1
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Che T, Roth BL. Molecular basis of opioid receptor signaling. Cell 2023; 186:5203-5219. [PMID: 37995655 PMCID: PMC10710086 DOI: 10.1016/j.cell.2023.10.029] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Revised: 10/13/2023] [Accepted: 10/27/2023] [Indexed: 11/25/2023]
Abstract
Opioids are used for pain management despite the side effects that contribute to the opioid crisis. The pursuit of non-addictive opioid analgesics remains unattained due to the unresolved intricacies of opioid actions, receptor signaling cascades, and neuronal plasticity. Advancements in structural, molecular, and computational tools illuminate the dynamic interplay between opioids and opioid receptors, as well as the molecular determinants of signaling pathways, which are potentially interlinked with pharmacological responses. Here, we review the molecular basis of opioid receptor signaling with a focus on the structures of opioid receptors bound to endogenous peptides or pharmacological agents. These insights unveil specific interactions that dictate ligand selectivity and likely their distinctive pharmacological profiles. Biochemical analysis further unveils molecular features governing opioid receptor signaling. Simultaneously, the synergy between computational biology and medicinal chemistry continues to expedite the discovery of novel chemotypes with the promise of yielding more efficacious and safer opioid compounds.
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Affiliation(s)
- Tao Che
- Department of Anesthesiology, Washington University School of Medicine, Saint Louis, MO 63110, USA; Center for Clinical Pharmacology, University of Health Sciences & Pharmacy and Washington University School of Medicine, Saint Louis, MO 63110, USA.
| | - Bryan L Roth
- Department of Pharmacology, University of North Carolina Chapel Hill School of Medicine, Chapel Hill 27599, NC, USA.
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2
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Tompkins E, Mimic B, Penn RB, Pera T. The biased M3 mAChR ligand PD 102807 mediates qualitatively distinct signaling to regulate airway smooth muscle phenotype. J Biol Chem 2023; 299:105209. [PMID: 37660916 PMCID: PMC10520882 DOI: 10.1016/j.jbc.2023.105209] [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: 01/12/2023] [Revised: 08/14/2023] [Accepted: 08/22/2023] [Indexed: 09/05/2023] Open
Abstract
Airway smooth muscle (ASM) cells attain a hypercontractile phenotype during obstructive airway diseases. We recently identified a biased M3 muscarinic acetylcholine receptor (mAChR) ligand, PD 102807, that induces GRK-/arrestin-dependent AMP-activated protein kinase (AMPK) activation to inhibit transforming growth factor-β-induced hypercontractile ASM phenotype. Conversely, the balanced mAChR agonist, methacholine (MCh), activates AMPK yet does not regulate ASM phenotype. In the current study, we demonstrate that PD 102807- and MCh-induced AMPK activation both depend on Ca2+/calmodulin-dependent kinase kinases (CaMKKs). However, MCh-induced AMPK activation is calcium-dependent and mediated by CaMKK1 and CaMKK2 isoforms. In contrast, PD 102807-induced signaling is calcium-independent and mediated by the atypical subtype protein kinase C-iota and the CaMKK1 (but not CaMKK2) isoform. Both MCh- and PD 102807-induced AMPK activation involve the AMPK α1 isoform. PD 102807-induced AMPK α1 (but not AMPK α2) isoform activation mediates inhibition of the mammalian target of rapamycin complex 1 (mTORC1) in ASM cells, as demonstrated by increased Raptor (regulatory-associated protein of mTOR) phosphorylation as well as inhibition of phospho-S6 protein and serum response element-luciferase activity. The mTORC1 inhibitor rapamycin and the AMPK activator metformin both mimic the ability of PD 102807 to attenuate transforming growth factor-β-induced α-smooth muscle actin expression (a marker of hypercontractile ASM). These data indicate that PD 102807 transduces a signaling pathway (AMPK-mediated mTORC1 inhibition) qualitatively distinct from canonical M3 mAChR signaling to prevent pathogenic remodeling of ASM, thus demonstrating PD 102807 is a biased M3 mAChR ligand with therapeutic potential for the management of obstructive airway disease.
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Affiliation(s)
- Eric Tompkins
- Department of Medicine, Center for Translational Medicine, Jane and Leonard Korman Respiratory Institute, Philadelphia, Pennsylvania, USA
| | - Bogdana Mimic
- Department of Medicine, Center for Translational Medicine, Jane and Leonard Korman Respiratory Institute, Philadelphia, Pennsylvania, USA
| | - Raymond B Penn
- Department of Medicine, Center for Translational Medicine, Jane and Leonard Korman Respiratory Institute, Philadelphia, Pennsylvania, USA
| | - Tonio Pera
- Department of Medicine, Center for Translational Medicine, Jane and Leonard Korman Respiratory Institute, Philadelphia, Pennsylvania, USA.
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3
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Gao ZG, Levitan IM, Inoue A, Wei Q, Jacobson KA. A 2B adenosine receptor activation and modulation by protein kinase C. iScience 2023; 26:107178. [PMID: 37404375 PMCID: PMC10316653 DOI: 10.1016/j.isci.2023.107178] [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: 02/23/2023] [Revised: 05/25/2023] [Accepted: 06/15/2023] [Indexed: 07/06/2023] Open
Abstract
Protein kinase C (PKC) isoforms regulate many important signaling pathways. Here, we report that PKC activation by phorbol 12-myristate 13-acetate (PMA) enhanced A2B adenosine receptor (AR)-mediated, but not β2-adrenergic receptor-mediated, cAMP accumulation, in H9C2 cardiomyocyte-like and HEK293 cells. In addition to enhancement, PKC (PMA-treatment) also activated A2BAR with low Emax (H9C2 and NIH3T3 cells endogenously expressing A2BAR), or with high Emax (A2BAR-overexpressing HEK293 cells) to induce cAMP accumulation. A2BAR activation induced by PKC was inhibited by A2BAR and PKC inhibitors but enhanced by A2BAR overexpression. Gαi isoforms and PKCγ isoform were found to be involved in both enhancement of A2BAR function and A2BAR activation. Thus, we establish PKC as an endogenous modulator and activator of A2BAR, involving Giα and PKCγ. Depending on signaling pathway, PKC could activate and enhance, or alternatively inhibit A2BAR activity. These findings are relevant to common functions of A2BAR and PKC, e.g. cardioprotection and cancer progression/treatment.
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Affiliation(s)
- Zhan-Guo Gao
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, NIDDK, National Institutes of Health, 9000 Rockville Pike, Bethesda, MD 20892, USA
| | - Ian M. Levitan
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, NIDDK, National Institutes of Health, 9000 Rockville Pike, Bethesda, MD 20892, USA
| | - Asuka Inoue
- Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Miyagi 980-8578, Japan
| | - Qiang Wei
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, NIDDK, National Institutes of Health, 9000 Rockville Pike, Bethesda, MD 20892, USA
| | - Kenneth A. Jacobson
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, NIDDK, National Institutes of Health, 9000 Rockville Pike, Bethesda, MD 20892, USA
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4
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Continuous exposure to isoprenaline reduced myotube size by delaying myoblast differentiation and fusion through the NFAT-MEF2C signaling pathway. Sci Rep 2023; 13:436. [PMID: 36624121 PMCID: PMC9829891 DOI: 10.1038/s41598-022-22330-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2022] [Accepted: 10/13/2022] [Indexed: 01/11/2023] Open
Abstract
We aimed to explore whether superfluous sympathetic activity affects myoblast differentiation, fusion, and myofiber types using a continuous single-dose isoprenaline exposure model in vitro and to further confirm the role of distinct NFATs in ISO-mediated effects. Compared with delivery of single and interval single, continuous single-dose ISO most obviously diminished myotube size while postponing myoblast differentiation/fusion in a time- and dose-dependent pattern, accompanied by an apparent decrease in nuclear NFATc1/c2 levels and a slight increase in nuclear NFATc3/c4 levels. Overexpression of NFATc1 or NFATc2, particularly NFATc1, markedly abolished the inhibitory effects of ISO on myoblast differentiation/fusion, myotube size and Myh7 expression, which was attributed to a remarkable increase in the nuclear NFATc1/c2 levels and a reduction in the nuclear NFATc4 levels and the associated increase in the numbers of MyoG and MEF2C positive nuclei within more than 3 nuclei myotubes, especially in MEF2C. Moreover, knockdown of NFATc3 by shRNA did not alter the inhibitory effect of ISO on myoblast differentiation/fusion or myotube size but partially recovered the expression of Myh7, which was related to the slightly increased nuclear levels of NFATc1/c2, MyoG and MEF2C. Knockdown of NFATc4 by shRNA prominently increased the number of MyHC +, MyoG or MEF2C + myoblast cells with 1 ~ 2 nuclei, causing fewer numbers and smaller myotube sizes. However, NFATc4 knockdown further deteriorated the effects of ISO on myoblast fusion and myotube size, with more than 5 nuclei and Myh1/2/4 expression, which was associated with a decrease in nuclear NFATc2/c3 levels. Therefore, ISO inhibited myoblast differentiation/fusion and myotube size through the NFAT-MyoG-MEF2C signaling pathway.
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5
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Ives A, Dunn HA, Afsari HS, Seckler HDS, Foroutan MJ, Chavez E, Melani RD, Fellers RT, LeDuc RD, Thomas PM, Martemyanov KA, Kelleher NL, Vafabakhsh R. Middle-Down Mass Spectrometry Reveals Activity-Modifying Phosphorylation Barcode in a Class C G Protein-Coupled Receptor. J Am Chem Soc 2022; 144:23104-23114. [PMID: 36475650 PMCID: PMC9785046 DOI: 10.1021/jacs.2c10697] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
G protein-coupled receptors (GPCRs) are the largest family of membrane receptors in humans. They mediate nearly all aspects of human physiology and thus are of high therapeutic interest. GPCR signaling is regulated in space and time by receptor phosphorylation. It is believed that different phosphorylation states are possible for a single receptor, and each encodes for unique signaling outcomes. Methods to determine the phosphorylation status of GPCRs are critical for understanding receptor physiology and signaling properties of GPCR ligands and therapeutics. However, common proteomic techniques have provided limited quantitative information regarding total receptor phosphorylation stoichiometry, relative abundances of isomeric modification states, and temporal dynamics of these parameters. Here, we report a novel middle-down proteomic strategy and parallel reaction monitoring (PRM) to quantify the phosphorylation states of the C-terminal tail of metabotropic glutamate receptor 2 (mGluR2). By this approach, we found that mGluR2 is subject to both basal and agonist-induced phosphorylation at up to four simultaneous sites with varying probability. Using a PRM tandem mass spectrometry methodology, we localized the positions and quantified the relative abundance of phosphorylations following treatment with an agonist. Our analysis showed that phosphorylation within specific regions of the C-terminal tail of mGluR2 is sensitive to receptor activation, and subsequent site-directed mutagenesis of these sites identified key regions which tune receptor sensitivity. This study demonstrates that middle-down purification followed by label-free quantification is a powerful, quantitative, and accessible tool for characterizing phosphorylation states of GPCRs and other challenging proteins.
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Affiliation(s)
- Ashley
N. Ives
- Department
of Chemistry, Northwestern University, Evanston, Illinois 60208 United States
| | - Henry A. Dunn
- Department
of Neuroscience, The Scripps Research Institute, Jupiter, Florida 33458, United States,Department
of Pharmacology and Therapeutics, University
of Manitoba, Winnipeg, Manitoba R3E 0T6, Canada,Division
of Neurodegenerative Disorders, St. Boniface Hospital Albrechtsen
Research Centre, Winnipeg, Manitoba R2H 2A6, Canada
| | - Hamid Samareh Afsari
- Department
of Molecular Biosciences, Northwestern University, Evanston, Illinois 60208, United States
| | | | - Max J. Foroutan
- Department
of Molecular Biosciences, Northwestern University, Evanston, Illinois 60208, United States
| | - Erica Chavez
- Department
of Molecular Biosciences, Northwestern University, Evanston, Illinois 60208, United States
| | - Rafael D. Melani
- Department
of Molecular Biosciences, Northwestern University, Evanston, Illinois 60208, United States,National
Resource for Translational and Developmental Proteomics, Northwestern University, Evanston, Illinois 60208, United States
| | - Ryan T. Fellers
- National
Resource for Translational and Developmental Proteomics, Northwestern University, Evanston, Illinois 60208, United States
| | - Richard D. LeDuc
- National
Resource for Translational and Developmental Proteomics, Northwestern University, Evanston, Illinois 60208, United States
| | - Paul M. Thomas
- Department
of Molecular Biosciences, Northwestern University, Evanston, Illinois 60208, United States,National
Resource for Translational and Developmental Proteomics, Northwestern University, Evanston, Illinois 60208, United States
| | - Kirill A. Martemyanov
- Department
of Neuroscience, The Scripps Research Institute, Jupiter, Florida 33458, United States
| | - Neil L. Kelleher
- Department
of Chemistry, Northwestern University, Evanston, Illinois 60208 United States,Department
of Molecular Biosciences, Northwestern University, Evanston, Illinois 60208, United States,National
Resource for Translational and Developmental Proteomics, Northwestern University, Evanston, Illinois 60208, United States
| | - Reza Vafabakhsh
- Department
of Molecular Biosciences, Northwestern University, Evanston, Illinois 60208, United States,
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6
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Benkel T, Zimmermann M, Zeiner J, Bravo S, Merten N, Lim VJY, Matthees ESF, Drube J, Miess-Tanneberg E, Malan D, Szpakowska M, Monteleone S, Grimes J, Koszegi Z, Lanoiselée Y, O'Brien S, Pavlaki N, Dobberstein N, Inoue A, Nikolaev V, Calebiro D, Chevigné A, Sasse P, Schulz S, Hoffmann C, Kolb P, Waldhoer M, Simon K, Gomeza J, Kostenis E. How Carvedilol activates β 2-adrenoceptors. Nat Commun 2022; 13:7109. [PMID: 36402762 PMCID: PMC9675828 DOI: 10.1038/s41467-022-34765-w] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2022] [Accepted: 11/05/2022] [Indexed: 11/21/2022] Open
Abstract
Carvedilol is among the most effective β-blockers for improving survival after myocardial infarction. Yet the mechanisms by which carvedilol achieves this superior clinical profile are still unclear. Beyond blockade of β1-adrenoceptors, arrestin-biased signalling via β2-adrenoceptors is a molecular mechanism proposed to explain the survival benefits. Here, we offer an alternative mechanism to rationalize carvedilol's cellular signalling. Using primary and immortalized cells genome-edited by CRISPR/Cas9 to lack either G proteins or arrestins; and combining biological, biochemical, and signalling assays with molecular dynamics simulations, we demonstrate that G proteins drive all detectable carvedilol signalling through β2ARs. Because a clear understanding of how drugs act is imperative to data interpretation in basic and clinical research, to the stratification of clinical trials or to the monitoring of drug effects on the target pathway, the mechanistic insight gained here provides a foundation for the rational development of signalling prototypes that target the β-adrenoceptor system.
