1
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Zhang M, Chen T, Lu X, Lan X, Chen Z, Lu S. G protein-coupled receptors (GPCRs): advances in structures, mechanisms, and drug discovery. Signal Transduct Target Ther 2024; 9:88. [PMID: 38594257 PMCID: PMC11004190 DOI: 10.1038/s41392-024-01803-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Revised: 02/19/2024] [Accepted: 03/13/2024] [Indexed: 04/11/2024] Open
Abstract
G protein-coupled receptors (GPCRs), the largest family of human membrane proteins and an important class of drug targets, play a role in maintaining numerous physiological processes. Agonist or antagonist, orthosteric effects or allosteric effects, and biased signaling or balanced signaling, characterize the complexity of GPCR dynamic features. In this study, we first review the structural advancements, activation mechanisms, and functional diversity of GPCRs. We then focus on GPCR drug discovery by revealing the detailed drug-target interactions and the underlying mechanisms of orthosteric drugs approved by the US Food and Drug Administration in the past five years. Particularly, an up-to-date analysis is performed on available GPCR structures complexed with synthetic small-molecule allosteric modulators to elucidate key receptor-ligand interactions and allosteric mechanisms. Finally, we highlight how the widespread GPCR-druggable allosteric sites can guide structure- or mechanism-based drug design and propose prospects of designing bitopic ligands for the future therapeutic potential of targeting this receptor family.
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Affiliation(s)
- Mingyang Zhang
- Key Laboratory of Protection, Development and Utilization of Medicinal Resources in Liupanshan Area, Ministry of Education, Peptide & Protein Drug Research Center, School of Pharmacy, Ningxia Medical University, Yinchuan, 750004, China
- Medicinal Chemistry and Bioinformatics Center, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Ting Chen
- Department of Cardiology, Changzheng Hospital, Affiliated to Naval Medical University, Shanghai, 200003, China
| | - Xun Lu
- Medicinal Chemistry and Bioinformatics Center, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Xiaobing Lan
- Key Laboratory of Protection, Development and Utilization of Medicinal Resources in Liupanshan Area, Ministry of Education, Peptide & Protein Drug Research Center, School of Pharmacy, Ningxia Medical University, Yinchuan, 750004, China
| | - Ziqiang Chen
- Department of Orthopedics, Changhai Hospital, Affiliated to Naval Medical University, Shanghai, 200433, China.
| | - Shaoyong Lu
- Key Laboratory of Protection, Development and Utilization of Medicinal Resources in Liupanshan Area, Ministry of Education, Peptide & Protein Drug Research Center, School of Pharmacy, Ningxia Medical University, Yinchuan, 750004, China.
- Medicinal Chemistry and Bioinformatics Center, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China.
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2
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Shin J, Park J, Jeong J, Lam JH, Qiu X, Wu D, Kim K, Lee JY, Robinson CV, Hyun J, Katritch V, Kim KP, Cho Y. Constitutive activation mechanism of a class C GPCR. Nat Struct Mol Biol 2024; 31:678-687. [PMID: 38332368 DOI: 10.1038/s41594-024-01224-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Accepted: 01/09/2024] [Indexed: 02/10/2024]
Abstract
Class C G-protein-coupled receptors (GPCRs) are activated through binding of agonists to the large extracellular domain (ECD) followed by rearrangement of the transmembrane domains (TMDs). GPR156, a class C orphan GPCR, is unique because it lacks an ECD and exhibits constitutive activity. Impaired GPR156-Gi signaling contributes to loss of hearing. Here we present the cryo-electron microscopy structures of human GPR156 in the Go-free and Go-coupled states. We found that an endogenous phospholipid molecule is located within each TMD of the GPR156 dimer. Asymmetric binding of Gα to the phospholipid-bound GPR156 dimer restructures the first and second intracellular loops and the carboxy-terminal part of the elongated transmembrane 7 (TM7) without altering dimer conformation. Our findings reveal that GPR156 is a transducer for phospholipid signaling. Constant binding of abundant phospholipid molecules and the G-protein-induced reshaping of the cytoplasmic face provide a basis for the constitutive activation of GPR156.
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Affiliation(s)
- Jinwoo Shin
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Republic of Korea
| | - Junhyeon Park
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Republic of Korea
| | - Jieun Jeong
- Department of Applied Chemistry, Global Center for Pharmaceutical Ingredient Materials, Kyung Hee University, Yongin, Republic of Korea
| | - Jordy Homing Lam
- Department of Quantitative and Computational Biology, University of Southern California, Los Angeles, CA, USA
- Bridge Institute and Michelson Center for Convergent Biosciences, University of Southern California, Los Angeles, CA, USA
| | - Xingyu Qiu
- Department of Chemistry, University of Oxford, Oxford, UK
- Kavli Institute for Nanoscience Discovery, University of Oxford, Oxford, UK
| | - Di Wu
- Department of Chemistry, University of Oxford, Oxford, UK
- Kavli Institute for Nanoscience Discovery, University of Oxford, Oxford, UK
| | - Kuglae Kim
- Department of Pharmacy, Yonsei University, Incheon, Republic of Korea
| | - Joo-Youn Lee
- Therapeutics and Biotechnology Division, Korea Research Institute of Chemical Technology, 141 Gajeong-ro, Yuseong-gu, Daejeon, Republic of Korea
| | - Carol V Robinson
- Department of Chemistry, University of Oxford, Oxford, UK
- Kavli Institute for Nanoscience Discovery, University of Oxford, Oxford, UK
| | - Jaekyung Hyun
- School of Pharmacy, Sungkyunkwan University, Suwon, Republic of Korea
| | - Vsevolod Katritch
- Department of Quantitative and Computational Biology, University of Southern California, Los Angeles, CA, USA
- Bridge Institute and Michelson Center for Convergent Biosciences, University of Southern California, Los Angeles, CA, USA
- Center for New Technologies in Drug Discovery and Development, University of Southern California, Los Angeles, CA, USA
- Department of Chemistry, University of Southern California, Los Angeles, CA, USA
| | - Kwang Pyo Kim
- Department of Applied Chemistry, Global Center for Pharmaceutical Ingredient Materials, Kyung Hee University, Yongin, Republic of Korea.
- Department of Biomedical Science and Technology, Kyung Hee Medical Science Research Institute, Kyung Hee University, Seoul, Republic of Korea.
| | - Yunje Cho
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Republic of Korea.
- Department of Medical Science and Engineering, Pohang University of Science and Technology, Pohang, Republic of Korea.
