1
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Tomašević N, Emser FS, Muratspahić E, Gattringer J, Hasinger S, Hellinger R, Keov P, Felkl M, Gertsch J, Becker CFW, Gruber CW. Discovery and development of macrocyclic peptide modulators of the cannabinoid 2 receptor. J Biol Chem 2024:107330. [PMID: 38679329 DOI: 10.1016/j.jbc.2024.107330] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2024] [Revised: 04/15/2024] [Accepted: 04/23/2024] [Indexed: 05/01/2024] Open
Abstract
The cannabinoid-type 2 receptor (CB2R), a G protein-coupled receptor (GPCR), is an important regulator of immune cell function and a promising target to treat chronic inflammation and fibrosis. While CB2R is typically targeted by small molecules, including endo-, phyto- and synthetic cannabinoids, peptides - owing to their size - may offer a different interaction space to facilitate differential interactions with the receptor. Here we explore plant-derived cyclic cystine-knot peptides as ligands of the CB2R. Cyclotides are known for their exceptional biochemical stability. Recently they gained attention as GPCR modulators and as templates for designing peptide ligands with improved pharmacokinetic properties over linear peptides. Cyclotide-based ligands for CB2R were profiled based on a peptide-enriched extract library comprising nine plants. Employing pharmacology-guided fractionation and peptidomics we identified cyclotide vodo-C1 from sweet violet (Viola odorata) as a full agonist of CB2R with an affinity (Ki) of 1μM and a potency (EC50) of 8μM. Leveraging deep learning networks we verified the structural topology of vodo-C1 and modelled its molecular volume in comparison to the CB2R ligand binding pocket. In a fragment-based approach we designed and characterized vodo-C1-based bicyclic peptides (vBCL1-4), aiming to reduce size and improve potency. Opposite to vodo-C1, the vBCL peptides lacked the ability to activate the receptor but acted as negative allosteric modulators or neutral antagonists of CB2R. This study introduces a macrocyclic peptide phytocannabinoid, which served as template for the development of synthetic CB2R peptide modulators. These findings offer opportunities for future peptide-based probe and drug development at cannabinoid receptors.
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Affiliation(s)
- Nataša Tomašević
- Center for Physiology and Pharmacology, Institute of Pharmacology, Medical University of Vienna, 1090 Vienna, Austria
| | - Fabiola Susanna Emser
- Center for Physiology and Pharmacology, Institute of Pharmacology, Medical University of Vienna, 1090 Vienna, Austria
| | - Edin Muratspahić
- Center for Physiology and Pharmacology, Institute of Pharmacology, Medical University of Vienna, 1090 Vienna, Austria
| | - Jasmin Gattringer
- Center for Physiology and Pharmacology, Institute of Pharmacology, Medical University of Vienna, 1090 Vienna, Austria
| | - Simon Hasinger
- Center for Physiology and Pharmacology, Institute of Pharmacology, Medical University of Vienna, 1090 Vienna, Austria
| | - Roland Hellinger
- Center for Physiology and Pharmacology, Institute of Pharmacology, Medical University of Vienna, 1090 Vienna, Austria
| | - Peter Keov
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, 3052, Australia; ARC Centre for Cryo-electron Microscopy of Membrane Proteins, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville 3052, VIC, Australia
| | - Manuel Felkl
- Institute of Biological Chemistry, Faculty of Chemistry, University of Vienna, 1090 Vienna, Austria
| | - Jürg Gertsch
- Institute of Biochemistry and Molecular Medicine, University of Bern, 3012 Bern, Switzerland
| | - Christian F W Becker
- Institute of Biological Chemistry, Faculty of Chemistry, University of Vienna, 1090 Vienna, Austria
| | - Christian W Gruber
- Center for Physiology and Pharmacology, Institute of Pharmacology, Medical University of Vienna, 1090 Vienna, Austria.
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2
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Keov P, Christopoulos G, Hick CA, Glendorf T, Ballarín-González B, Wootten D, Sexton PM. Development of a Novel Assay for Direct Assessment of Selective Amylin Receptor Activation Reveals Novel Differences in Behavior of Selective and Nonselective Peptide Agonists. Mol Pharmacol 2024; 105:359-373. [PMID: 38458773 DOI: 10.1124/molpharm.123.000865] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Revised: 02/22/2024] [Accepted: 02/26/2024] [Indexed: 03/10/2024] Open
Abstract
Dual amylin and calcitonin receptor agonists (DACRAs) show promise as efficacious therapeutics for treatment of metabolic disease, including obesity. However, differences in efficacy in vivo have been observed for individual DACRAs, indicating that detailed understanding of the pharmacology of these agents across target receptors is required for rational drug development. To date, such understanding has been hampered by lack of direct, subtype-selective, functional assays for the amylin receptors (AMYRs). Here, we describe the generation of receptor-specific assays for recruitment of Venus-tagged Gs protein through fusion of luciferase to either the human calcitonin receptor (CTR), human receptor activity-modifying protein (RAMP)-1, RAMP1 (AMY1R), human RAMP2 (AMY2R), or human RAMP3 (AMY3R). These assays revealed a complex pattern of receptor activation by calcitonin, amylin, or DACRA peptides that was distinct at each receptor subtype. Of particular note, although both of the CT-based DACRAs, sCT and AM1784, displayed relatively similar behaviors at CTR and AMY1R, they generated distinct responses at AMY2R and AMY3R. These data aid the rationalization of in vivo differences in response to DACRA peptides in rodent models of obesity. Direct assessment of the pharmacology of novel DACRAs at AMYR subtypes is likely to be important for development of optimized therapeutics for treatment of metabolic diseases. SIGNIFICANCE STATEMENT: Amylin receptors (AMYRs) are important obesity targets. Here we describe a novel assay that allows selective functional assessment of individual amylin receptor subtypes that provides unique insight into the pharmacology of potential therapeutic ligands. Direct assessment of the pharmacology of novel agonists at AMYR subtypes is likely to be important for development of optimized therapeutics for treatment of metabolic diseases.