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Affiliation(s)
- Tobias Benkel
- Molecular, Cellular and Pharmacobiology Section, Institute of Pharmaceutical Biology, University of Bonn, 53115, Bonn, Germany
- Research Training Group 1873, University of Bonn, 53127, Bonn, Germany
| | | | - Julian Zeiner
- Molecular, Cellular and Pharmacobiology Section, Institute of Pharmaceutical Biology, University of Bonn, 53115, Bonn, Germany
| | - Sergi Bravo
- Molecular, Cellular and Pharmacobiology Section, Institute of Pharmaceutical Biology, University of Bonn, 53115, Bonn, Germany
| | - Nicole Merten
- Molecular, Cellular and Pharmacobiology Section, Institute of Pharmaceutical Biology, University of Bonn, 53115, Bonn, Germany
| | - Victor Jun Yu Lim
- Department of Pharmaceutical Chemistry, Philipps-University of Marburg, 35032, Marburg, Germany
| | - Edda Sofie Fabienne Matthees
- Institute for Molecular Cell Biology, CMB-Center for Molecular Biomedicine, Jena University Hospital, Friedrich Schiller University of Jena, 07745, Jena, Germany
| | - Julia Drube
- Institute for Molecular Cell Biology, CMB-Center for Molecular Biomedicine, Jena University Hospital, Friedrich Schiller University of Jena, 07745, Jena, Germany
| | - Elke Miess-Tanneberg
- Institute of Pharmacology and Toxicology, Jena University Hospital, Friedrich Schiller University of Jena, 07747, Jena, Germany
| | - Daniela Malan
- Institute of Physiology I, Medical Faculty, University of Bonn, 53115, Bonn, Germany
| | - Martyna Szpakowska
- Department of Infection and Immunity, Luxembourg Institute of Health (LIH), L-4354, Esch-sur-Alzette, Luxembourg
| | - Stefania Monteleone
- Department of Pharmaceutical Chemistry, Philipps-University of Marburg, 35032, Marburg, Germany
| | - Jak Grimes
- Institute of Metabolism and Systems Research and Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham, Birmingham, B15 2TT, UK
| | - Zsombor Koszegi
- Institute of Metabolism and Systems Research and Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham, Birmingham, B15 2TT, UK
| | - Yann Lanoiselée
- Institute of Metabolism and Systems Research and Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham, Birmingham, B15 2TT, UK
| | - Shannon O'Brien
- Institute of Metabolism and Systems Research and Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham, Birmingham, B15 2TT, UK
| | - Nikoleta Pavlaki
- Institute of Experimental Cardiovascular Research, University Medical Center Hamburg-Eppendorf, 20246, Hamburg, Germany
| | | | - Asuka Inoue
- Graduate School of Pharmaceutical Science, Tohoku University, Sendai, 980-8578, Japan
| | - Viacheslav Nikolaev
- Institute of Experimental Cardiovascular Research, University Medical Center Hamburg-Eppendorf, 20246, Hamburg, Germany
| | - Davide Calebiro
- Institute of Metabolism and Systems Research and Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham, Birmingham, B15 2TT, UK
| | - Andy Chevigné
- Department of Infection and Immunity, Luxembourg Institute of Health (LIH), L-4354, Esch-sur-Alzette, Luxembourg
| | - Philipp Sasse
- Institute of Physiology I, Medical Faculty, University of Bonn, 53115, Bonn, Germany
| | - Stefan Schulz
- Institute of Pharmacology and Toxicology, Jena University Hospital, Friedrich Schiller University of Jena, 07747, Jena, Germany
- 7TM Antibodies GmbH, 07745, Jena, Germany
| | - Carsten Hoffmann
- Institute for Molecular Cell Biology, CMB-Center for Molecular Biomedicine, Jena University Hospital, Friedrich Schiller University of Jena, 07745, Jena, Germany
| | - Peter Kolb
- Department of Pharmaceutical Chemistry, Philipps-University of Marburg, 35032, Marburg, Germany
| | - Maria Waldhoer
- InterAx Biotech AG, 5234, Villigen, Switzerland
- Ikherma Consulting Ltd, Hitchin, SG4 0TY, UK
| | - Katharina Simon
- Molecular, Cellular and Pharmacobiology Section, Institute of Pharmaceutical Biology, University of Bonn, 53115, Bonn, Germany
| | - Jesus Gomeza
- Molecular, Cellular and Pharmacobiology Section, Institute of Pharmaceutical Biology, University of Bonn, 53115, Bonn, Germany
| | - Evi Kostenis
- Molecular, Cellular and Pharmacobiology Section, Institute of Pharmaceutical Biology, University of Bonn, 53115, Bonn, Germany.
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7
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Li Y, Heng J, Sun D, Zhang B, Zhang X, Zheng Y, Shi WW, Wang TY, Li JY, Sun X, Liu X, Zheng JS, Kobilka BK, Liu L. Chemical Synthesis of a Full-Length G-Protein-Coupled Receptor β 2-Adrenergic Receptor with Defined Modification Patterns at the C-Terminus. J Am Chem Soc 2021; 143:17566-17576. [PMID: 34663067 DOI: 10.1021/jacs.1c07369] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The β2-adrenergic receptor (β2AR) is a G-protein-coupled receptor (GPCR) that responds to the hormone adrenaline and is an important drug target in the context of respiratory diseases, including asthma. β2AR function can be regulated by post-translational modifications such as phosphorylation and ubiquitination at the C-terminus, but access to the full-length β2AR with well-defined and homogeneous modification patterns critical for biochemical and biophysical studies remains challenging. Here, we report a practical synthesis of differentially modified, full-length β2AR based on a combined native chemical ligation (NCL) and sortase ligation strategy. An array of homogeneous samples of full-length β2ARs with distinct modification patterns, including a full-length β2AR bearing both monoubiquitination and octaphosphorylation modifications, were successfully prepared for the first time. Using these homogeneously modified full-length β2AR receptors, we found that different phosphorylation patterns mediate different interactions with β-arrestin1 as reflected in different agonist binding affinities. Our experiments also indicated that ubiquitination can further modulate interactions between β2AR and β-arrestin1. Access to full-length β2AR with well-defined and homogeneous modification patterns at the C-terminus opens a door to further in-depth mechanistic studies into the structure and dynamics of β2AR complexes with downstream transducer proteins, including G proteins, arrestins, and GPCR kinases.
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Affiliation(s)
- Yulei Li
- Tsinghua-Peking Center for Life Sciences, Ministry of Education Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology, Center for Synthetic and Systems Biology, Department of Chemistry, Tsinghua University, Beijing 100084, China
| | - Jie Heng
- Beijing Advanced Innovation Center for Structural Biology, Beijing Frontier Research Center for Biological Structure, Tsinghua-Peking Joint Center for Life Sciences, School of Medicine, Tsinghua University, Beijing 100084, China
| | - Demeng Sun
- The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230001, China
| | - Baochang Zhang
- Tsinghua-Peking Center for Life Sciences, Ministry of Education Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology, Center for Synthetic and Systems Biology, Department of Chemistry, Tsinghua University, Beijing 100084, China
| | - Xin Zhang
- Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Pharmaceutical Sciences, Tsinghua University, Beijing 100084, China
| | - Yupeng Zheng
- Tsinghua-Peking Center for Life Sciences, Ministry of Education Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology, Center for Synthetic and Systems Biology, Department of Chemistry, Tsinghua University, Beijing 100084, China
| | - Wei-Wei Shi
- Tsinghua-Peking Center for Life Sciences, Ministry of Education Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology, Center for Synthetic and Systems Biology, Department of Chemistry, Tsinghua University, Beijing 100084, China
| | - Tong-Yue Wang
- Tsinghua-Peking Center for Life Sciences, Ministry of Education Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology, Center for Synthetic and Systems Biology, Department of Chemistry, Tsinghua University, Beijing 100084, China
| | - Jiu-Yi Li
- The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230001, China
| | - Xiaoou Sun
- Beijing Advanced Innovation Center for Structural Biology, Beijing Frontier Research Center for Biological Structure, Tsinghua-Peking Joint Center for Life Sciences, School of Medicine, Tsinghua University, Beijing 100084, China
| | - Xiangyu Liu
- Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Pharmaceutical Sciences, Tsinghua University, Beijing 100084, China
| | - Ji-Shen Zheng
- The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230001, China
| | - Brian K Kobilka
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, California 94305, United States
| | - Lei Liu
- Tsinghua-Peking Center for Life Sciences, Ministry of Education Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology, Center for Synthetic and Systems Biology, Department of Chemistry, Tsinghua University, Beijing 100084, China
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8
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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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9
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Calebiro D, Koszegi Z, Lanoiselée Y, Miljus T, O'Brien S. G protein-coupled receptor-G protein interactions: a single-molecule perspective. Physiol Rev 2020; 101:857-906. [PMID: 33331229 DOI: 10.1152/physrev.00021.2020] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
G protein-coupled receptors (GPCRs) regulate many cellular and physiological processes, responding to a diverse range of extracellular stimuli including hormones, neurotransmitters, odorants, and light. Decades of biochemical and pharmacological studies have provided fundamental insights into the mechanisms of GPCR signaling. Thanks to recent advances in structural biology, we now possess an atomistic understanding of receptor activation and G protein coupling. However, how GPCRs and G proteins interact in living cells to confer signaling efficiency and specificity remains insufficiently understood. The development of advanced optical methods, including single-molecule microscopy, has provided the means to study receptors and G proteins in living cells with unprecedented spatio-temporal resolution. The results of these studies reveal an unexpected level of complexity, whereby GPCRs undergo transient interactions among themselves as well as with G proteins and structural elements of the plasma membrane to form short-lived signaling nanodomains that likely confer both rapidity and specificity to GPCR signaling. These findings may provide new strategies to pharmaceutically modulate GPCR function, which might eventually pave the way to innovative drugs for common diseases such as diabetes or heart failure.
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Affiliation(s)
- Davide Calebiro
- Institute of Metabolism and Systems Research, University of Birmingham, Birmingham, United Kingdom; Centre of Membrane Proteins and Receptors (COMPARE), Universities of Nottingham and Birmingham, Birmingham, United Kingdom
| | - Zsombor Koszegi
- Institute of Metabolism and Systems Research, University of Birmingham, Birmingham, United Kingdom; Centre of Membrane Proteins and Receptors (COMPARE), Universities of Nottingham and Birmingham, Birmingham, United Kingdom
| | - Yann Lanoiselée
- Institute of Metabolism and Systems Research, University of Birmingham, Birmingham, United Kingdom; Centre of Membrane Proteins and Receptors (COMPARE), Universities of Nottingham and Birmingham, Birmingham, United Kingdom
| | - Tamara Miljus
- Institute of Metabolism and Systems Research, University of Birmingham, Birmingham, United Kingdom; Centre of Membrane Proteins and Receptors (COMPARE), Universities of Nottingham and Birmingham, Birmingham, United Kingdom
| | - Shannon O'Brien
- Institute of Metabolism and Systems Research, University of Birmingham, Birmingham, United Kingdom; Centre of Membrane Proteins and Receptors (COMPARE), Universities of Nottingham and Birmingham, Birmingham, United Kingdom
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10
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Levy-Pereira N, Yasui GS, Evangelista MM, Nascimento NF, Santos MP, Siqueira-Silva DH, Monzani PS, Senhorini JA, Pilarski F. In vivo phagocytosis and hematology in Astyanax altiparanae, a potential model for surrogate technology. BRAZ J BIOL 2020; 80:336-344. [DOI: 10.1590/1519-6984.205893] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Accepted: 10/31/2018] [Indexed: 01/02/2023] Open
Abstract
Abstract Although the potential of surrogate propagation technology for aquaculture and conservation of Neotropical fish, the poor understanding of the host immune system may results in rejection and destruction of the donor material. Thus, it is necessary to study and to develop methods to evaluate the effects of immunosuppressive drugs employment and to evaluate the immunocompatibility between donor and receptor. Thus, the present study aimed to optimize a methodology to assess in vivo phagocytosis in Astyanax altiparanae using Saccharomyces cerevisiae and to evaluate their hematological response resultant from the inflammatory induction. To this, S. cerevisiae were labeled with Congo red and injected in the coelomic cavity of A. altiparanae at the concentration of 2.5 x 106 cells mL-1. A PBS solution and a non-injected group were kept as control. Fish blood was sampled and the phagocytic capacity and index were determined at 1, 2, 3 and 6 h post-injection (hpi). The yeast injection successfully stimulated phagocytosis, with the best result for phagocytosis assessment after 2 hpi. Moreover, it was achieved a high traceability of phagocytized and non-phagocytized yeast under optic microscopy analysis due to the Congo red labeling. The hematological profile was similar to usually observed in early infections, indicating lymphocyte migration to inflammatory site and increase in number of circulating phagocytes due to natural response to inflammatory stimulus. In conclusion, our method was efficient to assess in vivo phagocytosis in A. altiparanae and will be an important tool to evaluate the efficacy of immunosuppressive drugs in this species. Additionally, these results may serve as support for further studies in fish immunocompetence, both in laboratory and in field conditions.
