion improves myocardial salvage index in patients with ST-elevation myocardial infarction. Patients (n = 48) were randomized in a 1:1 ratio to intracoronary and intravenous melatonin (total 50 mg) or placebo. The myocardial salvage index assessed by cardiac magnetic resonance imaging at day 4 (± 1 day) after primary percutaneous coronary intervention was similar in the melatonin group (n = 22) at 55.3% (95% CI 47.0-63.6) and the placebo group (n = 19) at 61.5% (95% CI 57.5-65.5), p = 0.21. The levels of high-sensitive troponin T, creatinine kinase myocardial band, and oxidative biomarkers (advanced oxidation protein products, malondialdehyde, myeloperoxidase) were similar in the groups. The frequency of clinical events at 90 days did not differ between the groups. In conclusion, melatonin did not improve the myocardial salvage index after primary percutaneous coronary intervention in patients with ST elevation myocardial infarction compared with placebo.
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Daugvilaite V, Madsen CM, Lückmann M, Echeverria CC, Sailer AW, Frimurer TM, Rosenkilde MM, Benned-Jensen T. Biased agonism and allosteric modulation of G protein-coupled receptor 183 - a 7TM receptor also known as Epstein-Barr virus-induced gene 2. Br J Pharmacol 2017; 174:2031-2042. [PMID: 28369721 DOI: 10.1111/bph.13801] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Revised: 03/07/2017] [Accepted: 03/09/2017] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND AND PURPOSE The GPCR Epstein-Barr virus-induced gene 2 (EBI2, also known as GPR183) is activated by oxysterols and plays a pivotal role in the regulation of B cell migration during immune responses. While the molecular basis of agonist binding has been addressed in several studies, the concept of biased agonism of the EBI2 receptor has not been explored. EXPERIMENTAL APPROACH We investigated the effects of the EBI2 endogenous agonist 7α,25-dihydroxycholesterol (7α,25-OHC) on G protein-dependent and -independent pathways as well as sodium ion allosterism using site-directed mutagenesis and functional studies. Moreover, we generated a homology model of the EBI2 receptor to investigate the structural basis of the allosteric modulation by sodium. KEY RESULTS Residue N114, located in the middle of transmembrane-III at position III:11/3.35, was found to function as an efficacy switch. Thus, substituting N114 with an alanine (N114A) completely abolished heterotrimeric G protein subunit Gi α activation by 7α,25-OHC even though the specific binding of [3 H]-7α,25-OHC increased. In contrast, the N114A mutant was still able to recruit β-arrestin and even had an enhanced potency (18.7-fold) compared with EBI2 wild type. Sodium had a negative allosteric effect on oxysterol binding that was mediated via N114, verifying the key role of N114. This was further supported by molecular modelling of the ion binding site based on a EBI2 receptor homology model. CONCLUSIONS AND IMPLICATIONS Collectively, our data point to N114 as a key residue for EBI2 signalling controlling the balance between G protein-dependent and -independent pathways and facilitating sodium binding.
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Affiliation(s)
- Viktorija Daugvilaite
- Department of Biomedical Sciences, Laboratory for Molecular Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | - Christian Medom Madsen
- Department of Biomedical Sciences, Laboratory for Molecular Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | - Michael Lückmann
- Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
| | - Clara Castello Echeverria
- Department of Biomedical Sciences, Laboratory for Molecular Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | - Andreas Walter Sailer
- Forum 1, Novartis Campus, CH-4056, Novartis Institutes for BioMedical Research, Basel, Switzerland
| | | | - Mette Marie Rosenkilde
- Department of Biomedical Sciences, Laboratory for Molecular Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | - Tau Benned-Jensen
- Department of Biomedical Sciences, Laboratory for Molecular Pharmacology, University of Copenhagen, Copenhagen, Denmark
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8
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Hassing HA, Fares S, Larsen O, Pad H, Hauge M, Jones RM, Schwartz TW, Hansen HS, Rosenkilde MM. Biased signaling of lipids and allosteric actions of synthetic molecules for GPR119. Biochem Pharmacol 2016; 119:66-75. [DOI: 10.1016/j.bcp.2016.08.018] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Accepted: 08/22/2016] [Indexed: 02/08/2023]
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9