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Affiliation(s)
- Peter Keov
- Drug Discovery Biology Theme (P.K., G.C., C.A.H., D.W., P.M.S.) and ARC Centre for Cryo-Electron Microscopy of Membrane Proteins (P.K., D.W., P.M.S.), Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia; and Research & Early Development, Novo Nordisk, Novo Nordisk Park, Maaloev, Denmark (T.G., B.B.-G.)
| | - George Christopoulos
- Drug Discovery Biology Theme (P.K., G.C., C.A.H., D.W., P.M.S.) and ARC Centre for Cryo-Electron Microscopy of Membrane Proteins (P.K., D.W., P.M.S.), Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia; and Research & Early Development, Novo Nordisk, Novo Nordisk Park, Maaloev, Denmark (T.G., B.B.-G.)
| | - Caroline A Hick
- Drug Discovery Biology Theme (P.K., G.C., C.A.H., D.W., P.M.S.) and ARC Centre for Cryo-Electron Microscopy of Membrane Proteins (P.K., D.W., P.M.S.), Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia; and Research & Early Development, Novo Nordisk, Novo Nordisk Park, Maaloev, Denmark (T.G., B.B.-G.)
| | - Tine Glendorf
- Drug Discovery Biology Theme (P.K., G.C., C.A.H., D.W., P.M.S.) and ARC Centre for Cryo-Electron Microscopy of Membrane Proteins (P.K., D.W., P.M.S.), Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia; and Research & Early Development, Novo Nordisk, Novo Nordisk Park, Maaloev, Denmark (T.G., B.B.-G.)
| | - Borja Ballarín-González
- Drug Discovery Biology Theme (P.K., G.C., C.A.H., D.W., P.M.S.) and ARC Centre for Cryo-Electron Microscopy of Membrane Proteins (P.K., D.W., P.M.S.), Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia; and Research & Early Development, Novo Nordisk, Novo Nordisk Park, Maaloev, Denmark (T.G., B.B.-G.)
| | - Denise Wootten
- Drug Discovery Biology Theme (P.K., G.C., C.A.H., D.W., P.M.S.) and ARC Centre for Cryo-Electron Microscopy of Membrane Proteins (P.K., D.W., P.M.S.), Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia; and Research & Early Development, Novo Nordisk, Novo Nordisk Park, Maaloev, Denmark (T.G., B.B.-G.)
| | - Patrick M Sexton
- Drug Discovery Biology Theme (P.K., G.C., C.A.H., D.W., P.M.S.) and ARC Centre for Cryo-Electron Microscopy of Membrane Proteins (P.K., D.W., P.M.S.), Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia; and Research & Early Development, Novo Nordisk, Novo Nordisk Park, Maaloev, Denmark (T.G., B.B.-G.)