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Affiliation(s)
- N. Levy-Pereira
- Universidade Estadual Paulista, Brasil; Instituto Chico Mendes de Conservação da Biodiversidade, Brasil
| | - G. S. Yasui
- Instituto Chico Mendes de Conservação da Biodiversidade, Brasil; Universidade Estadual Paulista, Brasil
| | - M. M. Evangelista
- Universidade Estadual Paulista, Brasil; Instituto Chico Mendes de Conservação da Biodiversidade, Brasil
| | | | | | - D. H. Siqueira-Silva
- Universidade de São Paulo, Brasil; Universidade Federal do Sul e Sudeste do Pará, Brasil
| | - P. S. Monzani
- Instituto Chico Mendes de Conservação da Biodiversidade, Brasil; Universidade de São Paulo, Brasil
| | - J. A. Senhorini
- Instituto Chico Mendes de Conservação da Biodiversidade, Brasil; Universidade Estadual Paulista, Brasil
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11
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Biased GPCR signaling: Possible mechanisms and inherent limitations. Pharmacol Ther 2020; 211:107540. [PMID: 32201315 DOI: 10.1016/j.pharmthera.2020.107540] [Citation(s) in RCA: 56] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Accepted: 03/17/2020] [Indexed: 02/06/2023]
Abstract
G protein-coupled receptors (GPCRs) are targeted by about a third of clinically used drugs. Many GPCRs couple to more than one type of heterotrimeric G proteins, become phosphorylated by any of several different GRKs, and then bind one or more types of arrestin. Thus, classical therapeutically active drugs simultaneously initiate several branches of signaling, some of which are beneficial, whereas others result in unwanted on-target side effects. The development of novel compounds to selectively channel the signaling into the desired direction has the potential to become a breakthrough in health care. However, there are natural and technological hurdles that must be overcome. The fact that most GPCRs are subject to homologous desensitization, where the active receptor couples to G proteins, is phosphorylated by GRKs, and then binds arrestins, suggest that in most cases the GPCR conformations that facilitate their interactions with these three classes of binding partners significantly overlap. Thus, while partner-specific conformations might exist, they are likely low-probability states. GPCRs are inherently flexible, which suggests that complete bias is highly unlikely to be feasible: in the conformational ensemble induced by any ligand, there would be some conformations facilitating receptor coupling to unwanted partners. Things are further complicated by the fact that virtually every cell expresses numerous G proteins, several GRK subtypes, and two non-visual arrestins with distinct signaling capabilities. Finally, novel screening methods for measuring ligand bias must be devised, as the existing methods are not specific for one particular branch of signaling.
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12
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He X, Yan L, Wu Q, Zhang G, Zhou N. Ligand-dependent internalization of Bombyx mori tachykinin-related peptide receptor is regulated by PKC, GRK5 and β-arrestin2/BmKurtz. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2020; 1867:118690. [PMID: 32112783 DOI: 10.1016/j.bbamcr.2020.118690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Revised: 02/18/2020] [Accepted: 02/23/2020] [Indexed: 10/24/2022]
Abstract
Tachykinin signaling system is present in both vertebrates and invertebrates, and functions as neuromodulator responsible for the regulation of various physiological processes. In human, the internalization of G protein-coupled receptors has been extensively characterized; however, the insect GPCR internalization has been rarely investigated. Here, we constructed two expression vectors of Bombyx tachykinin-related peptide receptor (BmTKRPR) fused with Enhanced Green Fluorescent Protein (EGFP) at the C-terminal end for direct visualization of receptor expression, localization, and trafficking in cultured mammalian HEK293 and insect Sf21 cells. Our results demonstrated that agonist-activated BmTKRPR underwent rapid internalization in a dose-and time-dependent manner via a clathrin-dependent pathway in both HEK293 and Sf21 cells. Further investigation via RNAi or specific inhibitors, or co-immunoprecipitation demonstrated that agonist-induced BmTKRPR internalization was mediated by PKC, GRK5 and β-arrestin2/BmKurtz. In addition, we also observed that most of the internalized BmTKRP receptors were recycled to the cell surface via early endosomes upon peptide ligand removal. Our study provides the first in-depth information on mechanisms underlying insect TKRP receptor internalization and perhaps aids in the interpretation of the signaling in the regulation of physiological processes.
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Affiliation(s)
- Xiaobai He
- Institute of Biochemistry, College of Life Sciences, Zijingang Campus, Zhejiang University, Hangzhou, Zhejiang 310058, China; College of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, Jiangsu 212018, China.
| | - Lili Yan
- Institute of Biochemistry, College of Life Sciences, Zijingang Campus, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Qi Wu
- College of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, Jiangsu 212018, China
| | - Guozheng Zhang
- Key Laboratory of Genetic Improvement of Sericulture, Ministry of Agriculture and Rural Affairs, Jiangsu University of Science and Technology, Zhenjiang, Jiangsu 212018, China
| | - Naiming Zhou
- Institute of Biochemistry, College of Life Sciences, Zijingang Campus, Zhejiang University, Hangzhou, Zhejiang 310058, China.
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13
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Plouffe B, Thomsen ARB, Irannejad R. Emerging Role of Compartmentalized G Protein-Coupled Receptor Signaling in the Cardiovascular Field. ACS Pharmacol Transl Sci 2020; 3:221-236. [PMID: 32296764 PMCID: PMC7155194 DOI: 10.1021/acsptsci.0c00006] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2020] [Indexed: 02/06/2023]
Abstract
G protein-coupled receptors (GPCRs) are cell surface receptors that for many years have been considered to function exclusively at the plasma membrane, where they bind to extracellular ligands and activate G protein signaling cascades. According to the conventional model, these signaling events are rapidly terminated by β-arrestin (β-arr) recruitment to the activated GPCR resulting in signal desensitization and receptor internalization. However, during the past decade, emerging evidence suggest that many GPCRs can continue to activate G proteins from intracellular compartments after they have been internalized. G protein signaling from intracellular compartments is in general more sustained compared to G protein signaling at the plasma membrane. Notably, the particular location closer to the nucleus is beneficial for selective cellular functions such as regulation of gene transcription. Here, we review key GPCRs that undergo compartmentalized G protein signaling and discuss molecular considerations and requirements for this signaling to occur. Our main focus will be on receptors involved in the regulation of important physiological and pathological cardiovascular functions. We also discuss how sustained G protein activation from intracellular compartments may be involved in cellular functions that are distinct from functions regulated by plasma membrane G protein signaling, and the corresponding significance in cardiovascular physiology.
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Affiliation(s)
- Bianca Plouffe
- Wellcome-Wolfson Institute for Experimental Medicine, Queen's University Belfast, Belfast BT9 7BL, United Kingdom
| | - Alex R B Thomsen
- Department of Basic Science and Craniofacial Biology, NYU College of Dentistry, New York, New York 10010, United States
| | - Roshanak Irannejad
- Department of Biochemistry and Biophysics, Cardiovascular Research Institute, University of California, San Francisco, California 94158, United States
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14
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Keretsu S, Bhujbal SP, Joo Cho S. Computational study of paroxetine-like inhibitors reveals new molecular insight to inhibit GRK2 with selectivity over ROCK1. Sci Rep 2019; 9:13053. [PMID: 31506468 PMCID: PMC6736929 DOI: 10.1038/s41598-019-48949-w] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Accepted: 07/19/2019] [Indexed: 01/08/2023] Open
Abstract
The G-protein coupled receptor kinase 2 (GRK2) regulates the desensitization of beta-adrenergic receptors (β-AR), and its overexpression has been implicated in heart failure. Hence, the inhibition of GRK2 is considered to be an important drug target for the treatment of heart failure. Due to the high sequence similarity of GRK2 with the A, G, and C family (AGC family) of kinases, the inhibition of GRK2 also leads to the inhibition of AGC kinases such as Rho-associated coiled-coil kinase 1 (ROCK1). Therefore, unraveling the mechanisms to selectively inhibit GRK2 poses an important challenge. We have performed molecular docking, three dimensional quantitative structure activity relationship (3D-QSAR), molecular dynamics (MD) simulation, and free energy calculations techniques on a series of 53 paroxetine-like compounds to understand the structural properties desirable for enhancing the inhibitory activity for GRK2 with selectivity over ROCK1. The formation of stable hydrogen bond interactions with the residues Phe202 and Lys220 of GRK2 seems to be important for selective inhibition of GRK2. Electropositive substituents at the piperidine ring and electronegative substituents near the amide linker between the benzene ring and pyrazole ring showed a higher inhibitory preference for GRK2 over ROCK1. This study may be used in designing more potent and selective GRK2 inhibitors for therapeutic intervention of heart failure.
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Affiliation(s)
- Seketoulie Keretsu
- Department of Biomedical Sciences, College of Medicine, Chosun University, Gwangju, 501-759, Republic of Korea
| | - Swapnil P Bhujbal
- Department of Biomedical Sciences, College of Medicine, Chosun University, Gwangju, 501-759, Republic of Korea
| | - Seung Joo Cho
- Department of Biomedical Sciences, College of Medicine, Chosun University, Gwangju, 501-759, Republic of Korea. .,Department of Cellular Molecular Medicine, College of Medicine, Chosun University, Gwangju, 501-759, Republic of Korea.
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15
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Chen SJ, Yue J, Zhang JX, Jiang M, Hu TQ, Leng WD, Xiang L, Li XY, Zhang L, Zheng F, Yuan Y, Guo LY, Pan YM, Yan YW, Wang JN, Chen SY, Tang JM. Continuous exposure of isoprenaline inhibits myoblast differentiation and fusion through PKA/ERK1/2-FOXO1 signaling pathway. Stem Cell Res Ther 2019; 10:70. [PMID: 30819239 PMCID: PMC6394105 DOI: 10.1186/s13287-019-1160-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2018] [Revised: 01/25/2019] [Accepted: 01/30/2019] [Indexed: 01/08/2023] Open
Abstract
Aim The objective of this study is to determine if exuberant sympathetic nerve activity is involved in muscle satellite cell differentiation and myoblast fusion. Methods and results By using immunoassaying and western blot analyses, we found that β1 and β2-adrenergic receptors (AdR) were expressed in C2C12 cells. The differentiated satellite cells exhibited an increased expression of β2-AdR, as compared with the proliferating cells. Continuous exposure of isoprenaline (ISO), a β-AdR agonist, delayed C2C12 cell differentiation, and myoblast fusion in time- and dose-dependent manner. ISO also increased short myotube numbers while decreasing long myotube numbers, consistent with the greater reduction in MyHC1, MyHC2a, and MyHC2x expression. Moreover, continuous exposure of ISO gradually decreased the ratio of PKA RI/RII, and PKA RI activator efficiently reversed the ISO effect on C2C12 cell differentiation and myoblast fusion while PKA inhibitor H-89 deteriorated the effects. Continuous single-dose ISO increased β1-AdR expression in C2C12 cells. More importantly, the cells showed enhanced phospho-ERK1/2 levels, resulting in increasing phospho-β2-AdR levels while decreasing β2-AdR levels, and the specific effects could be abolished by ERK1/2 inhibitor. Furthermore, continuous exposure of ISO induced FOXO1 nuclear translocation and increased the levels of FOXO1 in nuclear extracts while reducing pAKT, p-p38MAPK, and pFOXO1 levels. Conversely, blockade of ERK1/2 signaling partially abrogated ISO effects on AKT, p38MAPK, and FOXO1signaling, which partially restored C2C12 cell differentiation and myoblast fusion, leading to an increase in the numbers of medium myotube along with the increased expression of MyHC1 and MyHC2a. Conclusion Continuous exposure of ISO impedes satellite cell differentiation and myoblast fusion, at least in part, through PKA-ERK1/2-FOXO1 signaling pathways, which were associated with the reduced β2-AdR and increased β1-AdR levels. Electronic supplementary material The online version of this article (10.1186/s13287-019-1160-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Shao-Juan Chen
- Department of Cardiology, and Institute of Clinical Medicine, Renmin Hospital, Hubei University of Medicine, Shiyan, 442000, Hubei, People's Republic of China.,Department of Stomatology, Taihe Hospital, Hubei University of Medicine, Shiyan, 442000, Hubei, People's Republic of China
| | - Jing Yue
- Department of Cardiology, and Institute of Clinical Medicine, Renmin Hospital, Hubei University of Medicine, Shiyan, 442000, Hubei, People's Republic of China
| | - Jing-Xuan Zhang
- Department of Physiology, School of Basic Medical Sciences, Hubei University of Medicine, Shiyan, 442000, Hubei, People's Republic of China.,Institute of biomedicine and Key Lab of Human Embryonic Stem Cell of Hubei Province, Hubei University of Medicine, Shiyan, 442000, Hubei, People's Republic of China
| | - Miao Jiang
- Department of Cardiology, and Institute of Clinical Medicine, Renmin Hospital, Hubei University of Medicine, Shiyan, 442000, Hubei, People's Republic of China
| | - Tu-Qiang Hu
- Department of Stomatology, Renmin Hospital, Hubei University of Medicine, Shiyan, 442000, Hubei, People's Republic of China
| | - Wei-Dong Leng
- Department of Stomatology, Taihe Hospital, Hubei University of Medicine, Shiyan, 442000, Hubei, People's Republic of China
| | - Li Xiang
- Department of Cardiology, and Institute of Clinical Medicine, Renmin Hospital, Hubei University of Medicine, Shiyan, 442000, Hubei, People's Republic of China.,Department of Physiology, School of Basic Medical Sciences, Hubei University of Medicine, Shiyan, 442000, Hubei, People's Republic of China
| | - Xin-Yuan Li
- Department of Cardiology, and Institute of Clinical Medicine, Renmin Hospital, Hubei University of Medicine, Shiyan, 442000, Hubei, People's Republic of China
| | - Lei Zhang
- Department of Cardiology, and Institute of Clinical Medicine, Renmin Hospital, Hubei University of Medicine, Shiyan, 442000, Hubei, People's Republic of China.,Institute of biomedicine and Key Lab of Human Embryonic Stem Cell of Hubei Province, Hubei University of Medicine, Shiyan, 442000, Hubei, People's Republic of China
| | - Fei Zheng
- Department of Cardiology, and Institute of Clinical Medicine, Renmin Hospital, Hubei University of Medicine, Shiyan, 442000, Hubei, People's Republic of China
| | - Ye Yuan
- Department of Cardiology, and Institute of Clinical Medicine, Renmin Hospital, Hubei University of Medicine, Shiyan, 442000, Hubei, People's Republic of China
| | - Lin-Yun Guo
- Department of Cardiology, and Institute of Clinical Medicine, Renmin Hospital, Hubei University of Medicine, Shiyan, 442000, Hubei, People's Republic of China.,Institute of biomedicine and Key Lab of Human Embryonic Stem Cell of Hubei Province, Hubei University of Medicine, Shiyan, 442000, Hubei, People's Republic of China
| | - Ya-Mu Pan
- Department of Cardiology, and Institute of Clinical Medicine, Renmin Hospital, Hubei University of Medicine, Shiyan, 442000, Hubei, People's Republic of China
| | - Yu-Wen Yan
- Department of Cardiology, and Institute of Clinical Medicine, Renmin Hospital, Hubei University of Medicine, Shiyan, 442000, Hubei, People's Republic of China
| | - Jia-Ning Wang
- Department of Cardiology, and Institute of Clinical Medicine, Renmin Hospital, Hubei University of Medicine, Shiyan, 442000, Hubei, People's Republic of China.,Institute of biomedicine and Key Lab of Human Embryonic Stem Cell of Hubei Province, Hubei University of Medicine, Shiyan, 442000, Hubei, People's Republic of China
| | - Shi-You Chen
- Department of Physiology & Pharmacology, The University of Georgia, Athens, GA30602, USA
| | - Jun-Ming Tang
- Department of Cardiology, and Institute of Clinical Medicine, Renmin Hospital, Hubei University of Medicine, Shiyan, 442000, Hubei, People's Republic of China. .,Department of Physiology, School of Basic Medical Sciences, Hubei University of Medicine, Shiyan, 442000, Hubei, People's Republic of China. .,Institute of biomedicine and Key Lab of Human Embryonic Stem Cell of Hubei Province, Hubei University of Medicine, Shiyan, 442000, Hubei, People's Republic of China.
