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Junker H, Meiler J, Schoeder CT. Interplay of thermodynamics and evolution within the ternary ligand-GPCR-G protein complex. Curr Opin Struct Biol 2023; 82:102656. [PMID: 37467526 DOI: 10.1016/j.sbi.2023.102656] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 05/25/2023] [Accepted: 06/20/2023] [Indexed: 07/21/2023]
Abstract
Recent studies on G protein-coupled receptors (GPCRs) dynamics report that GPCRs adopt a wide range of conformations that coexist in equilibrium, with the apo state of a GPCR having a high entropy. The formation of a ligand-GPCR-transducer complex comes with a reduction of conformational space and therefore with an entropic cost. We hypothesize that the availability of binding partners, their binding affinity and the rigidity of the respective binding sites are reflected in a distinct degree of sequence conservation to balance the energetic cost of intra- and extracellular binding events. Here, we outline the current findings in delineating the conformational space and include sequential conservation of many-to-many ligand-receptor systems to discuss the entropic cost that comes with GPCR signal transduction.
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Affiliation(s)
- Hannes Junker
- Institute for Drug Discovery, University Leipzig, Faculty of Medicine, Leipzig, Germany
| | - Jens Meiler
- Institute for Drug Discovery, University Leipzig, Faculty of Medicine, Leipzig, Germany; Department of Chemistry, Vanderbilt University, Nashville, TN, United States; Center for Structural Biology, Vanderbilt University, Nashville, TN, United States
| | - Clara T Schoeder
- Institute for Drug Discovery, University Leipzig, Faculty of Medicine, Leipzig, Germany.
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2
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McKay K, Hamilton NB, Remington JM, Schneebeli ST, Li J. Essential Dynamics Ensemble Docking for Structure-Based GPCR Drug Discovery. Front Mol Biosci 2022; 9:879212. [PMID: 35847975 PMCID: PMC9277106 DOI: 10.3389/fmolb.2022.879212] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2022] [Accepted: 05/18/2022] [Indexed: 11/23/2022] Open
Abstract
The lack of biologically relevant protein structures can hinder rational design of small molecules to target G protein-coupled receptors (GPCRs). While ensemble docking using multiple models of the protein target is a promising technique for structure-based drug discovery, model clustering and selection still need further investigations to achieve both high accuracy and efficiency. In this work, we have developed an original ensemble docking approach, which identifies the most relevant conformations based on the essential dynamics of the protein pocket. This approach is applied to the study of small-molecule antagonists for the PAC1 receptor, a class B GPCR and a regulator of stress. As few as four representative PAC1 models are selected from simulations of a homology model and then used to screen three million compounds from the ZINC database and 23 experimentally validated compounds for PAC1 targeting. Our essential dynamics ensemble docking (EDED) approach can effectively reduce the number of false negatives in virtual screening and improve the accuracy to seek potent compounds. Given the cost and difficulties to determine membrane protein structures for all the relevant states, our methodology can be useful for future discovery of small molecules to target more other GPCRs, either with or without experimental structures.
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3
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Labouesse MA, Patriarchi T. A versatile GPCR toolkit to track in vivo neuromodulation: not a one-size-fits-all sensor. Neuropsychopharmacology 2021; 46:2043-2047. [PMID: 33603136 PMCID: PMC8505436 DOI: 10.1038/s41386-021-00982-y] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 01/12/2021] [Accepted: 01/23/2021] [Indexed: 12/23/2022]
Affiliation(s)
- Marie A Labouesse
- Department of Psychiatry, College of Physicians and Surgeons, Columbia University, Columbia, NY, USA
- Division of Molecular Therapeutics, New York State Psychiatric Institute, New York, NY, USA
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland
| | - Tommaso Patriarchi
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland.
- Neuroscience Center Zurich, University and ETH Zurich, Zurich, Switzerland.