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3
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Ham S, Mukaida S, Sato M, Keov P, Bengtsson T, Furness S, Holliday ND, Evans BA, Summers RJ, Hutchinson DS. Role of G protein-coupled receptor kinases (GRKs) in β 2 -adrenoceptor-mediated glucose uptake. Pharmacol Res Perspect 2024; 12:e1176. [PMID: 38332691 PMCID: PMC10853676 DOI: 10.1002/prp2.1176] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Revised: 12/17/2023] [Accepted: 01/22/2024] [Indexed: 02/10/2024] Open
Abstract
Truncation of the C-terminal tail of the β2 -AR, transfection of βARKct or over-expression of a kinase-dead GRK mutant reduces isoprenaline-stimulated glucose uptake, indicating that GRK is important for this response. We explored whether phosphorylation of the β2 -AR by GRK2 has a role in glucose uptake or if this response is related to the role of GRK2 as a scaffolding protein. CHO-GLUT4myc cells expressing wild-type and mutant β2 -ARs were generated and receptor affinity for [3 H]-CGP12177A and density of binding sites determined together with the affinity of isoprenaline and BRL37344. Following receptor activation by β2 -AR agonists, cAMP accumulation, GLUT4 translocation, [3 H]-2-deoxyglucose uptake, and β2 -AR internalization were measured. Bioluminescence resonance energy transfer was used to investigate interactions between β2 -AR and β-arrestin2 or between β2 -AR and GRK2. Glucose uptake after siRNA knockdown or GRK inhibitors was measured in response to β2 -AR agonists. BRL37344 was a poor partial agonist for cAMP generation but displayed similar potency and efficacy to isoprenaline for glucose uptake and GLUT4 translocation. These responses to β2 -AR agonists occurred in CHO-GLUT4myc cells expressing β2 -ARs lacking GRK or GRK/PKA phosphorylation sites as well as in cells expressing the wild-type β2 -AR. However, β2 -ARs lacking phosphorylation sites failed to recruit β-arrestin2 and did not internalize. GRK2 knock-down or GRK2 inhibitors decreased isoprenaline-stimulated glucose uptake in rat L6 skeletal muscle cells. Thus, GRK phosphorylation of the β2 -AR is not associated with isoprenaline- or BRL37344-stimulated glucose uptake. However, GRKs acting as scaffold proteins are important for glucose uptake as GRK2 knock-down or GRK2 inhibition reduces isoprenaline-stimulated glucose uptake.
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Affiliation(s)
- Seungmin Ham
- Drug Discovery BiologyMonash Institute of Pharmaceutical Sciences, Monash UniversityParkvilleVictoriaAustralia
| | - Saori Mukaida
- Drug Discovery BiologyMonash Institute of Pharmaceutical Sciences, Monash UniversityParkvilleVictoriaAustralia
| | - Masaaki Sato
- Drug Discovery BiologyMonash Institute of Pharmaceutical Sciences, Monash UniversityParkvilleVictoriaAustralia
| | - Peter Keov
- Drug Discovery BiologyMonash Institute of Pharmaceutical Sciences, Monash UniversityParkvilleVictoriaAustralia
| | - Tore Bengtsson
- Atrogi ABStockholmSweden
- Department of Molecular BiosciencesThe Wenner‐Gren Institute, Stockholm UniversityStockholmSweden
| | - Sebastian Furness
- Drug Discovery BiologyMonash Institute of Pharmaceutical Sciences, Monash UniversityParkvilleVictoriaAustralia
| | - Nicholas D. Holliday
- School of Life Sciences, The Medical School, Queen's Medical CentreUniversity of NottinghamNottinghamUK
- Excellerate Bioscience, BiocityNottinghamUK
| | - Bronwyn A. Evans
- Drug Discovery BiologyMonash Institute of Pharmaceutical Sciences, Monash UniversityParkvilleVictoriaAustralia
| | - Roger J. Summers
- Drug Discovery BiologyMonash Institute of Pharmaceutical Sciences, Monash UniversityParkvilleVictoriaAustralia
| | - Dana S. Hutchinson
- Drug Discovery BiologyMonash Institute of Pharmaceutical Sciences, Monash UniversityParkvilleVictoriaAustralia
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4
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Fletcher MM, Keov P, Truong TT, Mennen G, Hick CA, Zhao P, Furness SG, Kruse T, Clausen TR, Wootten D, Sexton PM. AM833 Is a Novel Agonist of Calcitonin Family G Protein–Coupled Receptors: Pharmacological Comparison with Six Selective and Nonselective Agonists. J Pharmacol Exp Ther 2021; 377:417-440. [DOI: 10.1124/jpet.121.000567] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Accepted: 03/11/2021] [Indexed: 01/14/2023] Open
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5
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Ngo T, Wilkins BP, So SS, Keov P, Chahal KK, Finch AM, Coleman JLJ, Kufareva I, Smith NJ. Orphan receptor GPR37L1 remains unliganded. Nat Chem Biol 2021; 17:383-386. [PMID: 33649602 DOI: 10.1038/s41589-021-00748-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Accepted: 01/25/2021] [Indexed: 11/09/2022]
Affiliation(s)
- Tony Ngo
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, CA, USA
| | - Brendan P Wilkins
- Molecular Pharmacology Laboratory, Victor Chang Cardiac Research Institute, Darlinghurst, New South Wales, Australia.,Orphan Receptor Pharmacology Laboratory, School of Medical Sciences, UNSW Sydney, Kensington, New South Wales, Australia
| | - Sean S So
- Molecular Pharmacology Laboratory, Victor Chang Cardiac Research Institute, Darlinghurst, New South Wales, Australia.,Orphan Receptor Pharmacology Laboratory, School of Medical Sciences, UNSW Sydney, Kensington, New South Wales, Australia
| | - Peter Keov
- Molecular Pharmacology Laboratory, Victor Chang Cardiac Research Institute, Darlinghurst, New South Wales, Australia
| | - Kirti K Chahal
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, CA, USA
| | - Angela M Finch
- G Protein-Coupled Receptor Laboratory, School of Medical Sciences, UNSW Sydney, Kensington, New South Wales, Australia
| | - James L J Coleman
- Molecular Pharmacology Laboratory, Victor Chang Cardiac Research Institute, Darlinghurst, New South Wales, Australia
| | - Irina Kufareva
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, CA, USA.
| | - Nicola J Smith
- Molecular Pharmacology Laboratory, Victor Chang Cardiac Research Institute, Darlinghurst, New South Wales, Australia. .,Orphan Receptor Pharmacology Laboratory, School of Medical Sciences, UNSW Sydney, Kensington, New South Wales, Australia.
