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Buckley SJ, Nguyen TV, Cummins SF, Elizur A, Fitzgibbon QP, Smith GS, Mykles DL, Ventura T. Evaluating conserved domains and motifs of decapod gonadotropin-releasing hormone G protein-coupled receptor superfamily. Front Endocrinol (Lausanne) 2024; 15:1348465. [PMID: 38444586 PMCID: PMC10912298 DOI: 10.3389/fendo.2024.1348465] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2023] [Accepted: 01/18/2024] [Indexed: 03/07/2024] Open
Abstract
G protein-coupled receptors (GPCRs) are an ancient family of signal transducers that are both abundant and consequential in metazoan endocrinology. The evolutionary history and function of the GPCRs of the decapod superfamilies of gonadotropin-releasing hormone (GnRH) are yet to be fully elucidated. As part of which, the use of traditional phylogenetics and the recycling of a diminutive set of mis-annotated databases has proven insufficient. To address this, we have collated and revised eight existing and three novel GPCR repertoires for GnRH of decapod species. We developed a novel bioinformatic workflow that included clustering analysis to capture likely GnRH receptor-like proteins, followed by phylogenetic analysis of the seven transmembrane-spanning domains. A high degree of conservation of the sequences and topology of the domains and motifs allowed the identification of species-specific variation (up to ~70%, especially in the extracellular loops) that is thought to be influential to ligand-binding and function. Given the key functional role of the DRY motif across GPCRs, the classification of receptors based on the variation of this motif can be universally applied to resolve cryptic GPCR families, as was achieved in this work. Our results contribute to the resolution of the evolutionary history of invertebrate GnRH receptors and inform the design of bioassays in their deorphanization and functional annotation.
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Affiliation(s)
- Sean J. Buckley
- Centre for Bioinnovation, University of the Sunshine Coast, Maroochydore, QLD, Australia
- School of Science, Technology and Engineering, University of the Sunshine Coast, Maroochydore, QLD, Australia
| | - Tuan Viet Nguyen
- Centre for AgriBioscience, Agriculture Victoria, Bundoora, VIC, Australia
| | - Scott F. Cummins
- Centre for Bioinnovation, University of the Sunshine Coast, Maroochydore, QLD, Australia
- School of Science, Technology and Engineering, University of the Sunshine Coast, Maroochydore, QLD, Australia
| | - Abigail Elizur
- Centre for Bioinnovation, University of the Sunshine Coast, Maroochydore, QLD, Australia
| | - Quinn P. Fitzgibbon
- Institute for Marine and Antarctic Studies (IMAS), University of Tasmania, Hobart, TAS, Australia
| | - Gregory S. Smith
- Institute for Marine and Antarctic Studies (IMAS), University of Tasmania, Hobart, TAS, Australia
| | - Donald L. Mykles
- Department of Biology, Colorado State University, Fort Collins, CO, United States
- University of California-Davis Bodega Marine Laboratory, Bodega Bay, CA, United States
| | - Tomer Ventura
- Centre for Bioinnovation, University of the Sunshine Coast, Maroochydore, QLD, Australia
- School of Science, Technology and Engineering, University of the Sunshine Coast, Maroochydore, QLD, Australia
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2
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Zhang X, Wang Y, Supekar S, Cao X, Zhou J, Dang J, Chen S, Jenkins L, Marsango S, Li X, Liu G, Milligan G, Feng M, Fan H, Gong W, Zhang C. Pro-phagocytic function and structural basis of GPR84 signaling. Nat Commun 2023; 14:5706. [PMID: 37709767 PMCID: PMC10502086 DOI: 10.1038/s41467-023-41201-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Accepted: 08/26/2023] [Indexed: 09/16/2023] Open
Abstract
GPR84 is a unique orphan G protein-coupled receptor (GPCR) that can be activated by endogenous medium-chain fatty acids (MCFAs). The signaling of GPR84 is largely pro-inflammatory, which can augment inflammatory response, and GPR84 also functions as a pro-phagocytic receptor to enhance phagocytic activities of macrophages. In this study, we show that the activation of GPR84 by the synthetic agonist 6-OAU can synergize with the blockade of CD47 on cancer cells to induce phagocytosis of cancer cells by macrophages. We also determine a high-resolution structure of the GPR84-Gi signaling complex with 6-OAU. This structure reveals an occluded binding pocket for 6-OAU, the molecular basis of receptor activation involving non-conserved structural motifs of GPR84, and an unusual Gi-coupling interface. Together with computational docking and simulations studies, this structure also suggests a mechanism for the high selectivity of GPR84 for MCFAs and a potential routes of ligand binding and dissociation. These results provide a framework for understanding GPR84 signaling and developing new drugs targeting GPR84.
