51
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Thibado JK, Tano JY, Lee J, Salas-Estrada L, Provasi D, Strauss A, Marcelo Lamim Ribeiro J, Xiang G, Broichhagen J, Filizola M, Lohse MJ, Levitz J. Differences in interactions between transmembrane domains tune the activation of metabotropic glutamate receptors. eLife 2021; 10:e67027. [PMID: 33880992 PMCID: PMC8102066 DOI: 10.7554/elife.67027] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Accepted: 04/19/2021] [Indexed: 12/16/2022] Open
Abstract
The metabotropic glutamate receptors (mGluRs) form a family of neuromodulatory G-protein-coupled receptors that contain both a seven-helix transmembrane domain (TMD) and a large extracellular ligand-binding domain (LBD) which enables stable dimerization. Although numerous studies have revealed variability across subtypes in the initial activation steps at the level of LBD dimers, an understanding of inter-TMD interaction and rearrangement remains limited. Here, we use a combination of single molecule fluorescence, molecular dynamics, functional assays, and conformational sensors to reveal that distinct TMD assembly properties drive differences between mGluR subtypes. We uncover a variable region within transmembrane helix 4 (TM4) that contributes to homo- and heterodimerization in a subtype-specific manner and tunes orthosteric, allosteric, and basal activation. We also confirm a critical role for a conserved inter-TM6 interface in stabilizing the active state during orthosteric or allosteric activation. Together this study shows that inter-TMD assembly and dynamic rearrangement drive mGluR function with distinct properties between subtypes.
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Affiliation(s)
- Jordana K Thibado
- Physiology, Biophysics and Systems Biology Graduate Program, Weill Cornell Graduate School of Medical SciencesNew YorkUnited States
| | | | - Joon Lee
- Department of Biochemistry, Weill Cornell MedicineNew YorkUnited States
| | - Leslie Salas-Estrada
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount SinaiNew YorkUnited States
| | - Davide Provasi
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount SinaiNew YorkUnited States
| | - Alexa Strauss
- Tri-Institutional PhD Program in Chemical BiologyNew YorkUnited States
| | | | - Guoqing Xiang
- Department of Biochemistry, Weill Cornell MedicineNew YorkUnited States
| | | | - Marta Filizola
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount SinaiNew YorkUnited States
| | - Martin J Lohse
- Max Delbrück Center for Molecular MedicineBerlinGermany
- ISAR Bioscience InstitutePlanegg-MunichGermany
| | - Joshua Levitz
- Physiology, Biophysics and Systems Biology Graduate Program, Weill Cornell Graduate School of Medical SciencesNew YorkUnited States
- Department of Biochemistry, Weill Cornell MedicineNew YorkUnited States
- Tri-Institutional PhD Program in Chemical BiologyNew YorkUnited States
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52
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Hilger D. The role of structural dynamics in GPCR‐mediated signaling. FEBS J 2021; 288:2461-2489. [DOI: 10.1111/febs.15841] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Revised: 03/19/2021] [Accepted: 03/24/2021] [Indexed: 12/18/2022]
Affiliation(s)
- Daniel Hilger
- Department of Pharmaceutical Chemistry Philipps‐University Marburg Germany
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53
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Structural mechanism of cooperative activation of the human calcium-sensing receptor by Ca 2+ ions and L-tryptophan. Cell Res 2021; 31:383-394. [PMID: 33603117 PMCID: PMC8115157 DOI: 10.1038/s41422-021-00474-0] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2020] [Accepted: 01/06/2021] [Indexed: 02/07/2023] Open
Abstract
The human calcium-sensing receptor (CaSR) is a class C G protein-coupled receptor (GPCR) responsible for maintaining Ca2+ homeostasis in the blood. The general consensus is that extracellular Ca2+ is the principal agonist of CaSR. Aliphatic and aromatic L-amino acids, such as L-Phe and L-Trp, increase the sensitivity of CaSR towards Ca2+ and are considered allosteric activators. Crystal structures of the extracellular domain (ECD) of CaSR dimer have demonstrated Ca2+ and L-Trp binding sites and conformational changes of the ECD upon Ca2+/L-Trp binding. However, it remains to be understood at the structural level how Ca2+/L-Trp binding to the ECD leads to conformational changes in transmembrane domains (TMDs) and consequent CaSR activation. Here, we determined the structures of full-length human CaSR in the inactive state, Ca2+- or L-Trp-bound states, and Ca2+/L-Trp-bound active state using single-particle cryo-electron microscopy. Structural studies demonstrate that L-Trp binding induces the closure of the Venus flytrap (VFT) domain of CaSR, bringing the receptor into an intermediate active state. Ca2+ binding relays the conformational changes from the VFT domains to the TMDs, consequently inducing close contact between the two TMDs of dimeric CaSR, activating the receptor. Importantly, our structural and functional studies reveal that Ca2+ ions and L-Trp activate CaSR cooperatively. Amino acids are not able to activate CaSR alone, but can promote the receptor activation in the presence of Ca2+. Our data provide complementary insights into the activation of class C GPCRs and may aid in the development of novel drugs targeting CaSR.