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6
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Dekan Z, Kremsmayr T, Keov P, Godin M, Teakle N, Dürrauer L, Xiang H, Gharib D, Bergmayr C, Hellinger R, Gay M, Vilaseca M, Kurzbach D, Albericio F, Alewood PF, Gruber CW, Muttenthaler M. Nature-inspired dimerization as a strategy to modulate neuropeptide pharmacology exemplified with vasopressin and oxytocin. Chem Sci 2021; 12:4057-4062. [PMID: 34163676 PMCID: PMC8179488 DOI: 10.1039/d0sc05501h] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Vasopressin (VP) and oxytocin (OT) are cyclic neuropeptides that regulate fundamental physiological functions via four G protein-coupled receptors, V1aR, V1bR, V2R, and OTR. Ligand development remains challenging for these receptors due to complex structure–activity relationships. Here, we investigated dimerization as a strategy for developing ligands with novel pharmacology. We regioselectively synthesised and systematically studied parallel, antiparallel and N- to C-terminal cyclized homo- and heterodimer constructs of VP, OT and dVDAVP (1-deamino-4-valine-8-d-arginine-VP). All disulfide-linked dimers, except for the head-to-tail cyclized constructs, retained nanomolar potency despite the structural implications of dimerization. Our results support a single chain interaction for receptor activation. Dimer orientation had little impact on activity, except for the dVDAVP homodimers, where an antagonist to agonist switch was observed at the V1aR. This study provides novel insights into the structural requirements of VP/OT receptor activation and spotlights dimerization as a strategy to modulate pharmacology, a concept also frequently observed in nature. Structural and pharmacological study of parallel, antiparallel and N- to C-terminal cyclized homo- and heterodimers of vasopressin and oxytocin. This study spotlights dimerization as a strategy to modulate the pharmacology of neuropeptides.![]()
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Affiliation(s)
- Zoltan Dekan
- Institute for Molecular Bioscience, The University of Queensland Brisbane 4072 Australia
| | - Thomas Kremsmayr
- Institute of Biological Chemistry, University of Vienna Währingerstraße 38 1090 Vienna Austria
| | - Peter Keov
- Faculty of Medicine, School of Biomedical Sciences, The University of Queensland Brisbane 4072 Australia
| | - Mathilde Godin
- Institute for Molecular Bioscience, The University of Queensland Brisbane 4072 Australia
| | - Ngari Teakle
- Institute for Molecular Bioscience, The University of Queensland Brisbane 4072 Australia
| | - Leopold Dürrauer
- Institute of Biological Chemistry, University of Vienna Währingerstraße 38 1090 Vienna Austria
| | - Huang Xiang
- Center for Physiology and Pharmacology, Medical University of Vienna Schwarzspanierstraße 17 1090 Vienna Austria
| | - Dalia Gharib
- Center for Physiology and Pharmacology, Medical University of Vienna Schwarzspanierstraße 17 1090 Vienna Austria
| | - Christian Bergmayr
- Center for Physiology and Pharmacology, Medical University of Vienna Schwarzspanierstraße 17 1090 Vienna Austria
| | - Roland Hellinger
- Center for Physiology and Pharmacology, Medical University of Vienna Schwarzspanierstraße 17 1090 Vienna Austria
| | - Marina Gay
- Institute for Research in Biomedicine Barcelona C/ Baldiri Reixac 10 08028 Barcelona Spain
| | - Marta Vilaseca
- Institute for Research in Biomedicine Barcelona C/ Baldiri Reixac 10 08028 Barcelona Spain
| | - Dennis Kurzbach
- Institute of Biological Chemistry, University of Vienna Währingerstraße 38 1090 Vienna Austria
| | - Fernando Albericio
- Department of Organic Chemistry, University of Barcelona Barcelona Science Park, Baldiri Reixac 10 08028 Barcelona Spain
| | - Paul F Alewood
- Institute for Molecular Bioscience, The University of Queensland Brisbane 4072 Australia
| | - Christian W Gruber
- Faculty of Medicine, School of Biomedical Sciences, The University of Queensland Brisbane 4072 Australia.,Center for Physiology and Pharmacology, Medical University of Vienna Schwarzspanierstraße 17 1090 Vienna Austria
| | - Markus Muttenthaler
- Institute for Molecular Bioscience, The University of Queensland Brisbane 4072 Australia .,Institute of Biological Chemistry, University of Vienna Währingerstraße 38 1090 Vienna Austria
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7
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Duerrauer L, Muratspahić E, Gattringer J, Keov P, Mendel HC, Pfleger KDG, Muttenthaler M, Gruber CW. I8-arachnotocin-an arthropod-derived G protein-biased ligand of the human vasopressin V 2 receptor. Sci Rep 2019; 9:19295. [PMID: 31848378 PMCID: PMC6917733 DOI: 10.1038/s41598-019-55675-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Accepted: 11/28/2019] [Indexed: 12/14/2022] Open