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Affiliation(s)
- Xuan Zhang
- Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, China
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, University of Pittsburgh, Pittsburgh, PA, 15261, USA
| | - Yujing Wang
- Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, China
| | - Shreyas Supekar
- Bioinformatics Institute (BII), Agency for Science, Technology and Research (A*STAR), Singapore, 138671, Singapore
| | - Xu Cao
- Department of Immuno-Oncology, Beckman Research Institute, City of Hope Comprehensive Cancer Center, Duarte, CA, 91010, USA
| | - Jingkai Zhou
- Department of Immuno-Oncology, Beckman Research Institute, City of Hope Comprehensive Cancer Center, Duarte, CA, 91010, USA
| | - Jessica Dang
- Department of Immuno-Oncology, Beckman Research Institute, City of Hope Comprehensive Cancer Center, Duarte, CA, 91010, USA
| | - Siqi Chen
- Department of Immuno-Oncology, Beckman Research Institute, City of Hope Comprehensive Cancer Center, Duarte, CA, 91010, USA
| | - Laura Jenkins
- Centre for Translational Pharmacology, School of Molecular Biosciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8QQ, Scotland, UK
| | - Sara Marsango
- Centre for Translational Pharmacology, School of Molecular Biosciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8QQ, Scotland, UK
| | - Xiu Li
- Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, China
| | - Guibing Liu
- Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, China
| | - Graeme Milligan
- Centre for Translational Pharmacology, School of Molecular Biosciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8QQ, Scotland, UK.
| | - Mingye Feng
- Department of Immuno-Oncology, Beckman Research Institute, City of Hope Comprehensive Cancer Center, Duarte, CA, 91010, USA.
| | - Hao Fan
- Bioinformatics Institute (BII), Agency for Science, Technology and Research (A*STAR), Singapore, 138671, Singapore.
- Synthetic Biology Translational Research Program and Department of Biochemistry, School of Medicine, National University of Singapore, Singapore, Singapore.
- Cancer and Stem Cell Biology Program, Duke-NUS Medical School, Singapore, Singapore.
| | - Weimin Gong
- Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, China.
| | - Cheng Zhang
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, University of Pittsburgh, Pittsburgh, PA, 15261, USA.
