1
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Zhang Z, Zhang Q, Dexheimer TS, Ren J, Neubig RR, Li W. Two highly related odorant receptors specifically detect α-bile acid pheromones in sea lamprey ( Petromyzon marinus). J Biol Chem 2020; 295:12153-12166. [PMID: 32636305 PMCID: PMC7443511 DOI: 10.1074/jbc.ra119.011532] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Revised: 07/01/2020] [Indexed: 10/23/2022] Open
Abstract
Pheromones play critical roles in habitat identification and reproductive behavior synchronization in the sea lamprey (Petromyzon marinus). The bile acid 3-keto petromyzonol sulfate (3kPZS) is a major component of the sex pheromone mixture from male sea lamprey that induces specific olfactory and behavioral responses in conspecific individuals. Olfactory receptors interact directly with pheromones, which is the first step in their detection, but identifying the cognate receptors of specific pheromones is often challenging. Here, we deorphanized two highly related odorant receptors (ORs), OR320a and OR320b, of P. marinus that respond to 3kPZS. In a heterologous expression system coupled to a cAMP-responsive CRE-luciferase, OR320a and OR320b specifically responded to C24 5α-bile acids, and both receptors were activated by the same set of 3kPZS analogs. OR320a displayed larger responses to all 3kPZS analogs than did OR320b. This difference appeared to be largely determined by a single amino acid residue, Cys-792.56, the C-terminal sixth residue relative to the most conserved residue in the second transmembrane domain (2.56) of OR320a. This region of TM2 residues 2.56-2.60 apparently is critical for the detection of steroid compounds by odorant receptors in lamprey, zebrafish, and humans. Finally, we identified OR320 orthologs in Japanese lamprey (Lethenteron camtschaticum), suggesting that the OR320 family may be widely present in lamprey species and that OR320 may be under purifying selection. Our results provide a system to examine the origin of olfactory steroid detection in vertebrates and to define a highly conserved molecular mechanism for steroid-ligand detection by G protein-coupled receptors.
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Affiliation(s)
- Zhe Zhang
- Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai, China; International Research Center for Marine Biosciences, Ministry of Science and Technology, Shanghai Ocean University, Shanghai, China; Shanghai Universities Key Laboratory of Marine Animal Taxonomy and Evolution, Shanghai Ocean University, Shanghai, China
| | - Qinghua Zhang
- Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai, China; International Research Center for Marine Biosciences, Ministry of Science and Technology, Shanghai Ocean University, Shanghai, China; Shanghai Universities Key Laboratory of Marine Animal Taxonomy and Evolution, Shanghai Ocean University, Shanghai, China
| | - Thomas S Dexheimer
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, Michigan, USA
| | - Jianfeng Ren
- Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai, China; International Research Center for Marine Biosciences, Ministry of Science and Technology, Shanghai Ocean University, Shanghai, China; Shanghai Universities Key Laboratory of Marine Animal Taxonomy and Evolution, Shanghai Ocean University, Shanghai, China
| | - Richard R Neubig
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, Michigan, USA.
| | - Weiming Li
- Department of Fisheries and Wildlife, Michigan State University, East Lansing, Michigan, USA.
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2
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Murillo-Rodríguez E, Arankowsky-Sandoval G, Pertwee RG, Parker L, Mechoulam R. Sleep and neurochemical modulation by cannabidiolic acid methyl ester in rats. Brain Res Bull 2020; 155:166-173. [DOI: 10.1016/j.brainresbull.2019.12.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Revised: 11/25/2019] [Accepted: 12/10/2019] [Indexed: 02/06/2023]
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3
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Structure-kinetic relationship studies of cannabinoid CB 2 receptor agonists reveal substituent-specific lipophilic effects on residence time. Biochem Pharmacol 2018; 152:129-142. [DOI: 10.1016/j.bcp.2018.03.018] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Accepted: 03/16/2018] [Indexed: 02/05/2023]
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4
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Ragusa G, Bencivenni S, Morales P, Callaway T, Hurst DP, Asproni B, Merighi S, Loriga G, Pinna GA, Reggio PH, Gessi S, Murineddu G. Synthesis, Pharmacological Evaluation, and Docking Studies of Novel Pyridazinone-Based Cannabinoid Receptor Type 2 Ligands. ChemMedChem 2018; 13:1102-1114. [PMID: 29575721 DOI: 10.1002/cmdc.201800152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Indexed: 11/12/2022]
Abstract
In recent years, cannabinoid type 2 receptors (CB2 R) have emerged as promising therapeutic targets in a wide variety of diseases. Selective ligands of CB2 R are devoid of the psychoactive effects typically observed for CB1 R ligands. Based on our recent studies on a class of pyridazinone 4-carboxamides, further structural modifications of the pyridazinone core were made to better investigate the structure-activity relationships for this promising scaffold with the aim to develop potent CB2 R ligands. In binding assays, two of the new synthesized compounds [6-(3,4-dichlorophenyl)-2-(4-fluorobenzyl)-cis-N-(4-methylcyclohexyl)-3-oxo-2,3-dihydropyridazine-4-carboxamide (2) and 6-(4-chloro-3-methylphenyl)-cis-N-(4-methylcyclohexyl)-3-oxo-2-pentyl-2,3-dihydropyridazine-4-carboxamide (22)] showed high CB2 R affinity, with Ki values of 2.1 and 1.6 nm, respectively. In addition, functional assays of these compounds and other new active related derivatives revealed their pharmacological profiles as CB2 R inverse agonists. Compound 22 displayed the highest CB2 R selectivity and potency, presenting a favorable in silico pharmacokinetic profile. Furthermore, a molecular modeling study revealed how 22 produces inverse agonism through blocking the movement of the toggle-switch residue, W6.48.
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Affiliation(s)
- Giulio Ragusa
- Department of Chemistry and Pharmacy, University of Sassari, via F. Muroni 23/A, 07100, Sassari, Italy
| | - Serena Bencivenni
- Dipartimento di Scienze Mediche, Sezione di Farmacologia, Università di Ferrara, Via Fossato di Mortara, 17-19, 44121, Ferrara, Italy
| | - Paula Morales
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, NC, 27402, USA
| | - Tyra Callaway
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, NC, 27402, USA
| | - Dow P Hurst
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, NC, 27402, USA
| | - Battistina Asproni
- Department of Chemistry and Pharmacy, University of Sassari, via F. Muroni 23/A, 07100, Sassari, Italy
| | - Stefania Merighi
- Dipartimento di Scienze Mediche, Sezione di Farmacologia, Università di Ferrara, Via Fossato di Mortara, 17-19, 44121, Ferrara, Italy
| | - Giovanni Loriga
- Institute of Translational Pharmacology, National Research Council, 09010 Pula, Cagliari, Italy
| | - Gerard A Pinna
- Department of Chemistry and Pharmacy, University of Sassari, via F. Muroni 23/A, 07100, Sassari, Italy
| | - Patricia H Reggio
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, NC, 27402, USA
| | - Stefania Gessi
- Dipartimento di Scienze Mediche, Sezione di Farmacologia, Università di Ferrara, Via Fossato di Mortara, 17-19, 44121, Ferrara, Italy
| | - Gabriele Murineddu
- Department of Chemistry and Pharmacy, University of Sassari, via F. Muroni 23/A, 07100, Sassari, Italy
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5
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Abstract
The Reggio group has constructed computer models of the inactive and G-protein-activated states of the cannabinoid CB1 and CB2 receptors, as well as, several orphan receptors that recognize a subset of cannabinoid compounds, including GPR55 and GPR18. These models have been used to design ligands, mutations, and covalent labeling studies. The resultant second-generation models have been used to design ligands with improved affinity, efficacy, and subtype selectivity. Herein, we provide a guide for the development of GPCR models using the most recent orphan receptor studied in our lab, GPR3. GPR3 is an orphan receptor that belongs to the Class A family of G-protein-coupled receptors. It shares high sequence similarity with GPR6, GPR12, the lysophospholipid receptors, and the cannabinoid receptors. GPR3 is predominantly expressed in mammalian brain and oocytes and it is known as a Gαs-coupled receptor activated constitutively in cells. GPR3 represents a possible target for the treatment of different pathological conditions such as Alzheimer's disease, oocyte maturation, or neuropathic pain. However, the lack of potent and selective GPR3 ligands is delaying the exploitation of this promising therapeutic target. In this context, we aim to develop a homology model that helps us to elucidate the structural determinants governing ligand-receptor interactions at GPR3. In this chapter, we detail the methods and rationale behind the construction of the GPR3 active-and inactive-state models. These homology models will enable the rational design of novel ligands, which may serve as research tools for further understanding of the biological role of GPR3.
