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Tokmakova A, Kim D, Guthrie B, Kim SK, Goddard WA, Liggett SB. Predicted structure and cell signaling of TAS2R14 reveal receptor hyper-flexibility for detecting diverse bitter tastes. iScience 2023; 26:106422. [PMID: 37096045 PMCID: PMC10121769 DOI: 10.1016/j.isci.2023.106422] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Revised: 02/24/2023] [Accepted: 03/11/2023] [Indexed: 03/18/2023] Open
Abstract
The 25 human bitter taste receptors (TAS2Rs) are expressed on taste and extra-oral cells representing an integrated chemosensory system. The archetypal TAS2R14 is activated by > 150 topographically diverse agonists, raising the question of how this uncharacteristic accommodation is achieved for these GPCRs. We report the computationally derived structure of TAS2R14 with binding sites and energies for five highly diverse agonists. Remarkably, the binding pocket is the same for all five agonists. The energies derived from molecular dynamics are consistent with experiments determining signal transduction coefficients in live cells. TAS2R14 accommodates agonists through the breaking of a TMD3 H-bond instead of the prototypic strong salt bridge, a TMD1,2,7 interaction different from Class A GPCRs, and agonist-promoted TMD3 salt bridges for high affinity (which we confirmed by receptor mutagenesis). Thus, the broadly tuned TAS2Rs accommodate diverse agonists via a single (vs multiple) binding pocket through unique TM interactions for sensing disparate micro-environments.
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Affiliation(s)
- Alina Tokmakova
- Materials and Process Simulation Center, California Institute of Technology, Pasadena, CA 91125, USA
| | - Donghwa Kim
- Department of Medicine, University of South Florida Morsani College of Medicine, Tampa, FL 33612, USA
- Center for Personalized Medicine and Genomics, University of South Florida Morsani College of Medicine, Tampa, FL 33612, USA
| | - Brian Guthrie
- Cargill Global Food Research Center, Wayzata, MN 55391, USA
| | - Soo-Kyung Kim
- Materials and Process Simulation Center, California Institute of Technology, Pasadena, CA 91125, USA
| | - William A. Goddard
- Materials and Process Simulation Center, California Institute of Technology, Pasadena, CA 91125, USA
| | - Stephen B. Liggett
- Department of Medicine, University of South Florida Morsani College of Medicine, Tampa, FL 33612, USA
- Center for Personalized Medicine and Genomics, University of South Florida Morsani College of Medicine, Tampa, FL 33612, USA
- Department of Molecular Pharmacology and Physiology, University of South Florida Morsani College of Medicine, Tampa, FL 33612, USA
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2
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Castner SA, Zhang L, Yang CR, Hao J, Cramer JW, Wang X, Bruns RF, Marston H, Svensson KA, Williams GV. Effects of DPTQ, a novel positive allosteric modulator of the dopamine D1 receptor, on spontaneous eye blink rate and spatial working memory in the nonhuman primate. Psychopharmacology (Berl) 2023; 240:1033-1048. [PMID: 36961560 PMCID: PMC10102062 DOI: 10.1007/s00213-022-06282-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Accepted: 11/23/2022] [Indexed: 03/25/2023]
Abstract
RATIONALE Dopamine (DA) signaling through the D1 receptor has been shown to be integral to multiple aspects of cognition, including the core process of working memory. The discovery of positive allosteric modulators (PAMs) of the D1 receptor has enabled treatment modalities that may have alternative benefits to orthosteric D1 agonists arising from a synergism of action with functional D1 receptor signaling. OBJECTIVES To investigate this potential, we have studied the effects of the novel D1 PAM DPTQ on a spatial delayed response working memory task in the rhesus monkey. Initial studies indicated that DPTQ binds to primate D1R with high affinity and selectivity and elevates spontaneous eye blink rate in rhesus monkeys in a dose-dependent manner consistent with plasma ligand exposures and central D1activation. RESULTS Based on those results, DPTQ was tested at 2.5 mg/kg IM in the working memory task. No acute effect was observed 1 h after dosing, but performance was impaired 48 h later. Remarkably, this deficit was immediately followed by a significant enhancement in cognition over the next 3 days. In a second experiment in which DPTQ was administered on days 1 and 5, the early impairment was smaller and did not reach statistical significance, but statistically significant enhancement of performance was observed over the following week. Lower doses of 0.1 and 1.0 mg/kg were also capable of producing this protracted enhancement without inducing any transient impairment. CONCLUSIONS DPTQ exemplifies a class of D1PAMs that may be capable of providing long-term improvements in working memory.
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Affiliation(s)
- Stacy A Castner
- Department of Comparative Medicine, Yale University, 310 Cedar St, New Haven, CT, 06520, USA
| | - Linli Zhang
- ChemPartner, 99 Lian He North Road, Zhe Lin Town, Fengxian Area, Shanghai, China
| | - Charles R Yang
- ChemPartner, 99 Lian He North Road, Zhe Lin Town, Fengxian Area, Shanghai, China
| | - Junliang Hao
- Eli Lilly & Co, Lilly Corporate Center, Indianapolis, IN, 46285, USA
| | - Jeffrey W Cramer
- Eli Lilly & Co, Lilly Corporate Center, Indianapolis, IN, 46285, USA
| | - Xushan Wang
- Eli Lilly & Co, Lilly Corporate Center, Indianapolis, IN, 46285, USA
| | - Robert F Bruns
- Eli Lilly & Co, Lilly Corporate Center, Indianapolis, IN, 46285, USA
| | | | - Kjell A Svensson
- Eli Lilly & Co, Lilly Corporate Center, Indianapolis, IN, 46285, USA
| | - Graham V Williams
- Department of Comparative Medicine, Yale University, 310 Cedar St, New Haven, CT, 06520, USA.
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3
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Yang Y. Functional Selectivity of Dopamine D 1 Receptor Signaling: Retrospect and Prospect. Int J Mol Sci 2021; 22:ijms222111914. [PMID: 34769344 PMCID: PMC8584964 DOI: 10.3390/ijms222111914] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Revised: 10/18/2021] [Accepted: 11/01/2021] [Indexed: 11/16/2022] Open
Abstract
Research progress on dopamine D1 receptors indicates that signaling no longer is limited to G protein-dependent cyclic adenosine monophosphate phosphorylation but also includes G protein-independent β-arrestin-related mitogen-activated protein kinase activation, regulation of ion channels, phospholipase C activation, and possibly more. This review summarizes recent studies revealing the complexity of D1 signaling and its clinical implications, and suggests functional selectivity as a promising strategy for drug discovery to magnify the merit of D1 signaling. Functional selectivity/biased receptor signaling has become a major research front because of its potential to improve therapeutics through precise targeting. Retrospective pharmacological review indicated that many D1 ligands have some degree of mild functional selectivity, and novel compounds with extreme bias at D1 signaling were reported recently. Behavioral and neurophysiological studies inspired new methods to investigate functional selectivity and gave insight into the biased signaling of several drugs. Results from recent clinical trials also supported D1 functional selectivity signaling as a promising strategy for discovery and development of better therapeutics.