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3
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Krámos B, Hadady Z, Makó A, Szántó G, Felföldi N, Magdó I, Bobok AÁ, Bata I, Román V, Visegrády A, Keserű G, Greiner I, Éles J. Novel-Type GABA B PAMs: Structure-Activity Relationship in Light of the Protein Structure. ACS Med Chem Lett 2024; 15:396-405. [PMID: 38505850 PMCID: PMC10945541 DOI: 10.1021/acsmedchemlett.3c00560] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Revised: 02/16/2024] [Accepted: 02/20/2024] [Indexed: 03/21/2024] Open
Abstract
Selecting a known HTS hit with the pyrazolo[1,5-a]pyrimidine core, our project was started from CMPPE, and its optimization was driven by a ligand-based pharmacophore model developed on the basis of published GABAB positive allosteric modulators (PAMs). Our primary goal was to improve the potency by finding new enthalpic interactions. Therefore, we included the lipophilic ligand efficiency (LLE or LipE) as an objective function in the optimization that led to a carboxylic acid derivative (34). This lead candidate offers the possibility to improve potency without drastically inflating the physicochemical properties. Although the discovery of the novel carboxyl feature was surprising, it turned out to be an important element of the GABAB PAM pharmacophore that can be perfectly explained based on the new protein structures. Rationalizing the binding mode of 34, we analyzed the intersubunit PAM binding site of GABAB receptor using the publicly available experimental structures.
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Affiliation(s)
- Balázs Krámos
- Spectroscopic
Research Department, Gedeon Richter Plc., Gyömrői út
19-21, Budapest, 1103 Hungary
| | - Zsuzsa Hadady
- Chemistry
Department, Gedeon Richter Plc., Gyömrői út
19-21, Budapest, 1103 Hungary
| | - Attila Makó
- Chemistry
Department, Gedeon Richter Plc., Gyömrői út
19-21, Budapest, 1103 Hungary
| | - Gábor Szántó
- Chemistry
Department, Gedeon Richter Plc., Gyömrői út
19-21, Budapest, 1103 Hungary
| | - Nóra Felföldi
- Chemistry
Department, Gedeon Richter Plc., Gyömrői út
19-21, Budapest, 1103 Hungary
| | - Ildikó Magdó
- Spectroscopic
Research Department, Gedeon Richter Plc., Gyömrői út
19-21, Budapest, 1103 Hungary
| | - Amrita Ágnes Bobok
- Pharmacological
and Drug Safety Research, Gedeon Richter
Plc., Gyömrői
út 19-21, Budapest, 1103 Hungary
| | - Imre Bata
- Chemistry
Department, Gedeon Richter Plc., Gyömrői út
19-21, Budapest, 1103 Hungary
| | - Viktor Román
- Pharmacological
and Drug Safety Research, Gedeon Richter
Plc., Gyömrői
út 19-21, Budapest, 1103 Hungary
| | - András Visegrády
- Pharmacological
and Drug Safety Research, Gedeon Richter
Plc., Gyömrői
út 19-21, Budapest, 1103 Hungary
| | - György
M. Keserű
- Medicinal
Chemistry Research Group, Research Centre
for Natural Sciences, Magyar tudósok krt. 2, Budapest, 1117 Hungary
| | - István Greiner
- Research
and Development Director, Gedeon Richter
Plc., Gyömrői
út 19-21, Budapest, 1103 Hungary
| | - János Éles
- Head
of Medicinal Chemistry, Gedeon Richter Plc., Gyömrői út
19-21, Budapest, 1103 Hungary
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4
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Sweeney A, Mulvaney T, Maiorca M, Topf M. ChemEM: Flexible Docking of Small Molecules in Cryo-EM Structures. J Med Chem 2024; 67:199-212. [PMID: 38157562 PMCID: PMC10788898 DOI: 10.1021/acs.jmedchem.3c01134] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Revised: 11/28/2023] [Accepted: 12/08/2023] [Indexed: 01/03/2024]
Abstract
Cryo-electron microscopy (cryo-EM), through resolution advancements, has become pivotal in structure-based drug discovery. However, most cryo-EM structures are solved at 3-4 Å resolution, posing challenges for small-molecule docking and structure-based virtual screening due to issues in the precise positioning of ligands and the surrounding side chains. We present ChemEM, a software package that employs cryo-EM data for the accurate docking of one or multiple ligands in a protein-binding site. Validated against a highly curated benchmark of high- and medium-resolution cryo-EM structures and the corresponding high-resolution controls, ChemEM displayed impressive performance, accurately placing ligands in all but one case, often surpassing cryo-EM PDB-deposited solutions. Even without including the cryo-EM density, the ChemEM scoring function outperformed the well-established AutoDock Vina score. Using ChemEM, we illustrate that valuable information can be extracted from maps at medium resolution and underline the utility of cryo-EM structures for drug discovery.
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Affiliation(s)
- Aaron Sweeney
- Leibniz Institute of Virology (LIV), Hamburg 20251, Germany
- Centre for Structural Systems Biology, Hamburg 22607, Germany
- Universitätsklinikum Hamburg
Eppendorf (UKE), Hamburg 20246, Germany
| | - Thomas Mulvaney
- Leibniz Institute of Virology (LIV), Hamburg 20251, Germany
- Centre for Structural Systems Biology, Hamburg 22607, Germany
- Universitätsklinikum Hamburg
Eppendorf (UKE), Hamburg 20246, Germany
| | - Mauro Maiorca
- Leibniz Institute of Virology (LIV), Hamburg 20251, Germany
- Centre for Structural Systems Biology, Hamburg 22607, Germany
- Universitätsklinikum Hamburg
Eppendorf (UKE), Hamburg 20246, Germany
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5
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Strauss A, Gonzalez-Hernandez AJ, Lee J, Abreu N, Selvakumar P, Salas-Estrada L, Kristt M, Marx DC, Gilliland K, Melancon BJ, Filizola M, Meyerson J, Levitz J. Structural basis of allosteric modulation of metabotropic glutamate receptor activation and desensitization. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.13.552748. [PMID: 37645747 PMCID: PMC10461995 DOI: 10.1101/2023.08.13.552748] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/31/2023]
Abstract
The metabotropic glutamate receptors (mGluRs) are neuromodulatory family C G protein coupled receptors which assemble as dimers and allosterically couple extracellular ligand binding domains (LBDs) to transmembrane domains (TMDs) to drive intracellular signaling. Pharmacologically, mGluRs can be targeted either at the LBDs by glutamate and synthetic orthosteric compounds or at the TMDs by allosteric modulators. Despite the potential of allosteric TMD-targeting compounds as therapeutics, an understanding of the functional and structural basis of their effects on mGluRs is limited. Here we use a battery of approaches to dissect the distinct functional and structural effects of orthosteric versus allosteric ligands. We find using electrophysiological and live cell imaging assays that both agonists and positive allosteric modulators (PAMs) can drive activation and desensitization of mGluRs. The effects of PAMs are pleiotropic, including both the ability to boost the maximal response to orthosteric agonists and to serve independently as desensitization-biased agonists across mGluR subtypes. Conformational sensors reveal PAM-driven inter-subunit re-arrangements at both the LBD and TMD. Motivated by this, we determine cryo-electron microscopy structures of mGluR3 in the presence of either an agonist or antagonist alone or in combination with a PAM. These structures reveal PAM-driven re-shaping of intra- and inter-subunit conformations and provide evidence for a rolling TMD dimer interface activation pathway that controls G protein and beta-arrestin coupling. Highlights -Agonists and PAMs drive mGluR activation, desensitization, and endocytosis-PAMs are desensitization-biased and synergistic with agonists-Four combinatorial ligand conditions reveal an ensemble of full-length mGluR structures with novel interfaces-Activation and desensitization involve rolling TMD interfaces which are re-shaped by PAM.