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4
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Zaidi SA, Katritch V. Structural Characterization of KOR Inactive and Active States for 3D Pharmacology and Drug Discovery. Handb Exp Pharmacol 2021; 271:41-64. [PMID: 33945028 DOI: 10.1007/164_2021_461] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The structure of the human kappa opioid receptor (KOR) in complex with the long-acting antagonist JDTic was solved crystallographically in 2012 and, along with structures of other opioid receptors, revolutionized our understanding of opioid system function and pharmacology. More recently, active state KOR structure was also determined, giving important insights into activation mechanisms of the receptor. In this review, we will discuss how the understanding of atomistic structures of KOR established a key platform for deciphering details of subtype and functional selectivity of KOR-targeting ligands and for discovery of new chemical probes with potentially beneficial pharmacological profiles.
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Affiliation(s)
- Saheem A Zaidi
- Department of Quantitative and Computational Biology, Bridge Institute, USC Michelson Center for Convergent Biosciences, University of Southern California, Los Angeles, CA, USA
| | - Vsevolod Katritch
- Department of Quantitative and Computational Biology, Bridge Institute, USC Michelson Center for Convergent Biosciences, University of Southern California, Los Angeles, CA, USA. .,Department of Chemistry, Bridge Institute, USC Michelson Center for Convergent Biosciences, University of Southern California, Los Angeles, CA, USA.
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5
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Kim M, Wei JD, Harmalkar DS, Goo JI, Lee K, Choi Y, Kim JH, Cho AE. Elucidation of Mechanism for Ligand Efficacy at Leukotriene B 4 Receptor 2 (BLT2). ACS Med Chem Lett 2020; 11:1529-1534. [PMID: 32832019 DOI: 10.1021/acsmedchemlett.0c00065] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Accepted: 07/14/2020] [Indexed: 12/12/2022] Open
Abstract
G protein-coupled receptors (GPCRs) have always been important drug targets in the pharmaceutical industry. One major question for the current GPCR drug discovery is how drugs have distinct efficacies at the same GPCR target. Related to this question, we studied how different ligands can have disparate efficacies at Leukotriene B4 receptor (BLT2). By using molecular modeling studies, we predicted that Tyr2716.51 located at TM6 of BLT2 performs as a key trigger for its activation and verified the prediction by site-directed mutagenesis, chemotactic motility studies, which included a chemical derivative of agonist CAY10583. We further identified Asn2756.55 located at TM6 as a weak activation trigger in BLT2 and performed double mutation studies to confirm our computational results. Our results provide strong evidence for the exact mechanism of ligand efficacy at BLT2.
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Affiliation(s)
- Minsup Kim
- inCerebro Co., Ltd. Drug Discovery Institute, Seoul Technopark, 232 Gongneung-ro, Nowon-gu, Seoul 01811, Korea
| | - Jun-Dong Wei
- Department of Biochemistry, Medical College, Taizhou University, Taizhou, 318000, Zhejjang, China
| | - Dipesh S. Harmalkar
- College of Life Sciences and Biotechnology, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea
- College of Pharmacy, Dongguk University, 32 Dongguk-ro,
Ilsandong-gu, Goyang-si 10326, Republic of Korea
| | - Ja-il Goo
- College of Life Sciences and Biotechnology, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea
| | - Kyeong Lee
- College of Pharmacy, Dongguk University, 32 Dongguk-ro,
Ilsandong-gu, Goyang-si 10326, Republic of Korea
| | - Yongseok Choi
- College of Life Sciences and Biotechnology, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea
| | - Jae-Hong Kim
- Department of Life Sciences, Korea University, Seoul 02841, Republic of Korea
| | - Art E. Cho
- Department of Bioinformatics, Korea University, 2511 Sejong-ro, Sejong 30019, Republic of Korea
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Abstract
Pharmacology, the chemical control of physiology, emerged as an offshoot of physiology when the physiologists using chemicals to probe physiological systems became more interested in the probes than the systems. Pharmacologists were always, and in many ways still are, bound to study drugs in systems they do not fully understand. Under these circumstances, null methods were the main ways in which conclusions about biologically active molecules were made. However, as understanding of the basic mechanisms of cellular function and biochemical systems were elucidated, so too did the understanding of how drugs affected these systems. Over the past 20 years, new ideas have emerged in the field that have completely changed and revitalized it; these are described herein. It will be seen how null methods in isolated tissues gave way to, first biochemical radioligand binding studies, and then to a wide array of functional assay technologies that can measure the effects of molecules on drug targets. In addition, the introduction of molecular dynamics, the appreciation of the allosteric nature of receptors, protein X-ray crystal structures, genetic manipulations in the form of knock-out and knock-in systems and Designer Receptors Exclusively Activated by Designer Drugs have revolutionized pharmacology.