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Affiliation(s)
- Paula Morales
- University of North Carolina at Greensboro, Greensboro, NC, United States.
| | - Dow P Hurst
- University of North Carolina at Greensboro, Greensboro, NC, United States
| | - Patricia H Reggio
- University of North Carolina at Greensboro, Greensboro, NC, United States
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6
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Zhou H, Peng Y, Halikhedkar A, Fan P, Janero DR, Thakur GA, Mercier RW, Sun X, Ma X, Makriyannis A. Human Cannabinoid Receptor 2 Ligand-Interaction Motif: Transmembrane Helix 2 Cysteine, C2.59(89), as Determinant of Classical Cannabinoid Agonist Activity and Binding Pose. ACS Chem Neurosci 2017; 8:1338-1347. [PMID: 28220706 DOI: 10.1021/acschemneuro.7b00003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Cannabinoid receptor 2 (CB2R)-dependent signaling is implicated in neuronal physiology and immune surveillance by brain microglia. Selective CB2R agonists hold therapeutic promise for inflammatory and other neurological disorders. Information on human CB2R (hCB2R) ligand-binding and functional domains is needed to inform the rational design and optimization of candidate druglike hCB2R agonists. Prior demonstration that hCB2R transmembrane helix 2 (TMH2) cysteine C2.59(89) reacts with small-molecule methanethiosulfonates showed that this cysteine residue is accessible to sulfhydryl derivatization reagents. We now report the design and application of two novel, pharmacologically active, high-affinity molecular probes, AM4073 and AM4099, as chemical reporters to interrogate directly the interaction of classical cannabinoid agonists with hCB2R cysteine residues. AM4073 has one electrophilic isothiocyanate (NCS) functionality at the C9 position of its cyclohexenyl C-ring, whereas AM4099 has NCS groups at that position and at the terminus of its aromatic A-ring C3 side chain. Pretreatment of wild-type hCB2R with either probe reduced subsequent [3H]CP55,940 specific binding by ∼60%. Conservative serine substitution of any hCB2R TMH cysteine residue except C2.59(89) did not affect the reduction of [3H]CP55,940 specific binding by either probe, suggesting that AM4073 and AM4099 interact irreversibly with this TMH2 cysteine. In contrast, AM841, an exceptionally potent hCB2R megagonist and direct AM4073/4099 congener bearing a single electrophilic NCS group at the terminus of its C3 side chain, had been demonstrated to bind covalently to TMH6 cysteine C6.47(257) and not C2.59(89). Molecular modeling indicates that the AM4073-hCB2R* interaction at C2.59(89) orients this classical cannabinoid away from TMH6 and toward the TMH2-TMH3 interface in the receptor's hydrophobic binding pocket, whereas the AM841-hCB2R* interaction at C6.47(257) favors agonist orientation toward TMH6/7. These data constitute initial evidence that TMH2 cysteine C2.59(89) is a component of the hCB2R binding pocket for classical cannabinoids. The results further demonstrate how interactions between classical cannabinoids and specific amino acids within the hCB2R* ligand-binding domain act as determinants of agonist pharmacological properties and the architecture of the agonist-hCB2R* conformational ensemble, allowing the receptor to adopt distinct activity states, such that interaction of classical cannabinoids with TMH6 cysteine C6.47(257) favors a binding pose more advantageous for agonist potency than does their interaction with TMH2 cysteine C2.59(89).
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Affiliation(s)
- Han Zhou
- Center for Drug Discovery and Departments of Chemistry and Chemical Biology, Pharmaceutical Sciences, and Bioengineering; College of Science, Bouvé College of Health Sciences, and College of Engineering, Northeastern University, Boston, Massachusetts 02115-5000, United States
| | - Yan Peng
- Center for Drug Discovery and Departments of Chemistry and Chemical Biology, Pharmaceutical Sciences, and Bioengineering; College of Science, Bouvé College of Health Sciences, and College of Engineering, Northeastern University, Boston, Massachusetts 02115-5000, United States
| | - Aneetha Halikhedkar
- Center for Drug Discovery and Departments of Chemistry and Chemical Biology, Pharmaceutical Sciences, and Bioengineering; College of Science, Bouvé College of Health Sciences, and College of Engineering, Northeastern University, Boston, Massachusetts 02115-5000, United States
| | - Pusheng Fan
- Center for Drug Discovery and Departments of Chemistry and Chemical Biology, Pharmaceutical Sciences, and Bioengineering; College of Science, Bouvé College of Health Sciences, and College of Engineering, Northeastern University, Boston, Massachusetts 02115-5000, United States
| | - David R. Janero
- Center for Drug Discovery and Departments of Chemistry and Chemical Biology, Pharmaceutical Sciences, and Bioengineering; College of Science, Bouvé College of Health Sciences, and College of Engineering, Northeastern University, Boston, Massachusetts 02115-5000, United States
| | - Ganesh A. Thakur
- Center for Drug Discovery and Departments of Chemistry and Chemical Biology, Pharmaceutical Sciences, and Bioengineering; College of Science, Bouvé College of Health Sciences, and College of Engineering, Northeastern University, Boston, Massachusetts 02115-5000, United States
| | - Richard W. Mercier
- Center for Drug Discovery and Departments of Chemistry and Chemical Biology, Pharmaceutical Sciences, and Bioengineering; College of Science, Bouvé College of Health Sciences, and College of Engineering, Northeastern University, Boston, Massachusetts 02115-5000, United States
| | - Xin Sun
- Center for Drug Discovery and Departments of Chemistry and Chemical Biology, Pharmaceutical Sciences, and Bioengineering; College of Science, Bouvé College of Health Sciences, and College of Engineering, Northeastern University, Boston, Massachusetts 02115-5000, United States
| | - Xiaoyu Ma
- Center for Drug Discovery and Departments of Chemistry and Chemical Biology, Pharmaceutical Sciences, and Bioengineering; College of Science, Bouvé College of Health Sciences, and College of Engineering, Northeastern University, Boston, Massachusetts 02115-5000, United States
| | - Alexandros Makriyannis
- Center for Drug Discovery and Departments of Chemistry and Chemical Biology, Pharmaceutical Sciences, and Bioengineering; College of Science, Bouvé College of Health Sciences, and College of Engineering, Northeastern University, Boston, Massachusetts 02115-5000, United States
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7
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Morales P, Gómez-Cañas M, Navarro G, Hurst DP, Carrillo-Salinas FJ, Lagartera L, Pazos R, Goya P, Reggio PH, Guaza C, Franco R, Fernández-Ruiz J, Jagerovic N. Chromenopyrazole, a Versatile Cannabinoid Scaffold with in Vivo Activity in a Model of Multiple Sclerosis. J Med Chem 2016; 59:6753-6771. [PMID: 27309150 DOI: 10.1021/acs.jmedchem.6b00397] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
A combination of molecular modeling and structure-activity relationship studies has been used to fine-tune CB2 selectivity in the chromenopyrazole ring, a versatile CB1/CB2 cannabinoid scaffold. Thus, a series of 36 new derivatives covering a wide range of structural diversity has been synthesized, and docking studies have been performed for some of them. Biological evaluation of the new compounds includes, among others, cannabinoid binding assays, functional studies, and surface plasmon resonance measurements. The most promising compound [43 (PM226)], a selective and potent CB2 agonist isoxazole derivative, was tested in the acute phase of Theiler's murine encephalomyelitis virus-induced demyelinating disease (TMEV-IDD), a well-established animal model of primary progressive multiple sclerosis. Compound 43 dampened neuroinflammation by reducing microglial activation in the TMEV.