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Affiliation(s)
- Yang Yang
- Department of Pharmacology, Penn State University College of Medicine, Hershey, PA 17033, USA
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4
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Abi-Dargham A, Javitch JA, Slifstein M, Anticevic A, Calkins ME, Cho YT, Fonteneau C, Gil R, Girgis R, Gur RE, Gur RC, Grinband J, Kantrowitz J, Kohler C, Krystal J, Murray J, Ranganathan M, Santamauro N, Van Snellenberg J, Tamayo Z, Wolf D, Gray D, Lieberman J. Dopamine D1R Receptor Stimulation as a Mechanistic Pro-cognitive Target for Schizophrenia. Schizophr Bull 2021; 48:199-210. [PMID: 34423843 PMCID: PMC8781338 DOI: 10.1093/schbul/sbab095] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Decades of research have highlighted the importance of optimal stimulation of cortical dopaminergic receptors, particularly the D1R receptor (D1R), for prefrontal-mediated cognition. This mechanism is particularly relevant to the cognitive deficits in schizophrenia, given the abnormalities in cortical dopamine (DA) neurotransmission and in the expression of D1R. Despite the critical need for D1R-based therapeutics, many factors have complicated their development and prevented this important therapeutic target from being adequately interrogated. Challenges include determination of the optimal level of D1R stimulation needed to improve cognitive performance, especially when D1R expression levels, affinity states, DA levels, and the resulting D1R occupancy by DA, are not clearly known in schizophrenia, and may display great interindividual and intraindividual variability related to cognitive states and other physiological variables. These directly affect the selection of the level of stimulation necessary to correct the underlying neurobiology. The optimal mechanism for stimulation is also unknown and could include partial or full agonism, biased agonism, or positive allosteric modulation. Furthermore, the development of D1R targeting drugs has been complicated by complexities in extrapolating from in vitro affinity determinations to in vivo use. Prior D1R-targeted drugs have been unsuccessful due to poor bioavailability, pharmacokinetics, and insufficient target engagement at tolerable doses. Newer drugs have recently become available, and these must be tested in the context of carefully designed paradigms that address methodological challenges. In this paper, we discuss how a better understanding of these challenges has shaped our proposed experimental design for testing a new D1R/D5R partial agonist, PF-06412562, renamed CVL-562.
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Affiliation(s)
- Anissa Abi-Dargham
- Department of Psychiatry, Stony Brook Renaissance School of Medicine, Stony Brook, NY, USA,Department of Psychiatry, New York State Psychaitric Institute, Columbia University, New York, NY, USA,Department of Psychiatry, Yale University, New Haven, CT, USA,Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA,Cerevel Therapeutics Research and Development, Boston, MA, USA,To whom correspondence should be addressed; Tel: +(631) 885-0814; e-mail:
| | - Jonathan A Javitch
- Department of Psychiatry, New York State Psychaitric Institute, Columbia University, New York, NY, USA
| | - Mark Slifstein
- Department of Psychiatry, Stony Brook Renaissance School of Medicine, Stony Brook, NY, USA
| | - Alan Anticevic
- Department of Psychiatry, Yale University, New Haven, CT, USA
| | - Monica E Calkins
- Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Youngsun T Cho
- Department of Psychiatry, Yale University, New Haven, CT, USA
| | - Clara Fonteneau
- Department of Psychiatry, Yale University, New Haven, CT, USA
| | - Roberto Gil
- Department of Psychiatry, Stony Brook Renaissance School of Medicine, Stony Brook, NY, USA
| | - Ragy Girgis
- Department of Psychiatry, New York State Psychaitric Institute, Columbia University, New York, NY, USA
| | - Raquel E Gur
- Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Ruben C Gur
- Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Jack Grinband
- Department of Psychiatry, New York State Psychaitric Institute, Columbia University, New York, NY, USA
| | - Joshua Kantrowitz
- Department of Psychiatry, New York State Psychaitric Institute, Columbia University, New York, NY, USA
| | - Christian Kohler
- Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - John Krystal
- Department of Psychiatry, Yale University, New Haven, CT, USA
| | - John Murray
- Department of Psychiatry, Yale University, New Haven, CT, USA
| | | | | | - Jared Van Snellenberg
- Department of Psychiatry, Stony Brook Renaissance School of Medicine, Stony Brook, NY, USA
| | - Zailyn Tamayo
- Department of Psychiatry, Yale University, New Haven, CT, USA
| | - Daniel Wolf
- Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | | | - David Gray
- Cerevel Therapeutics Research and Development, Boston, MA, USA
| | - Jeffrey Lieberman
- Department of Psychiatry, New York State Psychaitric Institute, Columbia University, New York, NY, USA
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5
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Fyfe TJ, Scammells PJ, Lane JR, Capuano B. Enantioenriched Positive Allosteric Modulators Display Distinct Pharmacology at the Dopamine D 1 Receptor. Molecules 2021; 26:molecules26133799. [PMID: 34206465 PMCID: PMC8270344 DOI: 10.3390/molecules26133799] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 06/15/2021] [Accepted: 06/17/2021] [Indexed: 12/19/2022] Open
Abstract
(1) Background: Two first-in-class racemic dopamine D1 receptor (D1R) positive allosteric modulator (PAM) chemotypes (1 and 2) were identified from a high-throughput screen. In particular, due to its selectivity for the D1R and reported lack of intrinsic activity, compound 2 shows promise as a starting point toward the development of small molecule allosteric modulators to ameliorate the cognitive deficits associated with some neuropsychiatric disease states; (2) Methods: Herein, we describe the enantioenrichment of optical isomers of 2 using chiral auxiliaries derived from (R)- and (S)-3-hydroxy-4,4-dimethyldihydrofuran-2(3H)-one (d- and l-pantolactone, respectively); (3) Results: We confirm both the racemate and enantiomers of 2 are active and selective for the D1R, but that the respective stereoisomers show a significant difference in their affinity and magnitude of positive allosteric cooperativity with dopamine; (4) Conclusions: These data warrant further investigation of asymmetric syntheses of optically pure analogues of 2 for the development of D1R PAMs with superior allosteric properties.
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Affiliation(s)
- Tim J. Fyfe
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC 3052, Australia; (T.J.F.); (P.J.S.)
| | - Peter J. Scammells
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC 3052, Australia; (T.J.F.); (P.J.S.)
| | - J. Robert Lane
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC 3052, Australia
- School of Life Sciences, Queen’s Medical Centre, University of Nottingham, Nottingham NG7 2UH, UK
- Correspondence: (J.R.L.); (B.C.)
| | - Ben Capuano
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC 3052, Australia; (T.J.F.); (P.J.S.)
- Correspondence: (J.R.L.); (B.C.)
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6
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Sałaciak K, Pytka K. Biased agonism in drug discovery: Is there a future for biased 5-HT 1A receptor agonists in the treatment of neuropsychiatric diseases? Pharmacol Ther 2021; 227:107872. [PMID: 33905796 DOI: 10.1016/j.pharmthera.2021.107872] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Revised: 04/17/2021] [Accepted: 04/19/2021] [Indexed: 12/11/2022]
Abstract
Serotonin (5-HT) is one of the fundamental neurotransmitters that contribute to the information essential for an organism's normal, physiological function. Serotonin acts centrally and systemically. The 5-HT1A receptor is the most widespread serotonin receptor, and participates in many brain-related disorders, including anxiety, depression, and cognitive impairments. The 5-HT1A receptor can activate several different biochemical pathways and signals through both G protein-dependent and G protein-independent pathways. Preclinical experiments indicate that distinct signaling pathways in specific brain regions may be crucial for antidepressant-like, anxiolytic-like, and procognitive responses. Therefore, the development of new ligands that selectively target a particular signaling pathway(s) could open new possibilities for more effective and safer pharmacotherapy. This review discusses the current state of preclinical studies focusing on the concept of functional selectivity (biased agonism) regarding the 5-HT1A receptor and its role in antidepressant-like, anxiolytic-like, and procognitive regulation. Such work highlights not only the differential effects of targeted autoreceptors, vs. heteroreceptors, but also the importance of targeting specific downstream intracellular signaling processes, thereby enhancing favorable over unfavorable signaling activation.
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Affiliation(s)
- Kinga Sałaciak
- Department of Pharmacodynamics, Faculty of Pharmacy, Jagiellonian University Medical College, Medyczna 9, 30-688 Krakow, Poland
| | - Karolina Pytka
- Department of Pharmacodynamics, Faculty of Pharmacy, Jagiellonian University Medical College, Medyczna 9, 30-688 Krakow, Poland.