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Affiliation(s)
- Terry Kenakin
- Department of Pharmacology, University of North Carolina School of Medicine, Chapel Hill, NC, USA.
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8
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Ashokan A, Aradhyam GK. Measurement of intracellular Ca 2+ mobilization to study GPCR signal transduction. Methods Cell Biol 2017; 142:59-66. [DOI: 10.1016/bs.mcb.2017.07.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
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9
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Kumar P, Ashokan A, Aradhyam GK. Apelin binding to human APJ receptor leads to biased signaling. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2016; 1864:1748-1756. [DOI: 10.1016/j.bbapap.2016.09.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Revised: 08/26/2016] [Accepted: 09/22/2016] [Indexed: 12/15/2022]
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10
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Multiscale design of coarse-grained elastic network-based potentials for the μ opioid receptor. J Mol Model 2016; 22:227. [DOI: 10.1007/s00894-016-3092-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Accepted: 08/08/2016] [Indexed: 01/10/2023]
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Abstract
AbstractIncreasing evidence suggests that most proteins occur and function in complexes rather than as isolated entities when embedded in cellular membranes. Nuclear magnetic resonance (NMR) provides increasing possibilities to study structure, dynamics and assembly of such systems. In our review, we discuss recent methodological progress to study membrane–protein complexes (MPCs) by NMR, starting with expression, isotope-labeling and reconstitution protocols. We review approaches to deal with spectral complexity and limited spectral spectroscopic sensitivity that are usually encountered in NMR-based studies of MPCs. We highlight NMR applications in various classes of MPCs, including G-protein-coupled receptors, ion channels and retinal proteins and extend our discussion to protein–protein complexes that span entire cellular compartments or orchestrate processes such as protein transport across or within membranes. These examples demonstrate the growing potential of NMR-based studies of MPCs to provide critical insight into the energetics of protein–ligand and protein–protein interactions that underlie essential biological functions in cellular membranes.
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12
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Abstract
To understand brain function, it is essential that we discover how cellular signaling specifies normal and pathological brain function. In this regard, chemogenetic technologies represent valuable platforms for manipulating neuronal and non-neuronal signal transduction in a cell-type-specific fashion in freely moving animals. Designer Receptors Exclusively Activated by Designer Drugs (DREADD)-based chemogenetic tools are now commonly used by neuroscientists to identify the circuitry and cellular signals that specify behavior, perceptions, emotions, innate drives, and motor functions in species ranging from flies to nonhuman primates. Here I provide a primer on DREADDs highlighting key technical and conceptual considerations and identify challenges for chemogenetics going forward.
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13
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Pachov DV, Fonseca R, Arnol D, Bernauer J, van den Bedem H. Coupled Motions in β2AR:Gαs Conformational Ensembles. J Chem Theory Comput 2016; 12:946-56. [DOI: 10.1021/acs.jctc.5b00995] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Affiliation(s)
- Dimitar V. Pachov
- Department
of Chemistry, Stanford University, Stanford, California 94305, United States
- Division
of Biosciences, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, California 94025, United States
| | - Rasmus Fonseca
- Division
of Biosciences, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, California 94025, United States
- AMIB
INRIA - Bioinformatics group, LIX, École Polytechnique, 91128 Palaiseau, France
| | - Damien Arnol
- INRIA Saclay-Île de France, 1 rue Honoré d'Estienne
d'Orves, Bâtiment Alan Turing, Campus de l'École
Polytechnique, 91120 Palaiseau, France
- Laboratoire
d'Informatique de l'École Polytechnique (LIX), CNRS
UMR 7161, École Polytechnique, 91128 Palaiseau, France
| | - Julie Bernauer
- INRIA Saclay-Île de France, 1 rue Honoré d'Estienne
d'Orves, Bâtiment Alan Turing, Campus de l'École
Polytechnique, 91120 Palaiseau, France
- Laboratoire
d'Informatique de l'École Polytechnique (LIX), CNRS
UMR 7161, École Polytechnique, 91128 Palaiseau, France
| | - Henry van den Bedem
- Division
of Biosciences, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, California 94025, United States
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14
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New Technologies for Elucidating Opioid Receptor Function. Trends Pharmacol Sci 2016; 37:279-289. [PMID: 26833118 DOI: 10.1016/j.tips.2016.01.001] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Revised: 12/22/2015] [Accepted: 01/04/2016] [Indexed: 01/25/2023]
Abstract
Recent advances in technology, including high resolution crystal structures of opioid receptors, novel chemical tools, and new genetic approaches have provided an unparalleled palette of tools for deconstructing opioid receptor actions in vitro and in vivo. Here we provide a brief description of our understanding of opioid receptor function from both molecular and atomic perspectives, as well as their role in neural circuits in vivo. We then show how insights into the molecular details of opioid actions can facilitate the creation of functionally selective (biased) and photoswitchable opioid ligands. Finally, we describe how newly engineered opioid receptor-based chemogenetic and optogenetic tools, and new mouse lines, are expanding and transforming our understanding of opioid function and, perhaps, paving the way for new therapeutics.