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54
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Porcu A, Mostallino R, Serra V, Melis M, Sogos V, Beggiato S, Ferraro L, Manetti F, Gianibbi B, Bettler B, Corelli F, Mugnaini C, Castelli MP. COR758, a negative allosteric modulator of GABA B receptors. Neuropharmacology 2021; 189:108537. [PMID: 33798546 DOI: 10.1016/j.neuropharm.2021.108537] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Revised: 03/20/2021] [Accepted: 03/22/2021] [Indexed: 10/21/2022]
Abstract
Allosteric modulators of G protein coupled receptors (GPCRs), including GABABRs (GABABRs), are promising therapeutic candidates. While several positive allosteric modulators (PAM) of GABABRs have been characterized, only recently the first negative allosteric modulator (NAM) has been described. In the present study, we report the characterization of COR758, which acts as GABABR NAM in rat cortical membranes and CHO cells stably expressing GABABRs (CHO-GABAB). COR758 failed to displace the antagonist [3H]CGP54626 from the orthosteric binding site of GABABRs showing that it acts through an allosteric binding site. Docking studies revealed a possible new allosteric binding site for COR758 in the intrahelical pocket of the GABAB1 monomer. COR758 inhibited basal and GABABR-stimulated O-(3-[35Sthio)-triphosphate ([35S]GTPγS) binding in brain membranes and blocked the enhancement of GABABR-stimulated [35S]GTPγS binding by the PAM GS39783. Bioluminescent resonance energy transfer (BRET) measurements in CHO-GABAB cells showed that COR758 inhibited G protein activation by GABA and altered GABABR subunit rearrangements. Additionally, the compound altered GABABR-mediated signaling such as baclofen-induced inhibition of cAMP production in transfected HEK293 cells, agonist-induced Ca2+ mobilization as well as baclofen and the ago-PAM CGP7930 induced phosphorylation of extracellular signal-regulated kinases (ERK1/2) in CHO-GABAB cells. COR758 also prevented baclofen-induced outward currents recorded from rat dopamine neurons, substantiating its property as a NAM for GABABRs. Altogether, these data indicate that COR758 inhibits G protein signaling by GABABRs, likely by interacting with an allosteric binding-site. Therefore, COR758 might serve as a scaffold to develop additional NAMs for therapeutic intervention.
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Affiliation(s)
- Alessandra Porcu
- Department of Biomedical Sciences, University of Cagliari, 09042, Monserrato, Italy; Department of Biomedicine, University of Basel, Klingelbergstrasse 50-70, CH-4056, Basel, Switzerland
| | - Rafaela Mostallino
- Department of Biomedical Sciences, University of Cagliari, 09042, Monserrato, Italy
| | - Valeria Serra
- Department of Biomedical Sciences, University of Cagliari, 09042, Monserrato, Italy
| | - Miriam Melis
- Department of Biomedical Sciences, University of Cagliari, 09042, Monserrato, Italy
| | - Valeria Sogos
- Department of Biomedical Sciences, University of Cagliari, 09042, Monserrato, Italy
| | - Sarah Beggiato
- Department of Life Sciences and Biotechnology, Section of Medicinal and Health Products, and LTTA Center, University of Ferrara, Ferrara, Italy; Department of Medical, Oral and Biotechnological Sciences, University of Chieti-Pescara, 66100, Chieti, Italy
| | - Luca Ferraro
- Department of Life Sciences and Biotechnology, Section of Medicinal and Health Products, and LTTA Center, University of Ferrara, Ferrara, Italy
| | - Fabrizio Manetti
- Department of Biotechnology, Chemistry, and Pharmacy, University of Siena, I-53100, Siena, SI, Italy
| | - Beatrice Gianibbi
- Department of Biotechnology, Chemistry, and Pharmacy, University of Siena, I-53100, Siena, SI, Italy
| | - Bernhard Bettler
- Department of Biomedicine, University of Basel, Klingelbergstrasse 50-70, CH-4056, Basel, Switzerland
| | - Federico Corelli
- Department of Biotechnology, Chemistry, and Pharmacy, University of Siena, I-53100, Siena, SI, Italy
| | - Claudia Mugnaini
- Department of Biotechnology, Chemistry, and Pharmacy, University of Siena, I-53100, Siena, SI, Italy
| | - M Paola Castelli
- Department of Biomedical Sciences, University of Cagliari, 09042, Monserrato, Italy; Guy Everett Laboratory, University of Cagliari, 09042, Monserrato, Italy; Center of Excellence "Neurobiology of Addiction", University of Cagliari, 09042, Monserrato, Italy.