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6
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Liu L, Lin L, Shen C, Rondard P, Pin JP, Xu C, Liu J. Asymmetric activation of dimeric GABA B and metabotropic glutamate receptors. Am J Physiol Cell Physiol 2023; 325:C79-C89. [PMID: 37184233 DOI: 10.1152/ajpcell.00150.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Revised: 04/27/2023] [Accepted: 05/11/2023] [Indexed: 05/16/2023]
Abstract
G protein-coupled receptors (GPCRs) represent the largest family of membrane proteins and are important drug targets. GPCRs are allosteric machines that transduce an extracellular signal to the cell by activating heterotrimeric G proteins. Herein, we summarize the recent advancements in the molecular activation mechanism of the γ-aminobutyric acid type B (GABAB) and metabotropic glutamate (mGlu) receptors, the most important class C GPCRs that modulate synaptic transmission in the brain. Both are mandatory dimers, this quaternary structure being needed for their function The structures of these receptors in different conformations and in complexes with G proteins have revealed their asymmetric activation. This asymmetry is further highlighted by the recent discovery of mGlu heterodimers, where the eight mGlu subunits can form specific and functional heterodimers. Finally, the development of allosteric modulators has revealed new possibilities for regulating the function of these receptors by targeting the transmembrane dimer interface. This family of receptors never ceases to astonish and serve as models to better understand the diversity and asymmetric functioning of GPCRs.NEW & NOTEWORTHY γ-aminobutyric acid type B (GABAB) and metabotropic glutamate (mGlu) receptors form constitutive dimers, which are required for their function. They serve as models to better understand the diversity and activation of G protein-coupled receptors (GPCRs). The structures of these receptors in different conformations and in complexes with G proteins have revealed their asymmetric activation. This asymmetry is further highlighted by the recent discovery of specific and functional mGlu heterodimers. Allosteric modulators can be developed to target the transmembrane interface and modulate the asymmetry.
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Affiliation(s)
- Lei Liu
- Cellular Signaling Laboratory, International Research Center for Sensory Biology and Technology of MOST, Key Laboratory of Molecular Biophysics of MOE, and College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, People's Republic of China
| | - Li Lin
- Cellular Signaling Laboratory, International Research Center for Sensory Biology and Technology of MOST, Key Laboratory of Molecular Biophysics of MOE, and College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, People's Republic of China
| | - Cangsong Shen
- Cellular Signaling Laboratory, International Research Center for Sensory Biology and Technology of MOST, Key Laboratory of Molecular Biophysics of MOE, and College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, People's Republic of China
| | - Philippe Rondard
- Institut de Génomique Fonctionnelle, Université de Montpellier, CNRS, INSERM, Montpellier, France
| | - Jean-Philippe Pin
- Institut de Génomique Fonctionnelle, Université de Montpellier, CNRS, INSERM, Montpellier, France
| | - Chanjuan Xu
- Cellular Signaling Laboratory, International Research Center for Sensory Biology and Technology of MOST, Key Laboratory of Molecular Biophysics of MOE, and College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, People's Republic of China
| | - Jianfeng Liu
- Cellular Signaling Laboratory, International Research Center for Sensory Biology and Technology of MOST, Key Laboratory of Molecular Biophysics of MOE, and College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, People's Republic of China
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7
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Gusach A, García-Nafría J, Tate CG. New insights into GPCR coupling and dimerisation from cryo-EM structures. Curr Opin Struct Biol 2023; 80:102574. [PMID: 36963163 PMCID: PMC10423944 DOI: 10.1016/j.sbi.2023.102574] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Revised: 02/01/2023] [Accepted: 02/19/2023] [Indexed: 03/26/2023]
Abstract
Over the past three years (2020-2022) more structures of GPCRs have been determined than in the previous twenty years (2000-2019), primarily of GPCR complexes that are large enough for structure determination by single-particle cryo-EM. This review will present some structural highlights that have advanced our molecular understanding of promiscuous G protein coupling, how a G protein receptor kinase and β-arrestins couple to GPCRs, and GPCR dimerisation. We will also discuss advances in the use of gene fusions, nanobodies, and Fab fragments to facilitate the structure determination of GPCRs in the inactive state that, on their own, are too small for structure determination by single-particle cryo-EM.
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Affiliation(s)
- Anastasiia Gusach
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 2QH, UK. https://twitter.com/GusachAnastasia
| | - Javier García-Nafría
- Institute for Biocomputation and Physics of Complex Systems (BIFI) and Laboratorio de Microscopías Avanzadas (LMA), University of Zaragoza, 50018, Zaragoza, Spain. https://twitter.com/JGarciaNafria
| | - Christopher G Tate
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 2QH, UK.
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8
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Wong TS, Li G, Li S, Gao W, Chen G, Gan S, Zhang M, Li H, Wu S, Du Y. G protein-coupled receptors in neurodegenerative diseases and psychiatric disorders. Signal Transduct Target Ther 2023; 8:177. [PMID: 37137892 PMCID: PMC10154768 DOI: 10.1038/s41392-023-01427-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Revised: 02/17/2023] [Accepted: 03/30/2023] [Indexed: 05/05/2023] Open
Abstract
Neuropsychiatric disorders are multifactorial disorders with diverse aetiological factors. Identifying treatment targets is challenging because the diseases are resulting from heterogeneous biological, genetic, and environmental factors. Nevertheless, the increasing understanding of G protein-coupled receptor (GPCR) opens a new possibility in drug discovery. Harnessing our knowledge of molecular mechanisms and structural information of GPCRs will be advantageous for developing effective drugs. This review provides an overview of the role of GPCRs in various neurodegenerative and psychiatric diseases. Besides, we highlight the emerging opportunities of novel GPCR targets and address recent progress in GPCR drug development.
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Affiliation(s)
- Thian-Sze Wong
- Kobilka Institute of Innovative Drug Discovery, Shenzhen Key Laboratory of Steroid Drug Discovery and Development, School of Medicine, The Chinese University of Hong Kong, 518172, Shenzhen, Guangdong, China
- School of Medicine, Tsinghua University, 100084, Beijing, China
| | - Guangzhi Li
- Institute of Urology, The Affiliated Luohu Hospital of Shenzhen University, Shenzhen University, 518000, Shenzhen, Guangdong, China
| | - Shiliang Li
- Shanghai Key Laboratory of New Drug Design, School of Pharmacy, East China University of Science and Technology, 200237, Shanghai, China
- Innovation Center for AI and Drug Discovery, East China Normal University, 200062, Shanghai, China
| | - Wei Gao
- Kobilka Institute of Innovative Drug Discovery, Shenzhen Key Laboratory of Steroid Drug Discovery and Development, School of Medicine, The Chinese University of Hong Kong, 518172, Shenzhen, Guangdong, China
- Innovation Center for AI and Drug Discovery, East China Normal University, 200062, Shanghai, China
| | - Geng Chen
- Kobilka Institute of Innovative Drug Discovery, Shenzhen Key Laboratory of Steroid Drug Discovery and Development, School of Medicine, The Chinese University of Hong Kong, 518172, Shenzhen, Guangdong, China
| | - Shiyi Gan
- Kobilka Institute of Innovative Drug Discovery, Shenzhen Key Laboratory of Steroid Drug Discovery and Development, School of Medicine, The Chinese University of Hong Kong, 518172, Shenzhen, Guangdong, China
| | - Manzhan Zhang
- Shanghai Key Laboratory of New Drug Design, School of Pharmacy, East China University of Science and Technology, 200237, Shanghai, China
- Innovation Center for AI and Drug Discovery, East China Normal University, 200062, Shanghai, China
| | - Honglin Li
- Shanghai Key Laboratory of New Drug Design, School of Pharmacy, East China University of Science and Technology, 200237, Shanghai, China.