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16
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Abstract
Protein kinase C (PKC) isozymes belong to a family of Ser/Thr kinases whose activity is governed by reversible release of an autoinhibitory pseudosubstrate. For conventional and novel isozymes, this is effected by binding the lipid second messenger, diacylglycerol, but for atypical PKC isozymes, this is effected by binding protein scaffolds. PKC shot into the limelight following the discovery in the 1980s that the diacylglycerol-sensitive isozymes are "receptors" for the potent tumor-promoting phorbol esters. This set in place a concept that PKC isozymes are oncoproteins. Yet three decades of cancer clinical trials targeting PKC with inhibitors failed and, in some cases, worsened patient outcome. Emerging evidence from cancer-associated mutations and protein expression levels provide a reason: PKC isozymes generally function as tumor suppressors and their activity should be restored, not inhibited, in cancer therapies. And whereas not enough activity is associated with cancer, variants with enhanced activity are associated with degenerative diseases such as Alzheimer's disease. This review describes the tightly controlled mechanisms that ensure PKC activity is perfectly balanced and what happens when these controls are deregulated. PKC isozymes serve as a paradigm for the wisdom of Confucius: "to go beyond is as wrong as to fall short."
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Affiliation(s)
- Alexandra C Newton
- a Department of Pharmacology , University of California at San Diego , La Jolla , CA , USA
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17
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Bellinger DL, Lorton D. Sympathetic Nerve Hyperactivity in the Spleen: Causal for Nonpathogenic-Driven Chronic Immune-Mediated Inflammatory Diseases (IMIDs)? Int J Mol Sci 2018; 19:ijms19041188. [PMID: 29652832 PMCID: PMC5979464 DOI: 10.3390/ijms19041188] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2018] [Revised: 04/05/2018] [Accepted: 04/05/2018] [Indexed: 12/21/2022] Open
Abstract
Immune-Mediated Inflammatory Diseases (IMIDs) is a descriptive term coined for an eclectic group of diseases or conditions that share common inflammatory pathways, and for which there is no definitive etiology. IMIDs affect the elderly most severely, with many older individuals having two or more IMIDs. These diseases include, but are not limited to, type-1 diabetes, obesity, hypertension, chronic pulmonary disease, coronary heart disease, inflammatory bowel disease, and autoimmunity, such as rheumatoid arthritis (RA), Sjőgren's syndrome, systemic lupus erythematosus, psoriasis, psoriatic arthritis, and multiple sclerosis. These diseases are ostensibly unrelated mechanistically, but increase in frequency with age and share chronic systemic inflammation, implicating major roles for the spleen. Chronic systemic and regional inflammation underlies the disease manifestations of IMIDs. Regional inflammation and immune dysfunction promotes targeted end organ tissue damage, whereas systemic inflammation increases morbidity and mortality by affecting multiple organ systems. Chronic inflammation and skewed dysregulated cell-mediated immune responses drive many of these age-related medical disorders. IMIDs are commonly autoimmune-mediated or suspected to be autoimmune diseases. Another shared feature is dysregulation of the autonomic nervous system and hypothalamic pituitary adrenal (HPA) axis. Here, we focus on dysautonomia. In many IMIDs, dysautonomia manifests as an imbalance in activity/reactivity of the sympathetic and parasympathetic divisions of the autonomic nervous system (ANS). These major autonomic pathways are essential for allostasis of the immune system, and regulating inflammatory processes and innate and adaptive immunity. Pathology in ANS is a hallmark and causal feature of all IMIDs. Chronic systemic inflammation comorbid with stress pathway dysregulation implicate neural-immune cross-talk in the etiology and pathophysiology of IMIDs. Using a rodent model of inflammatory arthritis as an IMID model, we report disease-specific maladaptive changes in β₂-adrenergic receptor (AR) signaling from protein kinase A (PKA) to mitogen activated protein kinase (MAPK) pathways in the spleen. Beta₂-AR signal "shutdown" in the spleen and switching from PKA to G-coupled protein receptor kinase (GRK) pathways in lymph node cells drives inflammation and disease advancement. Based on these findings and the existing literature in other IMIDs, we present and discuss relevant literature that support the hypothesis that unresolvable immune stimulation from chronic inflammation leads to a maladaptive disease-inducing and perpetuating sympathetic response in an attempt to maintain allostasis. Since the role of sympathetic dysfunction in IMIDs is best studied in RA and rodent models of RA, this IMID is the primary one used to evaluate data relevant to our hypothesis. Here, we review the relevant literature and discuss sympathetic dysfunction as a significant contributor to the pathophysiology of IMIDs, and then discuss a novel target for treatment. Based on our findings in inflammatory arthritis and our understanding of common inflammatory process that are used by the immune system across all IMIDs, novel strategies to restore SNS homeostasis are expected to provide safe, cost-effective approaches to treat IMIDs, lower comorbidities, and increase longevity.
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Affiliation(s)
- Denise L Bellinger
- Department of Pathology and Human Anatomy, School of Medicine, Loma Linda University, Loma Linda, CA 92350, USA.
| | - Dianne Lorton
- College of Arts and Sciences, Kent State University, Kent, OH 44304, USA.
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18
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Calebiro D, Godbole A. Internalization of G-protein-coupled receptors: Implication in receptor function, physiology and diseases. Best Pract Res Clin Endocrinol Metab 2018; 32:83-91. [PMID: 29678288 DOI: 10.1016/j.beem.2018.01.004] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
G protein-coupled receptors (GPCRs) are the largest family of membrane receptors and mediate the effects of numerous hormones and neurotransmitters. The nearly 1000 GPCRs encoded by the human genome regulate virtually all physiological functions and are implicated in the pathogenesis of prevalent human diseases such as thyroid disorders, hypertension or Parkinson's disease. As a result, 30-50% of all currently prescribed drugs are targeting these receptors. Once activated, GPCRs induce signals at the cell surface. This is often followed by internalization, a process that results in the transfer of receptors from the plasma membrane to membranes of the endosomal compartment. Internalization was initially thought to be mainly implicated in signal desensitization, a mechanism of adaptation to prolonged receptor stimulation. However, several unexpected functions have subsequently emerged. Most notably, accumulating evidence indicates that internalization can induce prolonged receptor signaling on intracellular membranes, which is apparently required for at least some biological effects of hormones like TSH, LH and adrenaline. These findings reveal an even stronger connection between receptor internalization and signaling than previously thought. Whereas new studies are just beginning to reveal an important physiological role for GPCR signaling after internalization and ways to exploit it for therapeutic purposes, future investigations will be required to explore its involvement in human disease.
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Affiliation(s)
- Davide Calebiro
- Institute of Metabolism and Systems Research, University of Birmingham, Birmingham, UK; Centre of Membrane Proteins and Receptors (COMPARE), Universities of Birmingham and Nottingham, UK; Institute of Pharmacology and Toxicology and Bio-Imaging Center, University of Würzburg, Würzburg, Germany.
| | - Amod Godbole
- Institute of Pharmacology and Toxicology and Bio-Imaging Center, University of Würzburg, Würzburg, Germany; Institute for Molecular Cell Biology, CMB-Center for Molecular Biomedicine, University Hospital Jena, Friedrich Schiller University Jena, Jena, Germany
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19
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Protein kinase C as a tumor suppressor. Semin Cancer Biol 2017; 48:18-26. [PMID: 28476658 DOI: 10.1016/j.semcancer.2017.04.017] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2017] [Revised: 03/31/2017] [Accepted: 04/28/2017] [Indexed: 01/01/2023]
Abstract
Protein kinase C (PKC) has historically been considered an oncoprotein. This stems in large part from the discovery in the early 1980s that PKC is directly activated by tumor-promoting phorbol esters. Yet three decades of clinical trials using PKC inhibitors in cancer therapies not only failed, but in some cases worsened patient outcome. Why has targeting PKC in cancer eluded successful therapies? Recent studies looking at the disease for insight provide an explanation: cancer-associated mutations in PKC are generally loss-of-function (LOF), supporting an unexpected function as tumor suppressors. And, contrasting with LOF mutations in cancer, germline mutations that enhance the activity of some PKC isozymes are associated with degenerative diseases such as Alzheimer's disease. This review provides a background on the diverse mechanisms that ensure PKC is only active when, where, and for the appropriate duration needed and summarizes recent findings converging on a paradigm reversal: PKC family members generally function by suppressing, rather than promoting, survival signaling.
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20
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Shi Q, Li M, Mika D, Fu Q, Kim S, Phan J, Shen A, Vandecasteele G, Xiang YK. Heterologous desensitization of cardiac β-adrenergic signal via hormone-induced βAR/arrestin/PDE4 complexes. Cardiovasc Res 2017; 113:656-670. [PMID: 28339772 PMCID: PMC5852637 DOI: 10.1093/cvr/cvx036] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2016] [Revised: 10/20/2017] [Accepted: 02/17/2017] [Indexed: 12/22/2022] Open
Abstract
AIMS Cardiac β-adrenergic receptor (βAR) signalling is susceptible to heterologous desensitization by different neurohormonal stimuli in clinical conditions associated with heart failure. We aim to examine the underlying mechanism of cross talk between βARs and a set of G-protein coupled receptors (GPCRs) activated by hormones/agonists. METHODS AND RESULTS Rat ventricular cardiomyocytes were used to determine heterologous phosphorylation of βARs under a series of GPCR agonists. Activation of Gs-coupled dopamine receptor, adenosine receptor, relaxin receptor and prostaglandin E2 receptor, and Gq-coupled α1 adrenergic receptor and angiotensin II type 1 receptor promotes phosphorylation of β1AR and β2AR at putative protein kinase A (PKA) phosphorylation sites; but activation of Gi-coupled α2 adrenergic receptor and activation of protease-activated receptor does not. The GPCR agonists that promote β2AR phosphorylation effectively inhibit βAR agonist isoproterenol-induced PKA phosphorylation of phospholamban and contractile function in ventricular cardiomyocytes. Heterologous GPCR stimuli have minimal to small effect on isoproterenol-induced β2AR activation and G-protein coupling for cyclic adenosine monophosphate (cAMP) production. However, these GPCR stimuli significantly promote phosphorylation of phosphodiesterase 4D (PDE4D), and recruit PDE4D to the phosphorylated β2AR in a β-arrestin 2 dependent manner without promoting β2AR endocytosis. The increased binding between β2AR and PDE4D effectively hydrolyzes cAMP signal generated by subsequent stimulation with isoproterenol. Mutation of PKA phosphorylation sites in β2AR, inhibition of PDE4, or genetic ablation of PDE4D or β-arrestin 2 abolishes this heterologous inhibitory effect. Ablation of β-arrestin 2 or PDE4D gene also rescues β-adrenergic stimuli-induced myocyte contractile function. CONCLUSIONS These data reveal essential roles of β-arrestin 2 and PDE4D in a common mechanism for heterologous desensitization of cardiac βARs under hormonal stimulation, which is associated with impaired cardiac function during the development of pathophysiological conditions.