Abstract
The neuropeptides oxytocin (OT) and vasopressin (VP) and their G protein-coupled receptors OTR, V1aR, V1bR, and V2R form an important and widely-distributed neuroendocrine signaling system. In mammals, this signaling system regulates water homeostasis, blood pressure, reproduction, as well as social behaviors such as pair bonding, trust and aggression. There exists high demand for ligands with differing pharmacological profiles to study the physiological and pathological functions of the individual receptor subtypes. Here, we present the pharmacological characterization of an arthropod (Metaseiulus occidentalis) OT/VP-like nonapeptide across the human OT/VP receptors. I8-arachnotocin is a full agonist with respect to second messenger signaling at human V2R (EC50 34 nM) and V1bR (EC50 1.2 µM), a partial agonist at OTR (EC50 790 nM), and a competitive antagonist at V1aR [pA2 6.25 (558 nM)]. Intriguingly, I8-arachnotocin activated the Gαs pathway of V2R without recruiting either β-arrestin-1 or β-arrestin-2. I8-arachnotocin might thus be a novel pharmacological tool to study the (patho)physiological relevance of β-arrestin-1 or -2 recruitment to the V2R. These findings furthermore highlight arthropods as a novel, vast and untapped source for the discovery of novel pharmacological probes and potential drug leads targeting neurohormone receptors.
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Affiliation(s)
- Leopold Duerrauer
- Institute of Pharmacology, Center for Pharmacology and Physiology, Medical University of Vienna, Vienna, Austria.,School of Biomedical Sciences, Faculty of Medicine, The University of Queensland, Brisbane, Queensland, Australia.,Institute of Biological Chemistry, Faculty of Chemistry, University of Vienna, Vienna, Austria
| | - Edin Muratspahić
- Institute of Pharmacology, Center for Pharmacology and Physiology, Medical University of Vienna, Vienna, Austria
| | - Jasmin Gattringer
- Institute of Pharmacology, Center for Pharmacology and Physiology, Medical University of Vienna, Vienna, Austria
| | - Peter Keov
- School of Biomedical Sciences, Faculty of Medicine, The University of Queensland, Brisbane, Queensland, Australia.,Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
| | - Helen C Mendel
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, Australia
| | - Kevin D G Pfleger
- Centre for Medical Research, The University of Western Australia and Harry Perkins Institute of Medical Research, Nedlands, Western Australia, Australia
| | - Markus Muttenthaler
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, Australia.,Institute of Biological Chemistry, Faculty of Chemistry, University of Vienna, Vienna, Austria
| | - Christian W Gruber
- Institute of Pharmacology, Center for Pharmacology and Physiology, Medical University of Vienna, Vienna, Austria. .,School of Biomedical Sciences, Faculty of Medicine, The University of Queensland, Brisbane, Queensland, Australia.
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8
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Baratchi S, Keov P, Darby WG, Lai A, Khoshmanesh K, Thurgood P, Vahidi P, Ejendal K, McIntyre P. The TRPV4 Agonist GSK1016790A Regulates the Membrane Expression of TRPV4 Channels. Front Pharmacol 2019; 10:6. [PMID: 30728775 PMCID: PMC6351496 DOI: 10.3389/fphar.2019.00006] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Accepted: 01/04/2019] [Indexed: 02/05/2023] Open
Abstract
TRPV4 is a non-selective cation channel that tunes the function of different tissues including the vascular endothelium, lung, chondrocytes, and neurons. GSK1016790A is the selective and potent agonist of TRPV4 and a pharmacological tool that is used to study the TRPV4 physiological function in vitro and in vivo. It remains unknown how the sensitivity of TRPV4 to this agonist is regulated. The spatial and temporal dynamics of receptors are the major determinants of cellular responses to stimuli. Membrane translocation has been shown to control the response of several members of the transient receptor potential (TRP) family of ion channels to different stimuli. Here, we show that TRPV4 stimulation with GSK1016790A caused an increase in [Ca2+]i that is stable for a few minutes. Single molecule analysis of TRPV4 channels showed that the density of TRPV4 at the plasma membrane is controlled through two modes of membrane trafficking, complete, and partial vesicular fusion. Further, we show that the density of TRPV4 at the plasma membrane decreased within 20 min, as they translocate to the recycling endosomes and that the surface density is dependent on the release of calcium from the intracellular stores and is controlled via a PI3K, PKC, and RhoA signaling pathway.