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55
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Structural Characterization of Receptor-Receptor Interactions in the Allosteric Modulation of G Protein-Coupled Receptor (GPCR) Dimers. Int J Mol Sci 2021; 22:ijms22063241. [PMID: 33810175 PMCID: PMC8005122 DOI: 10.3390/ijms22063241] [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: 02/26/2021] [Revised: 03/17/2021] [Accepted: 03/20/2021] [Indexed: 01/07/2023] Open
Abstract
G protein-coupled receptor (GPCR) oligomerization, while contentious, continues to attract the attention of researchers. Numerous experimental investigations have validated the presence of GPCR dimers, and the relevance of dimerization in the effectuation of physiological functions intensifies the attractiveness of this concept as a potential therapeutic target. GPCRs, as a single entity, have been the main source of scrutiny for drug design objectives for multiple diseases such as cancer, inflammation, cardiac, and respiratory diseases. The existence of dimers broadens the research scope of GPCR functions, revealing new signaling pathways that can be targeted for disease pathogenesis that have not previously been reported when GPCRs were only viewed in their monomeric form. This review will highlight several aspects of GPCR dimerization, which include a summary of the structural elucidation of the allosteric modulation of class C GPCR activation offered through recent solutions to the three-dimensional, full-length structures of metabotropic glutamate receptor and γ-aminobutyric acid B receptor as well as the role of dimerization in the modification of GPCR function and allostery. With the growing influence of computational methods in the study of GPCRs, we will also be reviewing recent computational tools that have been utilized to map protein-protein interactions (PPI).
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56
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Yang D, Zhou Q, Labroska V, Qin S, Darbalaei S, Wu Y, Yuliantie E, Xie L, Tao H, Cheng J, Liu Q, Zhao S, Shui W, Jiang Y, Wang MW. G protein-coupled receptors: structure- and function-based drug discovery. Signal Transduct Target Ther 2021; 6:7. [PMID: 33414387 PMCID: PMC7790836 DOI: 10.1038/s41392-020-00435-w] [Citation(s) in RCA: 208] [Impact Index Per Article: 69.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Revised: 11/30/2020] [Accepted: 12/05/2020] [Indexed: 02/08/2023] Open
Abstract
As one of the most successful therapeutic target families, G protein-coupled receptors (GPCRs) have experienced a transformation from random ligand screening to knowledge-driven drug design. We are eye-witnessing tremendous progresses made recently in the understanding of their structure-function relationships that facilitated drug development at an unprecedented pace. This article intends to provide a comprehensive overview of this important field to a broader readership that shares some common interests in drug discovery.
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Affiliation(s)
- Dehua Yang
- The National Center for Drug Screening, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 201203, Shanghai, China.,The CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 201203, Shanghai, China
| | - Qingtong Zhou
- School of Basic Medical Sciences, Fudan University, 200032, Shanghai, China
| | - Viktorija Labroska
- The National Center for Drug Screening, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 201203, Shanghai, China.,University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Shanshan Qin
- iHuman Institute, ShanghaiTech University, 201210, Shanghai, China
| | - Sanaz Darbalaei
- The National Center for Drug Screening, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 201203, Shanghai, China.,University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Yiran Wu
- iHuman Institute, ShanghaiTech University, 201210, Shanghai, China
| | - Elita Yuliantie
- The National Center for Drug Screening, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 201203, Shanghai, China.,University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Linshan Xie
- iHuman Institute, ShanghaiTech University, 201210, Shanghai, China.,School of Life Science and Technology, ShanghaiTech University, 201210, Shanghai, China
| | - Houchao Tao
- iHuman Institute, ShanghaiTech University, 201210, Shanghai, China
| | - Jianjun Cheng
- iHuman Institute, ShanghaiTech University, 201210, Shanghai, China
| | - Qing Liu
- The National Center for Drug Screening, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 201203, Shanghai, China.,The CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 201203, Shanghai, China
| | - Suwen Zhao
- iHuman Institute, ShanghaiTech University, 201210, Shanghai, China.,School of Life Science and Technology, ShanghaiTech University, 201210, Shanghai, China
| | - Wenqing Shui
- iHuman Institute, ShanghaiTech University, 201210, Shanghai, China. .,School of Life Science and Technology, ShanghaiTech University, 201210, Shanghai, China.