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MESH Headings
- Animals
- Cells, Cultured
- Cyclic AMP-Dependent Protein Kinases/metabolism
- Cyclic Nucleotide Phosphodiesterases, Type 4/genetics
- Cyclic Nucleotide Phosphodiesterases, Type 4/metabolism
- Hormones/pharmacology
- Male
- Mice, Knockout
- Myocardial Contraction/drug effects
- Myocytes, Cardiac/drug effects
- Myocytes, Cardiac/metabolism
- Phosphorylation
- Protein Kinase C/metabolism
- Rats
- Receptor Cross-Talk
- Receptors, Adrenergic, beta-1/drug effects
- Receptors, Adrenergic, beta-1/genetics
- Receptors, Adrenergic, beta-1/metabolism
- Receptors, Adrenergic, beta-2/drug effects
- Receptors, Adrenergic, beta-2/genetics
- Receptors, Adrenergic, beta-2/metabolism
- Signal Transduction/drug effects
- Time Factors
- beta-Arrestin 1/genetics
- beta-Arrestin 1/metabolism
- beta-Arrestin 2/genetics
- beta-Arrestin 2/metabolism
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Affiliation(s)
- Qian Shi
- Department of Pharmacology, University of California at Davis, Davis, CA 95616, USA
| | - Minghui Li
- Department of Pharmacology, University of California at Davis, Davis, CA 95616, USA
- Department of Cardiology, Nanjing First Hospital, Nanjing Medical University, Nanjing 210001, China
| | - Delphine Mika
- INSERM UMR-S 1180, Univ. Paris-Sud, Université Paris-Saclay, Châtenay-Malabry, France
| | - Qin Fu
- Department of Pharmacology, Tongji Medical College, Huazhong University of Technology and Sciences, Wuhan 430030, China
| | - Sungjin Kim
- Department of Pharmacology, University of California at Davis, Davis, CA 95616, USA
| | - Jason Phan
- Department of Pharmacology, University of California at Davis, Davis, CA 95616, USA
| | - Ao Shen
- Department of Pharmacology, University of California at Davis, Davis, CA 95616, USA
| | | | - Yang K. Xiang
- Department of Pharmacology, University of California at Davis, Davis, CA 95616, USA
- VA Northern California Health care system, Mather, CA 95655, USA
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21
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Yang Z, Yang F, Zhang D, Liu Z, Lin A, Liu C, Xiao P, Yu X, Sun JP. Phosphorylation of G Protein-Coupled Receptors: From the Barcode Hypothesis to the Flute Model. Mol Pharmacol 2017; 92:201-210. [DOI: 10.1124/mol.116.107839] [Citation(s) in RCA: 75] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2016] [Accepted: 02/23/2017] [Indexed: 12/21/2022] Open
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22
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Rajagopal S, Shenoy SK. GPCR desensitization: Acute and prolonged phases. Cell Signal 2017; 41:9-16. [PMID: 28137506 DOI: 10.1016/j.cellsig.2017.01.024] [Citation(s) in RCA: 195] [Impact Index Per Article: 27.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2017] [Accepted: 01/25/2017] [Indexed: 01/04/2023]
Abstract
G protein-coupled receptors (GPCRs) transduce a wide array of extracellular signals and regulate virtually every aspect of physiology. While GPCR signaling is essential, overstimulation can be deleterious, resulting in cellular toxicity or uncontrolled cellular growth. Accordingly, nature has developed a number of mechanisms for limiting GPCR signaling, which are broadly referred to as desensitization, and refer to a decrease in response to repeated or continuous stimulation. Short-term desensitization occurs over minutes, and is primarily associated with β-arrestins preventing G protein interaction with a GPCR. Longer-term desensitization, referred to as downregulation, occurs over hours to days, and involves receptor internalization into vesicles, degradation in lysosomes and decreased receptor mRNA levels through unclear mechanisms. Phosphorylation of the receptor by GPCR kinases (GRKs) and the recruitment of β-arrestins is critical to both these short- and long-term desensitization mechanisms. In addition to phosphorylation, both the GPCR and β-arrestins are modified post-translationally in several ways, including by ubiquitination. For many GPCRs, receptor ubiquitination promotes degradation of agonist-activated receptors in the lysosomes. Other proteins also play important roles in desensitization, including phosphodiesterases, RGS family proteins and A-kinase-anchoring proteins. Together, this intricate network of kinases, ubiquitin ligases, and adaptor proteins orchestrate the acute and prolonged desensitization of GPCRs.
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Affiliation(s)
| | - Sudha K Shenoy
- Department of Medicine (Cardiology), Durham, NC, USA; Department of Cell Biology, Duke University Medical Center, Durham, NC, USA.
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23
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Venkatasamy R, Spina D. Novel relaxant effects of RPL554 on guinea pig tracheal smooth muscle contractility. Br J Pharmacol 2016; 173:2335-51. [PMID: 27174172 PMCID: PMC4945770 DOI: 10.1111/bph.13512] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Revised: 03/31/2016] [Accepted: 05/02/2016] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND AND PURPOSE We investigated the effectiveness of RPL554, a dual PDE3 and 4 enzyme inhibitor, on airway smooth muscle relaxation and compared it with that induced by salbutamol, ipratropium bromide, glycopyrrolate or their combination on bronchomotor tone induced by different spasmogenic agents. EXPERIMENTAL APPROACH Guinea pig tracheal preparations were suspended under 1 g tension in Krebs-Henseleit solution maintained at 37°C and aerated with 95% O2 /5% CO2 and incubated in the presence of indomethacin (5 μM). Relaxation induced by cumulative concentrations of muscarinic receptor antagonists (ipratropium bromide or glycopyrrolate), β2 -adrenoceptor agonists (salbutamol or formoterol), PDE3 inhibitors (cilostamide, cilostazol or siguazodan) or a PDE4 inhibitor (roflumilast) was evaluated in comparison with RPL554. Maximal relaxation was calculated (% Emax papaverine) and expressed as mean ± SEM. KEY RESULTS Bronchomotor tone induced by the various spasmogens was reduced by the different bronchodilators to varying degrees. RPL554 (10-300 μM) caused near maximum relaxation irrespective of the spasmogen examined, whereas the efficacy of the other relaxant agents varied according to the contractile stimulus used. During the evaluation of potential synergistic interactions between bronchodilators, RPL554 proved superior to salbutamol when either was combined with muscarinic receptor antagonists. CONCLUSIONS AND IMPLICATIONS RPL554 produced near maximal relaxation of highly contracted respiratory smooth muscle and provided additional relaxation compared with that produced by other clinically used bronchodilator drugs. This suggests that RPL554 has the potential to produce additional beneficial bronchodilation over and above that of maximal clinical doses of standard bronchodilators in highly constricted airways of patients.
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Affiliation(s)
- R Venkatasamy
- Sackler Institute of Pulmonary Pharmacology, Institute of Pharmaceutical Science, King's College London, UK
| | - D Spina
- Sackler Institute of Pulmonary Pharmacology, Institute of Pharmaceutical Science, King's College London, UK
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24
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Smith JS, Rajagopal S. The β-Arrestins: Multifunctional Regulators of G Protein-coupled Receptors. J Biol Chem 2016; 291:8969-77. [PMID: 26984408 DOI: 10.1074/jbc.r115.713313] [Citation(s) in RCA: 209] [Impact Index Per Article: 26.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The β-arrestins (βarrs) are versatile, multifunctional adapter proteins that are best known for their ability to desensitize G protein-coupled receptors (GPCRs), but also regulate a diverse array of cellular functions. To signal in such a complex fashion, βarrs adopt multiple conformations and are regulated at multiple levels to differentially activate downstream pathways. Recent structural studies have demonstrated that βarrs have a conserved structure and activation mechanism, with plasticity of their structural fold, allowing them to adopt a wide array of conformations. Novel roles for βarrs continue to be identified, demonstrating the importance of these dynamic regulators of cellular signaling.
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Affiliation(s)
| | - Sudarshan Rajagopal
- From the Departments of Biochemistry and Medicine, Duke University Medical Center, Durham, North Carolina 27710
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25
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Chandran S, Cairns MT, O'Brien M, O'Connell E, Mashayekhi K, Smith TJ. Effects of combined progesterone and 17β-estradiol treatment on the transcriptome of cultured human myometrial smooth muscle cells. Physiol Genomics 2015; 48:50-61. [PMID: 26534934 DOI: 10.1152/physiolgenomics.00021.2015] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Accepted: 10/23/2015] [Indexed: 11/22/2022] Open
Abstract
A transcriptomic analysis of cultured human uterine smooth muscle cells (hUtSMCs) was performed to examine gene expression profiles in smooth muscle in an environment containing the two major steroid hormones that regulate the human myometrium in physiological states associated with estrous, pregnancy, labor, and pathophysiological states such as leiomyoma and endometrial cancer. hUtSMCs were treated with progesterone (P4) and 17β-estradiol (E2) individually and in combination, in the presence and absence of RU486 (mifepristone). Transcription of many genes was modulated in the presence of P4 or E2 alone, but almost six times more genes were transcriptionally modulated in the presence of the P4/E2 hormone combination. In total 796 annotated genes were significantly differentially expressed in the presence of both P4 and E2 relative to their expression in untreated cells. Functional withdrawal of P4 by addition of RU486 effectively reversed almost all transcriptional changes caused by P4/E2 treatment. Gene ontology analysis of differentially expressed genes revealed a strong association between P4/E2 treatment and downregulated expression of genes involved in cell communication, signal transduction, channel activity, inflammatory response, and differentiation. Upregulated processes included cell survival, gene transcription, steroid hormone biosynthesis, muscle development, insulin receptor signaling, and cell growth.
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Affiliation(s)
- Sreenath Chandran
- National Centre for Biomedical Engineering Science, National University of Ireland Galway, Galway, Ireland
| | - Michael T Cairns
- National Centre for Biomedical Engineering Science, National University of Ireland Galway, Galway, Ireland
| | - Margaret O'Brien
- National Centre for Biomedical Engineering Science, National University of Ireland Galway, Galway, Ireland
| | - Enda O'Connell
- National Centre for Biomedical Engineering Science, National University of Ireland Galway, Galway, Ireland
| | - Kaveh Mashayekhi
- National Centre for Biomedical Engineering Science, National University of Ireland Galway, Galway, Ireland
| | - Terry J Smith
- National Centre for Biomedical Engineering Science, National University of Ireland Galway, Galway, Ireland
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26
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Zheng M, Zhang X, Guo S, Zhang X, Choi HJ, Lee MY, Kim KM. PKCβII inhibits the ubiquitination of β-arrestin2 in an autophosphorylation-dependent manner. FEBS Lett 2015; 589:3929-37. [DOI: 10.1016/j.febslet.2015.10.031] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Revised: 09/07/2015] [Accepted: 10/23/2015] [Indexed: 01/19/2023]
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27
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Gardella TJ, Vilardaga JP. International Union of Basic and Clinical Pharmacology. XCIII. The parathyroid hormone receptors--family B G protein-coupled receptors. Pharmacol Rev 2015; 67:310-37. [PMID: 25713287 DOI: 10.1124/pr.114.009464] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The type-1 parathyroid hormone receptor (PTHR1) is a family B G protein-coupled receptor (GPCR) that mediates the actions of two polypeptide ligands; parathyroid hormone (PTH), an endocrine hormone that regulates the levels of calcium and inorganic phosphate in the blood by acting on bone and kidney, and PTH-related protein (PTHrP), a paracrine-factor that regulates cell differentiation and proliferation programs in developing bone and other tissues. The type-2 parathyroid hormone receptor (PTHR2) binds a peptide ligand, called tuberoinfundibular peptide-39 (TIP39), and while the biologic role of the PTHR2/TIP39 system is not as defined as that of the PTHR1, it likely plays a role in the central nervous system as well as in spermatogenesis. Mechanisms of action at these receptors have been explored through a variety of pharmacological and biochemical approaches, and the data obtained support a basic "two-site" mode of ligand binding now thought to be used by each of the family B peptide hormone GPCRs. Recent crystallographic studies on the family B GPCRs are providing new insights that help to further refine the specifics of the overall receptor architecture and modes of ligand docking. One intriguing pharmacological finding for the PTHR1 is that it can form surprisingly stable complexes with certain PTH/PTHrP ligand analogs and thereby mediate markedly prolonged cell signaling responses that persist even when the bulk of the complexes are found in internalized vesicles. The PTHR1 thus appears to be able to activate the Gα(s)/cAMP pathway not only from the plasma membrane but also from the endosomal domain. The cumulative findings could have an impact on efforts to develop new drug therapies for the PTH receptors.
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Affiliation(s)
- Thomas J Gardella
- Endocrine Unit, Massachusetts General Hospital, Boston, Massachusetts (T.J.G.); and Laboratory for GPCR Biology, Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania (J.-P.V.)
| | - Jean-Pierre Vilardaga
- Endocrine Unit, Massachusetts General Hospital, Boston, Massachusetts (T.J.G.); and Laboratory for GPCR Biology, Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania (J.-P.V.)