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7
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Yang Y, Lee SM, Imamura F, Gowda K, Amin S, Mailman RB. D1 dopamine receptors intrinsic activity and functional selectivity affect working memory in prefrontal cortex. Mol Psychiatry 2021; 26:645-655. [PMID: 30532019 PMCID: PMC9710464 DOI: 10.1038/s41380-018-0312-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Revised: 11/14/2018] [Accepted: 11/15/2018] [Indexed: 01/29/2023]
Abstract
Dopamine D1 agonists enhance cognition, but the role of different signaling pathways (e.g., cAMP or β-arrestin) is unclear. The current study compared 2-methyldihydrexidine and CY208,243, drugs with different degrees of both D1 intrinsic activity and functional selectivity. 2-Methyldihydrexidine is a full agonist at adenylate cyclase and a super-agonist at β-arrestin recruitment, whereas CY208,243 has relatively high intrinsic activity at adenylate cyclase, but much lower at β-arrestin recruitment. Both drugs decreased, albeit in dissimilar ways, the firing rate of neurons in prefrontal cortex sensitive to outcome-related aspects of a working memory task. 2-Methyldihydrexidine was superior to CY208,243 in prospectively enhancing similarity and retrospectively distinguishing differences between correct and error outcomes based on firing rates, enhancing the micro-network measured by oscillations of spikes and local field potentials, and improving behavioral performance. This study is the first to examine how ligand signaling bias affects both behavioral and neurophysiological endpoints in the intact animal. The data show that maximal enhancement of cognition via D1 activation occurred with a pattern of signaling that involved full unbiased intrinsic activity, or agonists with high β-arrestin activity.
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Affiliation(s)
- Yang Yang
- Department of Pharmacology, Penn State University College of Medicine, Hershey, PA, 17033, USA.
| | - Sang-Min Lee
- Department of Pharmacology, Penn State University College of Medicine, Hershey PA 17033
| | - Fumiaki Imamura
- Department of Pharmacology, Penn State University College of Medicine, Hershey PA 17033
| | - Krishne Gowda
- Department of Pharmacology, Penn State University College of Medicine, Hershey PA 17033
| | - Shantu Amin
- Department of Pharmacology, Penn State University College of Medicine, Hershey PA 17033
| | - Richard B. Mailman
- Department of Neurology, Penn State University College of Medicine, Hershey PA 17033.,Department of Pharmacology, Penn State University College of Medicine, Hershey PA 17033.,Correspondence to: ,
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8
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Zhao Z, Kang K, Yue J, Ji X, Qiao H, Fan P, Zheng X. Research progress in biological activities of isochroman derivatives. Eur J Med Chem 2020; 210:113073. [PMID: 33310287 DOI: 10.1016/j.ejmech.2020.113073] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Revised: 11/16/2020] [Accepted: 11/29/2020] [Indexed: 10/22/2022]
Abstract
Isochromans are well recognized heterocyclic compounds in drug discovery which produce diverse therapeutically related applications in pharmacological practices. Medicinal chemistry investigators have synthesized drug-like isochroman candidates with multiple medicinal features including central nervous system (CNS), antioxidant, antimicrobial, antihypertensive, antitumor and anti-inflammatory agents. Simultaneously, SAR (Structure-Activity Relationship) analysis has drawn attentions among medicinal chemists, along with a great deal of derivatives have been derived for potential targets. In this article, we thoroughly summarize the biological activities and part of typical SAR for isochroman derivatives reported on existing literatures and patents, wishing to provide an overall retrospect and prospect on the isochroman analogues.
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Affiliation(s)
- Zefeng Zhao
- College of Acupuncture & Massage, Shaanxi University of Chinese Medicine, Xixian New Area, Shaanxi Province, 712046, PR China; Shaanxi Key Laboratory of Acupuncture & Medicine, Xixian New Area, Shaanxi Province, 712046, PR China; School of Pharmacy, Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, Biomedicine Key Laboratory of Shaanxi Province, Northwest University, 229 Taibai Road, Xi'an, 710069, PR China
| | - Kaiwen Kang
- Shaanxi Key Laboratory of Acupuncture & Medicine, Xixian New Area, Shaanxi Province, 712046, PR China
| | - Jiangxin Yue
- Shaanxi Key Laboratory of Acupuncture & Medicine, Xixian New Area, Shaanxi Province, 712046, PR China
| | - Xiaotong Ji
- Shaanxi Key Laboratory of Acupuncture & Medicine, Xixian New Area, Shaanxi Province, 712046, PR China
| | - Haifa Qiao
- College of Acupuncture & Massage, Shaanxi University of Chinese Medicine, Xixian New Area, Shaanxi Province, 712046, PR China; Shaanxi Key Laboratory of Acupuncture & Medicine, Xixian New Area, Shaanxi Province, 712046, PR China.
| | - Peinan Fan
- School of Pharmacy, Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, Biomedicine Key Laboratory of Shaanxi Province, Northwest University, 229 Taibai Road, Xi'an, 710069, PR China
| | - Xiaohui Zheng
- School of Pharmacy, Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, Biomedicine Key Laboratory of Shaanxi Province, Northwest University, 229 Taibai Road, Xi'an, 710069, PR China
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9
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Seyedabadi M, Ghahremani MH, Albert PR. Biased signaling of G protein coupled receptors (GPCRs): Molecular determinants of GPCR/transducer selectivity and therapeutic potential. Pharmacol Ther 2019; 200:148-178. [PMID: 31075355 DOI: 10.1016/j.pharmthera.2019.05.006] [Citation(s) in RCA: 89] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Accepted: 04/26/2019] [Indexed: 02/07/2023]
Abstract
G protein coupled receptors (GPCRs) convey signals across membranes via interaction with G proteins. Originally, an individual GPCR was thought to signal through one G protein family, comprising cognate G proteins that mediate canonical receptor signaling. However, several deviations from canonical signaling pathways for GPCRs have been described. It is now clear that GPCRs can engage with multiple G proteins and the line between cognate and non-cognate signaling is increasingly blurred. Furthermore, GPCRs couple to non-G protein transducers, including β-arrestins or other scaffold proteins, to initiate additional signaling cascades. Receptor/transducer selectivity is dictated by agonist-induced receptor conformations as well as by collateral factors. In particular, ligands stabilize distinct receptor conformations to preferentially activate certain pathways, designated 'biased signaling'. In this regard, receptor sequence alignment and mutagenesis have helped to identify key receptor domains for receptor/transducer specificity. Furthermore, molecular structures of GPCRs bound to different ligands or transducers have provided detailed insights into mechanisms of coupling selectivity. However, receptor dimerization, compartmentalization, and trafficking, receptor-transducer-effector stoichiometry, and ligand residence and exposure times can each affect GPCR coupling. Extrinsic factors including cell type or assay conditions can also influence receptor signaling. Understanding these factors may lead to the development of improved biased ligands with the potential to enhance therapeutic benefit, while minimizing adverse effects. In this review, evidence for ligand-specific GPCR signaling toward different transducers or pathways is elaborated. Furthermore, molecular determinants of biased signaling toward these pathways and relevant examples of the potential clinical benefits and pitfalls of biased ligands are discussed.
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Affiliation(s)
- Mohammad Seyedabadi
- Department of Pharmacology, School of Medicine, Bushehr University of Medical Sciences, Iran; Education Development Center, Bushehr University of Medical Sciences, Iran
| | | | - Paul R Albert
- Ottawa Hospital Research Institute, Neuroscience, University of Ottawa, Canada.