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Affiliation(s)
- Paula Morales
- Instituto de Química Médica, Consejo Superior de Investigaciones Científicas, Calle Juan de la Cierva, 3, E-28006 Madrid, Spain
| | - María Gómez-Cañas
- Instituto Universitario de Investigación en Neuroquímica, Departamento de Bioquímica y Biología Molecular, Facultad de Medicina, Universidad Complutense de Madrid, E-28040 Madrid, Spain.,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), and Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), E-28040 Madrid, Spain
| | - Gemma Navarro
- Departamento de Bioquímica y Biología Molecular, Facultad de Biología, Universidad de Barcelona, E-08028 Barcelona, Spain
| | - Dow P Hurst
- Department of Chemistry and Biochemistry, University of North Carolina Greensboro, Greensboro, North Carolina 27402, United States
| | - Francisco J Carrillo-Salinas
- Grupo de Neuroinmunología Neurobiología Funcional y de Sistemas, Instituto Cajal, Consejo Superior de Investigaciones Científicas, E-28002 Madrid, Spain
| | - Laura Lagartera
- Instituto de Química Médica, Consejo Superior de Investigaciones Científicas, Calle Juan de la Cierva, 3, E-28006 Madrid, Spain
| | - Ruth Pazos
- Instituto Universitario de Investigación en Neuroquímica, Departamento de Bioquímica y Biología Molecular, Facultad de Medicina, Universidad Complutense de Madrid, E-28040 Madrid, Spain.,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), and Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), E-28040 Madrid, Spain
| | - Pilar Goya
- Instituto de Química Médica, Consejo Superior de Investigaciones Científicas, Calle Juan de la Cierva, 3, E-28006 Madrid, Spain
| | - Patricia H Reggio
- Department of Chemistry and Biochemistry, University of North Carolina Greensboro, Greensboro, North Carolina 27402, United States
| | - Carmen Guaza
- Grupo de Neuroinmunología Neurobiología Funcional y de Sistemas, Instituto Cajal, Consejo Superior de Investigaciones Científicas, E-28002 Madrid, Spain
| | - Rafael Franco
- Departamento de Bioquímica y Biología Molecular, Facultad de Biología, Universidad de Barcelona, E-08028 Barcelona, Spain
| | - Javier Fernández-Ruiz
- Instituto Universitario de Investigación en Neuroquímica, Departamento de Bioquímica y Biología Molecular, Facultad de Medicina, Universidad Complutense de Madrid, E-28040 Madrid, Spain.,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), and Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), E-28040 Madrid, Spain
| | - Nadine Jagerovic
- Instituto de Química Médica, Consejo Superior de Investigaciones Científicas, Calle Juan de la Cierva, 3, E-28006 Madrid, Spain
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8
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Lucchesi V, Hurst DP, Shore DM, Bertini S, Ehrmann BM, Allarà M, Lawrence L, Ligresti A, Minutolo F, Saccomanni G, Sharir H, Macchia M, Di Marzo V, Abood ME, Reggio PH, Manera C. CB2-selective cannabinoid receptor ligands: synthesis, pharmacological evaluation, and molecular modeling investigation of 1,8-Naphthyridin-2(1H)-one-3-carboxamides. J Med Chem 2014; 57:8777-91. [PMID: 25272206 PMCID: PMC4234427 DOI: 10.1021/jm500807e] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
![]()
We
have recently identified 1,8-naphthyridin-2(1H)-one-3-carboxamide
as a new scaffold very suitable for the development
of new CB2 receptor potent and selective ligands. In this paper we
describe a number of additional derivatives in which the same central
scaffold has been variously functionalized in position 1 or 6. All
new compounds showed high selectivity and affinity in the nanomolar
range for the CB2 receptor. Furthermore, we found that their functional
activity is controlled by the presence of the substituents at position
C-6 of the naphthyridine scaffold. In fact, the introduction of substituents
in this position determined a functionality switch from agonist to
antagonists/inverse agonists. Finally, docking studies showed that
the difference between the pharmacology of these ligands may be in
the ability/inability to block the Toggle Switch W6.48(258) (χ1 g+ → trans) transition.
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Affiliation(s)
- Valentina Lucchesi
- Dipartimento di Farmacia, Università di Pisa , Via Bonanno 6, 56126 Pisa, Italy
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9
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Zhao P, Lane TR, Gao HGL, Hurst DP, Kotsikorou E, Le L, Brailoiu E, Reggio PH, Abood ME. Crucial positively charged residues for ligand activation of the GPR35 receptor. J Biol Chem 2013; 289:3625-38. [PMID: 24347166 DOI: 10.1074/jbc.m113.508382] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
GPR35 is a G protein-coupled receptor expressed in the immune, gastrointestinal, and nervous systems in gastric carcinomas and is implicated in heart failure and pain perception. We investigated residues in GPR35 responsible for ligand activation and the receptor structure in the active state. GPR35 contains numerous positively charged amino acids that face into the binding pocket that cluster in two distinct receptor regions, TMH3-4-5-6 and TMH1-2-7. Computer modeling implicated TMH3-4-5-6 for activation by the GPR35 agonists zaprinast and pamoic acid. Mutation results for the TMH1-2-7 region of GPR35 showed no change in ligand efficacies at the K1.32A, R2.65A, R7.33A, and K7.40A mutants. However, mutation of arginine residues in the TMH3-4-5-6 region (R4.60, R6.58, R3.36, R(164), and R(167) in the EC2 loop) had effects on signaling for one or both agonists tested. R4.60A resulted in a total ablation of agonist-induced activation in both the β-arrestin trafficking and ERK1/2 activation assays. R6.58A increased the potency of zaprinast 30-fold in the pERK assay. The R(167)A mutant decreased the potency of pamoic acid in the β-arrestin trafficking assay. The R(164)A and R(164)L mutants decreased potencies of both agonists. Similar trends for R6.58A and R(167)A were observed in calcium responses. Computer modeling showed that the R6.58A mutant has additional interactions with zaprinast. R3.36A did not express on the cell surface but was trapped in the cytoplasm. The lack of surface expression of R3.36A was rescued by a GPR35 antagonist, CID2745687. These results clearly show that R4.60, R(164), R(167), and R6.58 play crucial roles in the agonist initiated activation of GPR35.
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10
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Kimura T, Vukoti K, Lynch DL, Hurst DP, Grossfield A, Pitman MC, Reggio PH, Yeliseev AA, Gawrisch K. Global fold of human cannabinoid type 2 receptor probed by solid-state 13C-, 15N-MAS NMR and molecular dynamics simulations. Proteins 2013; 82:452-65. [PMID: 23999926 DOI: 10.1002/prot.24411] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2013] [Revised: 08/12/2013] [Accepted: 08/21/2013] [Indexed: 12/12/2022]
Abstract
The global fold of human cannabinoid type 2 (CB2 ) receptor in the agonist-bound active state in lipid bilayers was investigated by solid-state (13)C- and (15)N magic-angle spinning (MAS) NMR, in combination with chemical-shift prediction from a structural model of the receptor obtained by microsecond-long molecular dynamics (MD) simulations. Uniformly (13)C- and (15)N-labeled CB2 receptor was expressed in milligram quantities by bacterial fermentation, purified, and functionally reconstituted into liposomes. (13)C MAS NMR spectra were recorded without sensitivity enhancement for direct comparison of Cα, Cβ, and C=O bands of superimposed resonances with predictions from protein structures generated by MD. The experimental NMR spectra matched the calculated spectra reasonably well indicating agreement of the global fold of the protein between experiment and simulations. In particular, the (13) C chemical shift distribution of Cα resonances was shown to be very sensitive to both the primary amino acid sequence and the secondary structure of CB2. Thus the shape of the Cα band can be used as an indicator of CB2 global fold. The prediction from MD simulations indicated that upon receptor activation a rather limited number of amino acid residues, mainly located in the extracellular Loop 2 and the second half of intracellular Loop 3, change their chemical shifts significantly (≥ 1.5 ppm for carbons and ≥ 5.0 ppm for nitrogens). Simulated two-dimensional (13) Cα(i)-(13)C=O(i) and (13)C=O(i)-(15)NH(i + 1) dipolar-interaction correlation spectra provide guidance for selective amino acid labeling and signal assignment schemes to study the molecular mechanism of activation of CB2 by solid-state MAS NMR.