- Innovation Center for AI and Drug Discovery, East China Normal University, 200062, Shanghai, China.
| | - Song Wu
- Institute of Urology, The Affiliated Luohu Hospital of Shenzhen University, Shenzhen University, 518000, Shenzhen, Guangdong, China.
- Department of Urology, South China Hospital, Health Science Center, Shenzhen University, 518116, Shenzhen, Guangdong, China.
| | - Yang Du
- Kobilka Institute of Innovative Drug Discovery, Shenzhen Key Laboratory of Steroid Drug Discovery and Development, School of Medicine, The Chinese University of Hong Kong, 518172, Shenzhen, Guangdong, China.
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9
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Zhang L, Mobbs JI, May LT, Glukhova A, Thal DM. The impact of cryo-EM on determining allosteric modulator-bound structures of G protein-coupled receptors. Curr Opin Struct Biol 2023; 79:102560. [PMID: 36848776 DOI: 10.1016/j.sbi.2023.102560] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Revised: 01/23/2023] [Accepted: 01/31/2023] [Indexed: 02/27/2023]
Abstract
G-protein coupled receptors (GPCRs) are important therapeutic targets for the treatment of human disease. Although GPCRs are highly successful drug targets, there are many challenges associated with the discovery and translation of small molecule ligands that target the endogenous ligand-binding site for GPCRs. Allosteric modulators are a class of ligands that target alternative binding sites known as allosteric sites and offer fresh opportunities for the development of new therapeutics. However, only a few allosteric modulators have been approved as drugs. Advances in GPCR structural biology enabled by the cryogenic electron microscopy (cryo-EM) revolution have provided new insights into the molecular mechanism and binding location of small molecule allosteric modulators. This review highlights the latest findings from allosteric modulator-bound structures of Class A, B, and C GPCRs with a focus on small molecule ligands. Emerging methods that will facilitate cryo-EM structures of more difficult ligand-bound GPCR complexes are also discussed. The results of these studies are anticipated to aid future structure-based drug discovery efforts across many different GPCRs.
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Affiliation(s)
- Liudi Zhang
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville 3052, Victoria Australia; ARC Centre for Cryo-electron Microscopy of Membrane Proteins, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville 3052, Victoria Australia
| | - Jesse I Mobbs
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville 3052, Victoria Australia; ARC Centre for Cryo-electron Microscopy of Membrane Proteins, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville 3052, Victoria Australia. https://twitter.com/@JesseMobbs
| | - Lauren T May
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville 3052, Victoria Australia. https://twitter.com/@laurentmay
| | - Alisa Glukhova
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville 3052, Victoria Australia; ARC Centre for Cryo-electron Microscopy of Membrane Proteins, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville 3052, Victoria Australia; The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia; Department of Biochemistry and Pharmacology, The University of Melbourne, Melbourne, Victoria 3010, Australia. https://twitter.com/@gl_alisa
| | - David M Thal
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville 3052, Victoria Australia; ARC Centre for Cryo-electron Microscopy of Membrane Proteins, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville 3052, Victoria Australia.
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10
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Isu UH, Badiee SA, Khodadadi E, Moradi M. Cholesterol in Class C GPCRs: Role, Relevance, and Localization. MEMBRANES 2023; 13:301. [PMID: 36984688 PMCID: PMC10056374 DOI: 10.3390/membranes13030301] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Revised: 02/21/2023] [Accepted: 02/28/2023] [Indexed: 06/18/2023]
Abstract
G-protein coupled receptors (GPCRs), one of the largest superfamilies of cell-surface receptors, are heptahelical integral membrane proteins that play critical roles in virtually every organ system. G-protein-coupled receptors operate in membranes rich in cholesterol, with an imbalance in cholesterol level within the vicinity of GPCR transmembrane domains affecting the structure and/or function of many GPCRs, a phenomenon that has been linked to several diseases. These effects of cholesterol could result in indirect changes by altering the mechanical properties of the lipid environment or direct changes by binding to specific sites on the protein. There are a number of studies and reviews on how cholesterol modulates class A GPCRs; however, this area of study is yet to be explored for class C GPCRs, which are characterized by a large extracellular region and often form constitutive dimers. This review highlights specific sites of interaction, functions, and structural dynamics involved in the cholesterol recognition of the class C GPCRs. We summarize recent data from some typical family members to explain the effects of membrane cholesterol on the structural features and functions of class C GPCRs and speculate on their corresponding therapeutic potential.
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11
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Moreau CJ, Audic G, Lemel L, García-Fernández MD, Nieścierowicz K. Interactions of cholesterol molecules with GPCRs in different states: A comparative analysis of GPCRs' structures. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2023; 1865:184100. [PMID: 36521554 DOI: 10.1016/j.bbamem.2022.184100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Revised: 11/30/2022] [Accepted: 12/01/2022] [Indexed: 12/14/2022]
Affiliation(s)
| | - Guillaume Audic
- Univ. Grenoble Alpes, CNRS, CEA, IBS, F-38000 Grenoble, France
| | - Laura Lemel
- Univ. Grenoble Alpes, CNRS, CEA, IBS, F-38000 Grenoble, France
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12
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Shen S, Zhao C, Wu C, Sun S, Li Z, Yan W, Shao Z. Allosteric modulation of G protein-coupled receptor signaling. Front Endocrinol (Lausanne) 2023; 14:1137604. [PMID: 36875468 PMCID: PMC9978769 DOI: 10.3389/fendo.2023.1137604] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Accepted: 01/31/2023] [Indexed: 02/18/2023] Open
Abstract
G protein-coupled receptors (GPCRs), the largest family of transmembrane proteins, regulate a wide array of physiological processes in response to extracellular signals. Although these receptors have proven to be the most successful class of drug targets, their complicated signal transduction pathways (including different effector G proteins and β-arrestins) and mediation by orthosteric ligands often cause difficulties for drug development, such as on- or off-target effects. Interestingly, identification of ligands that engage allosteric binding sites, which are different from classic orthosteric sites, can promote pathway-specific effects in cooperation with orthosteric ligands. Such pharmacological properties of allosteric modulators offer new strategies to design safer GPCR-targeted therapeutics for various diseases. Here, we explore recent structural studies of GPCRs bound to allosteric modulators. Our inspection of all GPCR families reveals recognition mechanisms of allosteric regulation. More importantly, this review highlights the diversity of allosteric sites and presents how allosteric modulators control specific GPCR pathways to provide opportunities for the development of new valuable agents.