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10
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Yano H, Cai NS, Xu M, Verma RK, Rea W, Hoffman AF, Shi L, Javitch JA, Bonci A, Ferré S. Gs- versus Golf-dependent functional selectivity mediated by the dopamine D 1 receptor. Nat Commun 2018; 9:486. [PMID: 29402888 PMCID: PMC5799184 DOI: 10.1038/s41467-017-02606-w] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2017] [Accepted: 12/09/2017] [Indexed: 12/13/2022] Open
Abstract
The two highly homologous subtypes of stimulatory G proteins Gαs (Gs) and Gαolf (Golf) display contrasting expression patterns in the brain. Golf is predominant in the striatum, while Gs is predominant in the cortex. Yet, little is known about their functional distinctions. The dopamine D1 receptor (D1R) couples to Gs/olf and is highly expressed in cortical and striatal areas, making it an important therapeutic target for neuropsychiatric disorders. Using novel drug screening methods that allow analysis of specific G-protein subtype coupling, we found that, relative to dopamine, dihydrexidine and N-propyl-apomorphine behave as full D1R agonists when coupled to Gs, but as partial D1R agonists when coupled to Golf. The Gs/Golf-dependent biased agonism by dihydrexidine was consistently observed at the levels of cellular signaling, neuronal function, and behavior. Our findings of Gs/Golf-dependent functional selectivity in D1R ligands open a new avenue for the treatment of cortex-specific or striatum-specific neuropsychiatric dysfunction.
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Affiliation(s)
- Hideaki Yano
- National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD, 21224, USA.
| | - Ning-Sheng Cai
- National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD, 21224, USA
| | - Min Xu
- National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD, 21224, USA
| | - Ravi Kumar Verma
- National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD, 21224, USA
| | - William Rea
- National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD, 21224, USA
| | - Alexander F Hoffman
- National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD, 21224, USA
| | - Lei Shi
- National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD, 21224, USA
| | - Jonathan A Javitch
- Department of Psychiatry, College of Physicians & Surgeons, Columbia University, New York, NY, 10032, USA
- Division of Molecular Therapeutics, New York State Psychiatric Institute, New York, NY, 10032, USA
| | - Antonello Bonci
- National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD, 21224, USA
| | - Sergi Ferré
- National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD, 21224, USA
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11
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Mallipeddi S, Janero DR, Zvonok N, Makriyannis A. Functional selectivity at G-protein coupled receptors: Advancing cannabinoid receptors as drug targets. Biochem Pharmacol 2017; 128:1-11. [PMID: 27890725 PMCID: PMC5470118 DOI: 10.1016/j.bcp.2016.11.014] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Accepted: 11/14/2016] [Indexed: 12/11/2022]
Abstract
The phenomenon of functional selectivity, whereby a ligand preferentially directs the information output of a G-protein coupled receptor (GPCR) along (a) particular effector pathway(s) and away from others, has redefined traditional GPCR signaling paradigms to provide a new approach to structure-based drug design. The two principal cannabinoid receptors (CBRs) 1 and 2 belong to the class-A GPCR subfamily and are considered tenable therapeutic targets for several indications. Yet conventional orthosteric ligands (agonists, antagonists/inverse agonists) for these receptors have had very limited clinical utility due to their propensity to incite on-target adverse events. Chemically distinct classes of cannabinergic ligands exhibit signaling bias at CBRs towards individual subsets of signal transduction pathways. In this review, we discuss the known signaling pathways regulated by CBRs and examine the current evidence for functional selectivity at CBRs in response to endogenous and exogenous cannabinergic ligands as biased agonists. We further discuss the receptor and ligand structural features allowing for selective activation of CBR-dependent functional responses. The design and development of biased ligands may offer a pathway to therapeutic success for novel CBR-targeted drugs.
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Affiliation(s)
- Srikrishnan Mallipeddi
- Department of Pharmaceutical Sciences, Northeastern University, Boston, MA 02115, United States; Center for Drug Discovery, Northeastern University, Boston, MA 02115, United States
| | - David R Janero
- Department of Pharmaceutical Sciences, Northeastern University, Boston, MA 02115, United States; Center for Drug Discovery, Northeastern University, Boston, MA 02115, United States
| | - Nikolai Zvonok
- Department of Pharmaceutical Sciences, Northeastern University, Boston, MA 02115, United States; Center for Drug Discovery, Northeastern University, Boston, MA 02115, United States
| | - Alexandros Makriyannis
- Department of Pharmaceutical Sciences, Northeastern University, Boston, MA 02115, United States; Center for Drug Discovery, Northeastern University, Boston, MA 02115, United States; Department of Chemistry and Chemical Biology, Northeastern University, Boston, MA 02115, United States.
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12
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Arnsten AF, Girgis RR, Gray DI, Mailman RB. Novel Dopamine Therapeutics for Cognitive Deficits in Schizophrenia. Biol Psychiatry 2017; 81:67-77. [PMID: 26946382 PMCID: PMC4949134 DOI: 10.1016/j.biopsych.2015.12.028] [Citation(s) in RCA: 111] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Revised: 11/25/2015] [Accepted: 12/31/2015] [Indexed: 11/30/2022]
Abstract
Schizophrenia is characterized by profound cognitive deficits that are not alleviated by currently available medications. Many of these cognitive deficits involve dysfunction of the newly evolved, dorsolateral prefrontal cortex (dlPFC). The brains of patients with schizophrenia show evidence of dlPFC pyramidal cell dendritic atrophy, likely reductions in cortical dopamine, and possible changes in dopamine D1 receptors (D1R). It has been appreciated for decades that optimal levels of dopamine are essential for dlPFC working memory function, with many beneficial actions arising from D1R stimulation. D1R are concentrated on dendritic spines in the primate dlPFC, where their stimulation produces an inverted-U dose response on dlPFC neuronal firing and cognitive performance during working memory tasks. Research in both academia and the pharmaceutical industry has led to the development of selective D1 agonists, e.g., the first full D1 agonist, dihydrexidine, which at low doses improved working memory in monkeys. Dihydrexidine has begun to be tested in patients with schizophrenia or schizotypal disorder. Initial results are encouraging, but studies are limited by the pharmacokinetics of the drug. These data, however, have spurred efforts toward the discovery and development of improved or novel new compounds, including D1 agonists with better pharmacokinetics, functionally selective D1 ligands, and D1R positive allosteric modulators. One or several of these approaches should allow optimization of the beneficial effects of D1R stimulation in the dlPFC that can be translated into clinical practice.
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Affiliation(s)
- Amy F.T. Arnsten
- Department of Neurobiology, Yale Medical School, New Haven, CT 06510
| | - Ragy R. Girgis
- Department of Psychiatry, College of Physicians and Surgeons, Columbia University, New York, NY 10032
| | - David I. Gray
- Neuroscience & Pain Research Unit, Pfizer Worldwide Research and Development, Cambridge, MA 02139
| | - Richard B. Mailman
- Department of Pharmacology, Pennsylvania State University College of Medicine, Hershey, PA 17036
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13
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Bai G, Cheung I, Shulha HP, Coelho JE, Li P, Dong X, Jakovcevski M, Wang Y, Grigorenko A, Jiang Y, Hoss A, Patel K, Zheng M, Rogaev E, Myers RH, Weng Z, Akbarian S, Chen JF. Epigenetic dysregulation of hairy and enhancer of split 4 (HES4) is associated with striatal degeneration in postmortem Huntington brains. Hum Mol Genet 2014; 24:1441-56. [PMID: 25480889 DOI: 10.1093/hmg/ddu561] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
To investigate epigenetic contributions to Huntington's disease (HD) pathogenesis, we carried out genome-wide mapping of the transcriptional mark, trimethyl-histone H3-lysine 4 (H3K4me3) in neuronal nuclei extracted from prefrontal cortex of HD cases and controls using chromatin immunoprecipitation followed by deep-sequencing. Neuron-specific mapping of the genome-wide distribution of H3K4me3 revealed 136 differentially enriched loci associated with genes implicated in neuronal development and neurodegeneration, including GPR3, TMEM106B, PDIA6 and the Notch signaling genes hairy and enhancer of split 4 (HES4) and JAGGED2, supporting the view that the neuronal epigenome is affected in HD. Importantly, loss of H3K4me3 at CpG-rich sequences on the HES4 promoter was associated with excessive DNA methylation, reduced binding of nuclear proteins to the methylated region and altered expression of HES4 and HES4 targeted genes MASH1 and P21 involved in striatal development. Moreover, hypermethylation of HES4 promoter sequences was strikingly correlated with measures of striatal degeneration and age-of-onset in a cohort of 25 HD brains (r = 0.56, P = 0.006). Lastly, shRNA knockdown of HES4 in human neuroblastoma cells altered MASH1 and P21 mRNA expression and markedly increased mutated HTT-induced aggregates and cell death. These findings, taken together, suggest that epigenetic dysregulation of HES4 could play a critical role in modifying HD disease pathogenesis and severity.