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Affiliation(s)
- Tomohiro Kimura
- Laboratory of Membrane Biochemistry and Biophysics, NIAAA, NIH, Bethesda, Maryland, 20892
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11
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Kotsikorou E, Navas F, Roche MJ, Gilliam AF, Thomas B, Seltzman HH, Kumar P, Song ZH, Hurst DP, Lynch DL, Reggio PH. The importance of hydrogen bonding and aromatic stacking to the affinity and efficacy of cannabinoid receptor CB2 antagonist, 5-(4-chloro-3-methylphenyl)-1-[(4-methylphenyl)methyl]-N-[(1S,2S,4R)-1,3,3-trimethylbicyclo[2.2.1]hept-2-yl]-1H-pyrazole-3-carboxamide (SR144528). J Med Chem 2013; 56:6593-612. [PMID: 23855811 PMCID: PMC3804063 DOI: 10.1021/jm400070u] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Despite the therapeutic promise of the subnanomolar affinity cannabinoid CB2 antagonist, 5-(4-chloro-3-methylphenyl)-1-[(4-methylphenyl)methyl]-N-[(1S,2S,4R)-1,3,3-trimethylbicyclo[2.2.1]hept-2-yl]-1H-pyrazole-3-carboxamide (SR144528, 1), little is known about its binding site interactions and no primary interaction site for 1 at CB2 has been identified. We report here the results of Glide docking studies in our cannabinoid CB2 inactive state model that were then tested via compound synthesis, binding, and functional assays. Our results show that the amide functional group of 1 is critical to its CB2 affinity and efficacy and that aromatic stacking interactions in the TMH5/6 aromatic cluster of CB2 are also important. Molecular modifications that increased the positive electrostatic potential in the region between the fenchyl and aromatic rings led to more efficacious compounds. This result is consistent with the EC-3 loop negatively charged amino acid, D275 (identified via Glide docking studies) acting as the primary interaction site for 1 and its analogues.
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Affiliation(s)
| | - Frank Navas
- Research Triangle Institute, Research Triangle Park, NC 27609
| | | | - Anne F. Gilliam
- Research Triangle Institute, Research Triangle Park, NC 27609
| | - Brian Thomas
- Research Triangle Institute, Research Triangle Park, NC 27609
| | | | - Pritesh Kumar
- Department of Pharmacology and Toxicology, University of Louisville, University of Louisville School of Medicine, Louisville, KY 40292
| | - Zhao-Hui Song
- Department of Pharmacology and Toxicology, University of Louisville, University of Louisville School of Medicine, Louisville, KY 40292
| | - Dow P. Hurst
- Center for Drug Discovery, Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, NC 27402
| | - Diane L. Lynch
- Center for Drug Discovery, Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, NC 27402
| | - Patricia H. Reggio
- Center for Drug Discovery, Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, NC 27402
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12
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Hurst DP, Schmeisser M, Reggio PH. Endogenous lipid activated G protein-coupled receptors: emerging structural features from crystallography and molecular dynamics simulations. Chem Phys Lipids 2013; 169:46-56. [PMID: 23485612 DOI: 10.1016/j.chemphyslip.2013.01.009] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2012] [Revised: 01/20/2013] [Accepted: 01/22/2013] [Indexed: 01/01/2023]
Abstract
Class A G-protein coupled receptors (GPCRs) are thought to have a common topology that includes seven transmembrane alpha helices (TMHs) that are arranged to form a closed bundle. This bundle forms the ligand binding pocket into which ligands are commonly thought to enter via the extracellular milieu. This ligand approach direction makes sense for GPCRs that have small positively charged ligands, such as the beta-2-adrenergic or the dopamine D2 receptor. However, there is a growing sub-group of Class A GPCRs that bind lipid-derived endogenous ligands, such as the cannabinoid CB1 and CB2 receptors (with endogenous ligands, N-arachidonoylethanolamine (anandamide) and sn-2-arachidonylglycerol (2-AG)) and the S1P1-5 receptors (with endogenous ligand, sphingosine-1-phosphate). Even the widely studied Class A GPCR, rhodopsin, binds a highly lipophillic chromophore (11-cis-retinal). For these receptors, ligand approach from the extracellular milieu has seemed unlikely given that the ligands of these receptors readily partition into lipid or are actually synthesized in the lipid bilayer. The recent X-ray-crystal structure of the sub-type 1 sphingosine-1-phosphate receptor (S1P1) provides important information on the key structural variations that may be the hallmarks for a Class A GPCR that binds lipid-derived ligands. These include an extracellular domain that is closed off to the extracellular milieu and the existence of an opening between transmembrane helices that may serve as a portal for ligand entry via the lipid bilayer. This review examines structural aspects that the cannabinoid receptors may share with the S1P1 receptor based upon sequence homology. This review also examines experimental and simulation results that suggest ligand entry via a lipid portal is quite likely for this emerging sub-group.
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Affiliation(s)
- Dow P Hurst
- Department of Chemistry and Biochemistry, University of North Carolina Greensboro, Greensboro, NC 27402, USA
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13
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Ahn KH, Mahmoud MM, Kendall DA. Allosteric modulator ORG27569 induces CB1 cannabinoid receptor high affinity agonist binding state, receptor internalization, and Gi protein-independent ERK1/2 kinase activation. J Biol Chem 2012; 287:12070-82. [PMID: 22343625 DOI: 10.1074/jbc.m111.316463] [Citation(s) in RCA: 112] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
The cannabinoid receptor 1 (CB1), a member of the class A G protein-coupled receptor family, is expressed in brain tissue where agonist stimulation primarily activates the pertussis toxin-sensitive inhibitory G protein (G(i)). Ligands such as CP55940 ((1R,3R,4R)-3-[2-hydroxy-4-(1,1-dimethylheptyl)phenyl]-4-(3- hydroxypropyl)cyclohexan-1-ol) and Δ(9)-tetrahydrocannabinol are orthosteric agonists for the receptor, bind the conventional binding pocket, and trigger G(i)-mediated effects including inhibition of adenylate cyclase. ORG27569 (5-chloro-3-ethyl-1H-indole-2-carboxylic acid [2-(4-piperidin-1-yl-phenyl)ethyl]amide) has been identified as an allosteric modulator that displays positive cooperativity for CP55940 binding to CB1 yet acts as an antagonist of G protein coupling. To examine this apparent conundrum, we used the wild-type CB1 and two mutants, T210A and T210I (D'Antona, A. M., Ahn, K. H., and Kendall, D. A. (2006) Biochemistry 45, 5606-5617), which collectively cover a spectrum of receptor states from inactive to partially active to more fully constitutively active. Using these receptors, we demonstrated that ORG27569 induces a CB1 receptor state that is characterized by enhanced agonist affinity and decreased inverse agonist affinity consistent with an active conformation. Also consistent with this conformation, the impact of ORG27569 binding was most dramatic on the inactive T210A receptor and less pronounced on the already active T210I receptor. Although ORG27569 antagonized CP55940-induced guanosine 5'-3-O-(thio)triphosphate binding, which is indicative of G protein coupling inhibition in a concentration-dependent manner, the ORG27569-induced conformational change of the CB1 receptor led to cellular internalization and downstream activation of ERK signaling, providing the first case of allosteric ligand-biased signaling via CB1. ORG27569-induced ERK phosphorylation persisted even after pertussis toxin treatment to abrogate G(i) and occurs in HEK293 and neuronal cells.