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3
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Abstract
Although G-protein–coupled receptors (GPCRs) control vast physiological pathways, their activation remains chemically and physically enigmatic. Our osmotic stress studies of the visual receptor rhodopsin have redefined the standard model of GPCR signaling by revealing the essential role of bulk water. We show results consistent with a large number of water molecules flooding the rhodopsin interior during activation to stabilize the effector binding conformation. These results suggest a model of GPCR activation in which the receptor becomes solvent-swollen upon formation of the active state. We thus demonstrate the mechanism whereby water acts as a powerful allosteric modulator of a pharmacologically important membrane protein family. The Rhodopsin family of G-protein–coupled receptors (GPCRs) comprises the targets of nearly a third of all pharmaceuticals. Despite structural water present in GPCR X-ray structures, the physiological relevance of these solvent molecules to rhodopsin signaling remains unknown. Here, we show experimental results consistent with the idea that rhodopsin activation in lipid membranes is coupled to bulk water movements into the protein. To quantify hydration changes, we measured reversible shifting of the metarhodopsin equilibrium due to osmotic stress using an extensive series of polyethylene glycol (PEG) osmolytes. We discovered clear evidence that light activation entails a large influx of bulk water (∼80–100 molecules) into the protein, giving insight into GPCR activation mechanisms. Various size polymer osmolytes directly control rhodopsin activation, in which large solutes are excluded from rhodopsin and dehydrate the protein, favoring the inactive state. In contrast, small osmolytes initially forward shift the activation equilibrium until a quantifiable saturation point is reached, similar to gain-of-function protein mutations. For the limit of increasing osmolyte size, a universal response of rhodopsin to osmotic stress is observed, suggesting it adopts a dynamic, hydrated sponge-like state upon photoactivation. Our results demand a rethinking of the role of water dynamics in modulating various intermediates in the GPCR energy landscape. We propose that besides bound water, an influx of bulk water plays a necessary role in establishing the active GPCR conformation that mediates signaling.
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Solís KH, Romero-Ávila MT, Guzmán-Silva A, García-Sáinz JA. The LPA 3 Receptor: Regulation and Activation of Signaling Pathways. Int J Mol Sci 2021; 22:ijms22136704. [PMID: 34201414 PMCID: PMC8269014 DOI: 10.3390/ijms22136704] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 06/08/2021] [Accepted: 06/12/2021] [Indexed: 12/17/2022] Open
Abstract
The lysophosphatidic acid 3 receptor (LPA3) participates in different physiological actions and in the pathogenesis of many diseases through the activation of different signal pathways. Knowledge of the regulation of the function of the LPA3 receptor is a crucial element for defining its roles in health and disease. This review describes what is known about the signaling pathways activated in terms of its various actions. Next, we review knowledge on the structure of the LPA3 receptor, the domains found, and the roles that the latter might play in ligand recognition, signaling, and cellular localization. Currently, there is some information on the action of LPA3 in different cells and whole organisms, but very little is known about the regulation of its function. Areas in which there is a gap in our knowledge are indicated in order to further stimulate experimental work on this receptor and on other members of the LPA receptor family. We are convinced that knowledge on how this receptor is activated, the signaling pathways employed and how the receptor internalization and desensitization are controlled will help design new therapeutic interventions for treating diseases in which the LPA3 receptor is implicated.
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Hilger D. The role of structural dynamics in GPCR‐mediated signaling. FEBS J 2021; 288:2461-2489. [DOI: 10.1111/febs.15841] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Revised: 03/19/2021] [Accepted: 03/24/2021] [Indexed: 12/18/2022]
Affiliation(s)
- Daniel Hilger
- Department of Pharmaceutical Chemistry Philipps‐University Marburg Germany
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Stephens BS, Ngo T, Kufareva I, Handel TM. Functional anatomy of the full-length CXCR4-CXCL12 complex systematically dissected by quantitative model-guided mutagenesis. Sci Signal 2020; 13:eaay5024. [PMID: 32665413 PMCID: PMC7437921 DOI: 10.1126/scisignal.aay5024] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Because of their prominent roles in development, cancer, and HIV, the chemokine receptor CXCR4 and its ligand CXCL12 have been the subject of numerous structural and functional studies, but the determinants of ligand binding, selectivity, and signaling are still poorly understood. Here, building on our latest structural model, we used a systematic mutagenesis strategy to dissect the functional anatomy of the CXCR4-CXCL12 complex. Key charge swap mutagenesis experiments provided evidence for pairwise interactions between oppositely charged residues in the receptor and chemokine, confirming the accuracy of the predicted orientation of the chemokine relative to the receptor and providing insight into ligand selectivity. Progressive deletion of N-terminal residues revealed an unexpected contribution of the receptor N terminus to chemokine signaling. This finding challenges a longstanding "two-site" hypothesis about the essential features of the receptor-chemokine interaction in which the N terminus contributes only to binding affinity. Our results suggest that although the interaction of the chemokine N terminus with the receptor-binding pocket is the key driver of signaling, the signaling amplitude depends on the extent to which the receptor N terminus binds the chemokine. Together with systematic characterization of other epitopes, these data enable us to propose an experimentally consistent structural model for how CXCL12 binds CXCR4 and initiates signal transmission through the receptor transmembrane domain.