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Affiliation(s)
- Guang Bai
- Department of Neural and Pain Sciences, University of Maryland Dental School, Baltimore, MD 21201, USA
| | - Iris Cheung
- Brudnick Neuropsychiatric Research Institute
| | - Hennady P Shulha
- Program in Bioinformatics and Integrative Biology, Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA 01604, USA
| | - Joana E Coelho
- Department of Neurology, Boston University School of Medicine, 715 Albany Street, Boston, MA 02118, USA
| | - Ping Li
- Department of Neurology, Boston University School of Medicine, 715 Albany Street, Boston, MA 02118, USA
| | - Xianjun Dong
- Program in Bioinformatics and Integrative Biology, Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA 01604, USA
| | | | - Yumei Wang
- Department of Neurology, Boston University School of Medicine, 715 Albany Street, Boston, MA 02118, USA
| | | | - Yan Jiang
- Friedman Brain Institute, Department of Psychiatry, Mount Sinai School of Medicine, New York, NY 10029, USA
| | - Andrew Hoss
- Department of Neurology, Boston University School of Medicine, 715 Albany Street, Boston, MA 02118, USA
| | - Krupal Patel
- Department of Neural and Pain Sciences, University of Maryland Dental School, Baltimore, MD 21201, USA
| | - Ming Zheng
- Department of Neural and Pain Sciences, University of Maryland Dental School, Baltimore, MD 21201, USA
| | | | - Richard H Myers
- Department of Neurology, Boston University School of Medicine, 715 Albany Street, Boston, MA 02118, USA, Genome Science Institute, Boston University School of Medicine, 72 East Concord Street, Boston, MA 02118, USA
| | - Zhiping Weng
- Program in Bioinformatics and Integrative Biology, Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA 01604, USA
| | - Schahram Akbarian
- Brudnick Neuropsychiatric Research Institute, Friedman Brain Institute, Department of Psychiatry, Mount Sinai School of Medicine, New York, NY 10029, USA
| | - Jiang-Fan Chen
- Department of Neurology, Boston University School of Medicine, 715 Albany Street, Boston, MA 02118, USA,
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14
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Lee SM, Yang Y, Mailman RB. Dopamine D1 receptor signaling: does GαQ-phospholipase C actually play a role? J Pharmacol Exp Ther 2014; 351:9-17. [PMID: 25052835 DOI: 10.1124/jpet.114.214411] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Despite numerous studies showing therapeutic potential, no central dopamine D1 receptor ligand has ever been approved, because of potential limitations, such as hypotension, seizures, and tolerance. Functional selectivity has been widely recognized as providing a potential mechanism to develop novel therapeutics from existing targets, and a highly biased, functionally selective D1 ligand might overcome some of the past limitations. SKF-83959 [6-chloro-3-methyl-1-(m-tolyl)-2,3,4,5-tetrahydro-1H-benzo[d]azepine-7,8-diol] is reported to be a highly biased D1 ligand, having full agonism at D1-mediated activation of phospholipase C (PLC) signaling (via GαQ) and antagonism at D1-mediated adenylate cyclase signaling (via GαOLF/S). For this reason, numerous studies have used this compound to elucidate the physiologic role of D1-PLC signaling, including a novel molecular mechanism (GαQ-PLC activation via D1-D2 heterodimers). There is, however, contradictory literature that suggests that SKF-83959 is actually a partial agonist at both D1-mediated adenylate cyclase and β-arrestin recruitment. Moreover, the D1-mediated PLC stimulation has also been questioned. This Minireview examines 30 years of relevant literature and proposes that the data strongly favor alternate hypotheses: first, that SKF-83959 is a typical D1 partial agonist; and second, that the reported activation of PLC by SKF-83959 and related benzazepines likely is due to off-target effects, not actions at D1 receptors. If these hypotheses are supported by future studies, it would suggest that caution should be used regarding the role of PLC and downstream pathways in D1 signaling.
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Affiliation(s)
- Sang-Min Lee
- Departments of Pharmacology (S.-M.L., Y.Y., R.B.M.) and Neurology (Y.Y., R.B.M.), Pennsylvania State University College of Medicine, Hershey, Pennsylvania
| | - Yang Yang
- Departments of Pharmacology (S.-M.L., Y.Y., R.B.M.) and Neurology (Y.Y., R.B.M.), Pennsylvania State University College of Medicine, Hershey, Pennsylvania
| | - Richard B Mailman
- Departments of Pharmacology (S.-M.L., Y.Y., R.B.M.) and Neurology (Y.Y., R.B.M.), Pennsylvania State University College of Medicine, Hershey, Pennsylvania
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15
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Luttrell LM. Minireview: More than just a hammer: ligand "bias" and pharmaceutical discovery. Mol Endocrinol 2014; 28:281-94. [PMID: 24433041 DOI: 10.1210/me.2013-1314] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Conventional orthosteric drug development programs targeting G protein-coupled receptors (GPCRs) have focused on the concepts of agonism and antagonism, in which receptor structure determines the nature of the downstream signal and ligand efficacy determines its intensity. Over the past decade, the emerging paradigms of "pluridimensional efficacy" and "functional selectivity" have revealed that GPCR signaling is not monolithic, and that ligand structure can "bias" signal output by stabilizing active receptor states in different proportions than the native ligand. Biased ligands are novel pharmacologic entities that possess the unique ability to qualitatively change GPCR signaling, in effect creating "new receptors" with distinct efficacy profiles driven by ligand structure. The promise of biased agonism lies in this ability to engender "mixed" effects not attainable using conventional agonists or antagonists, promoting therapeutically beneficial signals while antagonizing deleterious ones. Indeed, arrestin pathway-selective agonists for the type 1 parathyroid hormone and angiotensin AT1 receptors, and G protein pathway-selective agonists for the GPR109A nicotinic acid and μ-opioid receptors, have demonstrated unique, and potentially therapeutic, efficacy in cell-based assays and preclinical animal models. Conversely, activating GPCRs in "unnatural" ways may lead to downstream biological consequences that cannot be predicted from prior knowledge of the actions of the native ligand, especially in the case of ligands that selectively activate as-yet poorly characterized G protein-independent signaling networks mediated via arrestins. Although much needs to be done to realize the clinical potential of functional selectivity, biased GPCR ligands nonetheless appear to be important new additions to the pharmacologic toolbox.