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28
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Multifaceted role of β-arrestins in inflammation and disease. Genes Immun 2015; 16:499-513. [PMID: 26378652 PMCID: PMC4670277 DOI: 10.1038/gene.2015.37] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Revised: 07/05/2015] [Accepted: 07/31/2015] [Indexed: 12/19/2022]
Abstract
Arrestins are intracellular scaffolding proteins known to regulate a range of biochemical processes including G-protein coupled receptor (GPCR) desensitization, signal attenuation, receptor turnover and downstream signaling cascades. Their roles in regulation of signaling network have lately been extended to receptors outside of the GPCR family, demonstrating their roles as important scaffolding proteins in various physiological processes including proliferation, differentiation, and apoptosis. Recent studies have demonstrated a critical role for arrestins in immunological processes including key functions in inflammatory signaling pathways. In this review, we provide a comprehensive analysis of the different functions of the arrestin family of proteins especially related to immunity and inflammatory diseases.
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Nirujogi RS, Wright JD, Manda SS, Zhong J, Na CH, Meyerhoff J, Benton B, Jabbour R, Willis K, Kim MS, Pandey A, Sekowski JW. Phosphoproteomic analysis reveals compensatory effects in the piriform cortex of VX nerve agent exposed rats. Proteomics 2015; 15:487-99. [PMID: 25403869 DOI: 10.1002/pmic.201400371] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Revised: 10/01/2014] [Accepted: 11/12/2014] [Indexed: 01/15/2023]
Abstract
To gain insights into the toxicity induced by the nerve agent VX, an MS-based phosphoproteomic analysis was carried out on the piriform cortex region of brains from VX-treated rats. Using isobaric tag based TMT labeling followed by titanium dioxide enrichment strategy, we identified 9975 unique phosphosites derived from 3287 phosphoproteins. Temporal changes in the phosphorylation status of peptides were observed over a time period of 24 h in rats exposed to a 1× LD50, intravenous (i.v.) dose with the most notable changes occurring at the 1 h postexposure time point. Five major functional classes of proteins exhibited changes in their phosphorylation status: (i) ion channels/transporters, including ATPases, (ii) kinases/phosphatases, (iii) GTPases, (iv) structural proteins, and (v) transcriptional regulatory proteins. This study is the first quantitative phosphoproteomic analysis of VX toxicity in the brain. Understanding the toxicity and compensatory signaling mechanisms will improve the understanding of the complex toxicity of VX in the brain and aid in the elucidation of novel molecular targets that would be important for development of improved countermeasures. All MS data have been deposited in the ProteomeXchange with identifier PXD001184 (http://proteomecentral.proteomexchange.org/dataset/PXD001184).
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Affiliation(s)
- Raja Sekhar Nirujogi
- Institute of Bioinformatics, International Tech Park, Bangalore, India; School of Life Sciences, Centre for Bioinformatics, Pondicherry University, Puducherry, India; Department of Neuroscience, School of Medicine, Johns Hopkins University, Baltimore, MD, USA
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Role of post-translational modifications on structure, function and pharmacology of class C G protein-coupled receptors. Eur J Pharmacol 2015; 763:233-40. [PMID: 25981296 DOI: 10.1016/j.ejphar.2015.05.015] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2015] [Revised: 03/06/2015] [Accepted: 05/11/2015] [Indexed: 11/22/2022]
Abstract
G protein-coupled receptors are divided into three classes (A, B and C) based on homology of their seven transmembrane domains. Class C is the smallest class with 22 human receptor subtypes including eight metabotropic glutamate (mGlu1-8) receptors, two GABAB receptors (GABAB1 and GABAB2), three taste receptors (T1R1-3), one calcium-sensing (CaS) receptor, one GPCR, class C, group 6, subtype A (GPRC6) receptor, and seven orphan receptors. G protein-coupled receptors undergo a number of post-translational modifications, which regulate their structure, function and/or pharmacology. Here, we review the existence of post-translational modifications in class C G protein-coupled receptors and their regulatory roles, with particular focus on glycosylation, phosphorylation, ubiquitination, SUMOylation, disulphide bonding and lipidation.
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31
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Molecular mechanisms underlying β-adrenergic receptor-mediated cross-talk between sympathetic neurons and immune cells. Int J Mol Sci 2015; 16:5635-65. [PMID: 25768345 PMCID: PMC4394497 DOI: 10.3390/ijms16035635] [Citation(s) in RCA: 118] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2014] [Revised: 02/13/2015] [Accepted: 03/04/2015] [Indexed: 01/01/2023] Open
Abstract
Cross-talk between the sympathetic nervous system (SNS) and immune system is vital for health and well-being. Infection, tissue injury and inflammation raise firing rates of sympathetic nerves, increasing their release of norepinephrine (NE) in lymphoid organs and tissues. NE stimulation of β2-adrenergic receptors (ARs) in immune cells activates the cAMP-protein kinase A (PKA) intracellular signaling pathway, a pathway that interfaces with other signaling pathways that regulate proliferation, differentiation, maturation and effector functions in immune cells. Immune-SNS cross-talk is required to maintain homeostasis under normal conditions, to develop an immune response of appropriate magnitude after injury or immune challenge, and subsequently restore homeostasis. Typically, β2-AR-induced cAMP is immunosuppressive. However, many studies report actions of β2-AR stimulation in immune cells that are inconsistent with typical cAMP-PKA signal transduction. Research during the last decade in non-immune organs, has unveiled novel alternative signaling mechanisms induced by β2-AR activation, such as a signaling switch from cAMP-PKA to mitogen-activated protein kinase (MAPK) pathways. If alternative signaling occurs in immune cells, it may explain inconsistent findings of sympathetic regulation of immune function. Here, we review β2-AR signaling, assess the available evidence for alternative signaling in immune cells, and provide insight into the circumstances necessary for "signal switching" in immune cells.
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32
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Davis A, Abraham E, McEvoy E, Sonnenfeld S, Lewis C, Hubbard CS, Dolence EK, Rose JD, Coddington E. Corticosterone suppresses vasotocin-enhanced clasping behavior in male rough-skinned newts by novel mechanisms interfering with V1a receptor availability and receptor-mediated endocytosis. Horm Behav 2015; 69:39-49. [PMID: 25528549 DOI: 10.1016/j.yhbeh.2014.12.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/24/2014] [Revised: 11/14/2014] [Accepted: 12/11/2014] [Indexed: 12/17/2022]
Abstract
In rough-skinned newts, Taricha granulosa, exposure to an acute stressor results in the rapid release of corticosterone (CORT), which suppresses the ability of vasotocin (VT) to enhance clasping behavior. CORT also suppresses VT-induced spontaneous activity and sensory responsiveness of clasp-controlling neurons in the rostromedial reticular formation (Rf). The cellular mechanisms underlying this interaction remain unclear. We hypothesized that CORT blocks VT-enhanced clasping by interfering with V1a receptor availability and/or VT-induced endocytosis. We administered a physiologically active fluorescent VT conjugated to Oregon Green (VT-OG) to the fourth ventricle 9 min after an intraperitoneal injection of CORT (0, 10, 40 μg/0.1mL amphibian Ringers). The brains were collected 30 min post-VT-OG, fixed, and imaged with confocal microscopy. CORT diminished the number of endocytosed vesicles, percent area containing VT-OG, sum intensity of VT-OG, and the amount of VT-V1a within each vesicle; indicating that CORT was interfering with V1a receptor availability and VT-V1a receptor-mediated endocytosis. CORT actions were brain location-specific and season-dependent in a manner that is consistent with the natural and context-dependent expression of clasping behavior. Furthermore, the sensitivity of the Rf to CORT was much higher in animals during the breeding season, arguing for ethologically appropriate seasonal variation in CORT's ability to prevent VT-induced endocytosis. Our data are consistent with the time course and interaction effects of CORT and VT on clasping behavior and neurophysiology. CORT interference with VT-induced endocytosis may be a common mechanism employed by hormones across taxa for mediating rapid context- and season-specific behavioral responses.
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Affiliation(s)
- Audrey Davis
- Department of Biology, Willamette University, Salem, OR 97301, USA
| | - Emily Abraham
- Department of Biology, Willamette University, Salem, OR 97301, USA
| | - Erin McEvoy
- Department of Biology, Willamette University, Salem, OR 97301, USA
| | - Sarah Sonnenfeld
- Department of Biology, Willamette University, Salem, OR 97301, USA
| | - Christine Lewis
- Department of Zoology and Physiology, University of Wyoming, Laramie, WY, USA
| | - Catherine S Hubbard
- Department of Neural & Pain Sciences, School of Dentistry, University of Maryland, Baltimore, MD 21201, USA
| | - E Kurt Dolence
- School of Pharmacy, University of Wyoming, Laramie, WY, USA
| | - James D Rose
- Department of Zoology and Physiology, University of Wyoming, Laramie, WY, USA
| | - Emma Coddington
- Department of Biology, Willamette University, Salem, OR 97301, USA.
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Subramanian H, Gupta K, Parameswaran N, Ali H. Regulation of Fc∈RI signaling in mast cells by G protein-coupled receptor kinase 2 and its RH domain. J Biol Chem 2015; 289:20917-27. [PMID: 24904059 DOI: 10.1074/jbc.m113.523969] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Agonist-induced phosphorylation of G protein-coupled receptors (GPCRs) by GPCRkinases (GRKs) promotes their desensitization and internalization. Here, we sought to determine the role of GRK2 on Fc∈RI signaling and mediator release in mast cells. The strategies utilized included lentiviral shRNA-mediated GRK2 knockdown, GRK2 gene deletion (GRK2(flox/flox)/cre recombinase) and overexpression of GRK2 and its regulator of G protein signaling homology (RH) domain (GRK2-RH). We found that silencing GRK2 expression caused ~50% decrease in antigen-induced Ca(2+) mobilization and degranulation but resulted in ablation of cytokine (IL-6 and IL-13) generation. The effect of GRK2 on cytokine generation does not require its catalytic activity but is mediated via the phosphorylation of p38 and Akt. Overexpression of GRK2 or its RH domain (GRK2-RH) enhanced antigen-induced mast cell degranulation and cytokine generation without affecting the expression levels of any of the Fc∈RI subunits (α, β, and γ). GRK2 or GRK2-RH had no effect on antigen-induced phosphorylation of Fc∈RIγ or Src but enhanced tyrosine phosphorylation of Syk. These data demonstrate that GRK2 modulates Fc∈RI signaling in mast cells via at least two mechanisms.One involves GRK2-RH and modulates tyrosine phosphorylation of Syk, and the other is mediated via the phosphorylation of p38 and Akt.
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34
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Egom EE. Sphingosine-1-phosphate signalling as a therapeutic target for patients with abnormal glucose metabolism and ischaemic heart disease. J Cardiovasc Med (Hagerstown) 2015; 15:517-24. [PMID: 23839592 DOI: 10.2459/jcm.0b013e3283639755] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Abnormalities of glucose metabolism in patients with ischaemic heart disease (IHD) are common and are associated with a poor outcome in patients with and without diabetes. Sphingosine-1-phosphate (S1P) is a bioactive lipid which has been shown to increase insulin sensitivity in rodents and to increase myocardial tolerance to ischaemia. In the present review, I explore the relevance of S1P signalling pathway to IHD and abnormalities in glucose tolerance, and its potential as a therapeutic target for patients with abnormal glucose metabolism and IHD.
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Affiliation(s)
- Emmanuel E Egom
- Department of Physiology and Biophysics, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada
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Abstract
G-protein-coupled receptors (GPCRs) are the primary interaction partners for arrestins. The visual arrestins, arrestin1 and arrestin4, physiologically bind to only very few receptors, i.e., rhodopsin and the color opsins, respectively. In contrast, the ubiquitously expressed nonvisual variants β-arrestin1 and 2 bind to a large number of receptors in a fairly nonspecific manner. This binding requires two triggers, agonist activation and receptor phosphorylation by a G-protein-coupled receptor kinase (GRK). These two triggers are mediated by two different regions of the arrestins, the "phosphorylation sensor" in the core of the protein and a less well-defined "activation sensor." Binding appears to occur mostly in a 1:1 stoichiometry, involving the N-terminal domain of GPCRs, but in addition a second GPCR may loosely bind to the C-terminal domain when active receptors are abundant.Arrestin binding initially uncouples GPCRs from their G-proteins. It stabilizes receptors in an active conformation and also induces a conformational change in the arrestins that involves a rotation of the two domains relative to each other plus changes in the polar core. This conformational change appears to permit the interaction with further downstream proteins. The latter interaction, demonstrated mostly for β-arrestins, triggers receptor internalization as well as a number of nonclassical signaling pathways.Open questions concern the exact stoichiometry of the interaction, possible specificity with regard to the type of agonist and of GRK involved, selective regulation of downstream signaling (=biased signaling), and the options to use these mechanisms as therapeutic targets.