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Affiliation(s)
- Kwang H Ahn
- Department of Pharmaceutical Sciences, University of Connecticut, Storrs, Connecticut 06269, USA
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14
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Cumella J, Hernández-Folgado L, Girón R, Sánchez E, Morales P, Hurst DP, Gómez-Cañas M, Gómez-Ruiz M, Pinto DCGA, Goya P, Reggio PH, Martin MI, Fernández-Ruiz J, Silva AMS, Jagerovic N. Chromenopyrazoles: non-psychoactive and selective CB₁ cannabinoid agonists with peripheral antinociceptive properties. ChemMedChem 2012; 7:452-63. [PMID: 22302767 DOI: 10.1002/cmdc.201100568] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2011] [Revised: 01/18/2012] [Indexed: 01/01/2023]
Abstract
The unwanted psychoactive effects of cannabinoid receptor agonists have limited their development as medicines. These CB₁-mediated side effects are due to the fact that CB₁ receptors are largely expressed in the central nervous system (CNS). As it is known that CB₁ receptors are also located peripherally, there is growing interest in targeting cannabinoid receptors located outside the brain. A library of chromenopyrazoles designed analogously to the classical cannabinoid cannabinol were synthesized, characterized, and tested for cannabinoid activity. Radioligand binding assays were used to determine their affinities at CB₁ and CB₂ receptors. Structural features required for CB₁/CB₂ affinity and selectivity were explored by molecular modeling. Some compounds in the chromenopyrazole series were observed to be selective CB₁ ligands. These modeling studies suggest that full CB₁ selectivity over CB₂ can be explained by the presence of a pyrazole ring in the structure. The functional activities of selected chromenopyrazoles were evaluated in isolated tissues. In vivo behavioral tests were then carried out on the most effective CB₁ cannabinoid agonist, 13 a. Chromenopyrazole 13 a did not induce modifications in any of the tested parameters on the mouse cannabinoid tetrad, thus discounting CNS-mediated effects. This lack of agonistic activity in the CNS suggests that this compound does not readily cross the blood-brain barrier. Moreover, 13 a can induce antinociception in a rat peripheral model of orofacial pain. Taking into account the negative results obtained with the hot-plate test, the antinociception induced by 13 a in the orofacial test could be mediated through peripheral mechanisms.
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Affiliation(s)
- Jose Cumella
- Instituto de Química Médica, CSIC, Juan de la Cierva 3, 28006 Madrid, Spain
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15
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Howlett AC, Reggio PH, Childers SR, Hampson RE, Ulloa NM, Deutsch DG. Endocannabinoid tone versus constitutive activity of cannabinoid receptors. Br J Pharmacol 2012; 163:1329-43. [PMID: 21545414 DOI: 10.1111/j.1476-5381.2011.01364.x] [Citation(s) in RCA: 94] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
This review evaluates the cellular mechanisms of constitutive activity of the cannabinoid (CB) receptors, its reversal by inverse agonists, and discusses the pitfalls and problems in the interpretation of the research data. The notion is presented that endogenously produced anandamide (AEA) and 2-arachidonoylglycerol (2-AG) serve as autocrine or paracrine stimulators of the CB receptors, giving the appearance of constitutive activity. It is proposed that one cannot interpret inverse agonist studies without inference to the receptors' environment vis-à-vis the endocannabinoid agonists which themselves are highly lipophilic compounds with a preference for membranes. The endocannabinoid tone is governed by a combination of synthetic pathways and inactivation involving transport and degradation. The synthesis and degradation of 2-AG is well characterized, and 2-AG has been strongly implicated in retrograde signalling in neurons. Data implicating endocannabinoids in paracrine regulation have been described. Endocannabinoid ligands can traverse the cell's interior and potentially be stored on fatty acid-binding proteins (FABPs). Molecular modelling predicts that the endocannabinoids derived from membrane phospholipids can laterally diffuse to enter the CB receptor from the lipid bilayer. Considering that endocannabinoid signalling to CB receptors is a much more likely scenario than is receptor activation in the absence of agonist ligands, researchers are advised to refrain from assuming constitutive activity except for experimental models known to be devoid of endocannabinoid ligands.
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Affiliation(s)
- Allyn C Howlett
- Department of Physiology and Pharmacology, Wake Forest University Health Sciences, Winston-Salem, NC 27157, USA.
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16
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Fanelli F, De Benedetti PG. Update 1 of: computational modeling approaches to structure-function analysis of G protein-coupled receptors. Chem Rev 2011; 111:PR438-535. [PMID: 22165845 DOI: 10.1021/cr100437t] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Francesca Fanelli
- Dulbecco Telethon Institute, University of Modena and Reggio Emilia, via Campi 183, 41125 Modena, Italy.
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17
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Kotsikorou E, Madrigal KE, Hurst DP, Sharir H, Lynch DL, Heynen-Genel S, Milan LB, Chung TD, Seltzman HH, Bai Y, Caron MG, Barak L, Abood ME, Reggio PH. Identification of the GPR55 agonist binding site using a novel set of high-potency GPR55 selective ligands. Biochemistry 2011; 50:5633-47. [PMID: 21534610 PMCID: PMC3723401 DOI: 10.1021/bi200010k] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Marijuana is the most widely abused illegal drug, and its spectrum of effects suggests that several receptors are responsible for the activity. Two cannabinoid receptor subtypes, CB1 and CB2, have been identified, but the complex pharmacological properties of exogenous cannabinoids and endocannabinoids are not fully explained by their signaling. The orphan receptor GPR55 binds a subset of CB1 and CB2 ligands and has been proposed as a cannabinoid receptor. This designation, however, is controversial as a result of recent studies in which lysophosphatidylinositol (LPI) was identified as a GPR55 agonist. Defining a biological role for GPR55 requires GPR55 selective ligands that have been unavailable. From a β-arrestin, high-throughput, high-content screen of 300000 compounds run in collaboration with the Molecular Libraries Probe Production Centers Network initiative (PubChem AID1965), we identified potent GPR55 selective agonists. By modeling of the GPR55 activated state, we compared the GPR55 binding conformations of three of the novel agonists obtained from the screen, CID1792197, CID1172084, and CID2440433 (PubChem Compound IDs), with that of LPI. Our modeling indicates the molecular shapes and electrostatic potential distributions of these agonists mimic those of LPI; the GPR55 binding site accommodates ligands that have inverted-L or T shapes with long, thin profiles that can fit vertically deep in the receptor binding pocket while their broad head regions occupy a horizontal binding pocket near the GPR55 extracellular loops. Our results will allow the optimization and design of second-generation GPR55 ligands and provide a means for distinguishing GPR55 selective ligands from those interacting with cannabinoid receptors.
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Affiliation(s)
| | - Karla E. Madrigal
- Center for Drug Discovery, UNCG Greensboro, Greensboro, NC 27402 USA
| | - Dow P. Hurst
- Center for Drug Discovery, UNCG Greensboro, Greensboro, NC 27402 USA
| | - Haleli Sharir
- Department of Anatomy and Cell Biology and Center for Substance Abuse Research, Temple University, Philadelphia, PA 19140 USA
| | - Diane L. Lynch
- Center for Drug Discovery, UNCG Greensboro, Greensboro, NC 27402 USA
| | - Susanne Heynen-Genel
- Conrad Prebys Center for Chemical Genomics at Sanford-Burnham Medical Research Institute, La Jolla, CA 92037 USA
| | - Loribelle B. Milan
- Conrad Prebys Center for Chemical Genomics at Sanford-Burnham Medical Research Institute, La Jolla, CA 92037 USA
| | - Thomas D.Y. Chung
- Conrad Prebys Center for Chemical Genomics at Sanford-Burnham Medical Research Institute, La Jolla, CA 92037 USA
| | - Herbert H. Seltzman
- Center for Organic and Medicinal Chemistry, Research Triangle Institute, Research Triangle Park, NC 27709 USA
| | - Yushi Bai
- Department of Cell Biology, Duke University, Durham, NC 27708 USA
| | - Marc G. Caron
- Department of Cell Biology, Duke University, Durham, NC 27708 USA
| | - Larry Barak
- Department of Cell Biology, Duke University, Durham, NC 27708 USA
| | - Mary E. Abood
- Department of Anatomy and Cell Biology and Center for Substance Abuse Research, Temple University, Philadelphia, PA 19140 USA
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18
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Zhang Y, Xie Z, Wang L, Schreiter B, Lazo JS, Gertsch J, Xie XQ. Mutagenesis and computer modeling studies of a GPCR conserved residue W5.43(194) in ligand recognition and signal transduction for CB2 receptor. Int Immunopharmacol 2011; 11:1303-10. [PMID: 21539938 DOI: 10.1016/j.intimp.2011.04.013] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2010] [Revised: 04/15/2011] [Accepted: 04/18/2011] [Indexed: 10/18/2022]
Abstract
W5.43(194), a conserved tryptophan residue among G-protein coupled receptors (GPCRs) and cannabinoid receptors (CB), was examined in the present report for its significance in CB2 receptor ligand binding and adenylyl cyclase (AC) activity. Computer modeling postulates that this site in CB2 may be involved in the affinity of WIN55212-2 and SR144528 through aromatic contacts. In the present study, we reported that a CB2 receptor mutant, W5.43(194)Y, which had a tyrosine (Y) substitution for tryptophan (W), retained the binding affinity for CB agonist CP55940, but reduced binding affinity for CB2 agonist WIN55212-2 and inverse agonist SR144528 by 8-fold and 5-fold, respectively; the CB2 W5.43(194)F and W5.43(194)A mutations significantly affect the binding activities of CP55940, WIN55212-2 and SR144528. Furthermore, we found that agonist-mediated inhibition of the forskolin-induced cAMP production was dramatically diminished in the CB2 mutant W5.43(194)Y, whereas W5.43(194)F and W5.43(194)A mutants resulted in complete elimination of downstream signaling, suggesting that W5.43(194) was essential for the full activation of CB2. These results indicate that both aromatic interaction and hydrogen bonding are involved in ligand binding for the residue W5.43(194), and the mutations of this tryptophan site may affect the conformation of the ligand binding pocket and therefore control the active conformation of the wild type CB2 receptor. W5.43(194)Y/F/A mutations also displayed noticeable enhancement of the constitutive activation probably attributed to the receptor conformational changes resulted from the mutations.
