1
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Sokrat B, Nguyen AH, Thomsen ARB, Huang LY, Kobayashi H, Kahsai AW, Kim J, Ho BX, Ma S, Little J, Ehrhart C, Pyne I, Hammond E, Bouvier M. Role of the V2R-βarrestin-Gβγ complex in promoting G protein translocation to endosomes. Commun Biol 2024; 7:826. [PMID: 38972875 PMCID: PMC11228049 DOI: 10.1038/s42003-024-06512-y] [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: 06/08/2023] [Accepted: 06/27/2024] [Indexed: 07/09/2024] Open
Abstract
Classically, G protein-coupled receptors (GPCRs) promote signaling at the plasma membrane through activation of heterotrimeric Gαβγ proteins, followed by the recruitment of GPCR kinases and βarrestin (βarr) to initiate receptor desensitization and internalization. However, studies demonstrated that some GPCRs continue to signal from internalized compartments, with distinct cellular responses. Both βarr and Gβγ contribute to such non-canonical endosomal G protein signaling, but their specific roles and contributions remain poorly understood. Here, we demonstrate that the vasopressin V2 receptor (V2R)-βarr complex scaffolds Gβγ at the plasma membrane through a direct interaction with βarr, enabling its transport to endosomes. Gβγ subsequently potentiates Gαs endosomal translocation, presumably to regenerate an endosomal pool of heterotrimeric Gs. This work shines light on the mechanism underlying G protein subunits translocation from the plasma membrane to the endosomes and provides a basis for understanding the role of βarr in mediating sustained G protein signaling.
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Affiliation(s)
- Badr Sokrat
- Department of Biochemistry and Molecular Medicine, University of Montreal, Montreal, QC, H3T 1J4, Canada
- Institute for Research in Immunology and Cancer, University of Montreal, Montreal, QC, H3T 1J4, Canada
- Department of Molecular Pathobiology, New York University School of Dentistry, New York, NY, 10010, USA
| | - Anthony H Nguyen
- Department of Biochemistry, Duke University School of Medicine, Durham, NC, 27710, USA
| | - Alex R B Thomsen
- Department of Biochemistry, Duke University School of Medicine, Durham, NC, 27710, USA
- Department of Medicine, Duke University Medical Center, Durham, NC, 27710, USA
- Department of Molecular Pathobiology, New York University School of Dentistry, New York, NY, 10010, USA
| | - Li-Yin Huang
- Department of Biochemistry, Duke University School of Medicine, Durham, NC, 27710, USA
| | - Hiroyuki Kobayashi
- Institute for Research in Immunology and Cancer, University of Montreal, Montreal, QC, H3T 1J4, Canada
| | - Alem W Kahsai
- Department of Medicine, Duke University Medical Center, Durham, NC, 27710, USA
| | - Jihee Kim
- Department of Biochemistry, Duke University School of Medicine, Durham, NC, 27710, USA
| | - Bing X Ho
- Department of Biochemistry, Duke University School of Medicine, Durham, NC, 27710, USA
| | - Symon Ma
- Department of Biochemistry, Duke University School of Medicine, Durham, NC, 27710, USA
| | - John Little
- Department of Biochemistry, Duke University School of Medicine, Durham, NC, 27710, USA
| | - Catherine Ehrhart
- Department of Biochemistry, Duke University School of Medicine, Durham, NC, 27710, USA
| | - Ian Pyne
- Department of Biochemistry, Duke University School of Medicine, Durham, NC, 27710, USA
| | - Emmery Hammond
- Department of Biochemistry, Duke University School of Medicine, Durham, NC, 27710, USA
| | - Michel Bouvier
- Department of Biochemistry and Molecular Medicine, University of Montreal, Montreal, QC, H3T 1J4, Canada.
- Institute for Research in Immunology and Cancer, University of Montreal, Montreal, QC, H3T 1J4, Canada.
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2
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George K, Hoang HTM, Tibbs T, Nagaraja RY, Li G, Troyano-Rodriguez E, Ahmad M. Robust GRK2/3/6-dependent desensitization of oxytocin receptor in neurons. iScience 2024; 27:110047. [PMID: 38883814 PMCID: PMC11179071 DOI: 10.1016/j.isci.2024.110047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Revised: 02/22/2024] [Accepted: 05/17/2024] [Indexed: 06/18/2024] Open
Abstract
Oxytocin plays critical roles in the brain as a neuromodulator, regulating social and other affective behavior. However, the regulatory mechanisms controlling oxytocin receptor (OXTR) signaling in neurons remain unexplored. In this study, we have identified robust and rapid-onset desensitization of OXTR response in multiple regions of the mouse brain. Both cell autonomous spiking response and presynaptic activation undergo similar agonist-induced desensitization. G-protein-coupled receptor kinases (GRK) GRK2, GRK3, and GRK6 are recruited to the activated OXTR in neurons, followed by recruitment of β-arrestin-1 and -2. Neuronal OXTR desensitization was impaired by suppression of GRK2/3/6 kinase activity but remained unaltered with double knockout of β-arrestin-1 and -2. Additionally, we observed robust agonist-induced internalization of neuronal OXTR and its Rab5-dependent recruitment to early endosomes, which was impaired by GRK2/3/6 inhibition. This work defines distinctive aspects of the mechanisms governing OXTR desensitization and internalization in neurons compared to prior studies in heterologous cells.
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Affiliation(s)
- Kiran George
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | - Hanh T M Hoang
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | - Taryn Tibbs
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | - Raghavendra Y Nagaraja
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | - Guangpu Li
- Department of Biochemistry and Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | - Eva Troyano-Rodriguez
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | - Mohiuddin Ahmad
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
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3
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Saito A, Kise R, Inoue A. Generation of Comprehensive GPCR-Transducer-Deficient Cell Lines to Dissect the Complexity of GPCR Signaling. Pharmacol Rev 2024; 76:599-619. [PMID: 38719480 DOI: 10.1124/pharmrev.124.001186] [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: 01/16/2024] [Revised: 05/02/2024] [Accepted: 05/06/2024] [Indexed: 06/16/2024] Open
Abstract
G-protein-coupled receptors (GPCRs) compose the largest family of transmembrane receptors and are targets of approximately one-third of Food and Drug Administration-approved drugs owing to their involvement in almost all physiologic processes. GPCR signaling occurs through the activation of heterotrimeric G-protein complexes and β-arrestins, both of which serve as transducers, resulting in distinct cellular responses. Despite seeming simple at first glance, accumulating evidence indicates that activation of either transducer is not a straightforward process as a stimulation of a single molecule has the potential to activate multiple signaling branches. The complexity of GPCR signaling arises from the aspects of G-protein-coupling selectivity, biased signaling, interpathway crosstalk, and variable molecular modifications generating these diverse signaling patterns. Numerous questions relative to these aspects of signaling remained unanswered until the recent development of CRISPR genome-editing technology. Such genome editing technology presents opportunities to chronically eliminate the expression of G-protein subunits, β-arrestins, G-protein-coupled receptor kinases (GRKs), and many other signaling nodes in the GPCR pathways at one's convenience. Here, we review the practicality of using CRISPR-derived knockout (KO) cells in the experimental contexts of unraveling the molecular details of GPCR signaling mechanisms. To mention a few, KO cells have revealed the contribution of β-arrestins in ERK activation, Gα protein selectivity, GRK-based regulation of GPCRs, and many more, hence validating its broad applicability in GPCR studies. SIGNIFICANCE STATEMENT: This review emphasizes the practical application of G-protein-coupled receptor (GPCR) transducer knockout (KO) cells in dissecting the intricate regulatory mechanisms of the GPCR signaling network. Currently available cell lines, along with accumulating KO cell lines in diverse cell types, offer valuable resources for systematically elucidating GPCR signaling regulation. Given the association of GPCR signaling with numerous diseases, uncovering the system-based signaling map is crucial for advancing the development of novel drugs targeting specific diseases.
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Affiliation(s)
- Ayaki Saito
- Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan
| | - Ryoji Kise
- Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan
| | - Asuka Inoue
- Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan
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4
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Nguyen DM, Rath DH, Devost D, Pétrin D, Rizk R, Ji AX, Narayanan N, Yong D, Zhai A, Kuntz DA, Mian MUQ, Pomroy NC, Keszei AFA, Benlekbir S, Mazhab-Jafari MT, Rubinstein JL, Hébert TE, Privé GG. Structure and dynamics of a pentameric KCTD5/CUL3/Gβγ E3 ubiquitin ligase complex. Proc Natl Acad Sci U S A 2024; 121:e2315018121. [PMID: 38625940 PMCID: PMC11047111 DOI: 10.1073/pnas.2315018121] [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: 09/21/2023] [Accepted: 03/07/2024] [Indexed: 04/18/2024] Open
Abstract
Heterotrimeric G proteins can be regulated by posttranslational modifications, including ubiquitylation. KCTD5, a pentameric substrate receptor protein consisting of an N-terminal BTB domain and a C-terminal domain, engages CUL3 to form the central scaffold of a cullin-RING E3 ligase complex (CRL3KCTD5) that ubiquitylates Gβγ and reduces Gβγ protein levels in cells. The cryo-EM structure of a 5:5:5 KCTD5/CUL3NTD/Gβ1γ2 assembly reveals a highly dynamic complex with rotations of over 60° between the KCTD5BTB/CUL3NTD and KCTD5CTD/Gβγ moieties of the structure. CRL3KCTD5 engages the E3 ligase ARIH1 to ubiquitylate Gβγ in an E3-E3 superassembly, and extension of the structure to include full-length CUL3 with RBX1 and an ARIH1~ubiquitin conjugate reveals that some conformational states position the ARIH1~ubiquitin thioester bond to within 10 Å of lysine-23 of Gβ and likely represent priming complexes. Most previously described CRL/substrate structures have consisted of monovalent complexes and have involved flexible peptide substrates. The structure of the KCTD5/CUL3NTD/Gβγ complex shows that the oligomerization of a substrate receptor can generate a polyvalent E3 ligase complex and that the internal dynamics of the substrate receptor can position a structured target for ubiquitylation in a CRL3 complex.
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Affiliation(s)
- Duc Minh Nguyen
- Princess Margaret Cancer Centre, University Health Network, Toronto, ONM5G 1L7, Canada
- Department of Biochemistry, University of Toronto, Toronto, ONM5S 1A8, Canada
| | - Deanna H. Rath
- Princess Margaret Cancer Centre, University Health Network, Toronto, ONM5G 1L7, Canada
| | - Dominic Devost
- Department of Pharmacology and Therapeutics, McGill University, Montréal, QCH3G 1Y6, Canada
| | - Darlaine Pétrin
- Department of Pharmacology and Therapeutics, McGill University, Montréal, QCH3G 1Y6, Canada
| | - Robert Rizk
- Department of Pharmacology and Therapeutics, McGill University, Montréal, QCH3G 1Y6, Canada
| | - Alan X. Ji
- Princess Margaret Cancer Centre, University Health Network, Toronto, ONM5G 1L7, Canada
- Department of Biochemistry, University of Toronto, Toronto, ONM5S 1A8, Canada
| | - Naveen Narayanan
- Princess Margaret Cancer Centre, University Health Network, Toronto, ONM5G 1L7, Canada
| | - Darren Yong
- Princess Margaret Cancer Centre, University Health Network, Toronto, ONM5G 1L7, Canada
| | - Andrew Zhai
- Princess Margaret Cancer Centre, University Health Network, Toronto, ONM5G 1L7, Canada
| | - Douglas A. Kuntz
- Princess Margaret Cancer Centre, University Health Network, Toronto, ONM5G 1L7, Canada
| | - Maha U. Q. Mian
- Princess Margaret Cancer Centre, University Health Network, Toronto, ONM5G 1L7, Canada
| | - Neil C. Pomroy
- Princess Margaret Cancer Centre, University Health Network, Toronto, ONM5G 1L7, Canada
| | | | - Samir Benlekbir
- Molecular Medicine Program, The Hospital for Sick Children, Toronto, ONM5G 0A4, Canada
| | - Mohammad T. Mazhab-Jafari
- Princess Margaret Cancer Centre, University Health Network, Toronto, ONM5G 1L7, Canada
- Department of Medical Biophysics, University of Toronto, Toronto, ONM5G 2M9, Canada
| | - John L. Rubinstein
- Department of Biochemistry, University of Toronto, Toronto, ONM5S 1A8, Canada
- Molecular Medicine Program, The Hospital for Sick Children, Toronto, ONM5G 0A4, Canada
- Department of Medical Biophysics, University of Toronto, Toronto, ONM5G 2M9, Canada
| | - Terence E. Hébert
- Department of Pharmacology and Therapeutics, McGill University, Montréal, QCH3G 1Y6, Canada
| | - Gilbert G. Privé
- Princess Margaret Cancer Centre, University Health Network, Toronto, ONM5G 1L7, Canada
- Department of Biochemistry, University of Toronto, Toronto, ONM5S 1A8, Canada
- Department of Medical Biophysics, University of Toronto, Toronto, ONM5G 2M9, Canada
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5
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Yen YC, Li Y, Chen CL, Klose T, Watts VJ, Dessauer CW, Tesmer JJG. Structure of adenylyl cyclase 5 in complex with Gβγ offers insights into ADCY5-related dyskinesia. Nat Struct Mol Biol 2024:10.1038/s41594-024-01263-0. [PMID: 38589608 DOI: 10.1038/s41594-024-01263-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Accepted: 03/04/2024] [Indexed: 04/10/2024]
Abstract
The nine different membrane-anchored adenylyl cyclase isoforms (AC1-9) in mammals are stimulated by the heterotrimeric G protein, Gαs, but their response to Gβγ regulation is isoform specific. In the present study, we report cryo-electron microscope structures of ligand-free AC5 in complex with Gβγ and a dimeric form of AC5 that could be involved in its regulation. Gβγ binds to a coiled-coil domain that links the AC transmembrane region to its catalytic core as well as to a region (C1b) that is known to be a hub for isoform-specific regulation. We confirmed the Gβγ interaction with both purified proteins and cell-based assays. Gain-of-function mutations in AC5 associated with human familial dyskinesia are located at the interface of AC5 with Gβγ and show reduced conditional activation by Gβγ, emphasizing the importance of the observed interaction for motor function in humans. We propose a molecular mechanism wherein Gβγ either prevents dimerization of AC5 or allosterically modulates the coiled-coil domain, and hence the catalytic core. As our mechanistic understanding of how individual AC isoforms are uniquely regulated is limited, studies such as this may provide new avenues for isoform-specific drug development.