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Thiele S, Mungalpara J, Steen A, Rosenkilde MM, Våbenø J. Determination of the binding mode for the cyclopentapeptide CXCR4 antagonist FC131 using a dual approach of ligand modifications and receptor mutagenesis. Br J Pharmacol 2015; 171:5313-29. [PMID: 25039237 DOI: 10.1111/bph.12842] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2014] [Revised: 06/25/2014] [Accepted: 07/08/2014] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND AND PURPOSE The cyclopentapeptide FC131 (cyclo(-L-Arg(1) -L-Arg(2) -L-2-Nal(3) -Gly(4) -D-Tyr(5) -)) is an antagonist at the CXC chemokine receptor CXCR4, which plays a role in human immunodeficiency virus infection, cancer and stem cell recruitment. Binding modes for FC131 in CXCR4 have previously been suggested based on molecular docking guided by structure-activity relationship (SAR) data; however, none of these have been verified by in vitro experiments. EXPERIMENTAL APPROACH Heterologous (125) I-12G5-competition binding and functional assays (inhibition of CXCL12-mediated activation) of FC131 and three analogues were performed on wild-type CXCR4 and 25 receptor mutants. Computational modelling was used to rationalize the experimental data. KEY RESULTS The Arg(2) and 2-Nal(3) side chains of FC131 interact with residues in TM-3 (His(113) , Asp(171) ) and TM-5 (hydrophobic pocket) respectively. Arg(1) forms charge-charge interactions with Asp(187) in ECL-2, while D-Tyr(5) points to the extracellular side of CXCR4. Furthermore, the backbone of FC131 interacts with the chemokine receptor-conserved Glu(288) via two water molecules. Intriguingly, Tyr(116) and Glu(288) form a H-bond in CXCR4 crystal structures and mutation of either residue to Ala abolishes CXCR4 activity. CONCLUSIONS AND IMPLICATIONS Ligand modification, receptor mutagenesis and computational modelling approaches were used to identify the binding mode of FC131 in CXCR4, which was in agreement with binding modes suggested from previous SAR studies. Furthermore, insights into the mechanism for CXCR4 activation by CXCL12 were gained. The combined findings will facilitate future design of novel CXCR4 antagonists.
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Affiliation(s)
- S Thiele
- Laboratory for Molecular Pharmacology, Department of Neuroscience and Pharmacology, Faculty of Health and Medical Sciences, The Panum Institute, University of Copenhagen, Copenhagen, Denmark
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10
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Abstract
Cholesterol and components of the cholesterol biosynthetic pathway have fundamental roles in all mammalian cells. Hydroxylated forms of cholesterol are now emerging as important regulators of immune function. This involves effects on the cholesterol biosynthetic pathway and cell membrane properties, which can have antiviral and anti-inflammatory influences. In addition, a dihydroxylated form of cholesterol functions as an immune cell guidance cue by engaging the G protein-coupled receptor EBI2, and it is required for mounting adaptive immune responses. In this Review, we summarize the current understanding of the closely related oxysterols 25-hydroxycholesterol and 7α,25-dihydroxycholesterol, and the growing evidence that they have wide-ranging influences on innate and adaptive immunity.
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11
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Gilliland CT, Salanga CL, Kawamura T, Trejo J, Handel TM. The chemokine receptor CCR1 is constitutively active, which leads to G protein-independent, β-arrestin-mediated internalization. J Biol Chem 2013; 288:32194-32210. [PMID: 24056371 DOI: 10.1074/jbc.m113.503797] [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: 11/06/2022] Open
Abstract
Activation of G protein-coupled receptors by their associated ligands has been extensively studied, and increasing structural information about the molecular mechanisms underlying ligand-dependent receptor activation is beginning to emerge with the recent expansion in GPCR crystal structures. However, some GPCRs are also able to adopt active conformations in the absence of agonist binding that result in the initiation of signal transduction and receptor down-modulation. In this report, we show that the CC-type chemokine receptor 1 (CCR1) exhibits significant constitutive activity leading to a variety of cellular responses. CCR1 expression is sufficient to induce inhibition of cAMP formation, increased F-actin content, and basal migration of human and murine leukocytes. The constitutive activity leads to basal phosphorylation of the receptor, recruitment of β-arrestin-2, and subsequent receptor internalization. CCR1 concurrently engages Gαi and β-arrestin-2 in a multiprotein complex, which may be accommodated by homo-oligomerization or receptor clustering. The data suggest the presence of two functional states for CCR1; whereas receptor coupled to Gαi functions as a canonical GPCR, albeit with high constitutive activity, the CCR1·β-arrestin-2 complex is required for G protein-independent constitutive receptor internalization. The pertussis toxin-insensitive uptake of chemokine by the receptor suggests that the CCR1·β-arrestin-2 complex may be related to a potential scavenging function of the receptor, which may be important for maintenance of chemokine gradients and receptor responsiveness in complex fields of chemokines during inflammation.
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Affiliation(s)
| | | | | | - JoAnn Trejo
- the Department of Pharmacology, School of Medicine, University of California, San Diego, La Jolla, California 92093
| | - Tracy M Handel
- From the Skaggs School of Pharmacy and Pharmaceutical Sciences.