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Affiliation(s)
- Yuxun Zhang
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Pittsburgh, Pittsburgh, PA 15261, USA
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19
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Deflorian F, Jacobson KA. Comparison of three GPCR structural templates for modeling of the P2Y12 nucleotide receptor. J Comput Aided Mol Des 2011; 25:329-38. [PMID: 21461952 DOI: 10.1007/s10822-011-9423-3] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2011] [Accepted: 03/20/2011] [Indexed: 11/26/2022]
Abstract
The P2Y(12) receptor (P2Y(12)R) is an ADP-activated G protein-coupled receptor (GPCR) that is an important target for antithrombotic drugs. Three homology models of P2Y(12)R were compared, based on different GPCR structural templates: bovine rhodopsin (bRHO), human A(2A) adenosine receptor (A(2A)AR), and human C-X-C chemokine receptor type 4 (CXCR4). By criteria of sequence analysis (25.6% identity in transmembrane region), deviation from helicity in the second transmembrane helix (TM2), docked poses of ligands highlighting the role of key residues, accessibility of a conserved disulfide bridge that is reactive toward irreversibly-binding antagonists, and the presence of a shared disulfide bridge between the third extracellular loop (EL3) and the N-terminus, the CXCR4-based model appeared to be the most consistent with known characteristics of P2Y(12)R. The docked poses of agonist 2MeSADP and charged anthraquinone antagonist PSB-0739 in the binding pocket of P2Y(12)R-CXC agree with previously published site-directed mutagenesis studies of Arg256 and Lys280. A sulfonate at position 2 of the anthraquinone core created a strong interaction with the Lys174(EL2) side chain. The docking poses of the irreversibly-binding, active metabolite (existing as two diastereoisomers in vivo) of the clinically utilized antagonist Clopidogrel were compared. The free thiol group of the 4S diastereoisomer, but not the 4R isomer, was found in close proximity (~4.7 Å) to the sulfur atom of a disulfide bridge involving Cys175, suggesting greater activity in covalent binding. Therefore, ligand docking to the CXCR4-based model of the P2Y(12)R predicted poses of both reversibly and irreversibly-binding small molecules, consistent with observed pharmacology and mutagenesis studies.
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MESH Headings
- Amino Acid Sequence
- Animals
- Binding Sites
- Cattle
- Humans
- Ligands
- Models, Molecular
- Molecular Sequence Data
- Mutagenesis, Site-Directed
- Nucleotides/chemistry
- Protein Structure, Secondary
- Receptor, Adenosine A2A/chemistry
- Receptors, CXCR4/chemistry
- Receptors, Purinergic P2Y12/chemistry
- Receptors, Purinergic P2Y12/genetics
- Receptors, Purinergic P2Y12/metabolism
- Rhodopsin/chemistry
- Sequence Homology, Nucleic Acid
- Structural Homology, Protein
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Affiliation(s)
- Francesca Deflorian
- 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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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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Hurst DP, Grossfield A, Lynch DL, Feller S, Romo TD, Gawrisch K, Pitman MC, Reggio PH. A lipid pathway for ligand binding is necessary for a cannabinoid G protein-coupled receptor. J Biol Chem 2010; 285:17954-64. [PMID: 20220143 PMCID: PMC2878557 DOI: 10.1074/jbc.m109.041590] [Citation(s) in RCA: 176] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2009] [Revised: 02/13/2010] [Indexed: 11/06/2022] Open
Abstract
Recent isothiocyanate covalent labeling studies have suggested that a classical cannabinoid, (-)-7'-isothiocyanato-11-hydroxy-1',1'dimethylheptyl-hexahydrocannabinol (AM841), enters the cannabinoid CB2 receptor via the lipid bilayer (Pei, Y., Mercier, R. W., Anday, J. K., Thakur, G. A., Zvonok, A. M., Hurst, D., Reggio, P. H., Janero, D. R., and Makriyannis, A. (2008) Chem. Biol. 15, 1207-1219). However, the sequence of steps involved in such a lipid pathway entry has not yet been elucidated. Here, we test the hypothesis that the endogenous cannabinoid sn-2-arachidonoylglycerol (2-AG) attains access to the CB2 receptor via the lipid bilayer. To this end, we have employed microsecond time scale all-atom molecular dynamics (MD) simulations of the interaction of 2-AG with CB2 via a palmitoyl-oleoyl-phosphatidylcholine lipid bilayer. Results suggest the following: 1) 2-AG first partitions out of bulk lipid at the transmembrane alpha-helix (TMH) 6/7 interface; 2) 2-AG then enters the CB2 receptor binding pocket by passing between TMH6 and TMH7; 3) the entrance of the 2-AG headgroup into the CB2 binding pocket is sufficient to trigger breaking of the intracellular TMH3/6 ionic lock and the movement of the TMH6 intracellular end away from TMH3; and 4) subsequent to protonation at D3.49/D6.30, further 2-AG entry into the ligand binding pocket results in both a W6.48 toggle switch change and a large influx of water. To our knowledge, this is the first demonstration via unbiased molecular dynamics that a ligand can access the binding pocket of a class A G protein-coupled receptor via the lipid bilayer and the first demonstration via molecular dynamics of G protein-coupled receptor activation triggered by a ligand binding event.
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Affiliation(s)
- Dow P. Hurst
- From the Department of Chemistry and Biochemistry, Center for Drug Discovery, University of North Carolina, Greensboro, North Carolina 27402
| | - Alan Grossfield
- the Department of Biochemistry and Biophysics, University of Rochester Medical Center, Rochester, New York 14642
| | - Diane L. Lynch
- From the Department of Chemistry and Biochemistry, Center for Drug Discovery, University of North Carolina, Greensboro, North Carolina 27402
| | - Scott Feller
- the Department of Chemistry, Wabash College, Crawfordsville, Indiana 47933
| | - Tod D. Romo
- the Department of Biochemistry and Biophysics, University of Rochester Medical Center, Rochester, New York 14642
| | - Klaus Gawrisch
- Membrane Biochemistry/Biophysics, NIAAA, National Institutes of Health, Bethesda, Maryland 20892, and
| | - Michael C. Pitman
- the Computational Biology Center, IBM Thomas J. Watson Research Center, Yorktown Heights, New York 10598
| | - Patricia H. Reggio
- From the Department of Chemistry and Biochemistry, Center for Drug Discovery, University of North Carolina, Greensboro, North Carolina 27402
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22
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Pei Y, Mercier RW, Anday JK, Thakur GA, Zvonok AM, Hurst D, Reggio PH, Janero DR, Makriyannis A. Ligand-binding architecture of human CB2 cannabinoid receptor: evidence for receptor subtype-specific binding motif and modeling GPCR activation. ACTA ACUST UNITED AC 2009; 15:1207-19. [PMID: 19022181 DOI: 10.1016/j.chembiol.2008.10.011] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2008] [Revised: 09/17/2008] [Accepted: 10/02/2008] [Indexed: 11/26/2022]
Abstract
The extensive physiological influence of transmission through the CB2 cannabinoid receptor makes this G protein-coupled receptor (GPCR) a promising therapeutic target for treating neuropathic pain, inflammation, and immune disorders. However, there is little direct structural information pertaining to either GPCR or CB2-receptor ligand recognition and activation. The present work helps characterize experimentally the ligand-binding interactions of the human CB2 (hCB2) receptor. This study illustrates how our overall experimental approach, "ligand-assisted protein structure" (LAPS), affords direct determination of the requirements for ligand binding to the hCB2 receptor and discrimination among the binding motifs for ligands that activate therapeutically relevant GPCRs.