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Affiliation(s)
- Yu-Chen Yen
- Department of Biological Sciences, Purdue University, West Lafayette, IN, USA
| | - Yong Li
- Department of Integrative Biology and Pharmacology, McGovern Medical School, University of Texas Health Science Center, Houston, TX, USA
| | - Chun-Liang Chen
- Department of Biological Sciences, Purdue University, West Lafayette, IN, USA
| | - Thomas Klose
- Purdue Cryo-EM Facility, Hockmeyer Hall for Structural Biology, Purdue University, West Lafayette, IN, USA
| | - Val J Watts
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN, USA
| | - Carmen W Dessauer
- Department of Integrative Biology and Pharmacology, McGovern Medical School, University of Texas Health Science Center, Houston, TX, USA
| | - John J G Tesmer
- Department of Biological Sciences, Purdue University, West Lafayette, IN, USA.
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN, USA.
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6
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Gardner J, Eiger DS, Hicks C, Choi I, Pham U, Chundi A, Namjoshi O, Rajagopal S. GPCR kinases differentially modulate biased signaling downstream of CXCR3 depending on their subcellular localization. Sci Signal 2024; 17:eadd9139. [PMID: 38349966 PMCID: PMC10927030 DOI: 10.1126/scisignal.add9139] [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: 07/16/2022] [Accepted: 01/22/2024] [Indexed: 02/15/2024]
Abstract
Some G protein-coupled receptors (GPCRs) demonstrate biased signaling such that ligands of the same receptor exclusively or preferentially activate certain downstream signaling pathways over others. This phenomenon may result from ligand-specific receptor phosphorylation by GPCR kinases (GRKs). GPCR signaling can also exhibit location bias because GPCRs traffic to and signal from subcellular compartments in addition to the plasma membrane. Here, we investigated whether GRKs contributed to location bias in GPCR signaling. GRKs translocated to endosomes after stimulation of the chemokine receptor CXCR3 or other GPCRs in cultured cells. GRK2, GRK3, GRK5, and GRK6 showed distinct patterns of recruitment to the plasma membrane and to endosomes depending on the identity of the biased ligand used to activate CXCR3. Analysis of engineered forms of GRKs that localized to either the plasma membrane or endosomes demonstrated that biased CXCR3 ligands elicited different signaling profiles that depended on the subcellular location of the GRK. Each GRK exerted a distinct effect on the regulation of CXCR3 engagement of β-arrestin, internalization, and activation of the downstream effector kinase ERK. Our work highlights a role for GRKs in location-biased GPCR signaling and demonstrates the complex interactions between ligands, GRKs, and cellular location that contribute to biased signaling.
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Affiliation(s)
- Julia Gardner
- Trinity College, Duke University, Durham, NC, 27710, USA
| | | | - Chloe Hicks
- Trinity College, Duke University, Durham, NC, 27710, USA
| | - Issac Choi
- Department of Medicine, Duke University, Durham, NC, 27710, USA
| | - Uyen Pham
- Department of Biochemistry, Duke University, Durham, NC, 27710, USA
| | - Anand Chundi
- Pratt School of Engineering, Duke University, Durham, NC, 27710, USA
| | - Ojas Namjoshi
- Center for Drug Discovery RTI International, Research Triangle Park, NC, 27709, USA
- Present address: Engine Biosciences, 733 Industrial Rd., San Carlos, CA, 94070, USA
| | - Sudarshan Rajagopal
- Department of Biochemistry, Duke University, Durham, NC, 27710, USA
- Department of Medicine, Duke University, Durham, NC, 27710, USA
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7
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Duan J, Liu H, Zhao F, Yuan Q, Ji Y, Cai X, He X, Li X, Li J, Wu K, Gao T, Zhu S, Lin S, Wang MW, Cheng X, Yin W, Jiang Y, Yang D, Xu HE. GPCR activation and GRK2 assembly by a biased intracellular agonist. Nature 2023; 620:676-681. [PMID: 37532940 DOI: 10.1038/s41586-023-06395-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Accepted: 07/03/2023] [Indexed: 08/04/2023]
Abstract
Phosphorylation of G-protein-coupled receptors (GPCRs) by GPCR kinases (GRKs) desensitizes G-protein signalling and promotes arrestin signalling, which is also modulated by biased ligands1-6. The molecular assembly of GRKs on GPCRs and the basis of GRK-mediated biased signalling remain largely unknown owing to the weak GPCR-GRK interactions. Here we report the complex structure of neurotensin receptor 1 (NTSR1) bound to GRK2, Gαq and the arrestin-biased ligand SBI-5537. The density map reveals the arrangement of the intact GRK2 with the receptor, with the N-terminal helix of GRK2 docking into the open cytoplasmic pocket formed by the outward movement of the receptor transmembrane helix 6, analogous to the binding of the G protein to the receptor. SBI-553 binds at the interface between GRK2 and NTSR1 to enhance GRK2 binding. The binding mode of SBI-553 is compatible with arrestin binding but clashes with the binding of Gαq protein, thus providing a mechanism for its arrestin-biased signalling capability. In sum, our structure provides a rational model for understanding the details of GPCR-GRK interactions and GRK2-mediated biased signalling.
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Affiliation(s)
- Jia Duan
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China.
- Zhongshan Institute for Drug Discovery, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Zhongshan, China.
- University of Chinese Academy of Sciences, Beijing, China.
| | - Heng Liu
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Fenghui Zhao
- The National Center for Drug Screening, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Qingning Yuan
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Yujie Ji
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Xiaoqing Cai
- The National Center for Drug Screening, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Xinheng He
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Xinzhu Li
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Junrui Li
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Kai Wu
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Tianyu Gao
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China
| | - Shengnan Zhu
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Shi Lin
- Research Center for Deepsea Bioresources, Sanya, Hainan, China
| | - Ming-Wei Wang
- Research Center for Deepsea Bioresources, Sanya, Hainan, China
| | - Xi Cheng
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Wanchao Yin
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
- Zhongshan Institute for Drug Discovery, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Zhongshan, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Yi Jiang
- Lingang Laboratory, Shanghai, China
| | - Dehua Yang
- University of Chinese Academy of Sciences, Beijing, China.
- The National Center for Drug Screening, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China.
- Research Center for Deepsea Bioresources, Sanya, Hainan, China.
| | - H Eric Xu
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China.
- University of Chinese Academy of Sciences, Beijing, China.
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China.
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8
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Reinhardt R, Leonard TA. A critical evaluation of protein kinase regulation by activation loop autophosphorylation. eLife 2023; 12:e88210. [PMID: 37470698 PMCID: PMC10359097 DOI: 10.7554/elife.88210] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Accepted: 07/07/2023] [Indexed: 07/21/2023] Open
Abstract
Phosphorylation of proteins is a ubiquitous mechanism of regulating their function, localization, or activity. Protein kinases, enzymes that use ATP to phosphorylate protein substrates are, therefore, powerful signal transducers in eukaryotic cells. The mechanism of phosphoryl-transfer is universally conserved among protein kinases, which necessitates the tight regulation of kinase activity for the orchestration of cellular processes with high spatial and temporal fidelity. In response to a stimulus, many kinases enhance their own activity by autophosphorylating a conserved amino acid in their activation loop, but precisely how this reaction is performed is controversial. Classically, kinases that autophosphorylate their activation loop are thought to perform the reaction in trans, mediated by transient dimerization of their kinase domains. However, motivated by the recently discovered regulation mechanism of activation loop cis-autophosphorylation by a kinase that is autoinhibited in trans, we here review the various mechanisms of autoregulation that have been proposed. We provide a framework for critically evaluating biochemical, kinetic, and structural evidence for protein kinase dimerization and autophosphorylation, and share some thoughts on the implications of these mechanisms within physiological signaling networks.
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Affiliation(s)
- Ronja Reinhardt
- Max Perutz Labs, Vienna Biocenter Campus (VBC)ViennaAustria
- Medical University of Vienna, Center for Medical BiochemistryViennaAustria
| | - Thomas A Leonard
- Max Perutz Labs, Vienna Biocenter Campus (VBC)ViennaAustria
- Medical University of Vienna, Center for Medical BiochemistryViennaAustria
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9
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Jiang W, Wang W, Kong Y, Zheng S. Structural basis for the ubiquitination of G protein βγ subunits by KCTD5/Cullin3 E3 ligase. SCIENCE ADVANCES 2023; 9:eadg8369. [PMID: 37450587 PMCID: PMC10348674 DOI: 10.1126/sciadv.adg8369] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Accepted: 06/14/2023] [Indexed: 07/18/2023]
Abstract
G protein-coupled receptor (GPCR) signaling is precisely controlled to avoid overstimulation that results in detrimental consequences. Gβγ signaling is negatively regulated by a Cullin3 (Cul3)-dependent E3 ligase, KCTD5, which triggers ubiquitination and degradation of free Gβγ. Here, we report the cryo-electron microscopy structures of the KCTD5-Gβγ fusion complex and the KCTD7-Cul3 complex. KCTD5 in pentameric form engages symmetrically with five copies of Gβγ through its C-terminal domain. The unique pentameric assembly of the KCTD5/Cul3 E3 ligase places the ubiquitin-conjugating enzyme (E2) and the modification sites of Gβγ in close proximity and allows simultaneous transfer of ubiquitin from E2 to five Gβγ subunits. Moreover, we show that ubiquitination of Gβγ by KCTD5 is important for fine-tuning cyclic adenosine 3´,5´-monophosphate signaling of GPCRs. Our studies provide unprecedented insights into mechanisms of substrate recognition by unusual pentameric E3 ligases and highlight the KCTD family as emerging regulators of GPCR signaling.
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Affiliation(s)
- Wentong Jiang
- Graduate School of Peking Union Medical College, Beijing 100730, China
- National Institute of Biological Sciences, Beijing 102206, China
| | - Wei Wang
- National Institute of Biological Sciences, Beijing 102206, China
- School of Life Sciences, Peking University, Beijing 100871, China
| | - Yinfei Kong
- Peking-Tsinghua Center for Life Sciences, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, China
| | - Sanduo Zheng
- Graduate School of Peking Union Medical College, Beijing 100730, China
- National Institute of Biological Sciences, Beijing 102206, China
- Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, Beijing 100084, China
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10
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Liu H, Ma H, Zeng X, Wu C, Acharya S, Sudan SK, Zhang X. Ubiquitination of GRK2 Is Required for the β-Arrestin-Biased Signaling Pathway of Dopamine D2 Receptors to Activate ERK Kinases. Int J Mol Sci 2023; 24:10031. [PMID: 37373182 DOI: 10.3390/ijms241210031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2023] [Revised: 06/06/2023] [Accepted: 06/07/2023] [Indexed: 06/29/2023] Open
Abstract
A class-A GPCR dopamine D2 receptor (D2R) plays a critical role in the proper functioning of neuronal circuits through the downstream activation of both G-protein- and β-arrestin-dependent signaling pathways. Understanding the signaling pathways downstream of D2R is critical for developing effective therapies with which to treat dopamine (DA)-related disorders such as Parkinson's disease and schizophrenia. Extensive studies have focused on the regulation of D2R-mediated extracellular-signal-regulated kinase (ERK) 1/2 signaling; however, the manner in which ERKs are activated upon the stimulation of a specific signaling pathway of D2R remains unclear. The present study conducted a variety of experimental techniques, including loss-of-function experiments, site-directed mutagenesis, and the determination of protein interactions, in order to investigate the mechanisms underlying β-arrestin-biased signaling-pathway-mediated ERK activation. We found that the stimulation of the D2R β-arrestin signaling pathway caused Mdm2, an E3 ubiquitin ligase, to move from the nucleus to the cytoplasm and interact with tyrosine phosphorylated G-protein-coupled receptor kinase 2 (GRK2), which was facilitated by Src, a non-receptor tyrosine kinase. This interaction led to the ubiquitination of GRK2, which then moved to the plasma membrane and interacted with activated D2R, followed by the phosphorylation of D2R as well as the mediation of ERK activation. In conclusion, Mdm2-mediated GRK2 ubiquitination, which is selectively triggered by the stimulation of the D2R β-arrestin signaling pathway, is necessary for GRK2 membrane translocation and its interaction with D2R, which in turn mediates downstream ERK signaling. This study is primarily novel and provides essential information with which to better understand the detailed mechanisms of D2R-dependent signaling.