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12
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Benned-Jensen T, Madsen CM, Arfelt KN, Smethurts C, Blanchard A, Jepras R, Rosenkilde MM. Small molecule antagonism of oxysterol-induced Epstein-Barr virus induced gene 2 (EBI2) activation. FEBS Open Bio 2013; 3:156-60. [PMID: 23772388 PMCID: PMC3668520 DOI: 10.1016/j.fob.2013.02.003] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2013] [Revised: 02/14/2013] [Accepted: 02/14/2013] [Indexed: 10/27/2022] Open
Abstract
The Epstein-Barr virus induced gene 2 (EBI2) was recently identified as the first oxysterol-activated 7TM receptor. EBI2 is essential for B cell trafficking within lymphoid tissues and thus the humoral immune response in general. Here we characterize the antagonism of the non-peptide molecule GSK682753A, which blocks oxysterol-induced G-protein activation, β-arrestin recruitment and B-cell chemotaxis. We furthermore demonstrate that activation triggers pertussis toxin-sensitive MAP kinase phosphorylation, which is also inhibited by GSK682753A. Thus, EBI2 signalling in B cells mediates key phenotypic functions via signalling pathways amenable to manipulation providing additional therapeutic options for inhibiting EBI2 activity.
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Affiliation(s)
- Tau Benned-Jensen
- Laboratory for Molecular Pharmacology, Department of Neuroscience and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark
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13
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Benned-Jensen T, Norn C, Laurent S, Madsen CM, Larsen HM, Arfelt KN, Wolf RM, Frimurer T, Sailer AW, Rosenkilde MM. Molecular characterization of oxysterol binding to the Epstein-Barr virus-induced gene 2 (GPR183). J Biol Chem 2012; 287:35470-35483. [PMID: 22875855 PMCID: PMC3471686 DOI: 10.1074/jbc.m112.387894] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2012] [Indexed: 11/06/2022] Open
Abstract
Oxysterols are oxygenated cholesterol derivates that are emerging as a physiologically important group of molecules. Although they regulate a range of cellular processes, only few oxysterol-binding effector proteins have been identified, and the knowledge of their binding mode is limited. Recently, the family of G protein-coupled seven transmembrane-spanning receptors (7TM receptors) was added to this group. Specifically, the Epstein-Barr virus-induced gene 2 (EBI2 or GPR183) was shown to be activated by several oxysterols, most potently by 7α,25-dihydroxycholesterol (7α,25-OHC). Nothing is known about the binding mode, however. Using mutational analysis, we identify here four key residues for 7α,25-OHC binding: Arg-87 in TM-II (position II:20/2.60), Tyr-112 and Tyr-116 (positions III:09/3.33 and III:13/3.37) in TM-III, and Tyr-260 in TM-VI (position VI:16/6.51). Substituting these residues with Ala and/or Phe results in a severe decrease in agonist binding and receptor activation. Docking simulations suggest that Tyr-116 interacts with the 3β-OH group in the agonist, Tyr-260 with the 7α-OH group, and Arg-87, either directly or indirectly, with the 25-OH group, although nearby residues likely also contribute. In addition, Tyr-112 is involved in 7α,25-OHC binding but via hydrophobic interactions. Finally, we show that II:20/2.60 constitutes an important residue for ligand binding in receptors carrying a positively charged residue at this position. This group is dominated by lipid- and nucleotide-activated receptors, here exemplified by the CysLTs, P2Y12, and P2Y14. In conclusion, we present the first molecular characterization of oxysterol binding to a 7TM receptor and identify position II:20/2.60 as a generally important residue for ligand binding in certain 7TM receptors.
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Affiliation(s)
- Tau Benned-Jensen
- Laboratory for Molecular Pharmacology, Department of Neuroscience and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark
| | - Christoffer Norn
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark
| | - Stephane Laurent
- Developmental and Molecular Pathways, Novartis Institutes for BioMedical Research, 4056 Basel, Switzerland
| | - Christian M Madsen
- Laboratory for Molecular Pharmacology, Department of Neuroscience and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark
| | - Hjalte M Larsen
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark
| | - Kristine N Arfelt
- Laboratory for Molecular Pharmacology, Department of Neuroscience and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark
| | - Romain M Wolf
- Global Discovery Chemistry, Novartis Institutes for BioMedical Research, 4056 Basel, Switzerland
| | - Thomas Frimurer
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark; Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark
| | - Andreas W Sailer
- Developmental and Molecular Pathways, Novartis Institutes for BioMedical Research, 4056 Basel, Switzerland
| | - Mette M Rosenkilde
- Laboratory for Molecular Pharmacology, Department of Neuroscience and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark.