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Affiliation(s)
- Bryan S Stephens
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Tony Ngo
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Irina Kufareva
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, CA 92093, USA.
| | - Tracy M Handel
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, CA 92093, USA.
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7
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Stark T, Di Bartolomeo M, Di Marco R, Drazanova E, Platania CBM, Iannotti FA, Ruda-Kucerova J, D'Addario C, Kratka L, Pekarik V, Piscitelli F, Babinska Z, Fedotova J, Giurdanella G, Salomone S, Sulcova A, Bucolo C, Wotjak CT, Starcuk Z, Drago F, Mechoulam R, Di Marzo V, Micale V. Altered dopamine D3 receptor gene expression in MAM model of schizophrenia is reversed by peripubertal cannabidiol treatment. Biochem Pharmacol 2020; 177:114004. [PMID: 32360362 DOI: 10.1016/j.bcp.2020.114004] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Accepted: 04/24/2020] [Indexed: 12/16/2022]
Abstract
Gestational methylazoxymethanol acetate (MAM) treatment produces offspring with adult phenotype relevant to schizophrenia, including positive- and negative-like symptoms, cognitive deficits, dopaminergic dysfunction, structural and functional abnormalities. Here we show that adult rats prenatally treated with MAM at gestational day 17 display significant increase in dopamine D3 receptor (D3) mRNA expression in prefrontal cortex (PFC), hippocampus and nucleus accumbens, accompanied by increased expression of dopamine D2 receptor (D2) mRNA exclusively in the PFC. Furthermore, a significant change in the blood perfusion at the level of the circle of Willis and hippocampus, paralleled by the enlargement of lateral ventricles, was also detected by magnetic resonance imaging (MRI) techniques. Peripubertal treatment with the non-euphoric phytocannabinoid cannabidiol (30 mg/kg) from postnatal day (PND) 19 to PND 39 was able to reverse in MAM exposed rats: i) the up-regulation of the dopamine D3 receptor mRNA (only partially prevented by haloperidol 0.6 mg/kg/day); and ii) the regional blood flow changes in MAM exposed rats. Molecular modelling predicted that cannabidiol could bind preferentially to dopamine D3 receptor, where it may act as a partial agonist according to conformation of ionic-lock, which is highly conserved in GPCRs. In summary, our results demonstrate that the mRNA expression of both dopamine D2 and D3 receptors is altered in the MAM model; however only the transcript levels of D3 are affected by cannabidiol treatment, likely suggesting that this gene might not only contribute to the schizophrenia symptoms but also represent an unexplored target for the antipsychotic activity of cannabidiol.