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Affiliation(s)
- Martin J Lohse
- Institute of Pharmacology and Toxicology, University of Würzburg, Versbacher Straße 9, 97078, Würzburg, Germany,
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36
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Smith FD, Reichow SL, Esseltine JL, Shi D, Langeberg LK, Scott JD, Gonen T. Intrinsic disorder within an AKAP-protein kinase A complex guides local substrate phosphorylation. eLife 2013; 2:e01319. [PMID: 24192038 PMCID: PMC3814001 DOI: 10.7554/elife.01319] [Citation(s) in RCA: 91] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Anchoring proteins sequester kinases with their substrates to locally disseminate intracellular signals and avert indiscriminate transmission of these responses throughout the cell. Mechanistic understanding of this process is hampered by limited structural information on these macromolecular complexes. A-kinase anchoring proteins (AKAPs) spatially constrain phosphorylation by cAMP-dependent protein kinases (PKA). Electron microscopy and three-dimensional reconstructions of type-II PKA-AKAP18γ complexes reveal hetero-pentameric assemblies that adopt a range of flexible tripartite configurations. Intrinsically disordered regions within each PKA regulatory subunit impart the molecular plasticity that affords an ∼16 nanometer radius of motion to the associated catalytic subunits. Manipulating flexibility within the PKA holoenzyme augmented basal and cAMP responsive phosphorylation of AKAP-associated substrates. Cell-based analyses suggest that the catalytic subunit remains within type-II PKA-AKAP18γ complexes upon cAMP elevation. We propose that the dynamic movement of kinase sub-structures, in concert with the static AKAP-regulatory subunit interface, generates a solid-state signaling microenvironment for substrate phosphorylation. DOI:http://dx.doi.org/10.7554/eLife.01319.001 It was once thought that proteins needed to have structures that were both ordered and stable, but this view was changed by the discovery that certain proteins contain regions that are disordered and flexible. In some cases these regions of intrinsic disorder help the protein to function by linking more stable regions that are active. However, in other proteins the disordered regions are themselves biologically active and can, for example, function as enzymes. Protein kinase A is a family of enzymes that contains both ordered and disordered regions, with the ordered sections being involved in phosphorylation, a chemical process that is widely used for communication within cells. However, in order to initiate phosphorylation, these kinases must be anchored to a rigid substrate nearby, so a second group of proteins called AKAPs–which is short for A-kinase anchoring proteins–hold the kinases in place by binding to their disordered regions. These AKAPs also help the kinases to dock with other molecules involved in phosphorylation. A full structural picture of how the kinases induce phosphorylation has yet to be obtained, partly because it is extremely difficult to determine the structure of the disordered regions within the kinases. Moreover, the AKAPs are also disordered, which makes it difficult to work out how the kinases are held in position. Smith, Reichow et al. have used electron microscopy to reveal that the disordered region has two important roles: it determines how far away from the anchoring protein that the active region of the kinase can operate, and it influences how efficiently the kinase can bind to its target molecule in order to induce phosphorylation. Future challenges include investigating how the inherent flexibility of AKAP complexes contribute to the efficient phosphorylation of physiological targets. DOI:http://dx.doi.org/10.7554/eLife.01319.002
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Affiliation(s)
- F Donelson Smith
- Department of Pharmacology, Howard Hughes Medical Institute, University of Washington, Seattle, United States
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Altered sympathetic-to-immune cell signaling via β₂-adrenergic receptors in adjuvant arthritis. Clin Dev Immunol 2013; 2013:764395. [PMID: 24194774 PMCID: PMC3806360 DOI: 10.1155/2013/764395] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2013] [Accepted: 08/02/2013] [Indexed: 01/08/2023]
Abstract
Adjuvant-induced arthritic (AA) differentially affects norepinephrine concentrations in immune organs, and in vivo β-adrenergic receptor (β-AR) agonist treatment distinctly regulates ex vivo cytokine profiles in different immune organs. We examined the contribution of altered β-AR functioning in AA to understand these disparate findings. Twenty-one or 28 days after disease induction, we examined β2-AR expression in spleen and draining lymph nodes (DLNs) for the arthritic limbs using radioligand binding and western blots and splenocyte β-AR-stimulated cAMP production using enzyme-linked immunoassay (EIA). During severe disease, β-AR agonists failed to induce splenocyte cAMP production, and β-AR affinity and density declined, indicating receptor desensitization and downregulation. Splenocyte β2-AR phosphorylation (pβ2-AR) by protein kinase A (pβ2-ARPKA) decreased in severe disease, and pβ2-AR by G protein-coupled receptor kinases (pβ2-ARGRK) increased in chronic disease. Conversely, in DLN cells, pβ2-ARPKA rose during severe disease, but fell during chronic disease, and pβ2-ARGRK increased during both disease stages. A similar pβ2-AR pattern in DLN cells with the mycobacterial cell wall component of complete Freund's adjuvant suggests that pattern recognition receptors (i.e., toll-like receptors) are important for DLN pβ2-AR patterns. Collectively, our findings indicate lymphoid organ- and disease stage-specific sympathetic dysregulation, possibly explaining immune compartment-specific differences in β2-AR-mediated regulation of cytokine production in AA and rheumatoid arthritis.
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Cottrell GS. Roles of proteolysis in regulation of GPCR function. Br J Pharmacol 2013; 168:576-90. [PMID: 23043558 DOI: 10.1111/j.1476-5381.2012.02234.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2012] [Revised: 09/03/2012] [Accepted: 09/24/2012] [Indexed: 12/18/2022] Open
Abstract
The enzymatic activity of peptidases must be tightly regulated to prevent uncontrolled hydrolysis of peptide bonds, which could have devastating effects on biological systems. Peptidases are often generated as inactive propeptidases, secreted with endogenous inhibitors, or they are compartmentalized. Propeptidases become active after proteolytic removal of N-terminal activation peptides by other peptidases. Some peptidases only become active towards substrates only at certain pHs, thus confining activity to specific compartments or conditions. This review discusses the different roles proteolysis plays in regulating GPCRs. At the cell-surface, certain GPCRs are regulated by the hydrolytic inactivation of bioactive peptides by membrane-anchored peptidases, which prevent signalling. Conversely, cell-surface peptidases can also generate bioactive peptides, which directly activate GPCRs. Alternatively, cell-surface peptidases activated by GPCRs, can generate bioactive peptides to cause transactivation of receptor tyrosine kinases, thereby promoting signalling. Certain peptidases can signal directly to cells, by cleaving GPCR to initiate intracellular signalling cascades. Intracellular peptidases also regulate GPCRs; lysosomal peptidases destroy GPCRs in lysosomes to permanently terminate signalling and mediate down-regulation; endosomal peptidases cleave internalized peptide agonists to regulate GPCR recycling, resensitization and signalling; and soluble intracellular peptidases also participate in GPCR function by regulating the ubiquitination state of GPCRs, thereby altering GPCR signalling and fate. Although the use of peptidase inhibitors has already brought success in the treatment of diseases such as hypertension, the discovery of new regulatory mechanisms involving proteolysis that control GPCRs may provide additional targets to modulate dysregulated GPCR signalling in disease.
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Affiliation(s)
- G S Cottrell
- Reading School of Pharmacy, University of Reading, Reading, UK.
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Noncanonical GPCR signaling arising from a PTH receptor-arrestin-Gβγ complex. Proc Natl Acad Sci U S A 2013; 110:1530-5. [PMID: 23297229 DOI: 10.1073/pnas.1205756110] [Citation(s) in RCA: 117] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
G protein-coupled receptors (GPCRs) participate in ubiquitous transmembrane signal transduction processes by activating heterotrimeric G proteins. In the current "canonical" model of GPCR signaling, arrestins terminate receptor signaling by impairing receptor-G-protein coupling and promoting receptor internalization. However, parathyroid hormone receptor type 1 (PTHR), an essential GPCR involved in bone and mineral metabolism, does not follow this conventional desensitization paradigm. β-Arrestins prolong G protein (G(S))-mediated cAMP generation triggered by PTH, a process that correlates with the persistence of arrestin-PTHR complexes on endosomes and which is thought to be associated with prolonged physiological calcemic and phosphate responses. This presents an inescapable paradox for the current model of arrestin-mediated receptor-G-protein decoupling. Here we show that PTHR forms a ternary complex that includes arrestin and the Gβγ dimer in response to PTH stimulation, which in turn causes an accelerated rate of G(S) activation and increases the steady-state levels of activated G(S), leading to prolonged generation of cAMP. This work provides the mechanistic basis for an alternative model of GPCR signaling in which arrestins contribute to sustaining the effect of an agonist hormone on the receptor.
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Vilardaga JP, Gardella TJ, Wehbi VL, Feinstein TN. Non-canonical signaling of the PTH receptor. Trends Pharmacol Sci 2012; 33:423-31. [PMID: 22709554 DOI: 10.1016/j.tips.2012.05.004] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2012] [Revised: 05/11/2012] [Accepted: 05/15/2012] [Indexed: 12/31/2022]
Abstract
The classical model of arrestin-mediated desensitization of cell-surface G-protein-coupled receptors (GPCRs) is thought to be universal. However, this paradigm is incompatible with recent reports that the parathyroid hormone (PTH) receptor (PTHR), a crucial GPCR for bone and mineral ion metabolism, sustains G(S) activity and continues to generate cAMP for prolonged periods after ligand washout; during these periods the receptor is observed mainly in endosomes, associated with the bound ligand, G(S) and β-arrestins. In this review we discuss possible molecular mechanisms underlying sustained signaling by the PTHR, including modes of signal generation and attenuation within endosomes, as well as the biological relevance of such non-canonical signaling.
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Affiliation(s)
- Jean-Pierre Vilardaga
- Laboratory for GPCR Biology, Department of Pharmacology and Chemical Biology, University of Pittsburgh, School of Medicine, Pittsburgh, PA 15261, USA.
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Sigismund S, Confalonieri S, Ciliberto A, Polo S, Scita G, Di Fiore PP. Endocytosis and signaling: cell logistics shape the eukaryotic cell plan. Physiol Rev 2012; 92:273-366. [PMID: 22298658 DOI: 10.1152/physrev.00005.2011] [Citation(s) in RCA: 236] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Our understanding of endocytosis has evolved remarkably in little more than a decade. This is the result not only of advances in our knowledge of its molecular and biological workings, but also of a true paradigm shift in our understanding of what really constitutes endocytosis and of its role in homeostasis. Although endocytosis was initially discovered and studied as a relatively simple process to transport molecules across the plasma membrane, it was subsequently found to be inextricably linked with almost all aspects of cellular signaling. This led to the notion that endocytosis is actually the master organizer of cellular signaling, providing the cell with understandable messages that have been resolved in space and time. In essence, endocytosis provides the communications and supply routes (the logistics) of the cell. Although this may seem revolutionary, it is still likely to be only a small part of the entire story. A wealth of new evidence is uncovering the surprisingly pervasive nature of endocytosis in essentially all aspects of cellular regulation. In addition, many newly discovered functions of endocytic proteins are not immediately interpretable within the classical view of endocytosis. A possible framework, to rationalize all this new knowledge, requires us to "upgrade" our vision of endocytosis. By combining the analysis of biochemical, biological, and evolutionary evidence, we propose herein that endocytosis constitutes one of the major enabling conditions that in the history of life permitted the development of a higher level of organization, leading to the actuation of the eukaryotic cell plan.
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Affiliation(s)
- Sara Sigismund
- IFOM, Fondazione Istituto FIRC di Oncologia Molecolare, Milan, Italy
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42
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Pérez-Sayáns M, Somoza-Martín JM, Barros-Angueira F, Gayoso-Diz P, Otero-Rey EM, Gándra-Rey JM, García-García A. Activity of β2-adrenergic receptor in oral squamous cell carcinoma is mediated by overexpression of the ADRBK2 gene: a pilot study. Biotech Histochem 2011; 87:179-86. [PMID: 21916780 DOI: 10.3109/10520295.2011.592151] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The β2-adrenergic receptor is most frequently involved in carcinogenic processes. Earlier studies have established a relation between the β2-adrenergic receptor and various characteristics of cancer including cell proliferation, apoptosis, chemotaxis, metastasis, tumor growth and angiogenesis. Our goal was to determine differential expression of the genes involved in adrenergic receptors using DNA microarrays and to confirm their under- or overexpression using real-time quantitative PCR. Five of the nine genes investigated showed significantly altered expression levels in tumor cells (p < 0.05). The gene product with the highest Z-score (restrictive statistical technique for selection of appropriate genes to study) was ADRBK2. Significantly, most of the overexpressed genes were related to β-adrenergic receptors. Real-time PCR analysis confirmed the up regulation observed in the microarrays, which indicated overexpression in 100% of the tumors. In oral squamous cell carcinomas, malignant cells and surrounding tissue overexpress the ADRBK2 gene.
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Affiliation(s)
- M Pérez-Sayáns
- Oral Medicine, Oral Surgery and Implantology Unit, Faculty of Medicine and Dentistry, Entrerríos s/n, Santiago de Compostela, Spain.
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43
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Mizuno K, Kurokawa K, Shibasaki M, Ohkuma S. β₁-adrenergic receptor up-regulation induced by nadolol is mediated via signal transduction pathway coupled to α₁-adrenergic receptors. Brain Res 2011; 1414:10-21. [PMID: 21871614 DOI: 10.1016/j.brainres.2011.07.057] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2011] [Revised: 06/30/2011] [Accepted: 07/27/2011] [Indexed: 01/05/2023]
Abstract
Although up-regulation of β-adrenergic receptors (β-ARs) occurs after long-term use of their antagonists in various tissues, the available data are little on mechanisms of β-AR up-regulation induced by their continuous blockade. The present study attempted to clarify mechanisms of β-AR up-regulation using mouse cerebral cortical neurons continuously exposed to nadolol (10 nM), a non-selective β-AR antagonist, for 24 h. Nadolol dose-dependently induced both subtypes of β-ARs, β₁- and β₂-ARs, which were not suppressed by protein A kinase inhibition with KT5720. On the other hand, blockade of α₁-ARs, which are immunohistochemically confirmed to be co-localized with β-ARs in the same neurons, significantly inhibited only β₁-AR up-regulation and the expression of β₂-ARs did not alter. In addition, phenylephrine, an agonist specific to α₁-ARs up-regulated β₁-ARs, but not β₂-ARs. Under the conditions with β-AR up-regulation, the level of phosphorylated protein kinase Cα (pPKCα) increased, which is significantly suppressed by prazosin, an α1-AR antagonist. Furthermore, nadolol decreased the degradation of mRNA of β₁-ARs, but not β₂-ARs. These results indicate that the nadolol-induced β₁-AR up-regulation is mediated via PKC-relating pathway via α₁-AR activation with stabilizing β₁-AR mRNA and that the increased expression of β₂-ARs is regulated by pathways different from those for β₁-AR expression.