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Affiliation(s)
| | | | | | | | | | - Wei Yan
- Division of Nephrology and Kidney Research Institute, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Zhenhua Shao
- Division of Nephrology and Kidney Research Institute, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, Sichuan, China
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13
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Allosteric modulation of GPCRs: From structural insights to in silico drug discovery. Pharmacol Ther 2022; 237:108242. [DOI: 10.1016/j.pharmthera.2022.108242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Revised: 06/14/2022] [Accepted: 07/07/2022] [Indexed: 11/19/2022]
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14
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G protein coupling and activation of the metabotropic GABA B heterodimer. Nat Commun 2022; 13:4612. [PMID: 35941188 PMCID: PMC9360005 DOI: 10.1038/s41467-022-32213-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Accepted: 07/21/2022] [Indexed: 11/22/2022] Open
Abstract
Metabotropic γ-aminobutyric acid receptor (GABABR), a class C G protein-coupled receptor (GPCR) heterodimer, plays a crucial role in the central nervous system. Cryo-electron microscopy studies revealed a drastic conformational change upon activation and a unique G protein (GP) binding mode. However, little is known about the mechanism for GP coupling and activation for class C GPCRs. Here, we use molecular metadynamics computations to predict the mechanism by which the inactive GP induces conformational changes in the GABABR transmembrane domain (TMD) to form an intermediate pre-activated state. We find that the inactive GP first interacts with TM3, which further leads to the TMD rearrangement and deeper insertion of the α5 helix that causes the Gα subunit to open, releasing GDP, and forming the experimentally observed activated structure. This mechanism provides fresh insights into the mechanistic details of class C GPCRs activation expected to be useful for designing selective agonists and antagonists. Despite its crucial role in the central nervous system, little is known about the activation mechanism of GABAB receptor. Here, the authors predict that the inactive G protein induces conformational changes of the receptor to form an intermediate state.
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15
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Piper SJ, Johnson RM, Wootten D, Sexton PM. Membranes under the Magnetic Lens: A Dive into the Diverse World of Membrane Protein Structures Using Cryo-EM. Chem Rev 2022; 122:13989-14017. [PMID: 35849490 DOI: 10.1021/acs.chemrev.1c00837] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Membrane proteins are highly diverse in both structure and function and can, therefore, present different challenges for structure determination. They are biologically important for cells and organisms as gatekeepers for information and molecule transfer across membranes, but each class of membrane proteins can present unique obstacles to structure determination. Historically, many membrane protein structures have been investigated using highly engineered constructs or using larger fusion proteins to improve solubility and/or increase particle size. Other strategies included the deconstruction of the full-length protein to target smaller soluble domains. These manipulations were often required for crystal formation to support X-ray crystallography or to circumvent lower resolution due to high noise and dynamic motions of protein subdomains. However, recent revolutions in membrane protein biochemistry and cryo-electron microscopy now provide an opportunity to solve high resolution structures of both large, >1 megadalton (MDa), and small, <100 kDa (kDa), drug targets in near-native conditions, routinely reaching resolutions around or below 3 Å. This review provides insights into how the recent advances in membrane biology and biochemistry, as well as technical advances in cryo-electron microscopy, help us to solve structures of a large variety of membrane protein groups, from small receptors to large transporters and more complex machineries.
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Affiliation(s)
- Sarah J Piper
- Drug Discovery Biology theme, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville 3052, Victoria, Australia.,ARC Centre for Cryo-electron Microscopy of Membrane Proteins, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville 3052, Victoria, Australia
| | - Rachel M Johnson
- Drug Discovery Biology theme, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville 3052, Victoria, Australia.,ARC Centre for Cryo-electron Microscopy of Membrane Proteins, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville 3052, Victoria, Australia
| | - Denise Wootten
- Drug Discovery Biology theme, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville 3052, Victoria, Australia.,ARC Centre for Cryo-electron Microscopy of Membrane Proteins, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville 3052, Victoria, Australia
| | - Patrick M Sexton
- Drug Discovery Biology theme, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville 3052, Victoria, Australia.,ARC Centre for Cryo-electron Microscopy of Membrane Proteins, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville 3052, Victoria, Australia
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16
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Tian R, Yin J, Yao Q, Wang T, Chen J, Liang Q, Li Q, Zhao X. Development of an Allostery Responsive Chromatographic Method for Screening Potential Allosteric Modulator of Beta2-adrenoceptor from a Natural Product-Derived DNA-Encoded Chemical Library. Anal Chem 2022; 94:9048-9057. [PMID: 35695812 DOI: 10.1021/acs.analchem.2c01210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Allosteric ligands are promising drugs owing to their remote regulations of the orthosteric ligand signaling pathway. There are few allosteric ligands due to the lack of handy and efficacious method for the screening. Herein, we developed an affinity chromatographic method for allosteric ligand screening by immobilizing purified beta2 adrenoceptor (β2-AR) onto macroporous silica gel by a two-point tethering method. The method relies on the occupation of the orthosteric site by an antagonist and the chelation of N-terminal His-tag of the receptor and Ni2+ coated on the gel. The immobilized β2-AR demonstrated the greatest allosteric responsive feature when Cmpd-15 (0.25 μM) was included in the mobile phase. Under the same conditions, the association constants of three agonists (salbutamol, terbutaline, and tulobuterol) reduced to 47%, 19%, and 27% compared with the data without the inclusion of Cmpd-15 in the mobile phase. APF was screened as a potential allosteric modulator of β2-AR by applying the immobilized receptor in a natural product-derived DNA-encoded chemical library (DEL). Relying on these results, we reasoned that the current method has potential in screening allosteric ligands of the receptor. We expect that it is applicable for the discovery of new allosteric binding sites of a target protein and screening allosteric modulators of the other receptors from complex samples.
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Affiliation(s)
- Rui Tian
- College of Life Sciences, Northwest University, Xi'an 710069, China
| | - Jiatai Yin
- College of Life Sciences, Northwest University, Xi'an 710069, China
| | - Qingqing Yao
- College of Life Sciences, Northwest University, Xi'an 710069, China
| | - Taotao Wang
- College of Life Sciences, Northwest University, Xi'an 710069, China
| | - Jiahuan Chen
- College of Life Sciences, Northwest University, Xi'an 710069, China
| | - Qi Liang
- College of Life Sciences, Northwest University, Xi'an 710069, China
| | - Qian Li
- College of Life Sciences, Northwest University, Xi'an 710069, China
| | - Xinfeng Zhao
- College of Life Sciences, Northwest University, Xi'an 710069, China
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17
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Casadó-Anguera V, Casadó V. Unmasking allosteric binding sites: Novel targets for GPCR drug discovery. Expert Opin Drug Discov 2022; 17:897-923. [PMID: 35649692 DOI: 10.1080/17460441.2022.2085684] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
INTRODUCTION Unexpected non-apparent and hidden allosteric binding sites are non-classical and non-apparent allosteric centers in 3-D X-ray protein structures until orthosteric or allosteric ligands bind to them. The orthosteric center of one protomer that modulates binding centers of the other protomers within an oligomer is also an unexpected allosteric site. Furthermore, another partner protein can also produce these effects, acting as an unexpected allosteric modulator. AREAS COVERED This review summarizes both classical and non-classical allosterism. The authors focus on G protein-coupled receptor (GPCR) oligomers as a paradigm of allosteric molecules. Moreover, they show several examples of unexpected allosteric sites such as hidden allosteric sites in a protomer that appear after the interaction with other molecules and the allosterism exerted between orthosteric sites within GPCR oligomer, emphasizing on the allosteric modulations that can occur between binding sites. EXPERT OPINION The study of these new non-classical allosteric sites will expand the diversity of allosteric control on the function of orthosteric sites within proteins, whether GPCRs or other receptors, enzymes or transporters. Moreover, the design of new drugs targeting these hidden allosteric sites or already known orthosteric sites acting as allosteric sites in protein homo- or hetero-oligomers will increase the therapeutic potential of allosterism.