| | - Yi Jiang
- The CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 201203, Shanghai, China.
| | - Ming-Wei Wang
- The National Center for Drug Screening, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 201203, Shanghai, China. .,The CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 201203, Shanghai, China. .,School of Basic Medical Sciences, Fudan University, 200032, Shanghai, China. .,University of Chinese Academy of Sciences, 100049, Beijing, China. .,School of Life Science and Technology, ShanghaiTech University, 201210, Shanghai, China. .,School of Pharmacy, Fudan University, 201203, Shanghai, China.
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57
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Nygaard R, Yu J, Kim J, Ross DR, Parisi G, Clarke OB, Virshup DM, Mancia F. Structural Basis of WLS/Evi-Mediated Wnt Transport and Secretion. Cell 2021; 184:194-206.e14. [PMID: 33357447 PMCID: PMC7797000 DOI: 10.1016/j.cell.2020.11.038] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 09/26/2020] [Accepted: 11/20/2020] [Indexed: 12/12/2022]
Abstract
Wnts are evolutionarily conserved ligands that signal at short range to regulate morphogenesis, cell fate, and stem cell renewal. The first and essential steps in Wnt secretion are their O-palmitoleation and subsequent loading onto the dedicated transporter Wntless/evenness interrupted (WLS/Evi). We report the 3.2 Å resolution cryogenic electron microscopy (cryo-EM) structure of palmitoleated human WNT8A in complex with WLS. This is accompanied by biochemical experiments to probe the physiological implications of the observed association. The WLS membrane domain has close structural homology to G protein-coupled receptors (GPCRs). A Wnt hairpin inserts into a conserved hydrophobic cavity in the GPCR-like domain, and the palmitoleate protrudes between two helices into the bilayer. A conformational switch of highly conserved residues on a separate Wnt hairpin might contribute to its transfer to receiving cells. This work provides molecular-level insights into a central mechanism in animal body plan development and stem cell biology.
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Affiliation(s)
- Rie Nygaard
- Department of Physiology and Cellular Biophysics, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Jia Yu
- Programme in Cancer and Stem Cell Biology, Duke-NUS Medical School, Singapore 169857, Singapore
| | - Jonathan Kim
- Department of Physiology and Cellular Biophysics, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Daniel R Ross
- Department of Physiology and Cellular Biophysics, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Giacomo Parisi
- Department of Physiology and Cellular Biophysics, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Oliver B Clarke
- Department of Physiology and Cellular Biophysics, Columbia University Irving Medical Center, New York, NY 10032, USA; Department of Anesthesiology, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - David M Virshup
- Programme in Cancer and Stem Cell Biology, Duke-NUS Medical School, Singapore 169857, Singapore; Department of Pediatrics, Duke University School of Medicine, Durham, NC 27705, USA.
| | - Filippo Mancia
- Department of Physiology and Cellular Biophysics, Columbia University Irving Medical Center, New York, NY 10032, USA.