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Affiliation(s)
- Ying Pei
- School of Pharmacy, University of Connecticut, Storrs, CT 06269, USA
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23
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Nebane NM, Hurst DP, Carrasquer CA, Qiao Z, Reggio PH, Song ZH. Residues accessible in the binding-site crevice of transmembrane helix 6 of the CB2 cannabinoid receptor. Biochemistry 2009; 47:13811-21. [PMID: 19053233 DOI: 10.1021/bi8007802] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
We have used the substituted-cysteine accessibility method (SCAM) to map the residues in the sixth membrane-spanning segment of the CB2 cannabinoid receptor that contribute to the surface of the water-accessible binding-site crevice. Using a background of the mutant C2.59S which is relatively insensitive to the methanethiosulfonate (MTS) reagents, we mutated to cysteine, one at a time, 34 consecutive residues in TMH6 of the CB2 receptor. These mutant receptors were then expressed in HEK293 cells. By incubating HEK293 cells stably transfected with CB2 receptors with the small, charged, hydrophilic, thiol-specific reagent methanethiosulfonate ethylammonium (MTSEA), [(3)H]CP55940 binding was significantly inhibited for six mutant receptors. All six of the mutants that reacted with MTSEA were protected from the reaction when pretreated with the cannabinoid agonist WIN55212-2, suggesting that MTSEA modification occurred within the binding crevice. Therefore, the side chains of the residues at these reactive loci (V6.51, L6.52, L6.54, M6.55, L6.59, and T6.62) are on the water-accessible surface of the binding-site crevice. These residues are extracellular to the TMH6 CWXP hinge motif. The pattern of accessibility is consistent with a alpha-helical conformation for this segment of TMH6. Molecular modeling studies performed in the context of the CB2 model show that V6.51, L6.52, L6.54, M6.55, L6.59, and T6.62 face into the CB2 binding pocket, further confirming our SCAM results. These results are similar to the accessibility patterns determined by SCAM studies of TMH6 in the opioid and dopamine D2 receptors.
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Affiliation(s)
- Ntsang M Nebane
- Department of Pharmacology and Toxicology, University of Louisville School of Medicine, Louisville, Kentucky 40292, USA
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24
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Diaz P, Phatak SS, Xu J, Astruc-Diaz F, Cavasotto CN, Naguib M. 6-Methoxy-N-alkyl Isatin Acylhydrazone Derivatives as a Novel Series of Potent Selective Cannabinoid Receptor 2 Inverse Agonists: Design, Synthesis, and Binding Mode Prediction. J Med Chem 2008; 52:433-44. [DOI: 10.1021/jm801353p] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- Philippe Diaz
- Department of Anesthesiology and Pain Medicine, Unit 409, The University of Texas M. D. Anderson Cancer Center, 1400 Holcombe Boulevard, Houston, Texas 77030, School of Health Information Sciences, The University of Texas Health Science Center at Houston, 7000 Fannin, Suite 860B, Houston, Texas 77030
| | - Sharangdhar S. Phatak
- Department of Anesthesiology and Pain Medicine, Unit 409, The University of Texas M. D. Anderson Cancer Center, 1400 Holcombe Boulevard, Houston, Texas 77030, School of Health Information Sciences, The University of Texas Health Science Center at Houston, 7000 Fannin, Suite 860B, Houston, Texas 77030
| | - Jijun Xu
- Department of Anesthesiology and Pain Medicine, Unit 409, The University of Texas M. D. Anderson Cancer Center, 1400 Holcombe Boulevard, Houston, Texas 77030, School of Health Information Sciences, The University of Texas Health Science Center at Houston, 7000 Fannin, Suite 860B, Houston, Texas 77030
| | - Fanny Astruc-Diaz
- Department of Anesthesiology and Pain Medicine, Unit 409, The University of Texas M. D. Anderson Cancer Center, 1400 Holcombe Boulevard, Houston, Texas 77030, School of Health Information Sciences, The University of Texas Health Science Center at Houston, 7000 Fannin, Suite 860B, Houston, Texas 77030
| | - Claudio N. Cavasotto
- Department of Anesthesiology and Pain Medicine, Unit 409, The University of Texas M. D. Anderson Cancer Center, 1400 Holcombe Boulevard, Houston, Texas 77030, School of Health Information Sciences, The University of Texas Health Science Center at Houston, 7000 Fannin, Suite 860B, Houston, Texas 77030
| | - Mohamed Naguib
- Department of Anesthesiology and Pain Medicine, Unit 409, The University of Texas M. D. Anderson Cancer Center, 1400 Holcombe Boulevard, Houston, Texas 77030, School of Health Information Sciences, The University of Texas Health Science Center at Houston, 7000 Fannin, Suite 860B, Houston, Texas 77030
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Artigas RA, Gonzalez A, Riquelme E, Carvajal CA, Cattani A, Martínez-Aguayo A, Kalergis AM, Pérez-Acle T, Fardella CE. A novel adrenocorticotropin receptor mutation alters its structure and function, causing familial glucocorticoid deficiency. J Clin Endocrinol Metab 2008; 93:3097-105. [PMID: 18492762 DOI: 10.1210/jc.2008-0048] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
CONTEXT Familial glucocorticoid deficiency (FGD) is an autosomal recessive disorder characterized by unresponsiveness to ACTH. In this study, two mutations of the ACTH receptor (MC2R) gene are reported in this FGD clinical case. OBJECTIVE The objective of the study was to characterize a novel MC2R gene mutation in a compound heterozygous patient with FGD phenotype. DESIGN This was a clinical case description, biochemical, molecular, and bioinformatics analysis to describe a novel MC2R gene mutation. PATIENTS The subject of the study was a male diagnosed with primary adrenal insufficiency. The family history showed nonconsanguineous healthy parents, three healthy siblings, and one brother affected with FGD. MAIN OUTCOME MEASURES The mutant MC2R-Ala126Ser showed significantly lower activity when it was stimulated with ACTH-(1-24) than did cells transfected with wild-type MC2R. RESULTS The molecular studies demonstrated the presence of an adenine heterozygous insertion (InsA1347) in the MC2R gene (G217fs) in the patient. This insertion was due to a frame shift mutation in one allele and a premature stop codon codifying an aberrant receptor of 247 residues (27.2 kDa). We also found a novel heterozygous mutation alanine 126 by serine. Molecular dynamic simulations showed that serine 126 side chain fluctuates forming a noncanonical intrahelical hydrogen bond in the transmembrane helix 3 of the mutated receptor. This produces a structural rearrangement of the MC2R internal cavities that may affect the ligand recognition and signal transduction throughout the G protein. CONCLUSIONS We propose a molecular explanation for the reduced activity exhibited by the MC2R alanine 126 by serine mutant.
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Affiliation(s)
- Rocío A Artigas
- Departamento de Endocrinología, Facultad de Medicina, Pontificia Universidad Católica de Chile, Lira 85, 5 degrees piso, 8330074 Santiago, Chile
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26
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Whitnell RM, Hurst DP, Reggio PH, Guarnieri F. Conformational memories with variable bond angles. J Comput Chem 2008; 29:741-52. [PMID: 17876759 DOI: 10.1002/jcc.20822] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Conformational Memories (CM) is a simulated annealing/Monte Carlo method that explores peptide and protein dihedral conformational space completely and efficiently, independent of the original conformation. Here we extend the CM method to include the variation of a randomly chosen bond angle, in addition to the standard variation of two or three randomly chosen dihedral angles, in each Monte Carlo trial of the CM exploratory and biased phases. We test the hypothesis that the inclusion of variable bond angles in CM leads to an improved sampling of conformational space. We compare the results with variable bond angles to CM with no bond angle variation for the following systems: (1) the pentapeptide Met-enkephalin, which is a standard test case for conformational search methods; (2) the proline ring pucker in a 17mer model peptide, (Ala)(8)Pro(Ala)(8); and (3) the conformations of the Ser 7.39 chi(1) in transmembrane helix 7 (TMH7) of the cannabinoid CB1 receptor, a 25-residue system. In each case, analysis of the CM results shows that the inclusion of variable bond angles results in sampling of regions of conformational space that are inaccessible to CM calculations with only variable dihedral angles, and/or a shift in conformational populations from those calculated when variable bond angles are not included. The incorporation of variable bond angles leads to an improved sampling of conformational space without loss of efficiency. Our examples show that this improved sampling leads to better exploration of biologically relevant conformations that have been experimentally validated.