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Affiliation(s)
- Louis M Luttrell
- Department of Medicine and Department of Biochemistry & Molecular Biology, Medical University of South Carolina, Charleston, South Carolina 29425; and Ralph H. Johnson Veterans Affairs Medical Center, Charleston, South Carolina 29401
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16
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Abstract
It is now established that agonists do not uniformly activate pleiotropic signaling mechanisms initiated by receptors but rather can bias signals according to the unique receptor conformations they stabilize. One of the important emerging signaling systems where this can occur is through β-arrestin. This chapter discusses biased signaling where emphasis or de-emphasis of β-arrestin signaling is postulated (or been shown) to be beneficial. The chapter specifically focuses on methods to quantify biased effects; these methods furnish scales that can be used in the process of optimizing biased agonism (and antagonism) for therapeutic benefit. Specifically, methods to derive ΔΔLog(τ/K A) or ΔΔLog(Relative Activity) values are described to do this.
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Affiliation(s)
- Terry Kenakin
- Department of Pharmacology, University of North Carolina School of Medicine, 120 Mason Farm Road, Room 4042, Genetic Medicine Building, CB# 7365, Chapel Hill, NC, 27599-7365, USA,
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17
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Wanka L, Iqbal K, Schreiner PR. The lipophilic bullet hits the targets: medicinal chemistry of adamantane derivatives. Chem Rev 2013; 113:3516-604. [PMID: 23432396 PMCID: PMC3650105 DOI: 10.1021/cr100264t] [Citation(s) in RCA: 441] [Impact Index Per Article: 40.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Lukas Wanka
- Institute of Organic Chemistry, Justus-Liebig University Giessen, Heinrich-Buff-Ring 58, 35392 Giessen, Germany; Fax +49(641)9934309
- Department of Neurochemistry, New York State Institute for Basic Research in Developmental Disabilities, 1050 Forest Hill Road, Staten Island, NY 10314-6399, USA
| | - Khalid Iqbal
- Department of Neurochemistry, New York State Institute for Basic Research in Developmental Disabilities, 1050 Forest Hill Road, Staten Island, NY 10314-6399, USA
| | - Peter R. Schreiner
- Institute of Organic Chemistry, Justus-Liebig University Giessen, Heinrich-Buff-Ring 58, 35392 Giessen, Germany; Fax +49(641)9934309
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18
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Kenakin T. The potential for selective pharmacological therapies through biased receptor signaling. BMC Pharmacol Toxicol 2012; 13:3. [PMID: 22947056 PMCID: PMC3506267 DOI: 10.1186/2050-6511-13-3] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2012] [Accepted: 08/13/2012] [Indexed: 11/10/2022] Open
Abstract
The discovery that not all agonists uniformly activate cellular signaling pathways (biased signaling) has greatly changed the drug discovery process for agonists and the strategy for treatment of disease with agonists. Technological advances have enabled complex receptor behaviors to be viewed independently and through these assays, the bias for an agonist can be quantified. It is predicted that therapeutic phenotypes will be linked, through translational studies, to quantified scales of bias to guide medicinal chemists in the drug discovery process.
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Affiliation(s)
- Terry Kenakin
- Department of Pharmacology, University of North Carolina School of Medicine, 120 Mason Farm Road, Room 4042 Genetic Medicine Building, CB# 7365, Chapel Hill, NC 27599-7365, USA.
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19
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Malo M, Brive L, Luthman K, Svensson P. Investigation of D₁ receptor-agonist interactions and D₁/D₂ agonist selectivity using a combination of pharmacophore and receptor homology modeling. ChemMedChem 2012; 7:483-94, 338. [PMID: 22315216 PMCID: PMC3382191 DOI: 10.1002/cmdc.201100546] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2011] [Revised: 01/05/2012] [Indexed: 11/10/2022]
Abstract
The aim of this study was to use a combined structure and pharmacophore modeling approach to extract information regarding dopamine D₁ receptor agonism and D₁/D₂ agonist selectivity. A 3D structure model of the D₁ receptor in its agonist-bound state was constructed with a full D₁ agonist present in the binding site. Two different binding modes were identified using (+)-doxanthrine or SKF89626 in the modeling procedure. The 3D model was further compared with a selective D₁ agonist pharmacophore model. The pharmacophore feature arrangement was found to be in good agreement with the binding site composition of the receptor model, but the excluded volumes did not fully reflect the shape of the agonist binding pocket. A new receptor-based pharmacophore model was developed with forbidden volumes centered on atom positions of amino acids in the binding site. The new pharmacophore model showed a similar ability to discriminate as the previous model. A comparison of the 3D structures and pharmacophore models of D₁ and D₂ receptors revealed differences in shape and ligand-interacting features that determine selectivity of D₁ and D₂ receptor agonists. A hydrogen bond pharmacophoric feature (Ser-TM5) was shown to contribute most to the selectivity. Non-conserved residues in the binding pocket that strongly contribute to D₁/D₂ receptor agonist selectivity were also identified; those were Ser/Cys³·³⁶, Tyr/Phe⁵·³⁸, Ser/Tyr⁵·⁴¹, and Asn/His⁶·⁵⁵ in the transmembrane (TM) helix region, together with Ser/Ile and Leu/Asn in the second extracellular loop (EC2). This work provides useful information for the design of new selective D₁ and D₂ agonists. The combined receptor structure and pharmacophore modeling approach is considered to be general, and could therefore be applied to other ligand-protein interactions for which experimental information is limited.
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Affiliation(s)
- Marcus Malo
- Department of Chemistry, Medicinal Chemistry, University of Gothenburg, 41296 Göteborg, Sweden
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20
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Signalling bias in new drug discovery: detection, quantification and therapeutic impact. Nat Rev Drug Discov 2012; 12:205-16. [PMID: 23411724 DOI: 10.1038/nrd3954] [Citation(s) in RCA: 585] [Impact Index Per Article: 48.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Agonists of seven-transmembrane receptors, also known as G protein-coupled receptors (GPCRs), do not uniformly activate all cellular signalling pathways linked to a given seven-transmembrane receptor (a phenomenon termed ligand or agonist bias); this discovery has changed how high-throughput screens are designed and how lead compounds are optimized for therapeutic activity. The ability to experimentally detect ligand bias has necessitated the development of methods for quantifying agonist bias in a way that can be used to guide structure-activity studies and the selection of drug candidates. Here, we provide a viewpoint on which methods are appropriate for quantifying bias, based on knowledge of how cellular and intracellular signalling proteins control the conformation of seven-transmembrane receptors. We also discuss possible predictions of how biased molecules may perform in vivo, and what potential therapeutic advantages they may provide.
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21
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Chemel BR, Bonner LA, Watts VJ, Nichols DE. Ligand-specific roles for transmembrane 5 serine residues in the binding and efficacy of dopamine D(1) receptor catechol agonists. Mol Pharmacol 2012; 81:729-38. [PMID: 22334593 DOI: 10.1124/mol.111.077339] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
To refine further the structure-activity relationships of D(1) dopamine receptor agonists, we investigated the roles of three conserved serine residues [Ser198(5.42), Ser199(5.43), and Ser202(5.46)] in agonist binding and receptor activation. These transmembrane domain 5 (TM5) residues are believed to engage catechol ligands through polar interactions. We stably expressed wild-type or mutant (S198A, S199A, and S202A) D(1) receptors in human embryonic kidney cells. These receptors were expressed at similar levels (approximately 2000 fmol/mg) and bound the radioligand [(3)H]R(+)-7-chloro-8-hydroxy-3-methyl-1-phenyl-2,3,4,5-tetrahydro-1H-3-benzazepine (SCH 23390), although S198A and S199A displayed significant losses of affinity compared with that for wild-type receptors. The endogenous agonist, dopamine, had losses of potency at each of the mutant receptors. We tested cyclohexyl-substituted isochroman, carbocyclic, and chroman bicyclic dopamine analogs and found that the mutations affected the chroman to a lesser extent than the other compounds. These results support our hypothesis that the decreased D(1) activity of chroman analogs results from a ligand intramolecular hydrogen bond that impairs the ability of the catechol to engage the receptor. Sensitivities of these rigid catechol agonists to the effects of the serine mutations were dependent on ligand geometry, particularly with respect to the rotameric conformation of the ethylamine side chain and the distance between the amino group and each catechol hydroxyl. Functional experiments in striatal tissue suggest that the ability to engage TM5 serines is largely correlated with agonist efficacy for cAMP stimulation. These results provide a new understanding of the complexities of D(1) ligand recognition and agonist activation and have implications for the design of rigid catechol ligands.