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Affiliation(s)
- Haiping Liu
- School of Pharmaceutical Sciences, Guizhou University, Guiyang 550025, China
| | - Haixiang Ma
- School of Pharmaceutical Sciences, Guizhou University, Guiyang 550025, China
| | - Xingyue Zeng
- School of Pharmaceutical Sciences, Guizhou University, Guiyang 550025, China
| | - Chengyan Wu
- School of Pharmaceutical Sciences, Guizhou University, Guiyang 550025, China
| | - Srijan Acharya
- Mitchell Cancer Institute, School of Medicine, University of South Alabama, Mobile, AL 36604, USA
| | - Sarabjeet Kour Sudan
- Mitchell Cancer Institute, School of Medicine, University of South Alabama, Mobile, AL 36604, USA
| | - Xiaohan Zhang
- School of Pharmaceutical Sciences, Guizhou University, Guiyang 550025, China
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11
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Yen YC, Li Y, Chen CL, Klose T, Watts VJ, Dessauer CW, Tesmer JJG. Isoform Specific Regulation of Adenylyl Cyclase 5 by Gβγ. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.02.539090. [PMID: 37205557 PMCID: PMC10187219 DOI: 10.1101/2023.05.02.539090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
The nine different membrane-anchored adenylyl cyclase isoforms (AC1-9) in mammals are stimulated by the heterotrimeric G protein Gαs, but their response to Gβγ regulation is isoform-specific. For example, AC5 is conditionally activated by Gβγ. Here, we report cryo-EM structures of ligand-free AC5 in complex with Gβγ and of a dimeric form of AC5 that could be involved in its regulation. Gβγ binds to a coiled-coil domain that links the AC transmembrane region to its catalytic core as well as to a region (C1b) that is known to be a hub for isoform-specific regulation. We confirmed the Gβγ interaction with both purified proteins and cell-based assays. The interface with Gβγ involves AC5 residues that are subject to gain-of-function mutations in humans with familial dyskinesia, indicating that the observed interaction is important for motor function. A molecular mechanism wherein Gβγ either prevents dimerization of AC5 or allosterically modulates the coiled-coil domain, and hence the catalytic core, is proposed. Because our mechanistic understanding of how individual AC isoforms are uniquely regulated is limited, studies such as this may provide new avenues for isoform-specific drug development.
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Affiliation(s)
- Yu-Chen Yen
- Department of Biological Sciences, Purdue University, West Lafayette, IN, USA
| | - Yong Li
- Department Integrative Biology and Pharmacology, McGovern Medical School, University of Texas Health Science Center, Houston, TX, USA
| | - Chun-Liang Chen
- Department of Biological Sciences, Purdue University, West Lafayette, IN, USA
| | - Thomas Klose
- Purdue CryoEM Facility, Suite 171, Hockmeyer Hall for Structural Biology, Purdue University, West Lafayette, IN, USA
| | - Val J Watts
- Department of Molecular Pharmacology and Medicinal Chemistry, Purdue University, West Lafayette, IN, USA
| | - Carmen W Dessauer
- Department Integrative Biology and Pharmacology, McGovern Medical School, University of Texas Health Science Center, Houston, TX, USA
| | - John J. G. Tesmer
- Department of Biological Sciences, Purdue University, West Lafayette, IN, USA
- Department of Molecular Pharmacology and Medicinal Chemistry, Purdue University, West Lafayette, IN, USA
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12
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Rathinaswamy MK, Jenkins ML, Duewell BR, Zhang X, Harris NJ, Evans JT, Stariha JTB, Dalwadi U, Fleming KD, Ranga-Prasad H, Yip CK, Williams RL, Hansen SD, Burke JE. Molecular basis for differential activation of p101 and p84 complexes of PI3Kγ by Ras and GPCRs. Cell Rep 2023; 42:112172. [PMID: 36842083 PMCID: PMC10068899 DOI: 10.1016/j.celrep.2023.112172] [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: 07/29/2022] [Revised: 12/21/2022] [Accepted: 02/13/2023] [Indexed: 02/27/2023] Open
Abstract
Class IB phosphoinositide 3-kinase (PI3Kγ) is activated in immune cells and can form two distinct complexes (p110γ-p84 and p110γ-p101), which are differentially activated by G protein-coupled receptors (GPCRs) and Ras. Using a combination of X-ray crystallography, hydrogen deuterium exchange mass spectrometry (HDX-MS), electron microscopy, molecular modeling, single-molecule imaging, and activity assays, we identify molecular differences between p110γ-p84 and p110γ-p101 that explain their differential membrane recruitment and activation by Ras and GPCRs. The p110γ-p84 complex is dynamic compared with p110γ-p101. While p110γ-p101 is robustly recruited by Gβγ subunits, p110γ-p84 is weakly recruited to membranes by Gβγ subunits alone and requires recruitment by Ras to allow for Gβγ activation. We mapped two distinct Gβγ interfaces on p101 and the p110γ helical domain, with differences in the C-terminal domain of p84 and p101 conferring sensitivity of p110γ-p101 to Gβγ activation. Overall, our work provides key insight into the molecular basis for how PI3Kγ complexes are activated.
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Affiliation(s)
- Manoj K Rathinaswamy
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC V8W 2Y2, Canada
| | - Meredith L Jenkins
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC V8W 2Y2, Canada
| | - Benjamin R Duewell
- Department of Chemistry and Biochemistry, University of Oregon, Eugene, OR 97403, USA; Institute of Molecular Biology, University of Oregon, Eugene, OR 97403, USA
| | - Xuxiao Zhang
- MRC Laboratory of Molecular Biology, Cambridge, UK
| | - Noah J Harris
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC V8W 2Y2, Canada
| | - John T Evans
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC V8W 2Y2, Canada
| | - Jordan T B Stariha
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC V8W 2Y2, Canada
| | - Udit Dalwadi
- Department of Biochemistry and Molecular Biology, The University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - Kaelin D Fleming
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC V8W 2Y2, Canada
| | - Harish Ranga-Prasad
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC V8W 2Y2, Canada
| | - Calvin K Yip
- Department of Biochemistry and Molecular Biology, The University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | | | - Scott D Hansen
- Department of Chemistry and Biochemistry, University of Oregon, Eugene, OR 97403, USA; Institute of Molecular Biology, University of Oregon, Eugene, OR 97403, USA.
| | - John E Burke
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC V8W 2Y2, Canada; Department of Biochemistry and Molecular Biology, The University of British Columbia, Vancouver, BC V6T 1Z3, Canada.
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13
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Ubeysinghe S, Wijayaratna D, Kankanamge D, Karunarathne A. Molecular regulation of PLCβ signaling. Methods Enzymol 2023; 682:17-52. [PMID: 36948701 DOI: 10.1016/bs.mie.2023.01.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
Phospholipase C (PLC) enzymes convert the membrane phospholipid phosphatidylinositol-4,5-bisphosphate (PIP2) into inositol-1,4,5-triphosphate (IP3) and diacylglycerol (DAG). IP3 and DAG regulate numerous downstream pathways, eliciting diverse and profound cellular changes and physiological responses. In the six PLC subfamilies in higher eukaryotes, PLCβ is intensively studied due to its prominent role in regulating crucial cellular events underlying many processes including cardiovascular and neuronal signaling, and associated pathological conditions. In addition to GαqGTP, Gβγ generated upon G protein heterotrimer dissociation also regulates PLCβ activity. Here, we not only review how Gβγ directly activates PLCβ, and also extensively modulates Gαq-mediated PLCβ activity, but also provide a structure-function overview of PLC family members. Given that Gαq and PLCβ are oncogenes, and Gβγ shows unique cell-tissue-organ specific expression profiles, Gγ subtype-dependent signaling efficacies, and distinct subcellular activities, this review proposes that Gβγ is a major regulator of Gαq-dependent and independent PLCβ signaling.
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Affiliation(s)
| | | | - Dinesh Kankanamge
- Department of Anesthesiology, Washington University School of Medicine, St. Louis, MO, United States
| | - Ajith Karunarathne
- Department of Chemistry, St. Louis University, St. Louis, MO, United States.
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14
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Xiang G, Acosta-Ruiz A, Radoux-Mergault A, Kristt M, Kim J, Moon JD, Broichhagen J, Inoue A, Lee FS, Stoeber M, Dittman JS, Levitz J. Control of Gα q signaling dynamics and GPCR cross-talk by GRKs. SCIENCE ADVANCES 2022; 8:eabq3363. [PMID: 36427324 PMCID: PMC9699688 DOI: 10.1126/sciadv.abq3363] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Numerous processes contribute to the regulation of G protein-coupled receptors (GPCRs), but relatively little is known about rapid mechanisms that control signaling on the seconds time scale or regulate cross-talk between receptors. Here, we reveal that the ability of some GPCR kinases (GRKs) to bind Gαq both drives acute signaling desensitization and regulates functional interactions between GPCRs. GRK2/3-mediated acute desensitization occurs within seconds, is rapidly reversible, and can occur upon local, subcellular activation. This rapid desensitization is kinase independent, insensitive to pharmacological inhibition, and generalizable across receptor families and effectors. We also find that the ability of GRK2 to bind G proteins also enables it to regulate the extent and timing of Gαq-dependent signaling cross-talk between GPCRs. Last, we find that G protein/GRK2 interactions enable a novel form of GPCR trafficking cross-talk. Together, this work reveals potent forms of Gαq-dependent GPCR regulation with wide-ranging pharmacological and physiological implications.
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Affiliation(s)
- Guoqing Xiang
- Department of Biochemistry, Weill Cornell Medicine, New York, NY, USA
- Department of Psychiatry, Weill Cornell Medicine, New York, NY, USA
| | | | | | - Melanie Kristt
- Department of Biochemistry, Weill Cornell Medicine, New York, NY, USA
| | - Jihye Kim
- Department of Psychiatry, Weill Cornell Medicine, New York, NY, USA
| | - Jared D. Moon
- Department of Biochemistry, Weill Cornell Medicine, New York, NY, USA
| | | | - Asuka Inoue
- Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan
| | - Francis S. Lee
- Department of Psychiatry, Weill Cornell Medicine, New York, NY, USA
| | - Miriam Stoeber
- Department of Cell Physiology and Metabolism, University of Geneva, Geneva, Switzerland
| | - Jeremy S. Dittman
- Department of Biochemistry, Weill Cornell Medicine, New York, NY, USA
| | - Joshua Levitz
- Department of Biochemistry, Weill Cornell Medicine, New York, NY, USA
- Department of Psychiatry, Weill Cornell Medicine, New York, NY, USA
- Corresponding author.
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15
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Jiang H, Galtes D, Wang J, Rockman HA. G protein-coupled receptor signaling: transducers and effectors. Am J Physiol Cell Physiol 2022; 323:C731-C748. [PMID: 35816644 PMCID: PMC9448338 DOI: 10.1152/ajpcell.00210.2022] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Revised: 06/27/2022] [Accepted: 07/10/2022] [Indexed: 01/14/2023]
Abstract
G protein-coupled receptors (GPCRs) are of considerable interest due to their importance in a wide range of physiological functions and in a large number of Food and Drug Administration (FDA)-approved drugs as therapeutic entities. With continued study of their function and mechanism of action, there is a greater understanding of how effector molecules interact with a receptor to initiate downstream effector signaling. This review aims to explore the signaling pathways, dynamic structures, and physiological relevance in the cardiovascular system of the three most important GPCR signaling effectors: heterotrimeric G proteins, GPCR kinases (GRKs), and β-arrestins. We will first summarize their prominent roles in GPCR pharmacology before transitioning into less well-explored areas. As new technologies are developed and applied to studying GPCR structure and their downstream effectors, there is increasing appreciation for the elegance of the regulatory mechanisms that mediate intracellular signaling and function.
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Affiliation(s)
- Haoran Jiang
- Department of Medicine, Duke University Medical Center, Durham, North Carolina
| | - Daniella Galtes
- Department of Medicine, Duke University Medical Center, Durham, North Carolina
| | - Jialu Wang
- Department of Medicine, Duke University Medical Center, Durham, North Carolina
| | - Howard A Rockman
- Department of Medicine, Duke University Medical Center, Durham, North Carolina
- Department of Cell Biology, Duke University Medical Center, Durham, North Carolina
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16
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McIntire WE. A model for how Gβγ couples Gα to GPCR. J Gen Physiol 2022; 154:213096. [PMID: 35333292 PMCID: PMC8961292 DOI: 10.1085/jgp.202112982] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Accepted: 02/28/2022] [Indexed: 11/20/2022] Open
Abstract
Representing ∼5% of the human genome, G-protein-coupled receptors (GPCRs) are a primary target for drug discovery; however, the molecular details of how they couple to heterotrimeric G protein subunits are incompletely understood. Here, I propose a hypothetical initial docking model for the encounter between GPCR and Gβγ that is defined by transient interactions between the cytosolic surface of the GPCR and the prenyl moiety and the tripeptide motif, asparagine-proline-phenylalanine (NPF), in the C-terminus of the Gγ subunit. Analysis of class A GPCRs reveals a conserved NPF binding site formed by the interaction of the TM1 and H8. Functional studies using differentially prenylated proteins and peptides further suggest that the intracellular hydrophobic core of the GPCR is a prenyl binding site. Upon binding TM1 and H8 of GPCRs, the propensity of the C-terminal region of Gγ to convert into an α helix allows it to extend into the hydrophobic core of the GPCR, facilitating the GPCR active state. Conservation of the NPF motif in Gγ isoforms and interacting residues in TM1 and H8 suggest that this is a general mechanism of GPCR-G protein signaling. Analysis of the rhodopsin dimer also suggests that Gγ-rhodopsin interactions may facilitate GPCR dimer transactivation.