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Affiliation(s)
- Verònica Casadó-Anguera
- Laboratory of Molecular Neuropharmacology, Department of Biochemistry and Molecular Biomedicine, Faculty of Biology, Universitat de Barcelona, and Institute of Biomedicine of the Universitat de Barcelona, Barcelona, Spain.,Laboratory of Neuropharmacology-Neurophar, Department of Experimental and Health Sciences, Universitat Pompeu Fabra, Barcelona, Spain
| | - Vicent Casadó
- Laboratory of Molecular Neuropharmacology, Department of Biochemistry and Molecular Biomedicine, Faculty of Biology, Universitat de Barcelona, and Institute of Biomedicine of the Universitat de Barcelona, Barcelona, Spain
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18
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Keeping the Balance: GABAB Receptors in the Developing Brain and Beyond. Brain Sci 2022; 12:brainsci12040419. [PMID: 35447949 PMCID: PMC9031223 DOI: 10.3390/brainsci12040419] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Revised: 03/18/2022] [Accepted: 03/21/2022] [Indexed: 12/16/2022] Open
Abstract
The main neurotransmitter in the brain responsible for the inhibition of neuronal activity is γ-aminobutyric acid (GABA). It plays a crucial role in circuit formation during development, both via its primary effects as a neurotransmitter and also as a trophic factor. The GABAB receptors (GABABRs) are G protein-coupled metabotropic receptors; on one hand, they can influence proliferation and migration; and, on the other, they can inhibit cells by modulating the function of K+ and Ca2+ channels, doing so on a slower time scale and with a longer-lasting effect compared to ionotropic GABAA receptors. GABABRs are expressed pre- and post-synaptically, at both glutamatergic and GABAergic terminals, thus being able to shape neuronal activity, plasticity, and the balance between excitatory and inhibitory synaptic transmission in response to varying levels of extracellular GABA concentration. Furthermore, given their subunit composition and their ability to form complexes with several associated proteins, GABABRs display heterogeneity with regard to their function, which makes them a promising target for pharmacological interventions. This review will describe (i) the latest results concerning GABABRs/GABABR-complex structures, their function, and the developmental time course of their appearance and functional integration in the brain, (ii) their involvement in manifestation of various pathophysiological conditions, and (iii) the current status of preclinical and clinical studies involving GABABR-targeting drugs.
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19
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Luo F, Qin G, Wang L, Fang X. Single-Molecule Fluorescence Imaging Reveals GABAB Receptor Aggregation State Changes. Front Chem 2022; 9:779940. [PMID: 35127643 PMCID: PMC8807474 DOI: 10.3389/fchem.2021.779940] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Accepted: 10/28/2021] [Indexed: 11/13/2022] Open
Abstract
The GABAB receptor is a typical G protein–coupled receptor, and its functional impairment is related to a variety of diseases. While the premise of GABAB receptor activation is the formation of heterodimers, the receptor also forms a tetramer on the cell membrane. Thus, it is important to study the effect of the GABAB receptor aggregation state on its activation and signaling. In this study, we have applied single-molecule photobleaching step counting and single-molecule tracking methods to investigate the formation and change of GABAB dimers and tetramers. A single-molecule stoichiometry assay of the wild-type and mutant receptors revealed the key sites on the interface of ligand-binding domains of the receptor for its dimerization. Moreover, we found that the receptor showed different aggregation behaviors at different conditions. Our results offered new evidence for a better understanding of the molecular basis for GABAB receptor aggregation and activation.
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Affiliation(s)
- Fang Luo
- CAS Key Laboratory of Molecular Nanostructure and Nanotechnology, Beijing National Research Center for Molecular Science, Institute of Chemistry, Chinese Academy of Science, Beijing, China
- Department of Chemistry, University of the Chinese Academy of Sciences, Beijing, China
| | - GeGe Qin
- CAS Key Laboratory of Molecular Nanostructure and Nanotechnology, Beijing National Research Center for Molecular Science, Institute of Chemistry, Chinese Academy of Science, Beijing, China
- Department of Chemistry, University of the Chinese Academy of Sciences, Beijing, China
| | - Lina Wang
- CAS Key Laboratory of Molecular Nanostructure and Nanotechnology, Beijing National Research Center for Molecular Science, Institute of Chemistry, Chinese Academy of Science, Beijing, China
- Department of Chemistry, University of the Chinese Academy of Sciences, Beijing, China
| | - Xiaohong Fang
- CAS Key Laboratory of Molecular Nanostructure and Nanotechnology, Beijing National Research Center for Molecular Science, Institute of Chemistry, Chinese Academy of Science, Beijing, China
- Department of Chemistry, University of the Chinese Academy of Sciences, Beijing, China
- *Correspondence: Xiaohong Fang,
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20
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Symmetric activation and modulation of the human calcium-sensing receptor. Proc Natl Acad Sci U S A 2021; 118:2115849118. [PMID: 34916296 DOI: 10.1073/pnas.2115849118] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/10/2021] [Indexed: 01/14/2023] Open
Abstract
The human extracellular calcium-sensing (CaS) receptor controls plasma Ca2+ levels and contributes to nutrient-dependent maintenance and metabolism of diverse organs. Allosteric modulation of the CaS receptor corrects disorders of calcium homeostasis. Here, we report the cryogenic-electron microscopy reconstructions of a near-full-length CaS receptor in the absence and presence of allosteric modulators. Activation of the homodimeric CaS receptor requires a break in the transmembrane 6 (TM6) helix of each subunit, which facilitates the formation of a TM6-mediated homodimer interface and expansion of homodimer interactions. This transformation in TM6 occurs without a positive allosteric modulator. Two modulators with opposite functional roles bind to overlapping sites within the transmembrane domain through common interactions, acting to stabilize distinct rotamer conformations of key residues on the TM6 helix. The positive modulator reinforces TM6 distortion and maximizes subunit contact to enhance receptor activity, while the negative modulator strengthens an intact TM6 to dampen receptor function. In both active and inactive states, the receptor displays symmetrical transmembrane conformations that are consistent with its homodimeric assembly.