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Affiliation(s)
- Tibor Stark
- Department of Pharmacology, Faculty of Medicine, Masaryk University, Brno, Czech Republic; RG "Neuronal Plasticity", Max Planck Institute of Psychiatry, Munich, Germany
| | - Martina Di Bartolomeo
- Faculty of Bioscience and Technology for Food, Agriculture and Environment, University of Teramo, Teramo, Italy
| | - Roberta Di Marco
- Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, Italy
| | - Eva Drazanova
- Department of Pharmacology, Faculty of Medicine, Masaryk University, Brno, Czech Republic; Institute of Scientific Instruments of the Czech Academy of Sciences, Brno, Czech Republic
| | | | - Fabio Arturo Iannotti
- Institute of Biomolecular Chemistry, Consiglio Nazionale delle Ricerche, Endocannabinoid Research Group, Naples, Italy
| | - Jana Ruda-Kucerova
- Department of Pharmacology, Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - Claudio D'Addario
- Faculty of Bioscience and Technology for Food, Agriculture and Environment, University of Teramo, Teramo, Italy
| | - Lucie Kratka
- Institute of Scientific Instruments of the Czech Academy of Sciences, Brno, Czech Republic
| | - Vladimir Pekarik
- Department of Physiology, Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - Fabiana Piscitelli
- Institute of Biomolecular Chemistry, Consiglio Nazionale delle Ricerche, Endocannabinoid Research Group, Naples, Italy
| | - Zuzana Babinska
- Department of Pharmacology, Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - Julia Fedotova
- International Research Centre "Biotechnologies of the Third Millennium", ITMO University, St. Petersburg, Russian Federation; Laboratory of Neuroendocrinology, I.P. Pavlov Institute of Physiology RASci., St. Petersburg, Russian Federation; Lobachevsky State University of Nizhny Novgorod, Institute of Biology and Biomedicine, Nizhny Novgorod, Russian Federation
| | - Giovanni Giurdanella
- Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, Italy
| | - Salvatore Salomone
- Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, Italy
| | - Alexandra Sulcova
- ICCI - International Cannabis and Cannabinoid Institute, Praha, Czech Republic
| | - Claudio Bucolo
- Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, Italy
| | - Carsten T Wotjak
- RG "Neuronal Plasticity", Max Planck Institute of Psychiatry, Munich, Germany; Boehringer Ingelheim Pharma GmbH & KO KG, Germany
| | - Zenon Starcuk
- Institute of Scientific Instruments of the Czech Academy of Sciences, Brno, Czech Republic
| | - Filippo Drago
- Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, Italy
| | - Raphael Mechoulam
- Institute for Drug Research, Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Vincenzo Di Marzo
- Institute of Biomolecular Chemistry, Consiglio Nazionale delle Ricerche, Endocannabinoid Research Group, Naples, Italy; Canada Excellence Research Chair on the Microbiome-Endocannabinoidome Axis in Metabolic Health, Université Laval, Quebec City, Canada; Joint International Unit on Chemical and Biomolecular Research on the Microbiome and its Impact on Metabolic Health and Nutrition (UMI-MicroMeNu), Université Laval and Institute of Biomolecular Chemistry, CNR, Pozzuoli, Italy
| | - Vincenzo Micale
- Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, Italy; National Institute of Mental Health, Klecany, Czech Republic.
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8
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Ciancetta A, Rubio P, Lieberman DI, Jacobson KA. A 3 adenosine receptor activation mechanisms: molecular dynamics analysis of inactive, active, and fully active states. J Comput Aided Mol Des 2019; 33:983-996. [PMID: 31758354 DOI: 10.1007/s10822-019-00246-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Accepted: 11/02/2019] [Indexed: 12/12/2022]
Abstract
We investigated the Gi-coupled A3 adenosine receptor (A3AR) activation mechanism by running 7.2 µs of molecular dynamics (MD) simulations. Based on homology to G protein-coupled receptor (GPCR) structures, three constitutively active mutant (CAM) and the wild-type (WT) A3ARs in the apo form were modeled. Conformational signatures associated with three different receptor states (inactive R, active R*, and bound to Gi protein mimic) were predicted by analyzing and comparing the CAMs with WT receptor and by considering site-directed mutagenesis data. Detected signatures that were correlated with receptor state included: Persistent salt-bridges involving key charged residues for activation (including a novel, putative ionic lock), rotameric state of conserved W6.48, and Na+ ions and water molecules present. Active-coupled state signatures similar to the X-ray structures of β2 adrenergic receptor-Gs protein and A2AAR-mini-Gs and the recently solved cryo-EM A1AR-Gi complexes were found. Our MD analysis suggests that constitutive activation might arise from the D1073.49-R1083.50 ionic lock destabilization in R and the D1073.49-R1113.53 ionic lock stabilization in R* that presumably lowers the energy barrier associated with an R to R* transition. This study provides new opportunities to understand the underlying interactions of different receptor states of other Gi protein-coupled GPCRs.