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Affiliation(s)
- William E McIntire
- Department of Molecular Physiology and Biological Physics, University of Virginia Health System, Charlottesville, VA
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17
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Jones-Tabah J, Mohammad H, Paulus EG, Clarke PBS, Hébert TE. The Signaling and Pharmacology of the Dopamine D1 Receptor. Front Cell Neurosci 2022; 15:806618. [PMID: 35110997 PMCID: PMC8801442 DOI: 10.3389/fncel.2021.806618] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Accepted: 12/23/2021] [Indexed: 12/30/2022] Open
Abstract
The dopamine D1 receptor (D1R) is a Gαs/olf-coupled GPCR that is expressed in the midbrain and forebrain, regulating motor behavior, reward, motivational states, and cognitive processes. Although the D1R was initially identified as a promising drug target almost 40 years ago, the development of clinically useful ligands has until recently been hampered by a lack of suitable candidate molecules. The emergence of new non-catechol D1R agonists, biased agonists, and allosteric modulators has renewed clinical interest in drugs targeting this receptor, specifically for the treatment of motor impairment in Parkinson's Disease, and cognitive impairment in neuropsychiatric disorders. To develop better therapeutics, advances in ligand chemistry must be matched by an expanded understanding of D1R signaling across cell populations in the brain, and in disease states. Depending on the brain region, the D1R couples primarily to either Gαs or Gαolf through which it activates a cAMP/PKA-dependent signaling cascade that can regulate neuronal excitability, stimulate gene expression, and facilitate synaptic plasticity. However, like many GPCRs, the D1R can signal through multiple downstream pathways, and specific signaling signatures may differ between cell types or be altered in disease. To guide development of improved D1R ligands, it is important to understand how signaling unfolds in specific target cells, and how this signaling affects circuit function and behavior. In this review, we provide a summary of D1R-directed signaling in various neuronal populations and describe how specific pathways have been linked to physiological and behavioral outcomes. In addition, we address the current state of D1R drug development, including the pharmacology of newly developed non-catecholamine ligands, and discuss the potential utility of D1R-agonists in Parkinson's Disease and cognitive impairment.
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18
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Nanoluciferase-based complementation assay for systematic profiling of GPCR–GRK interactions. Methods Cell Biol 2022; 169:309-321. [DOI: 10.1016/bs.mcb.2022.04.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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19
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Encephalopathy-causing mutations in Gβ 1 ( GNB1) alter regulation of neuronal GIRK channels. iScience 2021; 24:103018. [PMID: 34522861 PMCID: PMC8426278 DOI: 10.1016/j.isci.2021.103018] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 08/04/2021] [Accepted: 08/18/2021] [Indexed: 11/24/2022] Open
Abstract
Mutations in the GNB1 gene, encoding the Gβ1 subunit of heterotrimeric G proteins, cause GNB1 Encephalopathy. Patients experience seizures, pointing to abnormal activity of ion channels or neurotransmitter receptors. We studied three Gβ1 mutations (K78R, I80N and I80T) using computational and functional approaches. In heterologous expression models, these mutations did not alter the coupling between G protein-coupled receptors to Gi/o, or the Gβγ regulation of the neuronal voltage-gated Ca2+ channel CaV2.2. However, the mutations profoundly affected the Gβγ regulation of the G protein-gated inwardly rectifying potassium channels (GIRK, or Kir3). Changes were observed in Gβ1 protein expression levels, Gβγ binding to cytosolic segments of GIRK subunits, and in Gβγ function, and included gain-of-function for K78R or loss-of-function for I80T/N, which were GIRK subunit-specific. Our findings offer new insights into subunit-dependent gating of GIRKs by Gβγ, and indicate diverse etiology of GNB1 Encephalopathy cases, bearing a potential for personalized treatment. GIRK channels are key players affected by GNB1 mutations under study (K78R and I80N/T) Effects of mutations (LoF or GoF) are channel subunit composition-specific The findings help to understand the GNB1 encephalopathy and to devise treatments The results yield new insights into mechanisms of Gβγ regulation of GIRKs
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20
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Structures of rhodopsin in complex with G-protein-coupled receptor kinase 1. Nature 2021; 595:600-605. [PMID: 34262173 PMCID: PMC8607881 DOI: 10.1038/s41586-021-03721-x] [Citation(s) in RCA: 56] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Accepted: 06/11/2021] [Indexed: 02/06/2023]
Abstract
G-protein-coupled receptor (GPCR) kinases (GRKs) selectively phosphorylate activated GPCRs, thereby priming them for desensitization1. Although it is unclear how GRKs recognize these receptors2-4, a conserved region at the GRK N terminus is essential for this process5-8. Here we report a series of cryo-electron microscopy single-particle reconstructions of light-activated rhodopsin (Rho*) bound to rhodopsin kinase (GRK1), wherein the N terminus of GRK1 forms a helix that docks into the open cytoplasmic cleft of Rho*. The helix also packs against the GRK1 kinase domain and stabilizes it in an active configuration. The complex is further stabilized by electrostatic interactions between basic residues that are conserved in most GPCRs and acidic residues that are conserved in GRKs. We did not observe any density for the regulator of G-protein signalling homology domain of GRK1 or the C terminus of rhodopsin. Crosslinking with mass spectrometry analysis confirmed these results and revealed dynamic behaviour in receptor-bound GRK1 that would allow the phosphorylation of multiple sites in the receptor tail. We have identified GRK1 residues whose mutation augments kinase activity and crosslinking with Rho*, as well as residues that are involved in activation by acidic phospholipids. From these data, we present a general model for how a small family of protein kinases can recognize and be activated by hundreds of different GPCRs.
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21
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Solís KH, Romero-Ávila MT, Guzmán-Silva A, García-Sáinz JA. The LPA 3 Receptor: Regulation and Activation of Signaling Pathways. Int J Mol Sci 2021; 22:ijms22136704. [PMID: 34201414 PMCID: PMC8269014 DOI: 10.3390/ijms22136704] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 06/08/2021] [Accepted: 06/12/2021] [Indexed: 12/17/2022] Open
Abstract
The lysophosphatidic acid 3 receptor (LPA3) participates in different physiological actions and in the pathogenesis of many diseases through the activation of different signal pathways. Knowledge of the regulation of the function of the LPA3 receptor is a crucial element for defining its roles in health and disease. This review describes what is known about the signaling pathways activated in terms of its various actions. Next, we review knowledge on the structure of the LPA3 receptor, the domains found, and the roles that the latter might play in ligand recognition, signaling, and cellular localization. Currently, there is some information on the action of LPA3 in different cells and whole organisms, but very little is known about the regulation of its function. Areas in which there is a gap in our knowledge are indicated in order to further stimulate experimental work on this receptor and on other members of the LPA receptor family. We are convinced that knowledge on how this receptor is activated, the signaling pathways employed and how the receptor internalization and desensitization are controlled will help design new therapeutic interventions for treating diseases in which the LPA3 receptor is implicated.
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22
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Abreu N, Acosta-Ruiz A, Xiang G, Levitz J. Mechanisms of differential desensitization of metabotropic glutamate receptors. Cell Rep 2021; 35:109050. [PMID: 33910009 PMCID: PMC9750234 DOI: 10.1016/j.celrep.2021.109050] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 03/04/2021] [Accepted: 04/07/2021] [Indexed: 12/16/2022] Open
Abstract
G protein-coupled receptors (GPCRs) interact with intracellular transducers to control both signal initiation and desensitization, but the distinct mechanisms that control the regulation of different GPCR subtypes are unclear. Here we use fluorescence imaging and electrophysiology to examine the metabotropic glutamate receptor (mGluR) family. We find distinct properties across subtypes in both rapid desensitization and internalization, with striking differences between the group II mGluRs. mGluR3, but not mGluR2, undergoes glutamate-dependent rapid desensitization, internalization, trafficking, and recycling. We map differences between mGluRs to variable Ser/Thr-rich sequences in the C-terminal domain (CTD) that control interaction with both GPCR kinases and β-arrestins. Finally, we identify a cancer-associated mutation, G848E, within the mGluR3 CTD that enhances β-arrestin coupling and internalization, enabling an analysis of mGluR3 β-arrestin-coupling properties and revealing biased variants. Together, this work provides a framework for understanding the distinct regulation and functional roles of mGluR subtypes.
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Affiliation(s)
- Nohely Abreu
- Biochemistry, Cell and Molecular Biology Graduate Program, Weill Cornell Medicine, New York, NY, USA; Department of Biochemistry, Weill Cornell Medicine, New York, NY, USA
| | - Amanda Acosta-Ruiz
- Biochemistry, Cell and Molecular Biology Graduate Program, Weill Cornell Medicine, New York, NY, USA; Department of Biochemistry, Weill Cornell Medicine, New York, NY, USA
| | - Guoqing Xiang
- Department of Biochemistry, Weill Cornell Medicine, New York, NY, USA
| | - Joshua Levitz
- Biochemistry, Cell and Molecular Biology Graduate Program, Weill Cornell Medicine, New York, NY, USA; Department of Biochemistry, Weill Cornell Medicine, New York, NY, USA.
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23
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Structural studies of phosphorylation-dependent interactions between the V2R receptor and arrestin-2. Nat Commun 2021; 12:2396. [PMID: 33888704 PMCID: PMC8062632 DOI: 10.1038/s41467-021-22731-x] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Accepted: 03/18/2021] [Indexed: 12/21/2022] Open
Abstract
Arrestins recognize different receptor phosphorylation patterns and convert this information to selective arrestin functions to expand the functional diversity of the G protein-coupled receptor (GPCR) superfamilies. However, the principles governing arrestin-phospho-receptor interactions, as well as the contribution of each single phospho-interaction to selective arrestin structural and functional states, are undefined. Here, we determined the crystal structures of arrestin2 in complex with four different phosphopeptides derived from the vasopressin receptor-2 (V2R) C-tail. A comparison of these four crystal structures with previously solved Arrestin2 structures demonstrated that a single phospho-interaction change results in measurable conformational changes at remote sites in the complex. This conformational bias introduced by specific phosphorylation patterns was further inspected by FRET and 1H NMR spectrum analysis facilitated via genetic code expansion. Moreover, an interdependent phospho-binding mechanism of phospho-receptor-arrestin interactions between different phospho-interaction sites was unexpectedly revealed. Taken together, our results provide evidence showing that phospho-interaction changes at different arrestin sites can elicit changes in affinity and structural states at remote sites, which correlate with selective arrestin functions. The interaction between a GPCR, such as the vasopressin receptor-2 (V2R), and arrestin depends on the receptors’ phosphorylation pattern. Here authors use FRET and NMR to analyze the phosphorylation patterns of the V2R-arrestin complex and show that phospho-interactions are the key determinants of selective arrestin conformational states and correlated functions.
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The Open Question of How GPCRs Interact with GPCR Kinases (GRKs). Biomolecules 2021; 11:biom11030447. [PMID: 33802765 PMCID: PMC8002388 DOI: 10.3390/biom11030447] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Revised: 03/13/2021] [Accepted: 03/15/2021] [Indexed: 01/14/2023] Open
Abstract
G protein-coupled receptors (GPCRs), which regulate a vast number of eukaryotic processes, are desensitized by various mechanisms but, most importantly, by the GPCR kinases (GRKs). Ever since GRKs were first identified, investigators have sought to determine which structural features of GRKs are used to select for the agonist-bound states of GPCRs and how this binding event in turn enhances GRK catalytic activity. Despite a wealth of molecular information from high-resolution crystal structures of GRKs, the mechanisms driving activation have remained elusive, in part because the GRK N-terminus and active site tether region, previously proposed to serve as a receptor docking site and to be key to kinase domain closure, are often disordered or adopt inconsistent conformations. However, two recent studies have implicated other regions of GRKs as being involved in direct interactions with active GPCRs. Atomic resolution structures of GPCR–GRK complexes would help refine these models but are, so far, lacking. Here, we assess three distinct models for how GRKs recognize activated GPCRs, discuss limitations in the approaches used to generate them, and then experimentally test a hypothetical GPCR interaction site in GRK2 suggested by the two newest models.
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25
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Benovic JL. Historical Perspective of the G Protein-Coupled Receptor Kinase Family. Cells 2021; 10:555. [PMID: 33806476 PMCID: PMC7999923 DOI: 10.3390/cells10030555] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Revised: 02/25/2021] [Accepted: 02/26/2021] [Indexed: 01/14/2023] Open
Abstract
Agonist activation of G protein-coupled receptors promotes sequential interaction of the receptor with heterotrimeric G proteins, G protein-coupled receptor kinases (GRKs), and arrestins. GRKs play a central role in mediating the switch from G protein to arrestin interaction and thereby control processes such as receptor desensitization and trafficking and arrestin-mediated signaling. In this review, I provide a historical perspective on some of the early studies that identified the family of GRKs with a primary focus on the non-visual GRKs. These studies included identification, purification, and cloning of the β-adrenergic receptor kinase in the mid- to late-1980s and subsequent cloning and characterization of additional members of the GRK family. This helped to lay the groundwork for ensuing work focused on understanding the structure and function of these important enzymes.
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Affiliation(s)
- Jeffrey L Benovic
- Department of Biochemistry and Molecular Biology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA 19107, USA
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26
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Muralidharan K, Van Camp MM, Lyon AM. Structure and regulation of phospholipase Cβ and ε at the membrane. Chem Phys Lipids 2021; 235:105050. [PMID: 33422547 DOI: 10.1016/j.chemphyslip.2021.105050] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Revised: 10/28/2020] [Accepted: 01/04/2021] [Indexed: 12/28/2022]
Abstract
Phospholipase C (PLC) β and ε enzymes hydrolyze phosphatidylinositol (PI) lipids in response to direct interactions with heterotrimeric G protein subunits and small GTPases, which are activated downstream of G protein-coupled receptors (GPCRs) and receptor tyrosine kinases (RTKs). PI hydrolysis generates second messengers that increase the intracellular Ca2+ concentration and activate protein kinase C (PKC), thereby regulating numerous physiological processes. PLCβ and PLCε share a highly conserved core required for lipase activity, but use different strategies and structural elements to autoinhibit basal activity, bind membranes, and engage G protein activators. In this review, we discuss recent structural insights into these enzymes and the implications for how they engage membranes alone or in complex with their G protein regulators.