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15
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Omotuyi OI, Adebowale DD, Famuti A, Tsuyoshi H. LPA 1extracellular loop residues 115 and 191 are not required for receptor activation but prevent Ki16425 super-antagonism. RSC Adv 2016. [DOI: 10.1039/c6ra04276g] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Extracellular loop residues (R115 and D191) are not required for receptor activation but repress Ki16425-type super-antagonism but not LPA-analogue antagonists using a combination of site-directed mutagenesis and intracellular calcium assay procedures.
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Affiliation(s)
- Olaposi I. Omotuyi
- Center for Bio-Computing and Drug Development
- Adekunle Ajasin University
- Nigeria
| | | | - Ayodeji Famuti
- Center for Bio-Computing and Drug Development
- Adekunle Ajasin University
- Nigeria
| | - Hamada Tsuyoshi
- Nagasaki University Advanced Computing Center
- Nagasaki University
- Nagasaki
- Japan
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16
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Jaremko Ł, Jaremko M, Giller K, Becker S, Zweckstetter M. Conformational Flexibility in the Transmembrane Protein TSPO. Chemistry 2015; 21:16555-63. [PMID: 26394723 DOI: 10.1002/chem.201502314] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Indexed: 12/13/2022]
Abstract
The translocator protein (TSPO) is an integral membrane protein that interacts with a wide variety of endogenous ligands, such as cholesterol and porphyrins, and is also the target for several small molecules with substantial in vivo efficacy. When complexed with the TSPO-specific radioligand (R)-PK11195, TSPO folds into a rigid five-helix bundle. However, little is known about the structure and dynamics of TSPO in the absence of high-affinity ligands. By means of NMR spectroscopy, we show that TSPO exchanges between multiple conformations in the absence of (R)-PK11195. Extensive motions on time scales from pico- to microseconds occur all along the primary sequence of the protein, leading to a loss of stable tertiary interactions and local unfolding of the helical structure in the vicinity of the ligand-binding site. The flexible nature of TSPO highlights the importance of conformational plasticity in integral membrane proteins.
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Affiliation(s)
- Łukasz Jaremko
- Department for NMR-Based Structural Biology, Max Planck Institute for Biophysical Chemistry, Göttingen (Germany).,German Center for Neurodegenerative Diseases (DZNE), Göttingen (Germany)
| | - Mariusz Jaremko
- Department for NMR-Based Structural Biology, Max Planck Institute for Biophysical Chemistry, Göttingen (Germany)
| | - Karin Giller
- Department for NMR-Based Structural Biology, Max Planck Institute for Biophysical Chemistry, Göttingen (Germany)
| | - Stefan Becker
- Department for NMR-Based Structural Biology, Max Planck Institute for Biophysical Chemistry, Göttingen (Germany)
| | - Markus Zweckstetter
- Department for NMR-Based Structural Biology, Max Planck Institute for Biophysical Chemistry, Göttingen (Germany). .,German Center for Neurodegenerative Diseases (DZNE), Göttingen (Germany). .,Center for Nanoscale Microscopy and Molecular Physiology of the Brain, University Medical Center, Göttingen (Germany).