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21
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Lees JA, Dias JM, Han S. Applications of Cryo-EM in small molecule and biologics drug design. Biochem Soc Trans 2021; 49:2627-2638. [PMID: 34812853 PMCID: PMC8786282 DOI: 10.1042/bst20210444] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 10/22/2021] [Accepted: 10/27/2021] [Indexed: 02/03/2023]
Abstract
Electron cryo-microscopy (cryo-EM) is a powerful technique for the structural characterization of biological macromolecules, enabling high-resolution analysis of targets once inaccessible to structural interrogation. In recent years, pharmaceutical companies have begun to utilize cryo-EM for structure-based drug design. Structural analysis of integral membrane proteins, which comprise a large proportion of druggable targets and pose particular challenges for X-ray crystallography, by cryo-EM has enabled insights into important drug target families such as G protein-coupled receptors (GPCRs), ion channels, and solute carrier (SLCs) proteins. Structural characterization of biologics, such as vaccines, viral vectors, and gene therapy agents, has also become significantly more tractable. As a result, cryo-EM has begun to make major impacts in bringing critical therapeutics to market. In this review, we discuss recent instructive examples of impacts from cryo-EM in therapeutics design, focusing largely on its implementation at Pfizer. We also discuss the opportunities afforded by emerging technological advances in cryo-EM, and the prospects for future development of the technique.
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Affiliation(s)
- Joshua A. Lees
- Discovery Sciences, Medicine Design, Pfizer Worldwide Research and Development, Groton, CT 06340, U.S.A
| | - Joao M. Dias
- Discovery Sciences, Medicine Design, Pfizer Worldwide Research and Development, Groton, CT 06340, U.S.A
| | - Seungil Han
- Discovery Sciences, Medicine Design, Pfizer Worldwide Research and Development, Groton, CT 06340, U.S.A
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22
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Liu L, Fan Z, Rovira X, Xue L, Roux S, Brabet I, Xin M, Pin JP, Rondard P, Liu J. Allosteric ligands control the activation of a class C GPCR heterodimer by acting at the transmembrane interface. eLife 2021; 10:70188. [PMID: 34866572 PMCID: PMC8700296 DOI: 10.7554/elife.70188] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2021] [Accepted: 12/02/2021] [Indexed: 01/02/2023] Open
Abstract
G protein-coupled receptors (GPCRs) are among the most promising drug targets. They often form homo- and heterodimers with allosteric cross-talk between receptor entities, which contributes to fine-tuning of transmembrane signaling. Specifically controlling the activity of GPCR dimers with ligands is a good approach to clarify their physiological roles and validate them as drug targets. Here, we examined the mode of action of positive allosteric modulators (PAMs) that bind at the interface of the transmembrane domains of the heterodimeric GABAB receptor. Our site-directed mutagenesis results show that mutations of this interface impact the function of the three PAMs tested. The data support the inference that they act at the active interface between both transmembrane domains, the binding site involving residues of the TM6s of the GABAB1 and the GABAB2 subunit. Importantly, the agonist activity of these PAMs involves a key region in the central core of the GABAB2 transmembrane domain, which also controls the constitutive activity of the GABAB receptor. This region corresponds to the sodium ion binding site in class A GPCRs that controls the basal state of the receptors. Overall, these data reveal the possibility of developing allosteric compounds able to specifically modulate the activity of GPCR homo- and heterodimers by acting at their transmembrane interface.
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Affiliation(s)
- Lei Liu
- Cellular Signaling Laboratory, International Research Center for Sensory Biology and Technology of MOST, Key Laboratory of Molecular Biophysics of MOE, and College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China.,Institut de Génomique Fonctionnelle, Université de Montpellier, CNRS, INSERM, Montpellier, France
| | - Zhiran Fan
- Cellular Signaling Laboratory, International Research Center for Sensory Biology and Technology of MOST, Key Laboratory of Molecular Biophysics of MOE, and College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
| | - Xavier Rovira
- MCS, Laboratory of Medicinal Chemistry, Institute for Advanced Chemistry of Catalonia (IQAC-CSIC), Barcelona, Spain
| | - Li Xue
- Cellular Signaling Laboratory, International Research Center for Sensory Biology and Technology of MOST, Key Laboratory of Molecular Biophysics of MOE, and College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China.,Institut de Génomique Fonctionnelle, Université de Montpellier, CNRS, INSERM, Montpellier, France
| | - Salomé Roux
- Institut de Génomique Fonctionnelle, Université de Montpellier, CNRS, INSERM, Montpellier, France
| | - Isabelle Brabet
- Institut de Génomique Fonctionnelle, Université de Montpellier, CNRS, INSERM, Montpellier, France
| | - Mingxia Xin
- Cellular Signaling Laboratory, International Research Center for Sensory Biology and Technology of MOST, Key Laboratory of Molecular Biophysics of MOE, and College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
| | - Jean-Philippe Pin
- Institut de Génomique Fonctionnelle, Université de Montpellier, CNRS, INSERM, Montpellier, France
| | - Philippe Rondard
- Institut de Génomique Fonctionnelle, Université de Montpellier, CNRS, INSERM, Montpellier, France
| | - Jianfeng Liu
- Cellular Signaling Laboratory, International Research Center for Sensory Biology and Technology of MOST, Key Laboratory of Molecular Biophysics of MOE, and College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
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23
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Structure of ABCB1/P-Glycoprotein in the Presence of the CFTR Potentiator Ivacaftor. MEMBRANES 2021; 11:membranes11120923. [PMID: 34940424 PMCID: PMC8703531 DOI: 10.3390/membranes11120923] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 11/16/2021] [Accepted: 11/23/2021] [Indexed: 12/26/2022]
Abstract
ABCB1/P-glycoprotein is an ATP binding cassette transporter that is involved in the clearance of xenobiotics, and it affects the disposition of many drugs in the body. Conformational flexibility of the protein within the membrane is an intrinsic part of its mechanism of action, but this has made structural studies challenging. Here, we have studied different conformations of P-glycoprotein simultaneously in the presence of ivacaftor, a known competitive inhibitor. In order to conduct this, we used high contrast cryo-electron microscopy imaging with a Volta phase plate. We associate the presence of ivacaftor with the appearance of an additional density in one of the conformational states detected. The additional density is in the central aqueous cavity and is associated with a wider separation of the two halves of the transporter in the inward-facing state. Conformational changes to the nucleotide-binding domains are also observed and may help to explain the stimulation of ATPase activity that occurs when transported substrate is bound in many ATP binding cassette transporters.
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24
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Jeong E, Kim Y, Jeong J, Cho Y. Structure of the class C orphan GPCR GPR158 in complex with RGS7-Gβ5. Nat Commun 2021; 12:6805. [PMID: 34815401 PMCID: PMC8611064 DOI: 10.1038/s41467-021-27147-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Accepted: 11/04/2021] [Indexed: 11/22/2022] Open
Abstract
GPR158, a class C orphan GPCR, functions in cognition, stress-induced mood control, and synaptic development. Among class C GPCRs, GPR158 is unique as it lacks a Venus flytrap-fold ligand-binding domain and terminates Gαi/o protein signaling through the RGS7-Gβ5 heterodimer. Here, we report the cryo-EM structures of GPR158 alone and in complex with one or two RGS7-Gβ5 heterodimers. GPR158 dimerizes through Per-Arnt-Sim-fold extracellular and transmembrane (TM) domains connected by an epidermal growth factor-like linker. The TM domain (TMD) reflects both inactive and active states of other class C GPCRs: a compact intracellular TMD, conformations of the two intracellular loops (ICLs) and the TMD interface formed by TM4/5. The ICL2, ICL3, TM3, and first helix of the cytoplasmic coiled-coil provide a platform for the DHEX domain of one RGS7 and the second helix recruits another RGS7. The unique features of the RGS7-binding site underlie the selectivity of GPR158 for RGS7.