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Affiliation(s)
- Kaushik Muralidharan
- Department of Biological Sciences, 560 Oval Drive, Purdue University, West Lafayette, IN, 47907, United States.
| | - Michelle M Van Camp
- Department of Chemistry, 560 Oval Drive, Purdue University, West Lafayette, IN, 47907, United States.
| | - Angeline M Lyon
- Department of Biological Sciences, 560 Oval Drive, Purdue University, West Lafayette, IN, 47907, United States; Department of Chemistry, 560 Oval Drive, Purdue University, West Lafayette, IN, 47907, United States.
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27
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Chung YK, Wong YH. Re‐examining the ‘Dissociation Model’ of G protein activation from the perspective of Gβγ signaling. FEBS J 2020; 288:2490-2501. [DOI: 10.1111/febs.15605] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2020] [Revised: 10/14/2020] [Accepted: 10/19/2020] [Indexed: 12/27/2022]
Affiliation(s)
- Yin Kwan Chung
- Division of Life Science and Biotechnology Research Institute Hong Kong University of Science and Technology Hong Kong China
| | - Yung Hou Wong
- Division of Life Science and Biotechnology Research Institute Hong Kong University of Science and Technology Hong Kong China
- State Key Laboratory of Molecular Neuroscience the Molecular Neuroscience Center Hong Kong University of Science and Technology Kowloon China
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28
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Gene Expression Profiling of Type 2 Diabetes Mellitus by Bioinformatics Analysis. COMPUTATIONAL AND MATHEMATICAL METHODS IN MEDICINE 2020; 2020:9602016. [PMID: 33149760 PMCID: PMC7603564 DOI: 10.1155/2020/9602016] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 07/22/2020] [Accepted: 08/03/2020] [Indexed: 02/07/2023]
Abstract
Objective The aim of this study was to identify the candidate genes in type 2 diabetes mellitus (T2DM) and explore their potential mechanisms. Methods The gene expression profile GSE26168 was downloaded from the Gene Expression Omnibus (GEO) database. The online tool GEO2R was used to obtain differentially expressed genes (DEGs). Gene Ontology (GO) term enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were performed by using Metascape for annotation, visualization, and comprehensive discovery. The protein-protein interaction (PPI) network of DEGs was constructed by using Cytoscape software to find the candidate genes and key pathways. Results A total of 981 DEGs were found in T2DM, including 301 upregulated genes and 680 downregulated genes. GO analyses from Metascape revealed that DEGs were significantly enriched in cell differentiation, cell adhesion, intracellular signal transduction, and regulation of protein kinase activity. KEGG pathway analysis revealed that DEGs were mainly enriched in the cAMP signaling pathway, Rap1 signaling pathway, regulation of lipolysis in adipocytes, PI3K-Akt signaling pathway, MAPK signaling pathway, and so on. On the basis of the PPI network of the DEGs, the following 6 candidate genes were identified: PIK3R1, RAC1, GNG3, GNAI1, CDC42, and ITGB1. Conclusion Our data provide a comprehensive bioinformatics analysis of genes, functions, and pathways, which may be related to the pathogenesis of T2DM.
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Barnett ME, Knapp BI, Bidlack JM. Unique Pharmacological Properties of the Kappa Opioid Receptor Signaling Through G αz as Shown with Bioluminescence Resonance Energy Tranfer. Mol Pharmacol 2020; 98:462-474. [PMID: 32958572 DOI: 10.1124/mol.120.119404] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Accepted: 07/16/2020] [Indexed: 12/11/2022] Open
Abstract
Opioid receptors (ORs) convert extracellular messages to signaling events by coupling to the heterotrimeric G proteins, Gα•βγ Classic pharmacological methods, such as [35S]GTPγS binding and inhibition of cyclic AMP production, allow for general opioid characterization, but they are subject to the varying endogenous Gα proteins in a given cell type. Bioluminescence resonance energy transfer (BRET) technology offers new insight by allowing the direct observation of Gα subunit-specific effects on opioid pharmacology. Using a Venus-tagged Gβγ and nanoluciferase-tagged truncated G protein receptor kinase 3, an increase in BRET signal correlated with OR activation mediated by a specific Gα protein. The magnitude of the BRET signal was normalized to the maximum response obtained with 10 µM 2-(3,4-dichlorophenyl)-N-methyl-N-[(1R,2R)-2-pyrrolidin-1-ylcyclohexyl]acetamide (U50,488) for the kappa OR (KOR). Opioids reached equilibrium with the KOR, and concentration-response curves were generated. Although the full agonists U50,488, salvinorin A, nalfurafine, and dynorphin peptides were equally efficacious regardless of the Gα subunit present, the concentration-response curves were leftward shifted when the KOR was signaling through Gαz compared with other Gαi/o subunits. In contrast, the Gα subunit distinctly affected both the efficacy and potency of partial kappa agonists, such as the benzomorphans, and the classic mu opioid antagonists, naloxone, naltrexone, and nalmefene. For example, (-)pentazocine had EC50 values of 7.3 and 110 nM and maximal stimulation values of 79% and 35% when the KOR signaled through Gαz and Gαi1, respectively. Together, these observations suggest KOR pharmacology varies based on the specific Gα subunit coupled to the KOR. SIGNIFICANCE STATEMENT: Opioid receptors couple to various heterotrimeric Gαβγ proteins to convert extracellular cues to precise intracellular events. This paper focuses on how the various inhibitory Gα subunits influence the pharmacology of full and partial agonists at the kappa opioid receptor. Using a bioluminescent assay, the efficacy and potency of kappa opioids was determined. Opioid signaling was more potent through Gαz compared with other Gα proteins. These observations suggest that Gαz may impact opioid pharmacology and cellular physiology more than previously thought.
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Affiliation(s)
- Miriam E Barnett
- Department of Pharmacology and Physiology, University of Rochester, School of Medicine and Dentistry, Rochester, New York
| | - Brian I Knapp
- Department of Pharmacology and Physiology, University of Rochester, School of Medicine and Dentistry, Rochester, New York
| | - Jean M Bidlack
- Department of Pharmacology and Physiology, University of Rochester, School of Medicine and Dentistry, Rochester, New York
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30
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Tahir M, Arshid S, Fontes B, S. Castro M, Sidoli S, Schwämmle V, Luz IS, Roepstorff P, Fontes W. Phosphoproteomic Analysis of Rat Neutrophils Shows the Effect of Intestinal Ischemia/Reperfusion and Preconditioning on Kinases and Phosphatases. Int J Mol Sci 2020; 21:ijms21165799. [PMID: 32823483 PMCID: PMC7460855 DOI: 10.3390/ijms21165799] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2020] [Revised: 03/11/2020] [Accepted: 04/17/2020] [Indexed: 01/02/2023] Open
Abstract
Intestinal ischemia reperfusion injury (iIRI) is a severe clinical condition presenting high morbidity and mortality worldwide. Some of the systemic consequences of IRI can be prevented by applying ischemic preconditioning (IPC), a series of short ischemia/reperfusion events preceding the major ischemia. Although neutrophils are key players in the pathophysiology of ischemic injuries, neither the dysregulation presented by these cells in iIRI nor the protective effect of iIPC have their regulation mechanisms fully understood. Protein phosphorylation, as well as the regulation of the respective phosphatases and kinases are responsible for regulating a large number of cellular functions in the inflammatory response. Moreover, in previous work we found hydrolases and transferases to be modulated in iIR and iIPC, suggesting the possible involvement of phosphatases and kinases in the process. Therefore, in the present study, we analyzed the phosphoproteome of neutrophils from rats submitted to mesenteric ischemia and reperfusion, either submitted or not to IPC, compared to quiescent controls and sham laparotomy. Proteomic analysis was performed by multi-step enrichment of phosphopeptides, isobaric labeling, and LC-MS/MS analysis. Bioinformatics was used to determine phosphosite and phosphopeptide abundance and clustering, as well as kinases and phosphatases sites and domains. We found that most of the phosphorylation-regulated proteins are involved in apoptosis and migration, and most of the regulatory kinases belong to CAMK and CMGC families. An interesting finding revealed groups of proteins that are modulated by iIR, but such modulation can be prevented by iIPC. Among the regulated proteins related to the iIPC protective effect, Vamp8 and Inpp5d/Ship are discussed as possible candidates for control of the iIR damage.
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Affiliation(s)
- Muhammad Tahir
- Laboratory of Protein Chemistry and Biochemistry, Department of Cell Biology, University of Brasilia, Brasilia 70910-900, Brazil; (M.T.); (S.A.); (M.S.C.); (I.S.L.)
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, DK-5230 Odense M, Denmark; (S.S.); (V.S.); (P.R.)
| | - Samina Arshid
- Laboratory of Protein Chemistry and Biochemistry, Department of Cell Biology, University of Brasilia, Brasilia 70910-900, Brazil; (M.T.); (S.A.); (M.S.C.); (I.S.L.)
- Laboratory of Surgical Physiopathology (LIM-62), Faculty of Medicine, University of São Paulo, São Paulo 01246903, Brazil;
| | - Belchor Fontes
- Laboratory of Surgical Physiopathology (LIM-62), Faculty of Medicine, University of São Paulo, São Paulo 01246903, Brazil;
| | - Mariana S. Castro
- Laboratory of Protein Chemistry and Biochemistry, Department of Cell Biology, University of Brasilia, Brasilia 70910-900, Brazil; (M.T.); (S.A.); (M.S.C.); (I.S.L.)
| | - Simone Sidoli
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, DK-5230 Odense M, Denmark; (S.S.); (V.S.); (P.R.)
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Veit Schwämmle
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, DK-5230 Odense M, Denmark; (S.S.); (V.S.); (P.R.)
| | - Isabelle S. Luz
- Laboratory of Protein Chemistry and Biochemistry, Department of Cell Biology, University of Brasilia, Brasilia 70910-900, Brazil; (M.T.); (S.A.); (M.S.C.); (I.S.L.)
| | - Peter Roepstorff
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, DK-5230 Odense M, Denmark; (S.S.); (V.S.); (P.R.)
| | - Wagner Fontes
- Laboratory of Protein Chemistry and Biochemistry, Department of Cell Biology, University of Brasilia, Brasilia 70910-900, Brazil; (M.T.); (S.A.); (M.S.C.); (I.S.L.)
- Correspondence:
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31
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Rojas G, Orellana I, Rosales-Rojas R, García-Olivares J, Comer J, Vergara-Jaque A. Structural Determinants of the Dopamine Transporter Regulation Mediated by G Proteins. J Chem Inf Model 2020; 60:3577-3586. [PMID: 32525311 DOI: 10.1021/acs.jcim.0c00236] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Dopamine clearance in the brain is controlled by the dopamine transporter (DAT), a protein residing in the plasma membrane, which drives reuptake of extracellular dopamine into presynaptic neurons. Studies have revealed that the βγ subunits of heterotrimeric G proteins modulate DAT function through a physical association with the C-terminal region of the transporter. Regulation of neurotransmitter transporters by Gβγ subunits is unprecedented in the literature; therefore, it is interesting to investigate the structural details of this particular protein-protein interaction. Here, we refined the crystal structure of the Drosophila melanogaster DAT (dDAT), modeling de novo the N- and C-terminal domains; subsequently, we used the full-length dDAT structure to generate a comparative model of human DAT (hDAT). Both proteins were assembled with Gβ1γ2 subunits employing protein-protein docking, and subsequent molecular dynamics simulations were run to identify the specific interactions governing the formation of the hDAT:Gβγ and dDAT:Gβγ complexes. A [L/F]R[Q/E]R sequence motif containing the residues R588 in hDAT and R587 in dDAT was found as key to bind the Gβγ subunits through electrostatic interactions with a cluster of negatively charged residues located at the top face of the Gβ subunit. Alterations of DAT function have been associated with multiple devastating neuropathological conditions; therefore, this work represents a step toward better understanding DAT regulation by signaling proteins, allowing us to predict therapeutic target regions.
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Affiliation(s)
- Genoveva Rojas
- Center for Bioinformatics and Molecular Simulation, Faculty of Engineering, Universidad de Talca, 2 Norte 685, Talca, Chile
| | - Ivana Orellana
- Center for Bioinformatics and Molecular Simulation, Faculty of Engineering, Universidad de Talca, 2 Norte 685, Talca, Chile
| | - Roberto Rosales-Rojas
- Center for Bioinformatics and Molecular Simulation, Faculty of Engineering, Universidad de Talca, 2 Norte 685, Talca, Chile
| | - Jennie García-Olivares
- Supernus Pharmaceuticals, 9715 Key West Avenue, Rockville, Maryland 20850, United States
| | - Jeffrey Comer
- Institute of Computational Comparative Medicine, Nanotechnology Innovation Center of Kansas State, Kansas State University, Manhattan, Kansas 66506, United States
| | - Ariela Vergara-Jaque
- Center for Bioinformatics and Molecular Simulation, Faculty of Engineering, Universidad de Talca, 2 Norte 685, Talca, Chile.,Millennium Nucleus of Ion Channels-associated Diseases (MiNICAD), Santiago, Chile
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Espinosa-Cantú A, Cruz-Bonilla E, Noda-Garcia L, DeLuna A. Multiple Forms of Multifunctional Proteins in Health and Disease. Front Cell Dev Biol 2020; 8:451. [PMID: 32587857 PMCID: PMC7297953 DOI: 10.3389/fcell.2020.00451] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Accepted: 05/14/2020] [Indexed: 12/23/2022] Open
Abstract
Protein science has moved from a focus on individual molecules to an integrated perspective in which proteins emerge as dynamic players with multiple functions, rather than monofunctional specialists. Annotation of the full functional repertoire of proteins has impacted the fields of biochemistry and genetics, and will continue to influence basic and applied science questions - from the genotype-to-phenotype problem, to our understanding of human pathologies and drug design. In this review, we address the phenomena of pleiotropy, multidomain proteins, promiscuity, and protein moonlighting, providing examples of multitasking biomolecules that underlie specific mechanisms of human disease. In doing so, we place in context different types of multifunctional proteins, highlighting useful attributes for their systematic definition and classification in future research directions.