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14
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Zhang L, Shih AY, Yang XV, Kuei C, Wu J, Deng X, Mani NS, Mirzadegan T, Sun S, Lovenberg TW, Liu C. Identification of structural motifs critical for epstein-barr virus-induced molecule 2 function and homology modeling of the ligand docking site. Mol Pharmacol 2012; 82:1094-103. [PMID: 22930711 DOI: 10.1124/mol.112.080275] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Epstein-Barr virus-induced molecule 2 (EBI2) (also known as G-protein-coupled receptor 183) is a G-protein-coupled receptor (GPCR) that is best known for its role in B cell migration and localization. Our recent deorphanization effort led to the discovery of 7α,25-dihydroxycholesterol (7α,25-OHC) as the endogenous ligand for EBI2, which provides a tool for mechanistic studies of EBI2 function. Because EBI2 is the first GPCR known to bind and to be activated by an oxysterol, the goal of this study was to understand the molecular and structural bases for its ligand-dependent activation; this was achieved by identifying structural moieties in EBI2 or in 7α,25-OHC that might affect receptor-ligand interactions. By using a series of chemically related OHC analogs, we demonstrated that all three hydroxyl groups in 7α,25-OHC contributed to ligand-induced activation of the receptor. To determine the location and composition of the ligand binding domain in EBI2, we used a site-directed mutagenesis approach and generated mutant receptors with single amino acid substitutions at selected positions of interest. Biochemical and pharmacological profiling of these mutant receptors allowed for structure-function analyses and revealed critical motifs that likely interact with 7α,25-OHC. By using a hybrid β(2)-adrenergic receptor-C-X-C chemokine receptor type 4 structure as a template, we created a homology model for EBI2 and optimized the docking of 7α,25-OHC into the putative ligand binding site, so that the hydroxyl groups interact with residues Arg87, Asn114, and Glu183. This model of ligand docking yields important structural insight into the molecular mechanisms mediating EBI2 function and may facilitate future efforts to design novel therapeutic agents that target EBI2.
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Affiliation(s)
- Li Zhang
- Janssen Pharmaceutical Research and Development, San Diego, California, USA
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15
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Jensen PC, Thiele S, Steen A, Elder A, Kolbeck R, Ghosh S, Frimurer TM, Rosenkilde MM. Reversed binding of a small molecule ligand in homologous chemokine receptors - differential role of extracellular loop 2. Br J Pharmacol 2012; 166:258-75. [PMID: 22050085 DOI: 10.1111/j.1476-5381.2011.01771.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND AND PURPOSE The majority of small molecule compounds targeting chemokine receptors share a similar pharmacophore with a centrally located aliphatic positive charge and flanking aromatic moieties. Here we describe a novel piperidine-based compound with structural similarity to previously described CCR8-specific agonists, but containing a unique phenyl-tetrazol moiety which, in addition to activity at CCR8 was also active at CCR1. EXPERIMENTAL APPROACH Single point mutations were introduced in CCR1 and CCR8, and their effect on small molecule ligand-induced receptor activation was examined through inositol trisphosphate (IP(3) ) accumulation. The molecular interaction profile of the agonist was verified by molecular modeling. KEY RESULTS The chemokine receptor conserved glutamic acid in TM-VII served as a common anchor for the positively charged amine in the piperidine ring. However, whereas the phenyl-tetrazol group interacted with TyrIV:24 (Tyr(172) ) and TyrIII:09 (Tyr(114) ) in the major binding pocket (delimited by TM-III to VII) of CCR8, it also interacted with TrpII:20 (Trp(90) ) and LysII:24 (Lys(94) ) in the minor counterpart (delimited TM-I to III, plus TM-VII) in CCR1. A straightening of TM-II by Ala-substitution of ProII:18 confirmed its unique role in CCR1. The extracellular loop 2 (ECL-2) contributed directly to the small molecule binding site in CCR1, whereas it contributed to efficacy, but not potency in CCR8. CONCLUSION AND IMPLICATIONS Despite high ligand potency and efficacy and receptor similarity, this dual-active and bitopic compound binds oppositely in CCR1 and CCR8 with different roles of ECL-2, thereby expanding and diversifying the influence of extracellular receptor regions in drug action.
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Affiliation(s)
- P C Jensen
- Department of Neuroscience and Pharmacology, Copenhagen University, Copenhagen, Denmark
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16
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Structural Diversity in Conserved Regions Like the DRY-Motif among Viral 7TM Receptors-A Consequence of Evolutionary Pressure? Adv Virol 2012; 2012:231813. [PMID: 22899926 PMCID: PMC3414077 DOI: 10.1155/2012/231813] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2012] [Accepted: 05/31/2012] [Indexed: 01/31/2023] Open
Abstract
Several herpes- and poxviruses have captured chemokine receptors from their hosts and modified these to their own benefit. The human and viral chemokine receptors belong to class A 7 transmembrane (TM) receptors which are characterized by several structural motifs like the DRY-motif in TM3 and the C-terminal tail. In the DRY-motif, the arginine residue serves important purposes by being directly involved in G protein coupling. Interestingly, among the viral receptors there is a greater diversity in the DRY-motif compared to their endogenous receptor homologous. The C-terminal receptor tail constitutes another regulatory region that through a number of phosphorylation sites is involved in signaling, desensitization, and internalization. Also this region is more variable among virus-encoded 7TM receptors compared to human class A receptors. In this review we will focus on these two structural motifs and discuss their role in viral 7TM receptor signaling compared to their endogenous counterparts.