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Affiliation(s)
- Sara Baratchi
- School of Health and Biomedical Sciences, RMIT University, Melbourne, VIC, Australia
| | - Peter Keov
- School of Health and Biomedical Sciences, RMIT University, Melbourne, VIC, Australia.,Molecular Pharmacology Division, Victor Chang Cardiac Research Institute, Darlinghurst, NSW, Australia.,St Vincent's Clinical School, University of New South Wales, Darlinghurst, NSW, Australia
| | - William G Darby
- School of Health and Biomedical Sciences, RMIT University, Melbourne, VIC, Australia
| | - Austin Lai
- School of Health and Biomedical Sciences, RMIT University, Melbourne, VIC, Australia
| | | | - Peter Thurgood
- School of Engineering, RMIT University, Melbourne, VIC, Australia
| | - Parisa Vahidi
- School of Health and Biomedical Sciences, RMIT University, Melbourne, VIC, Australia
| | - Karin Ejendal
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, United States
| | - Peter McIntyre
- School of Health and Biomedical Sciences, RMIT University, Melbourne, VIC, Australia
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9
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Abstract
Discovery and characterization of novel pharmaceutical compounds or biochemical probes rely on robust and physiologically relevant assay systems. We describe methods to measure ex vivo myometrium contractility. This assay can be used to investigate factors and molecules involved in the modulation of myometrial contraction and to determine their excitatory or inhibitory actions, and hence their therapeutic potential in vivo. Biopsies are obtained from women undergoing cesarean section delivery with informed consent. Fine strips of myometrium are dissected, clipped and attached to a force transducer within 1 mL organ baths superfused with physiological saline solution at 37 °C. Strips develop spontaneous contractions within 2-3 h under set tension and remain stable for many hours (>6 h). Strips can also be stimulated to contract such as by the endogenous hormones, oxytocin and vasopressin, which cause concentration-dependent modulation of contraction frequency, force and duration, to more closely resemble contractions in labor. Hence, the effect of known and novel drug leads can be tested on spontaneous and agonist-induced contractions. This protocol specifically details how this assay can be used to determine the potency of known and novel agents by measuring their effects on various parameters of human myometrial contraction. We use the oxytocin- and V1a receptor antagonists, atosiban and SR49059 as examples of known compounds which inhibit oxytocin- and vasopressin-induced contractions, and demonstrate how this method can be used to complement and validate pharmacological data obtained from cell-based assays to aid drug development. The effects of novel agonists in comparison to oxytocin and vasopressin can also be characterized. Whilst we use the example of the oxytocin/ vasopressin system, this method can also be used to study other receptors and ion channels that play a role in uterine contraction and relaxation to advance the understanding of human uterine physiology and pathophysiology.
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Affiliation(s)
- Sarah Arrowsmith
- Harris-Wellbeing Preterm Birth Research Centre, Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool;
| | - Peter Keov
- School of Biomedical Sciences, The University of Queensland
| | - Markus Muttenthaler
- Faculty of Chemistry, Institute of Biological Chemistry, University of Vienna; Institute for Molecular Bioscience, University of Queensland
| | - Christian W Gruber
- School of Biomedical Sciences, The University of Queensland; Center for Physiology and Pharmacology, Medical University of Vienna;
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10
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Fahradpour M, Keov P, Tognola C, Perez-Santamarina E, McCormick PJ, Ghassempour A, Gruber CW. Cyclotides Isolated from an Ipecac Root Extract Antagonize the Corticotropin Releasing Factor Type 1 Receptor. Front Pharmacol 2017; 8:616. [PMID: 29033832 PMCID: PMC5627009 DOI: 10.3389/fphar.2017.00616] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Accepted: 08/23/2017] [Indexed: 12/22/2022] Open
Abstract
Cyclotides are plant derived, cystine-knot stabilized peptides characterized by their natural abundance, sequence variability and structural plasticity. They are abundantly expressed in Rubiaceae, Psychotrieae in particular. Previously the cyclotide kalata B7 was identified to modulate the human oxytocin and vasopressin G protein-coupled receptors (GPCRs), providing molecular validation of the plants' uterotonic properties and further establishing cyclotides as valuable source for GPCR ligand design. In this study we screened a cyclotide extract derived from the root powder of the South American medicinal plant ipecac (Carapichea ipecacuanha) for its GPCR modulating activity of the corticotropin-releasing factor type 1 receptor (CRF1R). We identified and characterized seven novel cyclotides. One cyclotide, caripe 8, isolated from the most active fraction, was further analyzed and found to antagonize the CRF1R. A nanomolar concentration of this cyclotide (260 nM) reduced CRF potency by ∼4.5-fold. In contrast, caripe 8 did not inhibit forskolin-, or vasopressin-stimulated cAMP responses at the vasopressin V2 receptor, suggesting a CRF1R-specific mode-of-action. These results in conjunction with our previous findings establish cyclotides as modulators of both classes A and B GPCRs. Given the diversity of cyclotides, our data point to other cyclotide-GPCR interactions as potentially important sources of drug-like molecules.