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Affiliation(s)
- Adriana Espinosa-Cantú
- Unidad de Genómica Avanzada (Langebio), Centro de Investigación y de Estudios Avanzados, Guanajuato, Mexico
| | - Erika Cruz-Bonilla
- Unidad de Genómica Avanzada (Langebio), Centro de Investigación y de Estudios Avanzados, Guanajuato, Mexico
| | - Lianet Noda-Garcia
- Department of Plant Pathology and Microbiology, Robert H. Smith Faculty of Agriculture, Food, and Environment, The Hebrew University of Jerusalem, Rehovot, Israel
| | - Alexander DeLuna
- Unidad de Genómica Avanzada (Langebio), Centro de Investigación y de Estudios Avanzados, Guanajuato, Mexico
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Stoeber M, Jullié D, Li J, Chakraborty S, Majumdar S, Lambert NA, Manglik A, von Zastrow M. Agonist-selective recruitment of engineered protein probes and of GRK2 by opioid receptors in living cells. eLife 2020; 9:54208. [PMID: 32096468 PMCID: PMC7041944 DOI: 10.7554/elife.54208] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Accepted: 01/29/2020] [Indexed: 12/21/2022] Open
Abstract
G protein-coupled receptors (GPCRs) signal through allostery, and it is increasingly clear that chemically distinct agonists can produce different receptor-based effects. It has been proposed that agonists selectively promote receptors to recruit one cellular interacting partner over another, introducing allosteric ‘bias’ into the signaling system. However, the underlying hypothesis - that different agonists drive GPCRs to engage different cytoplasmic proteins in living cells - remains untested due to the complexity of readouts through which receptor-proximal interactions are typically inferred. We describe a cell-based assay to overcome this challenge, based on GPCR-interacting biosensors that are disconnected from endogenous transduction mechanisms. Focusing on opioid receptors, we directly demonstrate differences between biosensor recruitment produced by chemically distinct opioid ligands in living cells. We then show that selective recruitment applies to GRK2, a biologically relevant GPCR regulator, through discrete interactions of GRK2 with receptors or with G protein beta-gamma subunits which are differentially promoted by agonists. About a third of all drugs work by targeting a group of proteins known as G-protein coupled receptors, or GPCRs for short. These receptors are found on the surface of cells and transmit messages across the cell’s outer barrier. When a signaling molecule, like a hormone, is released in the body, it binds to a GPCR and changes the receptor’s shape. The change in structure affects how the GPCR interacts and binds to other proteins on the inside of the cell, triggering a series of reactions that alter the cell’s activity. Scientists have previously seen that a GPCR can trigger different responses depending on which signaling molecule is binding on the surface of the cell. However, the mechanism for this is unknown. One hypothesis is that different signaling molecules change the GPCR’s preference for binding to different proteins on the inside of the cell. The challenge has been to observe this happening without interfering with the process. Stoeber et al. have now tested this idea by attaching fluorescent tags to proteins that bind to activated GPCRs directly and without binding other signaling proteins. This meant these proteins could be tracked under a microscope as they made their way to bind to the GPCRs. Stoeber et al. focused on one particular GPCR, known as the opioid receptor, and tested the binding of two different opioid signaling molecules, etorphine and Dynorphin A. The experiments revealed that the different opioids did affect which of the engineered proteins would preferentially bind to the opioid receptor. This was followed by a similar experiment, where the engineered proteins were replaced with another protein called GRK2, which binds to the opioid receptor under normal conditions in the cell. This showed that GRK2 binds much more strongly to the opioid receptor when Dynorphin A is added compared to adding etorphine. These findings show that GPCRs can not only communicate that a signaling molecule is binding but can respond differently to convey what molecule it is more specifically. This could be important in developing drugs, particularly to specifically trigger the desired response and reduce side effects. Stoeber et al. suggest that an important next step for research is to understand how the GPCRs preferentially bind to different proteins.
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Affiliation(s)
- Miriam Stoeber
- Department of Psychiatry, University of California, San Francisco, San Francisco, United States.,Department of Cell Physiology and Metabolism, University of Geneva, Geneva, Switzerland
| | - Damien Jullié
- Department of Psychiatry, University of California, San Francisco, San Francisco, United States.,Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, United States
| | - Joy Li
- Department of Psychiatry, University of California, San Francisco, San Francisco, United States.,Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, United States
| | - Soumen Chakraborty
- Center for Clinical Pharmacology, Washington University School of Medicine, St. Louis, United States.,St Louis College of Pharmacy, St. Louis, United States
| | - Susruta Majumdar
- Center for Clinical Pharmacology, Washington University School of Medicine, St. Louis, United States.,St Louis College of Pharmacy, St. Louis, United States
| | - Nevin A Lambert
- Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta University, Augusta, United States
| | - Aashish Manglik
- Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, United States.,Department of Anesthesia, University of California, San Francisco, San Francisco, United States
| | - Mark von Zastrow
- Department of Psychiatry, University of California, San Francisco, San Francisco, United States.,Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, United States
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Endo W, Ikemoto S, Togashi N, Miyabayashi T, Nakajima E, Hamano SI, Shibuya M, Sato R, Takezawa Y, Okubo Y, Inui T, Kato M, Sengoku T, Ogata K, Hamanaka K, Mizuguchi T, Miyatake S, Nakashima M, Matsumoto N, Haginoya K. Phenotype-genotype correlations in patients with GNB1 gene variants, including the first three reported Japanese patients to exhibit spastic diplegia, dyskinetic quadriplegia, and infantile spasms. Brain Dev 2020; 42:199-204. [PMID: 31735425 DOI: 10.1016/j.braindev.2019.10.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Revised: 08/19/2019] [Accepted: 10/21/2019] [Indexed: 10/25/2022]
Abstract
We report the first three Japanese patients with missense variants in the GNB1 gene. Patients exhibited severe dyskinetic quadriplegia with cortical blindness and epileptic spasms, West syndrome (but with good outcomes), and hypotonic quadriplegia that later developed into spastic diplegia. Whole-exome sequencing revealed two recurrent GNB1 variants (p.Leu95Pro and p.Ile80Thr) and one novel variant (p.Ser74Leu). A recent investigation revealed large numbers of patients with GNB1 variants. Functional studies of such variants and genotype-phenotype correlation are required to enable future precision medicine.
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Affiliation(s)
- Wakaba Endo
- Department of Pediatric Neurology, Miyagi Children's Hospital Hospital, Sendai 989-3126, Japan
| | - Satoru Ikemoto
- Division of Neurology, Saitama Children's Medical Center, Saitama 330-8777, Japan
| | - Noriko Togashi
- Department of Pediatric Neurology, Miyagi Children's Hospital Hospital, Sendai 989-3126, Japan
| | - Takuya Miyabayashi
- Department of Pediatric Neurology, Miyagi Children's Hospital Hospital, Sendai 989-3126, Japan
| | - Erika Nakajima
- Division of Neurology, Saitama Children's Medical Center, Saitama 330-8777, Japan
| | - Shin-Ichiro Hamano
- Division of Neurology, Saitama Children's Medical Center, Saitama 330-8777, Japan
| | - Moriei Shibuya
- Department of Pediatric Neurology, Miyagi Children's Hospital Hospital, Sendai 989-3126, Japan
| | - Ryo Sato
- Department of Pediatric Neurology, Miyagi Children's Hospital Hospital, Sendai 989-3126, Japan
| | - Yusuke Takezawa
- Department of Pediatric Neurology, Miyagi Children's Hospital Hospital, Sendai 989-3126, Japan
| | - Yukimune Okubo
- Department of Pediatric Neurology, Miyagi Children's Hospital Hospital, Sendai 989-3126, Japan
| | - Takehiko Inui
- Department of Pediatric Neurology, Miyagi Children's Hospital Hospital, Sendai 989-3126, Japan
| | - Mitsuhiro Kato
- Department of Pediatrics, Showa University School of Medicine, Tokyo 152-8555, Japan
| | - Toru Sengoku
- Department of Biochemistry, Graduate School of Medicine, Yokohama City University, Yokohama, Japan
| | - Kazuhiro Ogata
- Department of Biochemistry, Graduate School of Medicine, Yokohama City University, Yokohama, Japan
| | - Kohei Hamanaka
- Department of Human Genetics, Graduate School of Medicine, Yokohama City University, Yokohama 236-0004, Japan
| | - Takeshi Mizuguchi
- Department of Human Genetics, Graduate School of Medicine, Yokohama City University, Yokohama 236-0004, Japan
| | - Satoko Miyatake
- Department of Human Genetics, Graduate School of Medicine, Yokohama City University, Yokohama 236-0004, Japan
| | - Mitsuko Nakashima
- Department of Human Genetics, Graduate School of Medicine, Yokohama City University, Yokohama 236-0004, Japan; Department of Biochemistry, Hamamatsu University School of Medicine, Hamamatsu 431-3192, Japan
| | - Naomichi Matsumoto
- Department of Human Genetics, Graduate School of Medicine, Yokohama City University, Yokohama 236-0004, Japan
| | - Kazuhiro Haginoya
- Department of Pediatric Neurology, Miyagi Children's Hospital Hospital, Sendai 989-3126, Japan.
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35
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Nguyen AH, Thomsen ARB, Cahill TJ, Huang R, Huang LY, Marcink T, Clarke OB, Heissel S, Masoudi A, Ben-Hail D, Samaan F, Dandey VP, Tan YZ, Hong C, Mahoney JP, Triest S, Little J, Chen X, Sunahara R, Steyaert J, Molina H, Yu Z, des Georges A, Lefkowitz RJ. Structure of an endosomal signaling GPCR-G protein-β-arrestin megacomplex. Nat Struct Mol Biol 2019; 26:1123-1131. [PMID: 31740855 PMCID: PMC7108872 DOI: 10.1038/s41594-019-0330-y] [Citation(s) in RCA: 124] [Impact Index Per Article: 24.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2019] [Accepted: 10/09/2019] [Indexed: 01/21/2023]
Abstract
Classically, G-protein-coupled receptors (GPCRs) are thought to activate G protein from the plasma membrane and are subsequently desensitized by β-arrestin (β-arr). However, some GPCRs continue to signal through G protein from internalized compartments, mediated by a GPCR-G protein-β-arr 'megaplex'. Nevertheless, the molecular architecture of the megaplex remains unknown. Here, we present its cryo-electron microscopy structure, which shows simultaneous engagement of human G protein and bovine β-arr to the core and phosphorylated tail, respectively, of a single active human chimeric β2-adrenergic receptor with the C-terminal tail of the arginine vasopressin type 2 receptor (β2V2R). All three components adopt their canonical active conformations, suggesting that a single megaplex GPCR is capable of simultaneously activating G protein and β-arr. Our findings provide a structural basis for GPCR-mediated sustained internalized G protein signaling.
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Affiliation(s)
- Anthony H. Nguyen
- Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA.,Department of Biochemistry, Duke University Medical Center, Durham, NC 27710, USA
| | - Alex R. B. Thomsen
- Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA.,Department of Surgery, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Thomas J. Cahill
- Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA.,Department of Biochemistry, Duke University Medical Center, Durham, NC 27710, USA
| | - Rick Huang
- Howard Hughes Medical Institute, Janelia Research Campus, Ashburn, VA 20147, USA
| | - Li-Yin Huang
- Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA
| | - Tara Marcink
- Department of Pediatrics, Columbia University Irving Medical Center, New York, NY 10032, USA.,Center for Host-Pathogen Interaction, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Oliver B. Clarke
- Department of Anesthesiology, Columbia University Irving Medical Center, New York, NY 10032, USA.,Department of Physiology and Cellular Biophysics, Columbia University Irving Medical Center, New York, NY 10032, USA.,The Irving Center for Clinical and Translational Research, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Søren Heissel
- Proteomics Resource Center, The Rockefeller University, New York, New York 10065, USA
| | - Ali Masoudi
- Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA
| | - Danya Ben-Hail
- Structural Biology Initiative, CUNY Advanced Science Research Center, NY 10031, USA
| | - Fadi Samaan
- Structural Biology Initiative, CUNY Advanced Science Research Center, NY 10031, USA
| | - Venkata P. Dandey
- The National Resource for Automated Molecular Microscopy, Simons Electron Microscopy Center, New York Structural Biology Center, New York, NY 10027, USA
| | - Yong Zi Tan
- The National Resource for Automated Molecular Microscopy, Simons Electron Microscopy Center, New York Structural Biology Center, New York, NY 10027, USA,Department of Biochemistry and Molecular Biophysics, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Chuan Hong
- Howard Hughes Medical Institute, Janelia Research Campus, Ashburn, VA 20147, USA
| | - Jacob P. Mahoney
- Department of Pharmacology, University of Michigan, Ann Arbor, MI 48109, USA,Present Address: Department of Structural Biology, Stanford University, Stanford, CA
| | - Sarah Triest
- Structural Biology Brussels, Vrije Universiteit Brussels, B-1050 Brussels, Belgium; Structural Biology Research Center, Vlaams Instituut voor Biotechnologie, B-1050 Brussels, Belgium
| | - John Little
- Department of Biochemistry, Duke University Medical Center, Durham, NC 27710, USA
| | - Xin Chen
- School of Pharmaceutical Engineering and Life Sciences, Changzhou University, Changzhou, Jiangsu 213164, China
| | - Roger Sunahara
- Department of Pharmacology, University of Michigan, Ann Arbor, MI 48109, USA,Department of Pharmacology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Jan Steyaert
- Structural Biology Brussels, Vrije Universiteit Brussels, B-1050 Brussels, Belgium; Structural Biology Research Center, Vlaams Instituut voor Biotechnologie, B-1050 Brussels, Belgium
| | - Henrik Molina
- Proteomics Resource Center, The Rockefeller University, New York, New York 10065, USA
| | - Zhiheng Yu
- Howard Hughes Medical Institute, Janelia Research Campus, Ashburn, VA 20147, USA
| | - Amedee des Georges
- Structural Biology Initiative, CUNY Advanced Science Research Center, NY 10031, USA,Department of Chemistry and Biochemistry, City College of New York, NY, USA,Biochemistry and Chemistry Ph.D. Programs, Graduate Center, City University of New York, NY, USA,Corresponding authors: (A.d.G.); (R.J.L.)
| | - Robert J. Lefkowitz
- Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA.,Department of Biochemistry, Duke University Medical Center, Durham, NC 27710, USA.,Howard Hughes Medical Institute, Duke University Medical Center, Durham, NC 27710, USA.,Corresponding authors: (A.d.G.); (R.J.L.)