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58
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Shen C, Mao C, Xu C, Jin N, Zhang H, Shen DD, Shen Q, Wang X, Hou T, Chen Z, Rondard P, Pin JP, Zhang Y, Liu J. Structural basis of GABA B receptor-G i protein coupling. Nature 2021; 594:594-598. [PMID: 33911284 PMCID: PMC8222003 DOI: 10.1038/s41586-021-03507-1] [Citation(s) in RCA: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Accepted: 03/29/2021] [Indexed: 02/03/2023]
Abstract
G-protein-coupled receptors (GPCRs) have central roles in intercellular communication1,2. Structural studies have revealed how GPCRs can activate G proteins. However, whether this mechanism is conserved among all classes of GPCR remains unknown. Here we report the structure of the class-C heterodimeric GABAB receptor, which is activated by the inhibitory transmitter GABA, in its active form complexed with Gi1 protein. We found that a single G protein interacts with the GB2 subunit of the GABAB receptor at a site that mainly involves intracellular loop 2 on the side of the transmembrane domain. This is in contrast to the G protein binding in a central cavity, as has been observed with other classes of GPCR. This binding mode results from the active form of the transmembrane domain of this GABAB receptor being different from that of other GPCRs, as it shows no outside movement of transmembrane helix 6. Our work also provides details of the inter- and intra-subunit changes that link agonist binding to G-protein activation in this heterodimeric complex.
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Affiliation(s)
- Cangsong Shen
- grid.33199.310000 0004 0368 7223ZJU-HUST Joint Laboratory of Cellular Signaling, Key Laboratory of Molecular Biophysics of MOE, International Research Center for Sensory Biology and Technology of MOST, College of Life Science and Technology, Huazhong University of Science and Technology (HUST), Wuhan, China ,grid.13402.340000 0004 1759 700XDepartment of Biophysics and Department of Pathology of Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China ,grid.13402.340000 0004 1759 700XLiangzhu Laboratory, Zhejiang University Medical Center, Hangzhou, China
| | - Chunyou Mao
- grid.13402.340000 0004 1759 700XDepartment of Biophysics and Department of Pathology of Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China ,grid.13402.340000 0004 1759 700XLiangzhu Laboratory, Zhejiang University Medical Center, Hangzhou, China ,Zhejiang Provincial Key Laboratory of Immunity and Inflammatory Diseases, Hangzhou, China
| | - Chanjuan Xu
- grid.33199.310000 0004 0368 7223ZJU-HUST Joint Laboratory of Cellular Signaling, Key Laboratory of Molecular Biophysics of MOE, International Research Center for Sensory Biology and Technology of MOST, College of Life Science and Technology, Huazhong University of Science and Technology (HUST), Wuhan, China ,grid.508040.9Bioland Laboratory, Guangzhou Regenerative Medicine and Health Guangdong Laboratory, Guangzhou, China
| | - Nan Jin
- grid.33199.310000 0004 0368 7223ZJU-HUST Joint Laboratory of Cellular Signaling, Key Laboratory of Molecular Biophysics of MOE, International Research Center for Sensory Biology and Technology of MOST, College of Life Science and Technology, Huazhong University of Science and Technology (HUST), Wuhan, China ,grid.13402.340000 0004 1759 700XDepartment of Biophysics and Department of Pathology of Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China ,grid.13402.340000 0004 1759 700XLiangzhu Laboratory, Zhejiang University Medical Center, Hangzhou, China
| | - Huibing Zhang
- grid.13402.340000 0004 1759 700XDepartment of Biophysics and Department of Pathology of Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China ,grid.13402.340000 0004 1759 700XLiangzhu Laboratory, Zhejiang University Medical Center, Hangzhou, China ,Zhejiang Provincial Key Laboratory of Immunity and Inflammatory Diseases, Hangzhou, China
| | - Dan-Dan Shen
- grid.13402.340000 0004 1759 700XDepartment of Biophysics and Department of Pathology of Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China ,grid.13402.340000 0004 1759 700XLiangzhu Laboratory, Zhejiang University Medical Center, Hangzhou, China ,Zhejiang Provincial Key Laboratory of Immunity and Inflammatory Diseases, Hangzhou, China
| | - Qingya Shen