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Affiliation(s)
- Mohsen Fahradpour
- Center for Physiology and Pharmacology, Medical University of ViennaVienna, Austria.,Medicinal Plants and Drugs Research Institute, Shahid Beheshti UniversityTehran, Iran
| | - Peter Keov
- Faculty of Medicine, School of Biomedical Sciences, The University of Queensland, BrisbaneQLD, Australia
| | - Carlotta Tognola
- Center for Physiology and Pharmacology, Medical University of ViennaVienna, Austria
| | | | - Peter J McCormick
- School of Veterinary Medicine, University of SurreyGuildford, United Kingdom
| | - Alireza Ghassempour
- Medicinal Plants and Drugs Research Institute, Shahid Beheshti UniversityTehran, Iran
| | - Christian W Gruber
- Center for Physiology and Pharmacology, Medical University of ViennaVienna, Austria.,Faculty of Medicine, School of Biomedical Sciences, The University of Queensland, BrisbaneQLD, Australia
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Di Giglio MG, Muttenthaler M, Harpsøe K, Liutkeviciute Z, Keov P, Eder T, Rattei T, Arrowsmith S, Wray S, Marek A, Elbert T, Alewood PF, Gloriam DE, Gruber CW. Development of a human vasopressin V 1a-receptor antagonist from an evolutionary-related insect neuropeptide. Sci Rep 2017; 7:41002. [PMID: 28145450 PMCID: PMC5286520 DOI: 10.1038/srep41002] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2016] [Accepted: 12/13/2016] [Indexed: 01/27/2023] Open
Abstract
Characterisation of G protein-coupled receptors (GPCR) relies on the availability of a toolbox of ligands that selectively modulate different functional states of the receptors. To uncover such molecules, we explored a unique strategy for ligand discovery that takes advantage of the evolutionary conservation of the 600-million-year-old oxytocin/vasopressin signalling system. We isolated the insect oxytocin/vasopressin orthologue inotocin from the black garden ant (Lasius niger), identified and cloned its cognate receptor and determined its pharmacological properties on the insect and human oxytocin/vasopressin receptors. Subsequently, we identified a functional dichotomy: inotocin activated the insect inotocin and the human vasopressin V1b receptors, but inhibited the human V1aR. Replacement of Arg8 of inotocin by D-Arg8 led to a potent, stable and competitive V1aR-antagonist ([D-Arg8]-inotocin) with a 3,000-fold binding selectivity for the human V1aR over the other three subtypes, OTR, V1bR and V2R. The Arg8/D-Arg8 ligand-pair was further investigated to gain novel insights into the oxytocin/vasopressin peptide-receptor interaction, which led to the identification of key residues of the receptors that are important for ligand functionality and selectivity. These observations could play an important role for development of oxytocin/vasopressin receptor modulators that would enable clear distinction of the physiological and pathological responses of the individual receptor subtypes.
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Affiliation(s)
- Maria Giulia Di Giglio
- Center for Physiology and Pharmacology, Medical University of Vienna, Schwarzspanierstrasse 17, 1090 Vienna, Austria
| | - Markus Muttenthaler
- Institute for Molecular Bioscience, The University of Queensland, QLD 4072 Brisbane, Australia
| | - Kasper Harpsøe
- Department of Drug Design and Pharmacology, University of Copenhagen, Jagtvej 162, 2100 Copenhagen, Denmark
| | - Zita Liutkeviciute
- Center for Physiology and Pharmacology, Medical University of Vienna, Schwarzspanierstrasse 17, 1090 Vienna, Austria
| | - Peter Keov
- School of Biomedical Sciences, The University of Queensland, QLD 4072 Brisbane, Australia
| | - Thomas Eder
- IST Austria (Institute of Science and Technology), Am Campus 1, 3400 Klosterneuburg, Austria
- CUBE-Division of Computational Systems Biology, Department of Microbiology and Ecosystem Science, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria
| | - Thomas Rattei
- CUBE-Division of Computational Systems Biology, Department of Microbiology and Ecosystem Science, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria
| | - Sarah Arrowsmith
- Harris-Wellbeing Preterm Birth Research Centre, Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, L69 3BX, United Kingdom
| | - Susan Wray
- Harris-Wellbeing Preterm Birth Research Centre, Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, L69 3BX, United Kingdom
| | - Ales Marek
- Laboratory of Radioisotopes, Institute of Organic Chemistry and Biochemistry CAS, Flemingovo nám. 2, CZ-16610 Prague 6, Czech Republic
| | - Tomas Elbert
- Laboratory of Radioisotopes, Institute of Organic Chemistry and Biochemistry CAS, Flemingovo nám. 2, CZ-16610 Prague 6, Czech Republic
| | - Paul F. Alewood
- Institute for Molecular Bioscience, The University of Queensland, QLD 4072 Brisbane, Australia
| | - David E. Gloriam
- Department of Drug Design and Pharmacology, University of Copenhagen, Jagtvej 162, 2100 Copenhagen, Denmark
| | - Christian W. Gruber
- Center for Physiology and Pharmacology, Medical University of Vienna, Schwarzspanierstrasse 17, 1090 Vienna, Austria
- School of Biomedical Sciences, The University of Queensland, QLD 4072 Brisbane, Australia