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36
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Altamish M, Samuel VP, Dahiya R, Singh Y, Deb PK, Bakshi HA, Tambuwala MM, Chellappan DK, Collet T, Dua K, Gupta G. Molecular signaling of G-protein-coupled receptor in chronic heart failure and associated complications. Drug Dev Res 2019; 81:23-31. [PMID: 31785110 DOI: 10.1002/ddr.21627] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2019] [Revised: 11/08/2019] [Accepted: 11/13/2019] [Indexed: 01/14/2023]
Abstract
The well-known condition of heart failure is a clinical syndrome that results when the myocardium's ability to pump enough blood to meet the body's metabolic needs is impaired. Most of the cardiac activity is maintained by adrenoceptors, are categorized into two main α and β and three distinct subtypes of β receptor: β1-, β2-, and β3-adrenoceptors. The β adrenoreceptor is the main regulatory macro proteins, predominantly available on heart and responsible for down regulatory cardiac signaling. Moreover, the pathological involvement of Angiotensin-converting enzyme 1 (ACE1)/angiotensin II (Ang II)/angiotensin II type 1 (AT1) axis and beneficial ACE2/Ang (1-7)/Mas receptor axis also shows protective role via Gi βγ, during heart failure these receptors get desensitized or internalized due to increase in the activity of G-protein-coupled receptor kinase 2 (GRK2) and GRK5, responsible for phosphorylation of G-protein-mediated down regulatory signaling. Here, we investigate the various clinical and preclinical data that exhibit the molecular mechanism of upset level of GRK change the cardiac activity during failing heart.
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Affiliation(s)
- Mohammad Altamish
- Department of Pharmacology, School of Pharmaceutical Education and Research, Jamia Hamdard, New Delhi, India
| | - Vijaya Paul Samuel
- Department of Anatomy, RAK College of Medicine, RAK Medical and Health Sciences University, Ras Al Khaimah, UAE
| | - Rajiv Dahiya
- Laboratory of Peptide Research and Development, School of Pharmacy, Faculty of Medical Sciences, The University of the West Indies, St. Augustine, Trinidad and Tobago
| | - Yogendra Singh
- Department of Pharmaceutical Sciences, Mahatma Gandhi College of Pharmaceutical Sciences, Jaipur, Rajasthan, India
| | | | - Hamid A Bakshi
- School of Pharmacy and Pharmaceutical Sciences, Ulster University, Coleraine, County Londonderry, BT52 1SA, Northern Ireland, United Kingdom
| | - Murtaza M Tambuwala
- School of Pharmacy and Pharmaceutical Sciences, Ulster University, Coleraine, County Londonderry, BT52 1SA, Northern Ireland, United Kingdom
| | - Dinesh K Chellappan
- Department of Life Sciences, School of Pharmacy, International Medical University, Bukit Jalil, Kuala Lumpur, Malaysia
| | - Trudi Collet
- Innovative Medicines Group, Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Queensland, Australia
| | - Kamal Dua
- Discipline of Pharmacy, Graduate School of Health, University of Technology Sydney, Ultimo, New South Wales, Australia.,School of Biomedical Sciences and Pharmacy, The University of Newcastle, Callaghan, New South Wales, Australia.,School of Pharmaceutical Sciences, Shoolini University, Bajhol, Sultanpur, Solan, Himachal Pradesh, 173 229, India
| | - Gaurav Gupta
- School of Pharmacy, Suresh Gyan Vihar University, Jaipur, Rajasthan, India
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37
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Penela P, Ribas C, Sánchez-Madrid F, Mayor F. G protein-coupled receptor kinase 2 (GRK2) as a multifunctional signaling hub. Cell Mol Life Sci 2019; 76:4423-4446. [PMID: 31432234 PMCID: PMC6841920 DOI: 10.1007/s00018-019-03274-3] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Revised: 08/06/2019] [Accepted: 08/12/2019] [Indexed: 12/18/2022]
Abstract
Accumulating evidence indicates that G protein-coupled receptor kinase 2 (GRK2) is a versatile protein that acts as a signaling hub by modulating G protein-coupled receptor (GPCR) signaling and also via phosphorylation or scaffolding interactions with an extensive number of non-GPCR cellular partners. GRK2 multifunctionality arises from its multidomain structure and from complex mechanisms of regulation of its expression levels, activity, and localization within the cell, what allows the precise spatio-temporal shaping of GRK2 targets. A better understanding of the GRK2 interactome and its modulation mechanisms is helping to identify the GRK2-interacting proteins and its substrates involved in the participation of this kinase in different cellular processes and pathophysiological contexts.
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Affiliation(s)
- Petronila Penela
- Departamento de Biología Molecular, Centro de Biología Molecular "Severo Ochoa" (UAM-CSIC), Universidad Autónoma de Madrid, C/Nicolás Cabrera 1, 28049, Madrid, Spain
- Instituto de Investigación Sanitaria La Princesa, 28006, Madrid, Spain
- CIBER de Enfermedades Cardiovasculares, ISCIII (CIBERCV), 28029, Madrid, Spain
| | - Catalina Ribas
- Departamento de Biología Molecular, Centro de Biología Molecular "Severo Ochoa" (UAM-CSIC), Universidad Autónoma de Madrid, C/Nicolás Cabrera 1, 28049, Madrid, Spain
- Instituto de Investigación Sanitaria La Princesa, 28006, Madrid, Spain
- CIBER de Enfermedades Cardiovasculares, ISCIII (CIBERCV), 28029, Madrid, Spain
| | - Francisco Sánchez-Madrid
- Instituto de Investigación Sanitaria La Princesa, 28006, Madrid, Spain
- CIBER de Enfermedades Cardiovasculares, ISCIII (CIBERCV), 28029, Madrid, Spain
- Cell-Cell Communication Laboratory, Vascular Pathophysiology Area, Centro Nacional Investigaciones Cardiovasculares (CNIC), 28029, Madrid, Spain
| | - Federico Mayor
- Departamento de Biología Molecular, Centro de Biología Molecular "Severo Ochoa" (UAM-CSIC), Universidad Autónoma de Madrid, C/Nicolás Cabrera 1, 28049, Madrid, Spain.
- Instituto de Investigación Sanitaria La Princesa, 28006, Madrid, Spain.
- CIBER de Enfermedades Cardiovasculares, ISCIII (CIBERCV), 28029, Madrid, Spain.
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38
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Smrcka AV, Fisher I. G-protein βγ subunits as multi-functional scaffolds and transducers in G-protein-coupled receptor signaling. Cell Mol Life Sci 2019; 76:4447-4459. [PMID: 31435698 PMCID: PMC6842434 DOI: 10.1007/s00018-019-03275-2] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Revised: 08/05/2019] [Accepted: 08/12/2019] [Indexed: 02/08/2023]
Abstract
G-protein βγ subunits are key participants in G-protein signaling. These subunits facilitate interactions between receptors and G proteins that are critical for the G protein activation cycle at the plasma membrane. In addition, they play roles in directly transducing signals to an ever expanding range of downstream targets, including integral membrane and cytosolic proteins. Emerging data indicate that Gβγ may play additional roles at intracellular compartments including endosomes, the Golgi apparatus, and the nucleus. Here, we discuss the molecular and structural basis for their ability to coordinate this wide range of cellular activities.
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Affiliation(s)
- Alan V Smrcka
- Department of Pharmacology, University of Michigan Medical School, Ann Arbor, MI, 48104, USA.
| | - Isaac Fisher
- Department of Pharmacology, University of Michigan Medical School, Ann Arbor, MI, 48104, USA
- Department of Pharmacology and Physiology, University of Rochester School of Medicine, Rochester, NY, 14629, USA
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39
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Cash JN, Urata S, Li S, Ravala SK, Avramova LV, Shost MD, Gutkind JS, Tesmer JJG, Cianfrocco MA. Cryo-electron microscopy structure and analysis of the P-Rex1-Gβγ signaling scaffold. SCIENCE ADVANCES 2019; 5:eaax8855. [PMID: 31663027 PMCID: PMC6795519 DOI: 10.1126/sciadv.aax8855] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Accepted: 09/22/2019] [Indexed: 05/29/2023]
Abstract
PIP3-dependent Rac exchanger 1 (P-Rex1) is activated downstream of G protein-coupled receptors to promote neutrophil migration and metastasis. The structure of more than half of the enzyme and its regulatory G protein binding site are unknown. Our 3.2 Å cryo-EM structure of the P-Rex1-Gβγ complex reveals that the carboxyl-terminal half of P-Rex1 adopts a complex fold most similar to those of Legionella phosphoinositide phosphatases. Although catalytically inert, the domain coalesces with a DEP domain and two PDZ domains to form an extensive docking site for Gβγ. Hydrogen-deuterium exchange mass spectrometry suggests that Gβγ binding induces allosteric changes in P-Rex1, but functional assays indicate that membrane localization is also required for full activation. Thus, a multidomain assembly is key to the regulation of P-Rex1 by Gβγ and the formation of a membrane-localized scaffold optimized for recruitment of other signaling proteins such as PKA and PTEN.
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Affiliation(s)
- Jennifer N. Cash
- Department of Biological Chemistry & Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA
| | - Sarah Urata
- Department of Medicine, University of California, San Diego, San Diego, CA, USA
| | - Sheng Li
- Department of Medicine, University of California, San Diego, San Diego, CA, USA
| | - Sandeep K. Ravala
- Departments of Biological Sciences and of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN, USA
| | - Larisa V. Avramova
- Departments of Biological Sciences and of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN, USA
| | - Michael D. Shost
- Department of Biological Chemistry & Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA
| | - J. Silvio Gutkind
- Department of Pharmacology and Moores Cancer Center, University of California, San Diego, San Diego, CA, USA
| | - John J. G. Tesmer
- Departments of Biological Sciences and of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN, USA
| | - Michael A. Cianfrocco
- Department of Biological Chemistry & Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA
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40
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Man KNM, Navedo MF, Horne MC, Hell JW. β 2 Adrenergic Receptor Complexes with the L-Type Ca 2+ Channel Ca V1.2 and AMPA-Type Glutamate Receptors: Paradigms for Pharmacological Targeting of Protein Interactions. Annu Rev Pharmacol Toxicol 2019; 60:155-174. [PMID: 31561738 DOI: 10.1146/annurev-pharmtox-010919-023404] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Formation of signaling complexes is crucial for the orchestration of fast, efficient, and specific signal transduction. Pharmacological disruption of defined signaling complexes has the potential for specific intervention in selected regulatory pathways without affecting organism-wide disruption of parallel pathways. Signaling by epinephrine and norepinephrine through α and β adrenergic receptors acts on many signaling pathways in many cell types. Here, we initially provide an overview of the signaling complexes formed between the paradigmatic β2 adrenergic receptor and two of its most important targets, the L-type Ca2+ channel CaV1.2 and the AMPA-type glutamate receptor. Importantly, both complexes contain the trimeric Gs protein, adenylyl cyclase, and the cAMP-dependent protein kinase, PKA. We then discuss the functional implications of the formation of these complexes, how those complexes can be specifically disrupted, and how such disruption could be utilized in the pharmacological treatment of disease.