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17
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Gatto D, Wood K, Brink R. EBI2 operates independently of but in cooperation with CXCR5 and CCR7 to direct B cell migration and organization in follicles and the germinal center. THE JOURNAL OF IMMUNOLOGY 2011; 187:4621-8. [PMID: 21948984 DOI: 10.4049/jimmunol.1101542] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Migration of B cells within lymphoid follicles is controlled by the chemokine receptors CXCR5 and CCR7 and the G-protein-coupled receptor EBI2 (GPR183). Whereas CXCR5 and CCR7 are known to mediate migration toward their respective chemokine ligands, it is unclear whether EBI2 acts by modulating these processes or by directly mediating chemotaxis toward its own spatially restricted ligand. It is also unknown how signals from these three receptors are integrated to control B cell localization. To answer these questions, we generated compound knockout mice deficient in expression of EBI2, CXCR5, or CCR7. Analysis of these mice revealed that EBI2 mediates B cell migration toward the outer areas of follicles and to bridging channels of the spleen independent of both CXCR5 and CCR7. Migratory signals delivered by EBI2 were shown to control B cell organization within the spleen and to be particularly important for positioning activated B cells in the early stages of Ab responses. An additional minor role for EBI2 was identified in the organization and affinity maturation of B cells in germinal centers. Thus, EBI2-mediated chemotaxis provides a third dimension to B cell migration that balances and integrates with the inputs from CXCR5 and CCR7 to determine B cell positioning.
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Affiliation(s)
- Dominique Gatto
- Garvan Institute of Medical Research, Darlinghurst, New South Wales 2010, Australia
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18
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Benned-Jensen T, Mokrosinski J, Rosenkilde MM. The E92K melanocortin 1 receptor mutant induces cAMP production and arrestin recruitment but not ERK activity indicating biased constitutive signaling. PLoS One 2011; 6:e24644. [PMID: 21931793 PMCID: PMC3172247 DOI: 10.1371/journal.pone.0024644] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2011] [Accepted: 08/17/2011] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND The melanocortin 1 receptor (MC1R) constitutes a key regulator of melanism. Consequently, many naturally-occurring MC1R mutations are associated with a change in color. An example is the Glu-to-Lys substitution found at position II:20/2.60 in the top of transmembrane helix II which has been identified in melanic mice and several other species. This mutation induces a pronounced increase in MC1R constitutive activity suggesting a link between constitutive activity and melanism which is corroborated by the attenuation of α-melanocyte stimulating hormone (αMSH) induced activation. However, the mechanism by which the mutation induces constitutive activity is currently not known. METHODOLOGY/PRINCIPAL FINDINGS Here we characterize the constitutive activity, cell surface expression and internalization of the mouse mutant, Mc1r E92K. As previously reported, only positively charged residues at position II:20/2.60 induced an increase in constitutive activity as measured by cAMP accumulation and CREB activation. Furthermore, the mutation induced a constitutive recruitment of β-arrestin. This phenomenon is only observed in MC1R, however, as the equivalent mutations in MC2-5R had no effect on receptor signaling. Interestingly, the mutation did not induce constitutive ERK1/2 phosphorylation or increase the internalization rate indicating the constitutive activity to be biased. Finally, to identify regions of importance for the increased constitutive activity of Mc1r E92K, we employed a chimeric approach and identified G102 and L110 in the extracellular loop 1 to be selectively important for the constitutive activity as this, but not αMSH-mediated activation, was abolished upon Ala substitution. CONCLUSIONS/SIGNIFICANCE It is concluded that the E92K mutation induces an active conformation distinct from that induced by αMSH and that the extracellular loop 1 is involved in maintaining this conformational state. In turn, the results suggest that in MC1R, which lacks an extracellular loop 2, the first extracellular loop may play a more prominent role during receptor activation than in general.