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Affiliation(s)
- Benjamin R Chemel
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, West Lafayette, Indiana 47907-2091, USA
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22
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Abstract
All currently efficacious antipsychotic drugs have as part of their mechanism the ability to attenuate some or all of the signaling through the dopamine D(2) receptor. More recently, the dopamine D(1) receptor has been hypothesized to be a promising target for the treatment of negative and/or cognitive aspects of schizophrenia that are not improved by current antipsychotics. Although cAMP has been presumed to be the primary messenger for signaling through the dopamine receptors, the last decade has unveiled a complexity that has provided exciting avenues for the future discovery of antipsychotic drugs (APDs). We review the signaling mechanisms of currently approved APDs at dopamine D(2) receptors, and note that aripiprazole is a compound that is clearly differentiated from other approved drugs. Although aripiprazole has been postulated to cause dopamine stabilization due to its partial D(2) agonist properties, a body of literature suggests that an alternative mechanism, functional selectivity, is of primary importance. Finally, we review the signaling at dopamine D(1) receptors, and the idea that drugs that activate D(1) receptors may have use as APDs for improving negative and cognitive symptoms. We address the current state of drug discovery in the D(1) area and its relationship to novel signaling mechanisms. Our conclusion is that although the first APD targeting dopamine receptors was discovered more than a half-century ago, recent research advances offer the possibility that novel and/or improved drugs will emerge in the next decade.
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23
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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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24
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Kenakin T. G protein coupled receptors as allosteric proteins and the role of allosteric modulators. J Recept Signal Transduct Res 2011; 30:313-21. [PMID: 20858023 DOI: 10.3109/10799893.2010.503964] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Seven transmembrane receptors (7TMRs) are proteins that convey signals through changes in conformation. These conformations are stabilized by external molecules (i.e. agonists, antagonists, modulators) and act upon other bodies (termed 'guests') which can be other molecules in the extracellular space, or proteins along the plane of the membrane (receptor oligomerization) or signaling proteins in the cytosol (i.e. G protein, β-arrestin). These elements comprise allosteric systems and a great deal of 7TMR pharmacology can be considered in terms of allosteric behavior. Allosteric ligands acting on 7TMRs possess four unique behaviors that can be valuable therapeutically; (1) the ability to alter the interaction of very large proteins, (2) probe dependence, (3) saturable effect, and (4) induction of separate changes in affinity and efficacy of other ligands. Two of these behaviors (namely probe dependence for CCR5-based HIV-1 entry inhibitors and functional selectivity for biased agonism) will be highlighted with examples.
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Affiliation(s)
- Terry Kenakin
- GlaxoSmithKline Research and Development, Research Triangle Park, NC 27709, USA.
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25
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Whalen EJ, Rajagopal S, Lefkowitz RJ. Therapeutic potential of β-arrestin- and G protein-biased agonists. Trends Mol Med 2010; 17:126-39. [PMID: 21183406 DOI: 10.1016/j.molmed.2010.11.004] [Citation(s) in RCA: 418] [Impact Index Per Article: 29.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2010] [Revised: 11/13/2010] [Accepted: 11/17/2010] [Indexed: 12/21/2022]
Abstract
Members of the seven-transmembrane receptor (7TMR), or G protein-coupled receptor (GPCR), superfamily represent some of the most successful targets of modern drug therapy, with proven efficacy in the treatment of a broad range of human conditions and disease processes. It is now appreciated that β-arrestins, once viewed simply as negative regulators of traditional 7TMR-stimulated G protein signaling, act as multifunctional adapter proteins that regulate 7TMR desensitization and trafficking and promote distinct intracellular signals in their own right. Moreover, several 7TMR biased agonists, which selectively activate these divergent signaling pathways, have been identified. Here we highlight the diversity of G protein- and β-arrestin-mediated functions and the therapeutic potential of selective targeting of these in disease states.
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Affiliation(s)
- Erin J Whalen
- Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA
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27
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Undieh AS. Pharmacology of signaling induced by dopamine D(1)-like receptor activation. Pharmacol Ther 2010; 128:37-60. [PMID: 20547182 DOI: 10.1016/j.pharmthera.2010.05.003] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2010] [Accepted: 05/19/2010] [Indexed: 12/30/2022]
Abstract
Dopamine D(1)-like receptors consisting of D(1) and D(5) subtypes are intimately implicated in dopaminergic regulation of fundamental neurophysiologic processes such as mood, motivation, cognitive function, and motor activity. Upon stimulation, D(1)-like receptors initiate signal transduction cascades that are mediated through adenylyl cyclase or phosphoinositide metabolism, with subsequent enhancement of multiple downstream kinase cascades. The latter actions propagate and further amplify the receptor signals, thus predisposing D(1)-like receptors to multifaceted interactions with various other mediators and receptor systems. The adenylyl cyclase response to dopamine or selective D(1)-like receptor agonists is reliably associated with the D(1) subtype, while emerging evidence indicates that the phosphoinositide responses in native brain tissues may be preferentially mediated through stimulation of the D(5) receptor. Besides classic coupling of each receptor subtype to specific G proteins, additional biophysical models are advanced in attempts to account for differential subcellular distribution, heteromolecular oligomerization, and activity-dependent selectivity of the receptors. It is expected that significant advances in understanding of dopamine neurobiology will emerge from current and anticipated studies directed at uncovering the molecular mechanisms of D(5) coupling to phosphoinositide signaling, the structural features that might enhance pharmacological selectivity for D(5) versus D(1) subtypes, the mechanism by which dopamine may modulate phosphoinositide synthesis, the contributions of the various responsive signal mediators to D(1) or D(5) interactions with D(2)-like receptors, and the spectrum of dopaminergic functions that may be attributed to each receptor subtype and signaling pathway.
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Affiliation(s)
- Ashiwel S Undieh
- Laboratory of Integrative Neuropharmacology, Department of Pharmaceutical Sciences, Thomas Jefferson University School of Pharmacy, 130 South 9th Street, Suite 1510, Philadelphia, PA 19107, USA.
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28
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Kenakin T, Miller LJ. Seven transmembrane receptors as shapeshifting proteins: the impact of allosteric modulation and functional selectivity on new drug discovery. Pharmacol Rev 2010; 62:265-304. [PMID: 20392808 DOI: 10.1124/pr.108.000992] [Citation(s) in RCA: 458] [Impact Index Per Article: 32.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
It is useful to consider seven transmembrane receptors (7TMRs) as disordered proteins able to allosterically respond to a number of binding partners. Considering 7TMRs as allosteric systems, affinity and efficacy can be thought of in terms of energy flow between a modulator, conduit (the receptor protein), and a number of guests. These guests can be other molecules, receptors, membrane-bound proteins, or signaling proteins in the cytosol. These vectorial flows of energy can yield standard canonical guest allostery (allosteric modification of drug effect), effects along the plane of the cell membrane (receptor oligomerization), or effects directed into the cytosol (differential signaling as functional selectivity). This review discusses these apparently diverse pharmacological effects in terms of molecular dynamics and protein ensemble theory, which tends to unify 7TMR behavior toward cells. Special consideration will be given to functional selectivity (biased agonism and biased antagonism) in terms of mechanism of action and potential therapeutic application. The explosion of technology that has enabled observation of diverse 7TMR behavior has also shown how drugs can have multiple (pluridimensional) efficacies and how this can cause paradoxical drug classification and nomenclatures.