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Affiliation(s)
- Kwun Nok Mimi Man
- Department of Pharmacology, University of California, Davis, California 95616, USA;
| | - Manuel F Navedo
- Department of Pharmacology, University of California, Davis, California 95616, USA;
| | - Mary C Horne
- Department of Pharmacology, University of California, Davis, California 95616, USA;
| | - Johannes W Hell
- Department of Pharmacology, University of California, Davis, California 95616, USA;
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41
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Zhang H, Nielsen AL, Strømgaard K. Recent achievements in developing selective Gqinhibitors. Med Res Rev 2019; 40:135-157. [DOI: 10.1002/med.21598] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Revised: 04/09/2019] [Accepted: 04/26/2019] [Indexed: 02/06/2023]
Affiliation(s)
- Hang Zhang
- Key Laboratory of Advanced Drug Preparation Technologies, Ministry of Education, Co‐innovation Center of Henan Province for New Drug R&D and Preclinical Safety, and School of Pharmaceutical SciencesZhengzhou UniversityZhengzhou Henan China
| | - Alexander L. Nielsen
- Department of Drug Design and Pharmacology, Center for BiopharmaceuticalsUniversity of CopenhagenCopenhagen Denmark
| | - Kristian Strømgaard
- Department of Drug Design and Pharmacology, Center for BiopharmaceuticalsUniversity of CopenhagenCopenhagen Denmark
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42
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Navot S, Kosloff M. Structural design principles that underlie the multi-specific interactions of Gα q with dissimilar partners. Sci Rep 2019; 9:6898. [PMID: 31053791 PMCID: PMC6499889 DOI: 10.1038/s41598-019-43395-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Accepted: 04/23/2019] [Indexed: 02/07/2023] Open
Abstract
Gαq is a ubiquitous molecular switch that activates the effectors phospholipase-C-β3 (PLC-β3) and Rho guanine-nucleotide exchange factors. Gαq is inactivated by regulators of G protein signaling proteins, as well as by PLC-β3. Gαq further interacts with G protein-coupled receptor kinase 2 (GRK2), although the functional role of this interaction is debated. While X-ray structures of Gαq bound to representatives of these partners have revealed details of their interactions, the mechanistic basis for differential Gαq interactions with multiple partners (i.e., Gαq multi-specificity) has not been elucidated at the individual residue resolution. Here, we map the structural determinants of Gαq multi-specificity using structure-based energy calculations. We delineate regions that specifically interact with GTPase Activating Proteins (GAPs) and residues that exclusively contribute to effector interactions, showing that only the Gαq “Switch II” region interacts with all partners. Our analysis further suggests that Gαq-GRK2 interactions are consistent with GRK2 functioning as an effector, rather than a GAP. Our multi-specificity analysis pinpoints Gαq residues that uniquely contribute to interactions with particular partners, enabling precise manipulation of these cascades. As such, we dissect the molecular basis of Gαq function as a central signaling hub, which can be used to target Gαq-mediated signaling in therapeutic interventions.
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Affiliation(s)
- Shir Navot
- The Department of Human Biology, Faculty of Natural Science, University of Haifa, Haifa, 3498838, Israel
| | - Mickey Kosloff
- The Department of Human Biology, Faculty of Natural Science, University of Haifa, Haifa, 3498838, Israel.
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43
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Brand CS, Lighthouse JK, Trembley MA. Protective transcriptional mechanisms in cardiomyocytes and cardiac fibroblasts. J Mol Cell Cardiol 2019; 132:1-12. [PMID: 31042488 DOI: 10.1016/j.yjmcc.2019.04.023] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Revised: 04/19/2019] [Accepted: 04/22/2019] [Indexed: 12/13/2022]
Abstract
Heart failure is the leading cause of morbidity and mortality worldwide. Several lines of evidence suggest that physical activity and exercise can pre-condition the heart to improve the response to acute cardiac injury such as myocardial infarction or ischemia/reperfusion injury, preventing the progression to heart failure. It is becoming more apparent that cardioprotection is a concerted effort between multiple cell types and converging signaling pathways. However, the molecular mechanisms of cardioprotection are not completely understood. What is clear is that the mechanisms underlying this protection involve acute activation of transcriptional activators and their corresponding gene expression programs. Here, we review the known stress-dependent transcriptional programs that are activated in cardiomyocytes and cardiac fibroblasts to preserve function in the adult heart after injury. Focus is given to prominent transcriptional pathways such as mechanical stress or reactive oxygen species (ROS)-dependent activation of myocardin-related transcription factors (MRTFs) and transforming growth factor beta (TGFβ), and gene expression that positively regulates protective PI3K/Akt signaling. Together, these pathways modulate both beneficial and pathological responses to cardiac injury in a cell-specific manner.
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Affiliation(s)
- Cameron S Brand
- Department of Pharmacology, School of Medicine, University of California - San Diego, 9500 Gilman Drive, Biomedical Sciences Building, La Jolla, CA 92093, USA.
| | - Janet K Lighthouse
- Aab Cardiovascular Research Institute, University of Rochester School of Medicine and Dentistry, 601 Elmwood Avenue, Box CVRI, Rochester, NY 14624, USA.
| | - Michael A Trembley
- Department of Cardiology, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA 02115, USA.
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44
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Structural basis for KCTD-mediated rapid desensitization of GABA B signalling. Nature 2019; 567:127-131. [PMID: 30814734 PMCID: PMC6405316 DOI: 10.1038/s41586-019-0990-0] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Accepted: 01/24/2019] [Indexed: 11/23/2022]
Abstract
The GABAB receptor is one of the principal inhibitory neurotransmitter receptors in the brain, and it signals through heterotrimeric G proteins to activate a variety of effectors including G protein-coupled inwardly-rectifying potassium channels (GIRKs)1,2. GABAB receptor signaling is tightly regulated by auxiliary subunits called KCTDs, which control the kinetics of GIRK activation and desensitization3–5. However, the mechanistic basis for KCTD modulation of GABAB signaling remains incompletely understood. Here, using a combination of X-ray crystallography, electron microscopy, functional and biochemical experiments we reveal the molecular details of KCTD binding to both GABAB receptors and Gβγ subunits. KCTDs associate with the receptor by forming an asymmetric pentameric ring around a region of the receptor C-terminal tail, while a second KCTD domain, H1, engages in a symmetric interaction with five copies of Gβγ in which the G protein subunits also directly interact with one another. We further show that KCTD binding to Gβγ is highly cooperative, defining a model in which KCTDs cooperatively strip G proteins from GIRK channels to induce rapid desensitization following receptor activation. These results provide a framework for understanding the molecular basis for the precise temporal control of GABAB signaling by KCTD proteins.
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45
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Gurevich VV, Gurevich EV. GPCR Signaling Regulation: The Role of GRKs and Arrestins. Front Pharmacol 2019; 10:125. [PMID: 30837883 PMCID: PMC6389790 DOI: 10.3389/fphar.2019.00125] [Citation(s) in RCA: 328] [Impact Index Per Article: 65.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Accepted: 01/31/2019] [Indexed: 12/13/2022] Open
Abstract
Every animal species expresses hundreds of different G protein-coupled receptors (GPCRs) that respond to a wide variety of external stimuli. GPCRs-driven signaling pathways are involved in pretty much every physiological function and in many pathologies. Therefore, GPCRs are targeted by about a third of clinically used drugs. The signaling of most GPCRs via G proteins is terminated by the phosphorylation of active receptor by specific kinases (GPCR kinases, or GRKs) and subsequent binding of arrestin proteins, that selectively recognize active phosphorylated receptors. In addition, GRKs and arrestins play a role in multiple signaling pathways in the cell, both GPCR-initiated and receptor-independent. Here we focus on the mechanisms of GRK- and arrestin-mediated regulation of GPCR signaling, which includes homologous desensitization and redirection of signaling to additional pathways by bound arrestins.
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Affiliation(s)
- Vsevolod V Gurevich
- Department of Pharmacology, Vanderbilt University, Nashville, TN, United States
| | - Eugenia V Gurevich
- Department of Pharmacology, Vanderbilt University, Nashville, TN, United States
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46
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Estrogen Regulation of GRK2 Inactivates Kappa Opioid Receptor Signaling Mediating Analgesia, But Not Aversion. J Neurosci 2018; 38:8031-8043. [PMID: 30076211 DOI: 10.1523/jneurosci.0653-18.2018] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Revised: 07/11/2018] [Accepted: 07/21/2018] [Indexed: 12/12/2022] Open
Abstract
Activation of κ opioid receptors (KORs) produces analgesia and aversion via distinct intracellular signaling pathways, but whether G protein-biased KOR agonists can be designed to have clinical utility will depend on a better understanding of the signaling mechanisms involved. We found that KOR activation produced conditioned place aversion and potentiated CPP for cocaine in male and female C57BL/6N mice. Consistent with this, males and females both showed arrestin-mediated increases in phospho-p38 MAPK following KOR activation. Unlike in males, however, KOR activation had inconsistent analgesic effects in females and KOR increased Gβγ-mediated ERK phosphorylation in males, but not females. KOR desensitization was not responsible for the lack of response in females because neither Grk3 nor Pdyn gene knock-out enhanced analgesia. Instead, responsiveness was estrous cycle dependent because KOR analgesia was evident during low estrogen phases of the cycle and in ovariectomized (OVX) females. Estradiol treatment of OVX females suppressed KOR-mediated analgesia, demonstrating that estradiol was sufficient to blunt Gβγ-mediated KOR signals. G protein-coupled receptor kinase 2 (GRK2) is known to regulate ERK activation, and we found that the inhibitory, phosphorylated form of GRK2 was significantly higher in intact females. GRK2/3 inhibition by CMPD101 increased KOR stimulation of phospho-ERK in females, decreased sex differences in KOR-mediated inhibition of dopamine release, and enhanced mu opioid receptor and KOR-mediated analgesia in females. In OVX females, estradiol increased the association between GRK2 and Gβγ. These studies suggest that estradiol, through increased phosphorylation of GRK2 and possible sequestration of Gβγ by GRK2, blunts G protein-mediated signals.SIGNIFICANCE STATEMENT Chronic pain disorders are more prevalent in females than males, but opioid receptor agonists show inconsistent analgesic efficacy in females. κ opioid receptor (KOR) agonists have been tested in clinical trials for treating pain disorders based on their analgesic properties and low addictive potential. However, the molecular mechanisms underlying sex differences in KOR actions were previously unknown. Our studies identify an intracellular mechanism involving estradiol regulation of G protein-coupled receptor kinase 2 that is responsible for sexually dimorphic analgesic responses following opioid receptor activation. Understanding this mechanism will be critical for developing effective nonaddictive opioid analgesics for use in women and characterizing sexually dimorphic effects in other inhibitory G protein-coupled receptor signaling responses.
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Targeting G protein-coupled receptor signaling at the G protein level with a selective nanobody inhibitor. Nat Commun 2018; 9:1996. [PMID: 29777099 PMCID: PMC5959942 DOI: 10.1038/s41467-018-04432-0] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2017] [Accepted: 04/25/2018] [Indexed: 01/06/2023] Open
Abstract
G protein-coupled receptors (GPCRs) activate heterotrimeric G proteins by mediating a GDP to GTP exchange in the Gα subunit. This leads to dissociation of the heterotrimer into Gα-GTP and Gβγ dimer. The Gα-GTP and Gβγ dimer each regulate a variety of downstream pathways to control various aspects of human physiology. Dysregulated Gβγ-signaling is a central element of various neurological and cancer-related anomalies. However, Gβγ also serves as a negative regulator of Gα that is essential for G protein inactivation, and thus has the potential for numerous side effects when targeted therapeutically. Here we report a llama-derived nanobody (Nb5) that binds tightly to the Gβγ dimer. Nb5 responds to all combinations of β-subtypes and γ-subtypes and competes with other Gβγ-regulatory proteins for a common binding site on the Gβγ dimer. Despite its inhibitory effect on Gβγ-mediated signaling, Nb5 has no effect on Gαq-mediated and Gαs-mediated signaling events in living cells.
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Gurevich VV, Gurevich EV. GPCRs and Signal Transducers: Interaction Stoichiometry. Trends Pharmacol Sci 2018; 39:672-684. [PMID: 29739625 DOI: 10.1016/j.tips.2018.04.002] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Revised: 04/11/2018] [Accepted: 04/13/2018] [Indexed: 12/12/2022]
Abstract
Until the late 1990s, class A G protein-coupled receptors (GPCRs) were believed to function as monomers. Indirect evidence that they might internalize or even signal as dimers has emerged, along with proof that class C GPCRs are obligatory dimers. Crystal structures of GPCRs and their much larger binding partners were consistent with the idea that two receptors might engage a single G protein, GRK, or arrestin. However, recent biophysical, biochemical, and structural evidence invariably suggests that a single GPCR binds G proteins, GRKs, and arrestins. Here we review existing evidence of the stoichiometry of GPCR interactions with signal transducers and discuss potential biological roles of class A GPCR oligomers, including proposed homo- and heterodimers.
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Affiliation(s)
- Vsevolod V Gurevich
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, USA.
| | - Eugenia V Gurevich
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, USA
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Gupta MK, Mohan ML, Naga Prasad SV. G Protein-Coupled Receptor Resensitization Paradigms. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2018; 339:63-91. [PMID: 29776605 DOI: 10.1016/bs.ircmb.2018.03.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Cellular responses to extracellular milieu/environment are driven by cell surface receptors that transmit the signal into the cells resulting in a synchronized and measured response. The ability to provide such exquisite responses to changes in external environment is mediated by the tight and yet, deliberate regulation of cell surface receptor function. In this regard, the seven transmembrane G protein-coupled receptors (GPCRs) are the largest family of cell surface receptors that regulate responses like cardiac contractility, vision, and olfaction including platelet activation. GPCRs regulate these plethora of events through GPCR-activation, -desensitization, and -resensitization. External stimuli (ligands or agonists) activate GPCR initiating downstream signals. The activated GPCR undergoes inactivation or desensitization by phosphorylation and binding of β-arrestin resulting in diminution of downstream signals. The desensitized GPCRs are internalized into endosomes, wherein they undergo dephosphorylation or resensitization by protein phosphatase to be recycled back to the cell membrane as naïve GPCR ready for the next wave of stimuli. Despite the knowledge that activation, desensitization, and resensitization shoulder an equal role in maintaining GPCR function, major advances have been made in understanding activation and desensitization compared to resensitization. However, increasing evidence shows that resensitization is exquisitely regulated process, thereby contributing to the dynamic regulation of GPCR function. In recognition of these observations, in this chapter we discuss the key advances on the mechanistic underpinning that drive and regulate GPCR function with a focus on resensitization.
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Affiliation(s)
- Manveen K Gupta
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, United States
| | - Maradumane L Mohan
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, United States
| | - Sathyamangla V Naga Prasad
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, United States.
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