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Affiliation(s)
- Tau Benned-Jensen
- Laboratory for Molecular Pharmacology, Department of Neuroscience and Pharmacology, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jacek Mokrosinski
- Laboratory for Molecular Pharmacology, Department of Neuroscience and Pharmacology, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Mette M. Rosenkilde
- Laboratory for Molecular Pharmacology, Department of Neuroscience and Pharmacology, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
- * E-mail:
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19
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Benned-Jensen T, Smethurst C, Holst PJ, Page KR, Sauls H, Sivertsen B, Schwartz TW, Blanchard A, Jepras R, Rosenkilde MM. Ligand modulation of the Epstein-Barr virus-induced seven-transmembrane receptor EBI2: identification of a potent and efficacious inverse agonist. J Biol Chem 2011; 286:29292-29302. [PMID: 21673108 PMCID: PMC3190735 DOI: 10.1074/jbc.m110.196345] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2010] [Revised: 06/10/2011] [Indexed: 12/20/2022] Open
Abstract
The Epstein-Barr virus-induced receptor 2 (EBI2) is a constitutively active seven-transmembrane receptor, which was recently shown to orchestrate the positioning of B cells in the follicle. To date, no ligands, endogenously or synthetic, have been identified that modulate EBI2 activity. Here we describe an inverse agonist, GSK682753A, which selectively inhibited the constitutive activity of EBI2 with high potency and efficacy. In cAMP-response element-binding protein-based reporter and guanosine 5'-3-O-(thio)triphosphate (GTPγS) binding assays, the potency of this compound was 2.6-53.6 nm, and its inhibitory efficacy was 75%. In addition, we show that EBI2 constitutively activated extracellular signal-regulated kinase (ERK) in a pertussis toxin-insensitive manner. Intriguingly, GSK682753A inhibited ERK phosphorylation, GTPγS binding, and cAMP-response element-binding protein activation with similar potency. Overexpression of EBI2 profoundly potentiated antibody-stimulated ex vivo proliferation of murine B cells compared with WT cells, whereas this was equivalently reduced for EBI2-deficient B cells. Inhibition of EBI2 constitutive activity suppressed the proliferation in all cases. Importantly, the suppression was of much higher potency (32-fold) in WT or EBI2-overexpressing B cells compared with EBI2-deficient counterparts. Finally, we screened GSK682753A against an EBI2 mutant library to determine putative molecular binding determinants in EBI2. We identified Phe(111) at position III:08/3.32 as being crucial for GSK682753A inverse agonism because Ala substitution resulted in a >500-fold decrease in IC(50). In conclusion, we present the first ligand targeting EBI2. In turn, this molecule provides a useful tool for further characterization of EBI2 as well as serving as a potent lead compound.
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Affiliation(s)
- Tau Benned-Jensen
- Laboratory for Molecular Pharmacology, Department of Neuroscience and Pharmacology, Faculty of Health Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark
| | | | - Peter J Holst
- Department of International Health, Immunology, and Microbiology, Faculty of Health Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark, and
| | - Kevin R Page
- GlaxoSmithKline, Gunnels Wood Road, Stevenage SG1 2NY, United Kingdom
| | - Howard Sauls
- GlaxoSmithKline, Research Triangle Park, North Carolina 27709
| | - Bjørn Sivertsen
- Laboratory for Molecular Pharmacology, Department of Neuroscience and Pharmacology, Faculty of Health Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark
| | - Thue W Schwartz
- Laboratory for Molecular Pharmacology, Department of Neuroscience and Pharmacology, Faculty of Health Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark
| | - Andy Blanchard
- GlaxoSmithKline, Gunnels Wood Road, Stevenage SG1 2NY, United Kingdom
| | - Robert Jepras
- GlaxoSmithKline, Gunnels Wood Road, Stevenage SG1 2NY, United Kingdom
| | - Mette M Rosenkilde
- Laboratory for Molecular Pharmacology, Department of Neuroscience and Pharmacology, Faculty of Health Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark,.
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20
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Mercier RW, Pei Y, Pandarinathan L, Janero DR, Zhang J, Makriyannis A. hCB2 ligand-interaction landscape: cysteine residues critical to biarylpyrazole antagonist binding motif and receptor modulation. ACTA ACUST UNITED AC 2011; 17:1132-42. [PMID: 21035736 DOI: 10.1016/j.chembiol.2010.08.010] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2010] [Revised: 08/09/2010] [Accepted: 08/12/2010] [Indexed: 11/19/2022]
Abstract
The human cannabinoid 2 GPCR (hCB2) is a prime therapeutic target. To define potential cysteine-related binding motifs critical to hCB2-ligand interaction, a library of hCB2 cysteine-substitution mutants and a novel, high-affinity biarylpyrazole hCB2 antagonist/inverse agonist (AM1336) functionalized to serve as a covalent affinity probe to target cysteine residues within (or in the microenvironment of) its hCB2 binding pocket were generated. The data provide direct experimental demonstration that both hCB2 TMH7 cysteines [i.e., C7.38(284) and C7.42(288)] are critical to optimal hCB2-AM1336 binding interaction and AM1336 pharmacological activity in a cell-based functional assay (cAMP formation). Elongating the AM1336 aliphatic side chain generated another novel hCB2 inverse agonist that binds covalently and selectively to C7.42(288) only. Identification of specific cysteine residues critical to hCB2 ligand interaction and function informs the structure-based design of hCB2-targeted medicines.