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Affiliation(s)
- Robert M Whitnell
- Chemistry Department, Guilford College, Greensboro, North Carolina 27410, USA.
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27
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Targeting the cannabinoid CB2 receptor: modelling and structural determinants of CB2 selective ligands. Br J Pharmacol 2007; 153:335-46. [PMID: 17982473 DOI: 10.1038/sj.bjp.0707567] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Recent developments indicate that CB2 receptor ligands have the potential to become therapeutically important. To explore this potential, it is necessary to develop compounds with high affinity for the CB2 receptor and little affinity for the CB1 receptor. This review will discuss structure-activity relations at both receptors for classical cannabinoids and cannabimimetic indoles. Examples of CB2 selective ligands from both classes of compounds are presented and the structural features leading to selectivity are described. Two approaches, receptor mutations and molecular modelling, have been employed to investigate the interaction of ligands with both cannabinoid receptors. These results obtained from these techniques are discussed.
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Kapur A, Hurst DP, Fleischer D, Whitnell R, Thakur GA, Makriyannis A, Reggio PH, Abood ME. Mutation studies of Ser7.39 and Ser2.60 in the human CB1 cannabinoid receptor: evidence for a serine-induced bend in CB1 transmembrane helix 7. Mol Pharmacol 2007; 71:1512-24. [PMID: 17384224 DOI: 10.1124/mol.107.034645] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Ligands of structurally diverse natures are able to bind at the CB(1) cannabinoid receptor, suggesting the existence of multiple binding sites on the receptor. Modeling studies have implicated Ser2.60(173) and Ser7.39(383) as possible interaction site(s) for CB(1) agonists. To test the importance of these residues for receptor recognition, recombinant human CB(1) receptors, stably expressed in human embryonic kidney 293 cells, were used to investigate the consequences of mutating Ser2.60 (to S2.60A) or Ser7.39 (to S7.39A) in radioligand binding and guanosine 5'-3-O-(thio)triphosphate functional assays. The S7.39A mutant resulted in a total ablation of [(3)H](-)-3-[2-hydroxyl-4-(1,1-dimethylheptyl)phenyl]-4-[3-hydroxylpropyl] cyclohexan-1-ol (CP55,940) high-affinity binding. However, [(3)H](R)-(+)-[2,3-dihydro-5-methyl-3-[(4-morpholinyl)methyl]-pyrrolo[1,2,3-de]-1,4-benzoxazin-6-yl](1-naphthalenyl)methanone (WIN55,212-2) binding properties at S7.39A were comparable with those of the wild-type (WT) receptor. The binding affinity of (-)-11beta-hydroxy-3-(1',1'-dimethylheptyl)hexahydrocannabinol (AM4056) and (-)-11-hydroxydimethylheptyl-Delta(8)-tetrahydrocannabinol (HU210) were drastically reduced (50- to 100-fold) at the S7.39A mutant. Likewise, the EC(50) for HU210 and AM4056-mediated activation of the S7.39A receptor was increased by >200-fold. In contrast, the binding affinity and potency of WIN55,212-2, CP55,940, HU210, and AM4056 were unaltered at the S2.60A mutant compared with WT human CB(1) receptors. These results clearly suggest that Ser7.39, but not Ser2.60, plays a crucial role in mediating ligand specific interactions for CP55,940, HU210, and AM4056 at the human CB(1) receptor. Our modeling studies predict that Ser7.39 in a g-chi1 conformation may induce a helix bend in TMH7 that provides docking space for CP55,940 binding; the S7.39A mutation may alter this binding space, precluding CP55,940 binding.
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Affiliation(s)
- Ankur Kapur
- California Pacific Medical Center Research Institute, San Francisco, CA 94107, USA
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29
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Reggio PH. Computational methods in drug design: modeling G protein-coupled receptor monomers, dimers, and oligomers. AAPS JOURNAL 2006; 8:E322-36. [PMID: 16796383 PMCID: PMC3231557 DOI: 10.1007/bf02854903] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
G protein-coupled receptors (GPCRs) are membrane proteins that serve as very important links through which cellular signal transduction mechanisms are activated. Many vital physiological events such as sensory perception, immune defense, cell communication, chemotaxis, and neurotransmission are mediated by GPCRs. Not surprisingly, GPCRs are major targets for drug development today. Most modeling studies in the GPCR field have focused upon the creation of a model of a single GPCR (ie, a GPCR monomer) based upon the crystal structure of the Class A GPCR, rhodopsin. However, the emerging concept of GPCR dimerization has challenged our notions of the monomeric GPCR as functional unit. Recent work has shown not only that many GPCRs exist as homo- and heterodimers but also that GPCR oligomeric assembly may have important functional roles. This review focuses first on methodology for the creation of monomeric GPCR models. Special emphasis is given to the identification of localized regions where the structure of a GPCR may diverge from that of bovine rhodopsin. The review then focuses on GPCR dimers and oligomers and the bioinformatics methods available for identifying homo- and heterodimer interfaces.
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Affiliation(s)
- Patricia H Reggio
- Center for Drug Design, Department of Chemistry and Biochemistry, University of North Carolina Greensboro, Greensboro, NC 27402, USA.
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McPartland JM, Matias I, Di Marzo V, Glass M. Evolutionary origins of the endocannabinoid system. Gene 2006; 370:64-74. [PMID: 16434153 DOI: 10.1016/j.gene.2005.11.004] [Citation(s) in RCA: 98] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2005] [Revised: 11/04/2005] [Accepted: 11/09/2005] [Indexed: 10/25/2022]
Abstract
Endocannabinoid system evolution was estimated by searching for functional orthologs in the genomes of twelve phylogenetically diverse organisms: Homo sapiens, Mus musculus, Takifugu rubripes, Ciona intestinalis, Caenorhabditis elegans, Drosophila melanogaster, Saccharomyces cerevisiae, Arabidopsis thaliana, Plasmodium falciparum, Tetrahymena thermophila, Archaeoglobus fulgidus, and Mycobacterium tuberculosis. Sequences similar to human endocannabinoid exon sequences were derived from filtered BLAST searches, and subjected to phylogenetic testing with ClustalX and tree building programs. Monophyletic clades that agreed with broader phylogenetic evidence (i.e., gene trees displaying topographical congruence with species trees) were considered orthologs. The capacity of orthologs to function as endocannabinoid proteins was predicted with pattern profilers (Pfam, Prosite, TMHMM, and pSORT), and by examining queried sequences for amino acid motifs known to serve critical roles in endocannabinoid protein function (obtained from a database of site-directed mutagenesis studies). This novel transfer of functional information onto gene trees enabled us to better predict the functional origins of the endocannabinoid system. Within this limited number of twelve organisms, the endocannabinoid genes exhibited heterogeneous evolutionary trajectories, with functional orthologs limited to mammals (TRPV1 and GPR55), or vertebrates (CB2 and DAGLbeta), or chordates (MAGL and COX2), or animals (DAGLalpha and CB1-like receptors), or opisthokonta (animals and fungi, NAPE-PLD), or eukaryotes (FAAH). Our methods identified fewer orthologs than did automated annotation systems, such as HomoloGene. Phylogenetic profiles, nonorthologous gene displacement, functional convergence, and coevolution are discussed.
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Affiliation(s)
- John M McPartland
- GW Pharmaceuticals, 53 Washington Street Ext., Middlebury, VT 05753, USA.
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Fanelli F, De Benedetti PG. Computational Modeling Approaches to Structure−Function Analysis of G Protein-Coupled Receptors. Chem Rev 2005; 105:3297-351. [PMID: 16159154 DOI: 10.1021/cr000095n] [Citation(s) in RCA: 129] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Francesca Fanelli
- Dulbecco Telethon Institute and Department of Chemistry, University of Modena and Reggio Emilia, via Campi 183, 41100 Modena, Italy.
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