- grid.13402.340000 0004 1759 700XDepartment of Biophysics and Department of Pathology of Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China ,grid.13402.340000 0004 1759 700XLiangzhu Laboratory, Zhejiang University Medical Center, Hangzhou, China ,Zhejiang Provincial Key Laboratory of Immunity and Inflammatory Diseases, Hangzhou, China
| | - Xiaomei Wang
- grid.33199.310000 0004 0368 7223ZJU-HUST Joint Laboratory of Cellular Signaling, Key Laboratory of Molecular Biophysics of MOE, International Research Center for Sensory Biology and Technology of MOST, College of Life Science and Technology, Huazhong University of Science and Technology (HUST), Wuhan, China
| | - Tingjun Hou
- grid.13402.340000 0004 1759 700XInnovation Institute for Artificial Intelligence in Medicine of Zhejiang University, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - Zhong Chen
- grid.268505.c0000 0000 8744 8924Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, Zhejiang Chinese Medical University, Hangzhou, China
| | - Philippe Rondard
- grid.121334.60000 0001 2097 0141Institut de Génomique Fonctionnelle (IGF), Université de Montpellier, CNRS, INSERM, 34094 Montpellier, France
| | - Jean-Philippe Pin
- grid.121334.60000 0001 2097 0141Institut de Génomique Fonctionnelle (IGF), Université de Montpellier, CNRS, INSERM, 34094 Montpellier, France
| | - Yan Zhang
- grid.13402.340000 0004 1759 700XDepartment of Biophysics and Department of Pathology of Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China ,grid.13402.340000 0004 1759 700XLiangzhu Laboratory, Zhejiang University Medical Center, Hangzhou, China ,Zhejiang Provincial Key Laboratory of Immunity and Inflammatory Diseases, Hangzhou, China ,grid.13402.340000 0004 1759 700XMOE Frontier Science Center for Brain Research and Brain-Machine Integration, Zhejiang University School of Medicine, Hangzhou, China
| | - Jianfeng Liu
- grid.33199.310000 0004 0368 7223ZJU-HUST Joint Laboratory of Cellular Signaling, Key Laboratory of Molecular Biophysics of MOE, International Research Center for Sensory Biology and Technology of MOST, College of Life Science and Technology, Huazhong University of Science and Technology (HUST), Wuhan, China ,grid.508040.9Bioland Laboratory, Guangzhou Regenerative Medicine and Health Guangdong Laboratory, Guangzhou, China
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59
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Ellaithy A, Gonzalez-Maeso J, Logothetis DA, Levitz J. Structural and Biophysical Mechanisms of Class C G Protein-Coupled Receptor Function. Trends Biochem Sci 2020; 45:1049-1064. [PMID: 32861513 PMCID: PMC7642020 DOI: 10.1016/j.tibs.2020.07.008] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 07/22/2020] [Accepted: 07/30/2020] [Indexed: 02/07/2023]
Abstract
Groundbreaking structural and spectroscopic studies of class A G protein-coupled receptors (GPCRs), such as rhodopsin and the β2 adrenergic receptor, have provided a picture of how structural rearrangements between transmembrane helices control ligand binding, receptor activation, and effector coupling. However, the activation mechanism of other GPCR classes remains more elusive, in large part due to complexity in their domain assembly and quaternary structure. In this review, we focus on the class C GPCRs, which include metabotropic glutamate receptors (mGluRs) and gamma-aminobutyric acid B (GABAB) receptors (GABABRs) most prominently. We discuss the unique biophysical questions raised by the presence of large extracellular ligand-binding domains (LBDs) and constitutive homo/heterodimerization. Furthermore, we discuss how recent studies have begun to unravel how these fundamental class C GPCR features impact the processes of ligand binding, receptor activation, signal transduction, regulation by accessory proteins, and crosstalk with other GPCRs.
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Affiliation(s)
- Amr Ellaithy
- Department of Neurology, University of Iowa, Iowa City, IA 52242, USA; Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA; Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Javier Gonzalez-Maeso
- Department of Physiology and Biophysics, Virginia Commonwealth University School of Medicine, Richmond, VA 23298, USA
| | - Diomedes A Logothetis
- Department of Pharmaceutical Sciences, School of Pharmacy, Bouvé College of Health Sciences, Northeastern University, Boston, MA 02115, USA; Department of Chemistry and Chemical Biology, College of Science and Center for Drug Discovery, Northeastern University, Boston, MA 02115, USA
| | - Joshua Levitz
- Department of Biochemistry, Weill Cornell Medicine, New York, NY 10065, USA.