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Affiliation(s)
- Eunyoung Jeong
- grid.49100.3c0000 0001 0742 4007Department of Life Science, Pohang University of Science and Technology, Pohang, Republic of Korea
| | - Yoojoong Kim
- grid.49100.3c0000 0001 0742 4007Department of Life Science, Pohang University of Science and Technology, Pohang, Republic of Korea
| | - Jihong Jeong
- grid.49100.3c0000 0001 0742 4007Department of Life Science, Pohang University of Science and Technology, Pohang, Republic of Korea
| | - Yunje Cho
- Department of Life Science, Pohang University of Science and Technology, Pohang, Republic of Korea.
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25
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Chen X, Wang L, Cui Q, Ding Z, Han L, Kou Y, Zhang W, Wang H, Jia X, Dai M, Shi Z, Li Y, Li X, Geng Y. Structural insights into the activation of human calcium-sensing receptor. eLife 2021; 10:68578. [PMID: 34467854 PMCID: PMC8476121 DOI: 10.7554/elife.68578] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Accepted: 08/31/2021] [Indexed: 12/16/2022] Open
Abstract
Human calcium-sensing receptor (CaSR) is a G-protein-coupled receptor that maintains Ca2+ homeostasis in serum. Here, we present the cryo-electron microscopy structures of the CaSR in the inactive and agonist+PAM bound states. Complemented with previously reported structures of CaSR, we show that in addition to the full inactive and active states, there are multiple intermediate states during the activation of CaSR. We used a negative allosteric nanobody to stabilize the CaSR in the fully inactive state and found a new binding site for Ca2+ ion that acts as a composite agonist with L-amino acid to stabilize the closure of active Venus flytraps. Our data show that agonist binding leads to compaction of the dimer, proximity of the cysteine-rich domains, large-scale transitions of seven-transmembrane domains, and inter- and intrasubunit conformational changes of seven-transmembrane domains to accommodate downstream transducers. Our results reveal the structural basis for activation mechanisms of CaSR and clarify the mode of action of Ca2+ ions and L-amino acid leading to the activation of the receptor.
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Affiliation(s)
- Xiaochen Chen
- The CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Lu Wang
- The CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Qianqian Cui
- The CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Zhanyu Ding
- The CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Li Han
- The CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Yongjun Kou
- The CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Wenqing Zhang
- The CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Haonan Wang
- The CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Xiaomin Jia
- The CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Mei Dai
- The CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Zhenzhong Shi
- The CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Yuying Li
- The CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Xiyang Li
- The CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Yong Geng
- The CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China.,University of Chinese Academy of Sciences, Beijing, China
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Multiscale simulations of large complexes in conjunction with cryo-EM analysis. Curr Opin Struct Biol 2021; 72:27-32. [PMID: 34399155 DOI: 10.1016/j.sbi.2021.07.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 07/15/2021] [Accepted: 07/16/2021] [Indexed: 11/21/2022]
Abstract
The cellular environment is highly crowded with most proteins and RNA/DNA forming homomeric and heteromeric complexes. Essential questions regarding how these complexes switch between functional, rest, and abnormal states with regulators or modifications remain challenging and complicated. Here, we review the recent progress integrating cryoelectron microscopy and multiscale molecular modeling to understand the dynamics and function-related mechanism in protein-RNA/DNA complexes, protein-protein complexes/assemblies, and membrane protein complexes. One future direction of multiscale simulations will be to interpret the large complex multibody regulation in assembly-induced function enhancement in conjunction with advanced atomic resolution structural-biology techniques and specialized computing architectures.
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Shaye H, Stauch B, Gati C, Cherezov V. Molecular mechanisms of metabotropic GABA B receptor function. SCIENCE ADVANCES 2021; 7:7/22/eabg3362. [PMID: 34049877 PMCID: PMC8163086 DOI: 10.1126/sciadv.abg3362] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Accepted: 04/14/2021] [Indexed: 05/06/2023]
Abstract
Metabotropic γ-aminobutyric acid G protein-coupled receptors (GABAB) represent one of the two main types of inhibitory neurotransmitter receptors in the brain. These receptors act both pre- and postsynaptically by modulating the transmission of neuronal signals and are involved in a range of neurological diseases, from alcohol addiction to epilepsy. A series of recent cryo-EM studies revealed critical details of the activation mechanism of GABAB Structures are now available for the receptor bound to ligands with different modes of action, including antagonists, agonists, and positive allosteric modulators, and captured in different conformational states from the inactive apo to the fully active state bound to a G protein. These discoveries provide comprehensive insights into the activation of the GABAB receptor, which not only broaden our understanding of its structure, pharmacology, and physiological effects but also will ultimately facilitate the discovery of new therapeutic drugs and neuromodulators.
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Affiliation(s)
- Hamidreza Shaye
- Department of Chemistry, University of Southern California, Los Angeles, CA, USA
- Bridge Institute, Michelson Center for Convergent Biosciences, University of Southern California, Los Angeles, CA, USA
| | - Benjamin Stauch
- Department of Chemistry, University of Southern California, Los Angeles, CA, USA
- Bridge Institute, Michelson Center for Convergent Biosciences, University of Southern California, Los Angeles, CA, USA
| | - Cornelius Gati
- Bridge Institute, Michelson Center for Convergent Biosciences, University of Southern California, Los Angeles, CA, USA
- Biosciences Division, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
- Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA
| | - Vadim Cherezov
- Department of Chemistry, University of Southern California, Los Angeles, CA, USA.
- Bridge Institute, Michelson Center for Convergent Biosciences, University of Southern California, Los Angeles, CA, USA
- Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA
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Amphipathic environments for determining the structure of membrane proteins by single-particle electron cryo-microscopy. Q Rev Biophys 2021; 54:e6. [PMID: 33785082 DOI: 10.1017/s0033583521000044] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Over the past decade, the structural biology of membrane proteins (MPs) has taken a new turn thanks to epoch-making technical progress in single-particle electron cryo-microscopy (cryo-EM) as well as to improvements in sample preparation. The present analysis provides an overview of the extent and modes of usage of the various types of surfactants for cryo-EM studies. Digitonin, dodecylmaltoside, protein-based nanodiscs, lauryl maltoside-neopentyl glycol, glyco-diosgenin, and amphipols (APols) are the most popular surfactants at the vitrification step. Surfactant exchange is frequently used between MP purification and grid preparation, requiring extensive optimization each time the study of a new MP is undertaken. The variety of both the surfactants and experimental approaches used over the past few years bears witness to the need to continue developing innovative surfactants and optimizing conditions for sample preparation. The possibilities offered by novel APols for EM applications are discussed.
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