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17
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Struts AV, Barmasov AV, Brown MF. SPECTRAL METHODS FOR STUDY OF THE G-PROTEIN-COUPLED RECEPTOR RHODOPSIN. I. VIBRATIONAL AND ELECTRONIC SPECTROSCOPY. OPTICS AND SPECTROSCOPY 2015; 118:711-717. [PMID: 28260815 PMCID: PMC5334778 DOI: 10.1134/s0030400x15050240] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Here we review the application of modern spectral methods for the study of G-protein-coupled receptors (GPCRs) using rhodopsin as a prototype. Because X-ray analysis gives us immobile snapshots of protein conformations, it is imperative to apply spectroscopic methods for elucidating their function: vibrational (Raman, FTIR), electronic (UV-visible absorption, fluorescence) spectroscopies, and magnetic resonance (electron paramagnetic resonance, EPR), and nuclear magnetic resonance, NMR). In the first of the two companion articles, we discuss the application of optical spectroscopy for studying rhodopsin in a membrane environment. Information is obtained regarding the time-ordered sequence of events in rhodopsin activation. Isomerization of the chromophore and deprotonation of the retinal Schiff base leads to a structural change of the protein involving the motion of helices H5 and H6 in a pH-dependent process. Information is obtained that is unavailable from X-ray crystallography, which can be combined with spectroscopic studies to achieve a more complete understanding of GPCR function.
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Affiliation(s)
- A V Struts
- St. Petersburg State Medical University, 194100 St. Petersburg, Russia; St. Petersburg State University, 199034 St. Petersburg, Russia; University of Arizona, Tucson, AZ 85721 USA
| | - A V Barmasov
- St. Petersburg State Medical University, 194100 St. Petersburg, Russia; St. Petersburg State University, 199034 St. Petersburg, Russia
| | - M F Brown
- University of Arizona, Tucson, AZ 85721 USA
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18
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Roth S, Bruggeman FJ. A conformation-equilibrium model captures ligand-ligand interactions and ligand-biased signalling by G-protein coupled receptors. FEBS J 2014; 281:4659-71. [DOI: 10.1111/febs.12970] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2014] [Revised: 07/07/2014] [Accepted: 08/11/2014] [Indexed: 12/31/2022]
Affiliation(s)
- Susanne Roth
- Systems Bioinformatics; VU University; Amsterdam The Netherlands
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White KL, Scopton AP, Rives ML, Bikbulatov RV, Polepally PR, Brown PJ, Kenakin T, Javitch JA, Zjawiony JK, Roth BL. Identification of novel functionally selective κ-opioid receptor scaffolds. Mol Pharmacol 2014; 85:83-90. [PMID: 24113749 PMCID: PMC3868907 DOI: 10.1124/mol.113.089649] [Citation(s) in RCA: 102] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2013] [Accepted: 10/10/2013] [Indexed: 11/22/2022] Open
Abstract
The κ-opioid receptor (KOR)-dynorphin system has been implicated in the control of affect, cognition, and motivation, and is thought to be dysregulated in mood and psychotic disorders, as well as in various phases of opioid dependence. KOR agonists exhibit analgesic effects, although the adverse effects produced by some KOR agonists, including sedation, dysphoria, and hallucinations, have limited their clinical use. Interestingly, KOR-mediated dysphoria, assessed in rodents as aversion, has recently been attributed to the activation of the p38 mitogen-activated protein kinase pathway following arrestin recruitment to the activated KOR. Therefore, KOR-selective G protein-biased agonists, which do not recruit arrestin, have been proposed to be more effective analgesics, without the adverse effects triggered by the arrestin pathway. As an initial step toward identifying novel biased KOR agonists, we applied a multifaceted screening strategy utilizing both in silico and parallel screening approaches. We identified several KOR-selective ligand scaffolds with a range of signaling bias in vitro. The arylacetamide-based scaffold includes both G protein- and β-arrestin-biased ligands, while the endogenous peptides and the diterpene scaffolds are G protein biased. Interestingly, we found scaffold screening to be more successful than library screening in identifying biased ligands. Many of the identified functionally selective ligands are potent selective KOR agonists that are reported to be active in the central nervous system. They therefore represent excellent candidates for in vivo studies aiming at determining the behavioral effects mediated by specific KOR-mediated signaling cascades.