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Affiliation(s)
- Antonella Ciancetta
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, 20892, USA.
- Sygnature Discovery, Nottingham, UK.
| | - Priscila Rubio
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, 20892, USA
| | - David I Lieberman
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Kenneth A Jacobson
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, 20892, USA.
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Al-Zoubi R, Morales P, Reggio PH. Structural Insights into CB1 Receptor Biased Signaling. Int J Mol Sci 2019; 20:E1837. [PMID: 31013934 PMCID: PMC6515405 DOI: 10.3390/ijms20081837] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Revised: 04/09/2019] [Accepted: 04/11/2019] [Indexed: 12/21/2022] Open
Abstract
The endocannabinoid system has emerged as a promising target for the treatment of numerous diseases, including cancer, neurodegenerative disorders, and metabolic syndromes. Thus far, two cannabinoid receptors, CB1 and CB2, have been discovered, which are found predominantly in the central nervous system (CB1) or the immune system (CB2), among other organs and tissues. CB1 receptor ligands have been shown to induce a complex pattern of intracellular effects. The binding of a ligand induces distinct conformational changes in the receptor, which will eventually translate into distinct intracellular signaling pathways through coupling to specific intracellular effector proteins. These proteins can mediate receptor desensitization, trafficking, or signaling. Ligand specificity and selectivity, complex cellular components, and the concomitant expression of other proteins (which either regulate the CB1 receptor or are regulated by the CB1 receptor) will affect the therapeutic outcome of its targeting. With an increased interest in G protein-coupled receptors (GPCR) research, in-depth studies using mutations, biological assays, and spectroscopic techniques (such as NMR, EPR, MS, FRET, and X-ray crystallography), as well as computational modelling, have begun to reveal a set of concerted structural features in Class A GPCRs which relate to signaling pathways and the mechanisms of ligand-induced activation, deactivation, or activity modulation. This review will focus on the structural features of the CB1 receptor, mutations known to bias its signaling, and reported studies of CB1 receptor ligands to control its specific signaling.
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Affiliation(s)
- Rufaida Al-Zoubi
- Department of Medicinal Chemistry and Pharmacognosy, Faculty of Pharmacy, Jordan University of Science & Technology, P.O.BOX 3030, Irbid 22110, Jordan.
| | - Paula Morales
- Departamento de Química-Física Biológica, Instituto de Química Física Rocasolano (IQFR-CSIC), Serrano 119, 28006 Madrid, Spain.
| | - Patricia H Reggio
- Chemistry and Biochemistry Department, UNC Greensboro, Greensboro, NC 27412, USA.