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12
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Keov P, López L, Devine SM, Valant C, Lane JR, Scammells PJ, Sexton PM, Christopoulos A. Molecular mechanisms of bitopic ligand engagement with the M1 muscarinic acetylcholine receptor. J Biol Chem 2014; 289:23817-37. [PMID: 25006252 DOI: 10.1074/jbc.m114.582874] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
TBPB and 77-LH-28-1 are selective agonists of the M1 muscarinic acetylcholine receptor (mAChR) that may gain their selectivity through a bitopic mechanism, interacting concomitantly with the orthosteric site and part of an allosteric site. The current study combined site-directed mutagenesis, analytical pharmacology,and molecular modeling to gain further insights into the structural basis underlying binding and signaling by these agonists. Mutations within the orthosteric binding site caused similar reductions in affinity and signaling efficacy for both selective and prototypical orthosteric ligands. In contrast, the mutation of residues within transmembrane helix (TM) 2 and the second extracellular loop (ECL2) discriminated between the different classes of ligand. In particular, ECL2 appears to be involved in the selective binding of bitopic ligands and in coordinating biased agonism between intracellular calcium mobilization and ERK1/2 phosphorylation. Molecular modeling of the interaction between TBPB and the M1 mAChR revealed a binding pose predicted to extend from the orthosteric site up toward a putative allosteric site bordered by TM2, TM3, and TM7, thus consistent with a bitopic mode of binding. Overall, these findings provide valuable structural and mechanistic insights into bitopic ligand actions and receptor activation and support a role for ECL2 in dictating the active states that can be adopted by a G protein-coupled receptor. This may enable greater selective ligand design and development for mAChRs and facilitate improved identification of bitopic ligands.
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Affiliation(s)
- Peter Keov
- From the Drug Discovery Biology Theme and Department of Pharmacology and
| | - Laura López
- From the Drug Discovery Biology Theme and Department of Pharmacology and
| | - Shane M Devine
- the Medicinal Chemistry Theme, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria 3052, Australia
| | - Celine Valant
- From the Drug Discovery Biology Theme and Department of Pharmacology and
| | - J Robert Lane
- From the Drug Discovery Biology Theme and Department of Pharmacology and
| | - Peter J Scammells
- the Medicinal Chemistry Theme, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria 3052, Australia
| | - Patrick M Sexton
- From the Drug Discovery Biology Theme and Department of Pharmacology and
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Abdul-Ridha A, López L, Keov P, Thal DM, Mistry SN, Sexton PM, Lane JR, Canals M, Christopoulos A. Molecular determinants of allosteric modulation at the M1 muscarinic acetylcholine receptor. J Biol Chem 2014; 289:6067-79. [PMID: 24443568 DOI: 10.1074/jbc.m113.539080] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Benzylquinolone carboxylic acid (BQCA) is an unprecedented example of a selective positive allosteric modulator of acetylcholine at the M1 muscarinic acetylcholine receptor (mAChR). To probe the structural basis underlying its selectivity, we utilized site-directed mutagenesis, analytical modeling, and molecular dynamics to delineate regions of the M1 mAChR that govern modulator binding and transmission of cooperativity. We identified Tyr-85(2.64) in transmembrane domain 2 (TMII), Tyr-179 and Phe-182 in the second extracellular loop (ECL2), and Glu-397(7.32) and Trp-400(7.35) in TMVII as residues that contribute to the BQCA binding pocket at the M1 mAChR, as well as to the transmission of cooperativity with the orthosteric agonist carbachol. As such, the BQCA binding pocket partially overlaps with the previously described "common" allosteric site in the extracellular vestibule of the M1 mAChR, suggesting that its high subtype selectivity derives from either additional contacts outside this region or through a subtype-specific cooperativity mechanism. Mutation of amino acid residues that form the orthosteric binding pocket caused a loss of carbachol response that could be rescued by BQCA. Two of these residues (Leu-102(3.29) and Asp-105(3.32)) were also identified as indirect contributors to the binding affinity of the modulator. This new insight into the structural basis of binding and function of BQCA can guide the design of new allosteric ligands with tailored pharmacological properties.
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Keov P, Valant C, Devine SM, Lane JR, Scammells PJ, Sexton PM, Christopoulos A. Reverse Engineering of the Selective Agonist TBPB Unveils Both Orthosteric and Allosteric Modes of Action at the M1 Muscarinic Acetylcholine Receptor. Mol Pharmacol 2013; 84:425-37. [DOI: 10.1124/mol.113.087320] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
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