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Affiliation(s)
- Terry Kenakin
- GlaxoSmithKline, 5 Moore Drive, Mailtstop V-287, Research Triangle Park, NC 27709, USA.
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29
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Peters MF, Scott CW. Evaluating Cellular Impedance Assays for Detection of GPCR Pleiotropic Signaling and Functional Selectivity. ACTA ACUST UNITED AC 2009; 14:246-55. [DOI: 10.1177/1087057108330115] [Citation(s) in RCA: 104] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
G-protein—coupled receptors can couple to different signal transduction pathways in different cell types (termed cell-specific signaling) and can activate different signaling pathways depending on the receptor conformation(s) stabilized by the activating ligand (functional selectivity). These concepts offer potential for developing pathway-specific drugs that increase efficacy and reduce side effects. Despite significant interest, functional selectivity has been difficult to exploit in drug discovery, in part due to the burden of multiple assays. Cellular impedance assays use an emerging technology that can qualitatively distinguish Gs, Gi/o, and Gq signaling in a single assay and is thereby suited for studying these pharmacological concepts. Cellular impedance confirmed cell-specific Gs and Gq coupling for the melanocortin-4 receptor and dual Gi and Gs signaling with the cannabinoid-1 (CB1) receptor. The balance of Gi versus Gs signaling depended on the cell line. In CB1-HEKs, Giand Gs-like responses combined to yield a novel impedance profile demonstrating the dynamic nature of these traces. Cellspecific signaling was observed with endogenous D1 receptor in U-2 cells and SK-N-MC cells, yet the pharmacological profile of partial and full agonists was similar in both cell lines. We conclude that the dynamic impedance profile encodes valuable relative signaling information and is sufficiently robust to help evaluate cell-specific signaling and functional selectivity. ( Journal of Biomolecular Screening 2009:246-255)
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Affiliation(s)
- Matthew F. Peters
- Lead Generation Department, AstraZeneca Pharmaceuticals LP, Wilmington, Delaware,
| | - Clay W. Scott
- Lead Generation Department, AstraZeneca Pharmaceuticals LP, Wilmington, Delaware
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Arttamangkul S, Quillinan N, Low MJ, von Zastrow M, Pintar J, Williams JT. Differential activation and trafficking of micro-opioid receptors in brain slices. Mol Pharmacol 2008; 74:972-9. [PMID: 18612077 DOI: 10.1124/mol.108.048512] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The activation of G protein-coupled receptors results in a cascade of events that include acute signaling, desensitization, and internalization, and it is thought that not all agonists affect each process to the same extent. The early steps in opioid receptor signaling, including desensitization, have been characterized electrophysiologically using brain slice preparations, whereas most previous studies of opioid receptor trafficking have been conducted in heterologous cell models. This study used transgenic mice that express an epitope-tagged (FLAG) micro-opioid receptor (FLAGMOR) targeted to catecholamine neurons by regulatory elements from the tyrosine hydroxylase gene. Brain slices from these mice were used to study tagged MOR receptors in neurons of the locus ceruleus. Activation of the FLAGMOR with [Met5]enkephalin (ME) produced a hyperpolarization that desensitized acutely to the same extent as native MOR in slices from wild-type mice. A series of opioid agonists were then used to study desensitization and receptor trafficking in brain slices, which was monitored with a monoclonal antibody against the FLAG epitope (M1) conjugated to Alexa 594. Three patterns of receptor trafficking and desensitization were observed: 1) ME, etorphine, and methadone resulted in both receptor desensitization and internalization; 2) morphine and oxymorphone caused significant desensitization without evidence for internalization; and 3) oxycodone was ineffective in both processes. These results show that two distinct forms of signaling were differentially engaged depending on the agonist used to activate the receptor, and they support the hypothesis that ligand-specific regulation of opioid receptors occurs in neurons maintained in brain slices from adult animals.
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Affiliation(s)
- Seksiri Arttamangkul
- Vollum Institute, L474, Department of Behavioral Neuroscience, Oregon Health Sciences University, 3181 W Sam Jackson Park Dr., Portland, OR 97239, USA
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Chang WC, Ng JK, Nguyen T, Pellissier L, Claeysen S, Hsiao EC, Conklin BR. Modifying ligand-induced and constitutive signaling of the human 5-HT4 receptor. PLoS One 2007; 2:e1317. [PMID: 18338032 PMCID: PMC2267039 DOI: 10.1371/journal.pone.0001317] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2007] [Accepted: 11/18/2007] [Indexed: 11/26/2022] Open
Abstract
G protein–coupled receptors (GPCRs) signal through a limited number of G-protein pathways and play crucial roles in many biological processes. Studies of their in vivo functions have been hampered by the molecular and functional diversity of GPCRs and the paucity of ligands with specific signaling effects. To better compare the effects of activating different G-protein signaling pathways through ligand-induced or constitutive signaling, we developed a new series of RASSLs (receptors activated solely by synthetic ligands) that activate different G-protein signaling pathways. These RASSLs are based on the human 5-HT4b receptor, a GPCR with high constitutive Gs signaling and strong ligand-induced G-protein activation of the Gs and Gs/q pathways. The first receptor in this series, 5-HT4-D100A or Rs1 (RASSL serotonin 1), is not activated by its endogenous agonist, serotonin, but is selectively activated by the small synthetic molecules GR113808, GR125487, and RO110-0235. All agonists potently induced Gs signaling, but only a few (e.g., zacopride) also induced signaling via the Gq pathway. Zacopride-induced Gq signaling was enhanced by replacing the C-terminus of Rs1 with the C-terminus of the human 5-HT2C receptor. Additional point mutations (D66A and D66N) blocked constitutive Gs signaling and lowered ligand-induced Gq signaling. Replacing the third intracellular loop of Rs1 with that of human 5-HT1A conferred ligand-mediated Gi signaling. This Gi-coupled RASSL, Rs1.3, exhibited no measurable signaling to the Gs or Gq pathway. These findings show that the signaling repertoire of Rs1 can be expanded and controlled by receptor engineering and drug selection.
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Affiliation(s)
- Wei Chun Chang
- Gladstone Institute of Cardiovascular Disease, University of California at San Francisco, San Francisco, California, United States of America
- Graduate Program in Pharmaceutical Sciences and Pharmacogenomics, University of California at San Francisco, San Francisco, California, United States of America
| | - Jennifer K. Ng
- Gladstone Institute of Cardiovascular Disease, University of California at San Francisco, San Francisco, California, United States of America
| | - Trieu Nguyen
- Gladstone Institute of Cardiovascular Disease, University of California at San Francisco, San Francisco, California, United States of America
| | - Lucie Pellissier
- Institut de Génomique Fonctionnelle, Universités de Montpellier, CNRS UMR 5203, Montpellier, France
- INSERM U661, Montpellier, France
| | - Sylvie Claeysen
- Institut de Génomique Fonctionnelle, Universités de Montpellier, CNRS UMR 5203, Montpellier, France
- INSERM U661, Montpellier, France
| | - Edward C. Hsiao
- Gladstone Institute of Cardiovascular Disease, University of California at San Francisco, San Francisco, California, United States of America
- Department of Medicine, University of California at San Francisco, San Francisco, California, United States of America
| | - Bruce R. Conklin
- Gladstone Institute of Cardiovascular Disease, University of California at San Francisco, San Francisco, California, United States of America
- Department of Medicine, University of California at San Francisco, San Francisco, California, United States of America
- Department of Cellular and Molecular Pharmacology, University of California at San Francisco, San Francisco, California, United States of America
- * To whom correspondence should be addressed. E-mail:
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