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60
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Structural Basis for Activation of the Heterodimeric GABAB Receptor. J Mol Biol 2020; 432:5966-5984. [DOI: 10.1016/j.jmb.2020.09.023] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2020] [Revised: 09/11/2020] [Accepted: 09/29/2020] [Indexed: 12/18/2022]
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61
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Vizurraga A, Adhikari R, Yeung J, Yu M, Tall GG. Mechanisms of adhesion G protein-coupled receptor activation. J Biol Chem 2020; 295:14065-14083. [PMID: 32763969 DOI: 10.1074/jbc.rev120.007423] [Citation(s) in RCA: 87] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 07/31/2020] [Indexed: 12/19/2022] Open
Abstract
Adhesion G protein-coupled receptors (AGPCRs) are a thirty-three-member subfamily of Class B GPCRs that control a wide array of physiological processes and are implicated in disease. AGPCRs uniquely contain large, self-proteolyzing extracellular regions that range from hundreds to thousands of residues in length. AGPCR autoproteolysis occurs within the extracellular GPCR autoproteolysis-inducing (GAIN) domain that is proximal to the N terminus of the G protein-coupling seven-transmembrane-spanning bundle. GAIN domain-mediated self-cleavage is constitutive and produces two-fragment holoreceptors that remain bound at the cell surface. It has been of recent interest to understand how AGPCRs are activated in relation to their two-fragment topologies. Dissociation of the AGPCR fragments stimulates G protein signaling through the action of the tethered-peptide agonist stalk that is occluded within the GAIN domain in the holoreceptor form. AGPCRs can also signal independently of fragment dissociation, and a few receptors possess GAIN domains incapable of self-proteolysis. This has resulted in complex theories as to how these receptors are activated in vivo, complicating pharmacological advances. Currently, there is no existing structure of an activated AGPCR to support any of the theories. Further confounding AGPCR research is that many of the receptors remain orphans and lack identified activating ligands. In this review, we provide a detailed layout of the current theorized modes of AGPCR activation with discussion of potential parallels to mechanisms used by other GPCR classes. We provide a classification means for the ligands that have been identified and discuss how these ligands may activate AGPCRs in physiological contexts.
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Affiliation(s)
- Alexander Vizurraga
- Department of Pharmacology, University of Michigan School of Medicine, Ann Arbor, Michigan, USA
| | - Rashmi Adhikari
- Department of Pharmacology, University of Michigan School of Medicine, Ann Arbor, Michigan, USA
| | - Jennifer Yeung
- Department of Pharmacology, University of Michigan School of Medicine, Ann Arbor, Michigan, USA
| | - Maiya Yu
- Department of Pharmacology, University of Michigan School of Medicine, Ann Arbor, Michigan, USA
| | - Gregory G Tall
- Department of Pharmacology, University of Michigan School of Medicine, Ann Arbor, Michigan, USA
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GABA B receptor pas de deux: insights from high-resolution structures. Cell Res 2020; 30:631-632. [PMID: 32651455 DOI: 10.1038/s41422-020-0373-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
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63
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Evenseth LSM, Gabrielsen M, Sylte I. The GABA B Receptor-Structure, Ligand Binding and Drug Development. Molecules 2020; 25:molecules25133093. [PMID: 32646032 PMCID: PMC7411975 DOI: 10.3390/molecules25133093] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 07/02/2020] [Accepted: 07/06/2020] [Indexed: 11/17/2022] Open
Abstract
The γ-aminobutyric acid (GABA) type B receptor (GABAB-R) belongs to class C of the G-protein coupled receptors (GPCRs). Together with the GABAA receptor, the receptor mediates the neurotransmission of GABA, the main inhibitory neurotransmitter in the central nervous system (CNS). In recent decades, the receptor has been extensively studied with the intention being to understand pathophysiological roles, structural mechanisms and develop drugs. The dysfunction of the receptor is linked to a broad variety of disorders, including anxiety, depression, alcohol addiction, memory and cancer. Despite extensive efforts, few compounds are known to target the receptor, and only the agonist baclofen is approved for clinical use. The receptor is a mandatory heterodimer of the GABAB1 and GABAB2 subunits, and each subunit is composed of an extracellular Venus Flytrap domain (VFT) and a transmembrane domain of seven α-helices (7TM domain). In this review, we briefly present the existing knowledge about the receptor structure, activation and compounds targeting the receptor, emphasizing the role of the receptor in previous and future drug design and discovery efforts.
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Affiliation(s)
- Linn Samira Mari Evenseth
- Molecular Pharmacology and Toxicology, Department of Medical Biology, Faculty of Health Sciences, UiT The Arctic University of Norway, NO-9037 Tromsø, Norway
| | - Mari Gabrielsen
- Molecular Pharmacology and Toxicology, Department of Medical Biology, Faculty of Health Sciences, UiT The Arctic University of Norway, NO-9037 Tromsø, Norway
| | - Ingebrigt Sylte
- Molecular Pharmacology and Toxicology, Department of Medical Biology, Faculty of Health Sciences, UiT The Arctic University of Norway, NO-9037 Tromsø, Norway
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