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Affiliation(s)
- Kate L White
- Department of Pharmacology (K.L.W., T.K., B.L.R.) and National Institute of Mental Health Psychoactive Drug Screening Program (B.L.R.), University of North Carolina, Chapel Hill, North Carolina; Departments of Psychiatry (M.-L.R, J.A.J.) and Pharmacology (J.A.J.), Columbia University, College of Physicians and Surgeons, New York, New York; New York Division of Molecular Therapeutics, New York State Psychiatric Institute, New York, New York (M.-L.R., J.A.J.); Department of Pharmacognosy, University of Mississippi, University, Mississippi (R.V.B., P.R.P., J.K.Z.); and Structural Genomics Consortium, University of Toronto, Toronto, Ontario, Canada (A.P.S., P.J.B.)
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Vardy E, Mosier PD, Frankowski KJ, Wu H, Katritch V, Westkaemper RB, Aubé J, Stevens RC, Roth BL. Chemotype-selective modes of action of κ-opioid receptor agonists. J Biol Chem 2013; 288:34470-83. [PMID: 24121503 DOI: 10.1074/jbc.m113.515668] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The crystal structures of opioid receptors provide a novel platform for inquiry into opioid receptor function. The molecular determinants for activation of the κ-opioid receptor (KOR) were studied using a combination of agonist docking, functional assays, and site-directed mutagenesis. Eighteen positions in the putative agonist binding site of KOR were selected and evaluated for their effects on receptor binding and activation by ligands representing four distinct chemotypes: the peptide dynorphin A(1-17), the arylacetamide U-69593, and the non-charged ligands salvinorin A and the octahydroisoquinolinone carboxamide 1xx. Minimally biased docking of the tested ligands into the antagonist-bound KOR structure generated distinct binding modes, which were then evaluated biochemically and pharmacologically. Our analysis identified two types of mutations: those that affect receptor function primarily via ligand binding and those that primarily affect function. The shared and differential mechanisms of agonist binding and activation in KOR are further discussed. Usually, mutations affecting function more than binding were located at the periphery of the binding site and did not interact strongly with the various ligands. Analysis of the crystal structure along with the present results provide fundamental insights into the activation mechanism of the KOR and suggest that "functional" residues, along with water molecules detected in the crystal structure, may be directly involved in transduction of the agonist binding event into structural changes at the conserved rotamer switches, thus leading to receptor activation.
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Affiliation(s)
- Eyal Vardy
- From the Department of Pharmacology, University of North Carolina School of Medicine, Chapel Hill, North Carolina 27599
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21
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Moreira IS. Structural features of the G-protein/GPCR interactions. Biochim Biophys Acta Gen Subj 2013; 1840:16-33. [PMID: 24016604 DOI: 10.1016/j.bbagen.2013.08.027] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2013] [Revised: 08/27/2013] [Accepted: 08/28/2013] [Indexed: 01/07/2023]
Abstract
BACKGROUND The details of the functional interaction between G proteins and the G protein coupled receptors (GPCRs) have long been subjected to extensive investigations with structural and functional assays and a large number of computational studies. SCOPE OF REVIEW The nature and sites of interaction in the G-protein/GPCR complexes, and the specificities of these interactions selecting coupling partners among the large number of families of GPCRs and G protein forms, are still poorly defined. MAJOR CONCLUSIONS Many of the contact sites between the two proteins in specific complexes have been identified, but the three dimensional molecular architecture of a receptor-Gα interface is only known for one pair. Consequently, many fundamental questions regarding this macromolecular assembly and its mechanism remain unanswered. GENERAL SIGNIFICANCE In the context of current structural data we review the structural details of the interfaces and recognition sites in complexes of sub-family A GPCRs with cognate G-proteins, with special emphasis on the consequences of activation on GPCR structure, the prevalence of preassembled GPCR/G-protein complexes, the key structural determinants for selective coupling and the possible involvement of GPCR oligomerization in this process.
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Affiliation(s)
- Irina S Moreira
- REQUIMTE/Departamento de Química e Bioquímica, Faculdade de Ciências da Universidade do Porto, Rua do Campo Alegre s/n, 4169-007 Porto, Portugal.
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