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Arimont M, van der Woude M, Leurs R, Vischer HF, de Graaf C, Nijmeijer S. Identification of Key Structural Motifs Involved in 7 Transmembrane Signaling of Adhesion GPCRs. ACS Pharmacol Transl Sci 2019. [DOI: 10.1021/acsptsci.8b00051] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- Marta Arimont
- Division of Medicinal Chemistry, Faculty of Sciences, Amsterdam Institute of Molecules, Medicines and Systems (AIMMS), Vrije Universiteit Amsterdam, De Boelelaan 1108, 1081 HZ Amsterdam, The Netherlands
| | - Melanie van der Woude
- Division of Medicinal Chemistry, Faculty of Sciences, Amsterdam Institute of Molecules, Medicines and Systems (AIMMS), Vrije Universiteit Amsterdam, De Boelelaan 1108, 1081 HZ Amsterdam, The Netherlands
| | - Rob Leurs
- Division of Medicinal Chemistry, Faculty of Sciences, Amsterdam Institute of Molecules, Medicines and Systems (AIMMS), Vrije Universiteit Amsterdam, De Boelelaan 1108, 1081 HZ Amsterdam, The Netherlands
| | - Henry F. Vischer
- Division of Medicinal Chemistry, Faculty of Sciences, Amsterdam Institute of Molecules, Medicines and Systems (AIMMS), Vrije Universiteit Amsterdam, De Boelelaan 1108, 1081 HZ Amsterdam, The Netherlands
| | - Chris de Graaf
- Division of Medicinal Chemistry, Faculty of Sciences, Amsterdam Institute of Molecules, Medicines and Systems (AIMMS), Vrije Universiteit Amsterdam, De Boelelaan 1108, 1081 HZ Amsterdam, The Netherlands
| | - Saskia Nijmeijer
- Division of Medicinal Chemistry, Faculty of Sciences, Amsterdam Institute of Molecules, Medicines and Systems (AIMMS), Vrije Universiteit Amsterdam, De Boelelaan 1108, 1081 HZ Amsterdam, The Netherlands
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11
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Blaho VA, Chun J. 'Crystal' Clear? Lysophospholipid Receptor Structure Insights and Controversies. Trends Pharmacol Sci 2018; 39:953-966. [PMID: 30343728 PMCID: PMC6201317 DOI: 10.1016/j.tips.2018.08.006] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2018] [Revised: 08/11/2018] [Accepted: 08/27/2018] [Indexed: 12/29/2022]
Abstract
Lysophospholipids (LPLs), particularly sphingosine 1-phosphate (S1P) and lysophosphatidic acid (LPA), are bioactive lipid modulators of cellular homeostasis and pathology. The discovery and characterization of five S1P- and six LPA-specific G protein-coupled receptors (GPCRs), S1P1-5 and LPA1-6, have expanded their known involvement in all mammalian physiological systems. Resolution of the S1P1, LPA1, and LPA6 crystal structures has fueled the growing interest in these receptors and their ligands as targets for pharmacological manipulation. In this review, we have attempted to provide an integrated overview of the three crystallized LPL GPCRs with biochemical and physiological structure-function data. Finally, we provide a novel discussion of how chaperones for LPLs may be considered when extrapolating crystallographic and computational data toward understanding actual biological interactions and phenotypes.
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Affiliation(s)
- Victoria A Blaho
- Sanford Burnham Prebys Medical Discovery Institute, Degenerative Diseases Program, La Jolla, CA 92037, USA.
| | - Jerold Chun
- Sanford Burnham Prebys Medical Discovery Institute, Degenerative Diseases Program, La Jolla, CA 92037, USA.
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12
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Conserved salt-bridge competition triggered by phosphorylation regulates the protein interactome. Proc Natl Acad Sci U S A 2017; 114:13453-13458. [PMID: 29208709 DOI: 10.1073/pnas.1711543114] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Phosphorylation is a major regulator of protein interactions; however, the mechanisms by which regulation occurs are not well understood. Here we identify a salt-bridge competition or "theft" mechanism that enables a phospho-triggered swap of protein partners by Raf Kinase Inhibitory Protein (RKIP). RKIP transitions from inhibiting Raf-1 to inhibiting G-protein-coupled receptor kinase 2 upon phosphorylation, thereby bridging MAP kinase and G-Protein-Coupled Receptor signaling. NMR and crystallography indicate that a phosphoserine, but not a phosphomimetic, competes for a lysine from a preexisting salt bridge, initiating a partial unfolding event and promoting new protein interactions. Structural elements underlying the theft occurred early in evolution and are found in 10% of homo-oligomers and 30% of hetero-oligomers including Bax, Troponin C, and Early Endosome Antigen 1. In contrast to a direct recognition of phosphorylated residues by binding partners, the salt-bridge theft mechanism represents a facile strategy for promoting or disrupting protein interactions using solvent-accessible residues, and it can provide additional specificity at protein interfaces through local unfolding or conformational change.
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