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Affiliation(s)
- Richard W Mercier
- School of Pharmacy, University of Connecticut, Storrs, CT 06269, USA
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21
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Bonde MM, Hansen JT, Sanni SJ, Haunsø S, Gammeltoft S, Lyngsø C, Hansen JL. Biased signaling of the angiotensin II type 1 receptor can be mediated through distinct mechanisms. PLoS One 2010; 5:e14135. [PMID: 21152433 PMCID: PMC2994726 DOI: 10.1371/journal.pone.0014135] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2010] [Accepted: 10/29/2010] [Indexed: 01/14/2023] Open
Abstract
BACKGROUND Seven transmembrane receptors (7TMRs) can adopt different active conformations facilitating a selective activation of either G protein or β-arrestin-dependent signaling pathways. This represents an opportunity for development of novel therapeutics targeting selective biological effects of a given receptor. Several studies on pathway separation have been performed, many of these on the Angiotensin II type 1 receptor (AT1R). It has been shown that certain ligands or mutations facilitate internalization and/or recruitment of β-arrestins without activation of G proteins. However, the underlying molecular mechanisms remain largely unresolved. For instance, it is unclear whether such selective G protein-uncoupling is caused by a lack of ability to interact with G proteins or rather by an increased ability of the receptor to recruit β-arrestins. Since uncoupling of G proteins by increased ability to recruit β-arrestins could lead to different cellular or in vivo outcomes than lack of ability to interact with G proteins, it is essential to distinguish between these two mechanisms. METHODOLOGY/PRINCIPAL FINDINGS We studied five AT1R mutants previously published to display pathway separation: D74N, DRY/AAY, Y292F, N298A, and Y302F (Ballesteros-Weinstein numbering: 2.50, 3.49-3.51, 7.43, 7.49, and 7.53). We find that D74N, DRY/AAY, and N298A mutants are more prone to β-arrestin recruitment than WT. In contrast, receptor mutants Y292F and Y302F showed impaired ability to recruit β-arrestin in response to Sar1-Ile4-Ile8 (SII) Ang II, a ligand solely activating the β-arrestin pathway. CONCLUSIONS/SIGNIFICANCE Our analysis reveals that the underlying conformations induced by these AT1R mutants most likely represent principally different mechanisms of uncoupling the G protein, which for some mutants may be due to their increased ability to recruit β-arrestin2. Hereby, these findings have important implications for drug discovery and 7TMR biology and illustrate the necessity of uncovering the exact molecular determinants for G protein-coupling and β-arrestin recruitment, respectively.
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Affiliation(s)
- Marie Mi Bonde
- Laboratory for Molecular Cardiology, The Danish National Research Foundation Centre for Cardiac Arrhythmia, The Heart Centre, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
- Department of Biomedical Sciences and The Danish National Research Foundation Centre for Cardiac Arrhythmia, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jonas Tind Hansen
- Department of Biomedical Sciences and The Danish National Research Foundation Centre for Cardiac Arrhythmia, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
- Department of Clinical Biochemistry, Glostrup Hospital, Glostrup, Denmark
| | - Samra Joke Sanni
- Department of Clinical Biochemistry, Glostrup Hospital, Glostrup, Denmark
| | - Stig Haunsø
- Laboratory for Molecular Cardiology, The Danish National Research Foundation Centre for Cardiac Arrhythmia, The Heart Centre, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| | - Steen Gammeltoft
- Department of Clinical Biochemistry, Glostrup Hospital, Glostrup, Denmark
| | - Christina Lyngsø
- Department of Biomedical Sciences and The Danish National Research Foundation Centre for Cardiac Arrhythmia, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
- Department of Clinical Biochemistry, Glostrup Hospital, Glostrup, Denmark
| | - Jakob Lerche Hansen
- Laboratory for Molecular Cardiology, The Danish National Research Foundation Centre for Cardiac Arrhythmia, The Heart Centre, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
- Department of Biomedical Sciences and The Danish National Research Foundation Centre for Cardiac Arrhythmia, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
- * E-mail:
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22
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Rosenkilde MM, Benned-Jensen T, Frimurer TM, Schwartz TW. The minor binding pocket: a major player in 7TM receptor activation. Trends Pharmacol Sci 2010; 31:567-74. [PMID: 20870300 DOI: 10.1016/j.tips.2010.08.006] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2010] [Revised: 08/21/2010] [Accepted: 08/27/2010] [Indexed: 01/09/2023]
Abstract
From the deep part of the main ligand-binding crevice, a minor, often shallower pocket extends between the extracellular ends of transmembrane domains (TM)-I, II, III and VII of 7TM receptors. This minor binding pocket is defined by a highly conserved kink in TM-II that is induced by a proline residue located in one of two adjacent positions. Here we argue that this minor binding pocket is important for receptor activation. Functional coupling of the receptors seems to be mediated through the hydrogen bond network located between the intracellular segments of these TMs, with the allosteric interface between TM-II and TM-VII being of particular significance. Importantly, the minor binding pocket, especially the proline-kink in TM-II, is involved in G protein versus arrestin pathway-biased signaling, for example in the angiotensin AT1 system. Consequently, this pocket could be specifically targeted in the development of functionally biased drugs.