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MESH Headings
- Adrenergic Agents/pharmacology
- Adrenergic beta-Antagonists/pharmacology
- Analysis of Variance
- Animals
- Benzophenanthridines/pharmacology
- Carbazoles/pharmacology
- Cells, Cultured
- Cerebral Cortex/cytology
- Dopamine beta-Hydroxylase/metabolism
- Embryo, Mammalian
- Enzyme Inhibitors/pharmacology
- Mice
- Mice, Inbred ICR
- Nadolol/pharmacology
- Neurons/drug effects
- Pyrroles/pharmacology
- Receptors, Adrenergic, alpha-1/genetics
- Receptors, Adrenergic, alpha-1/metabolism
- Receptors, Adrenergic, beta-1/genetics
- Receptors, Adrenergic, beta-1/metabolism
- Signal Transduction/drug effects
- Time Factors
- Up-Regulation/drug effects
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Affiliation(s)
- Koji Mizuno
- Department of Pharmacology, Kawasaki Medical School, Matsushima 577, Kurashiki 701-0192, Japan
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Feinstein TN, Wehbi VL, Ardura JA, Wheeler DS, Ferrandon S, Gardella TJ, Vilardaga JP. Retromer terminates the generation of cAMP by internalized PTH receptors. Nat Chem Biol 2011; 7:278-84. [PMID: 21445058 PMCID: PMC3079799 DOI: 10.1038/nchembio.545] [Citation(s) in RCA: 171] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2010] [Accepted: 01/24/2011] [Indexed: 12/12/2022]
Abstract
The generation of cAMP by G protein-coupled receptors (GPCRs) and its termination are currently thought to occur exclusively at the plasma membrane of cells. Under existing models of receptor regulation, this signal is primarily restricted by desensitization of the receptors through their binding to β-arrestins. However, this paradigm is not consistent with recent observations that the parathyroid hormone receptor type 1 (PTHR) continues to stimulate cAMP production even after receptor internalization, as β-arrestins are known to rapidly bind and internalize activated PTHR. Here we show that binding to β-arrestin1 prolongs rather than terminates the generation of cAMP by PTHR, and that cAMP generation correlates with the persistence of arrestin-receptor complexes on endosomes. PTHR signaling is instead turned off by the retromer complex, which regulates the movement of internalized receptor from endosomes to the Golgi apparatus. Thus, binding by the retromer complex regulates the sustained generation of cAMP triggered by an internalized GPCR.
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Affiliation(s)
- Timothy N Feinstein
- Laboratory for GPCR Biology, Department of Pharmacology and Chemical Biology, University of Pittsburgh, School of Medicine, Pittsburgh, Pennsylvania, USA
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Wolf A, Gosens R, Meurs H, Häberlein H. Pre-treatment with α-hederin increases β-adrenoceptor mediated relaxation of airway smooth muscle. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2011; 18:214-218. [PMID: 20637581 DOI: 10.1016/j.phymed.2010.05.010] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2010] [Accepted: 05/25/2010] [Indexed: 05/29/2023]
Abstract
Preparations of ivy leaves dry extract with secretolytic and bronchiolytic efficacy are widely used for the treatment of acute and chronic obstructive airway diseases. The mechanism by which ivy preparations improve lung functions is not fully understood. Here, we tested the influence of the three main saponins of ivy, α-hederin, hederacoside C and hederagenin, on the contraction and relaxation behaviour of isolated bovine tracheal smooth muscle strips by isometric tension measurements. None of the tested compounds altered histamine or methacholine-induced contraction of the smooth muscle strips. In contrast, the isoprenaline-induced relaxation of 100μM methacholine precontracted muscle strips was significantly enhanced when pre-treated with 1μM of α-hederin for 18h. The pre-treatment with hederacoside C or hederagenin had no effect on isoprenaline-induced relaxation. For the first time the bronchiolytic effect of α-hederin was demonstrated by isometric tension measurements using bovine tracheal smooth muscle strips. α-Hederin increases isoprenaline-induced relaxation indirectly, probably by inhibiting heterologous desensitization induced by high concentrations of muscarinic ligands like methacholine.
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Affiliation(s)
- Anne Wolf
- Institute of Biochemistry and Molecular Biology, Rheinische Friedrich-Wilhelms-Universität, Nussallee 11, 53115 Bonn, Germany
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46
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Rosethorne EM, Charlton SJ. Agonist-biased signaling at the histamine H4 receptor: JNJ7777120 recruits β-arrestin without activating G proteins. Mol Pharmacol 2010; 79:749-57. [PMID: 21134907 DOI: 10.1124/mol.110.068395] [Citation(s) in RCA: 92] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
The G(i/o)-coupled histamine H(4) receptor is highly expressed in hemopoietic cells and is a promising new target for the treatment of chronic inflammatory diseases. 1-[(5-Chloro-1H-indol-2-yl)carbonyl]-4-methyl-piperazine (JNJ7777120) has been described as a selective antagonist at the H(4) receptor and is widely used to characterize the physiological role of the H(4) receptor. We have investigated the pharmacological properties of JNJ7777120 using two distinct downstream signaling measurements, G protein activation and β-arrestin recruitment. The H(4) receptor agonists histamine and clobenpropit, but not JNJ7777120, were able to induce [(35)S]GTPγS binding in membranes prepared from U2OS-H(4) cells. Thioperamide, a dual H(3)/H(4) receptor antagonist, and JNJ7777120 were both able to inhibit the [(35)S]GTPγS binding induced by clobenpropit. Agonists and antagonists specific for other members of the histamine receptor family had no effect in this assay format. Histamine and clobenpropit increased β-arrestin recruitment to the H(4) receptor in a concentration-dependent manner. This β-arrestin recruitment could be inhibited by preincubation with thioperamide. We were surprised to find that preincubation with the H(4)-selective antagonist JNJ7777120 potentiated rather than antagonized the response to a submaximal concentration of clobenpropit. JNJ7777120 treatment alone resulted in an increase in β-arrestin recruitment, which again could be inhibited by preincubation with thioperamide. Schild analysis demonstrated competitive antagonism between thioperamide and both clobenpropit and JNJ7777120. Histamine and clobenpropit had comparable potencies for both [(35)S]GTPγS binding and β-arrestin recruitment, suggesting little difference in the levels of receptor reserve between the two assays. In conclusion, we have demonstrated that JNJ7777120 recruits β-arrestin to the H(4) receptor, independent of G protein activation.
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Soh UJK, Dores MR, Chen B, Trejo J. Signal transduction by protease-activated receptors. Br J Pharmacol 2010; 160:191-203. [PMID: 20423334 DOI: 10.1111/j.1476-5381.2010.00705.x] [Citation(s) in RCA: 213] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The family of G protein-coupled receptors (GPCRs) constitutes the largest class of signalling receptors in the human genome, controlling vast physiological responses and are the target of many drugs. After activation, GPCRs are rapidly desensitized by phosphorylation and beta-arrestin binding. Most classic GPCRs are internalized through a clathrin, dynamin and beta-arrestin-dependent pathway and then recycled back to the cell surface or sorted to lysosomes for degradation. Given the vast number and diversity of GPCRs, different mechanisms are likely to exist to precisely regulate the magnitude, duration and spatial aspects of receptor signalling. The G protein-coupled protease-activated receptors (PARs) provide elegant examples of GPCRs that are regulated by distinct desensitization and endocytic sorting mechanisms, processes that are critically important for the spatial and temporal fidelity of PAR signalling. PARs are irreversibly activated through proteolytic cleavage and transmit cellular responses to extracellular proteases. Activated PAR(1) internalizes through a clathrin- and dynamin-dependent pathway independent of beta-arrestins. Interestingly, PAR(1) is basally ubiquitinated and deubiquitinated after activation and traffics from endosomes to lysosomes independent of ubiquitination. In contrast, beta-arrestins mediate activated PAR(2) internalization and function as scaffolds that promote signalling from endocytic vesicles. Moreover, activated PAR(2) is modified with ubiquitin, which facilitates lysosomal degradation. Activated PARs also adopt distinct active conformations that signal to diverse effectors and are likely regulated by different mechanisms. Thus, the identification of the molecular machinery important for PAR signal regulation will enable the development of new strategies to manipulate receptor signalling and will provide novel targets for the development of drugs.
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Affiliation(s)
- Unice J K Soh
- Department of Pharmacology, University of California, San Diego, 92093-0636, USA
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Targeted transgenesis reveals discrete attenuator functions of GRK and PKA in airway beta2-adrenergic receptor physiologic signaling. Proc Natl Acad Sci U S A 2009; 106:15007-12. [PMID: 19706446 DOI: 10.1073/pnas.0906034106] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Phosphorylation by protein kinase A (PKA) and G protein-coupled receptor kinases (GRKs) desensitize beta2-adrenergic receptor (beta2AR) signaling, and these are thought to be mechanisms involved with cell and organ homeostasis and tolerance to agonists. However, there is little direct evidence that these events are relevant to beta2AR physiological function, such as airway smooth muscle (ASM) relaxation leading to bronchodilation. To maintain cell- and receptor-specificity without altering the natural complement of kinases/arrestins, transgenic mice were generated expressing the human WT and mutated beta2ARs lacking PKA and/or GRK phosphorylation sites on ASM at approximately 4-fold over background. Functional gains in response to beta-agonist from the selective loss of these mechanisms were determined in mouse airways. Relaxation kinetics were altered in all mutant airways compared with beta2WT. At low receptor occupancy, beta2PKA(-) had enhanced agonist-promoted relaxation, while beta2GRK(-) airways were unaffected. In contrast, at saturating agonist concentrations, the greatest relaxation enhancement was with beta2GRK(-), with no evidence for additivity when PKA sites were also removed. For the full range of responses, the beta2PKA(-)/GRK(-) airways had the greatest relaxation efficiency, indicating a graded effect of GRKs as agonist concentration increased. ASM cAMP levels paralleled relaxation phenotypes. No interaction between PKA phosphorylation of beta2AR and GRK-promoted events was identified by beta-arrestin-2 recruitment. Thus, these two mechanisms indeed impact a relevant beta2AR physiologic function, acting as attenuators of the acute response, and represent specific interfaces where adjunct therapy or biased ligands may improve beta-agonist treatment of obstructive lung disease.
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Dungan JR, Conley YP, Langaee TY, Johnson JA, Kneipp SM, Hess PJ, Yucha CB. Altered beta-2 adrenergic receptor gene expression in human clinical hypertension. Biol Res Nurs 2009; 11:17-26. [PMID: 19254913 DOI: 10.1177/1099800409332538] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
OBJECTIVES The beta-2 adrenergic receptor is involved in mediating vasodilatation via neurohumoral and sympathetic nervous system pathways. Alterations in beta-2 adrenergic receptor gene expression (mRNA transcription) may contribute to the hypertensive phenotype. Human gene expression in clinical phenotypes remains largely unexplored due to ethical constraints involved in obtaining human tissue. We devised a method to obtain normally discarded internal mammary artery tissue from coronary artery bypass graft patients. We then investigated differences in hypertensive and normotensive participants' beta-2 adrenergic receptor gene expression in this tissue. METHODS We collected arterial tissue samples from 46 coronary artery bypass patients in a surgical setting. Using 41 of the samples, we performed TaqMan real-time polymerase chain reaction (RT-PCR) and used the delta delta cycle threshold (DeltaDeltaCt) relative quantitation method for determination of fold-differences in gene expression between normotensive and hypertensive participants. The beta-2 adrenergic receptor target was normalized to glyceraldehyde-phosphate dehydrogenase. RESULTS Participants with hypertension had significantly less-expressed beta-2 adrenoceptor gene (2.76-fold, p<.05) compared to normotensive participants. After Bonferroni correction, gene expression did not differ by race, gender, type/dose of beta-blocker prescribed, positive family history of hypertension, or diagnosis of diabetes mellitus type 2. CONCLUSIONS These data support the possibility of a molecular basis for impaired adrenoceptor-mediated vascular tone in hypertension. Modification and extension of this research is required.
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Affiliation(s)
- Jennifer R Dungan
- Duke University School of Nursing, Durham, North Carolina 27710, USA.
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50
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Physiological and pharmacological implications of beta-arrestin regulation. Pharmacol Ther 2008; 121:285-93. [PMID: 19100766 DOI: 10.1016/j.pharmthera.2008.11.005] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2008] [Accepted: 11/18/2008] [Indexed: 02/08/2023]
Abstract
G protein-coupled receptor-targeted drug discovery as well as "compound reassessment" requires the utilization of diverse screens to determine agonist efficacies and potencies beyond the scope of ligand binding and G protein coupling. Such efforts have arisen from extensive studies, both in cellular and animal models, demonstrating that these seven transmembrane domain-spanning, G protein-coupled receptors may engage in more diverse functions than their name suggests and particular focus is drawn to their interactions with beta-arrestins (betaarrestins). As regulators, betaarrestins are involved in dampening G protein-coupling pathways. betaArrestins can also play pro-signaling roles in receptor mediated events and the coupling of receptors to betaarrestins may be as important as their potential to couple to G proteins in the physiological setting. In the last decade, the development of betaarrestin deficient mouse models has allowed for the assessment of the contribution of individual betaarrestins to receptor function in vivo. This review will discuss the current literature that implicates betaarrestins in receptor function in respect to physiological and behavioral responses observed in the live animal model.
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