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Affiliation(s)
- Mette M Rosenkilde
- Laboratory for Molecular Pharmacology, Institute for Neuroscience and Pharmacology, Faculty of Health Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen, Denmark.
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23
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Bonde MM, Yao R, Ma JN, Madabushi S, Haunsø S, Burstein ES, Whistler JL, Sheikh SP, Lichtarge O, Hansen JL. An angiotensin II type 1 receptor activation switch patch revealed through evolutionary trace analysis. Biochem Pharmacol 2010; 80:86-94. [PMID: 20227396 DOI: 10.1016/j.bcp.2010.03.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2009] [Revised: 02/08/2010] [Accepted: 03/04/2010] [Indexed: 12/21/2022]
Abstract
Seven transmembrane (7TM) or G protein-coupled receptors constitute a large superfamily of cell surface receptors sharing a structural motif of seven transmembrane spanning alpha helices. Their activation mechanism most likely involves concerted movements of the transmembrane helices, but remains to be completely resolved. Evolutionary Trace (ET) analysis is a computational method, which identifies clusters of functionally important residues by integrating information on evolutionary important residue variations with receptor structure. Combined with known mutational data, ET predicted a patch of residues in the cytoplasmic parts of TM2, TM3, and TM6 to form an activation switch that is common to all family A 7TM receptors. We tested this hypothesis in the rat Angiotensin II (Ang II) type 1a (AT1a) receptor. The receptor has important roles in the cardiovascular system, but has also frequently been applied as a model for 7TM receptor activation and signaling. Six mutations: F66A, L67R, L70R, L119R, D125A, and I245F were targeted to the putative switch and assayed for changes in activation state by their ligand binding, signaling, and trafficking properties. All but one receptor mutant (that was not expressed well) displayed phenotypes associated with changed activation state, such as increased agonist affinity or basal activity, promiscuous activation, or constitutive internalization highlighting the importance of testing different signaling pathways. We conclude that this evolutionary important patch mediates interactions important for maintaining the inactive state. More broadly, these observations in the AT1 receptor are consistent with computational predictions of a generic role for this patch in 7TM receptor activation.
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Affiliation(s)
- Marie Mi Bonde
- Laboratory for Molecular Cardiology, The Danish National Research Foundation Centre for Cardiac Arrhythmia, The Heart Centre, Copenhagen University Hospital, Rigshospitalet, Juliane Mariesvej 20, section 9312, DK-2100 Copenhagen, Denmark
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Benned-Jensen T, Rosenkilde MM. Distinct expression and ligand-binding profiles of two constitutively active GPR17 splice variants. Br J Pharmacol 2010; 159:1092-105. [PMID: 20148890 PMCID: PMC2839267 DOI: 10.1111/j.1476-5381.2009.00633.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
Background and purpose: In humans and non-human primates, the 7TM receptor GPR17 exists in two isoforms differing only by the length of the N-terminus. Of these, only the short isoform has previously been characterized. Hence, we investigated gene expression and ligand-binding profiles of both splice variants and furthermore uncovered and characterized constitutive activity of both isoforms. Experimental approach: Expression levels of the hGPR17 isoforms were determined in several brain regions as well as heart and kidney using quantitative RT-PCR. A CREB reporter assay and [35S]-GTPγS binding were employed to assess the constitutive activity and the activation by UDP, UDP-glucose and -galactose and the cysteinyl leukotrienes LTC4 and LTD4. Leukotriene binding and induction of internalization were furthermore tested using homologous competition binding and antibody-feeding experiments respectively. Key results: The short isoform (hGPR17-S) was expressed more abundantly (eight- to 23-fold) in the brain than the long isoform (hGPR17-L), whereas the opposite was observed in heart and kidney. As previously reported, the uracil nucleotides activated hGPR17-S with micromolar potencies. However, much lower potencies were observed for hGPR17-L with a 50- to 170-fold increase in EC50. Furthermore, contrary to previous reports, neither of the isoforms was activated or bound by the cysteinyl leukotrienes. Finally, both receptors were demonstrated to be constitutively active through Gαi. Conclusions and implications: We present the first isoform-specific characterization of GPR17 and show that differences exist between the isoforms, in both expression pattern and pharmacological profile. In turn, our results indicate that the two human isoforms might serve tissue-specific functions.
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Affiliation(s)
- T Benned-Jensen
- Department of Neuroscience and Pharmacology, The Panum Institute, Copenhagen University, Denmark
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Guidance of B Cells by the Orphan G Protein-Coupled Receptor EBI2 Shapes Humoral Immune Responses. Immunity 2009; 31:259-69. [DOI: 10.1016/j.immuni.2009.06.016] [Citation(s) in RCA: 213] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2009] [Revised: 06/25/2009] [Accepted: 06/25/2009] [Indexed: 01/22/2023]
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