1
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Qiu GH, Yu B, Ma M. G protein-coupled receptor-mediated signaling of immunomodulation in tumor progression. FASEB J 2024; 38:e23829. [PMID: 39017658 DOI: 10.1096/fj.202400458r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2024] [Revised: 06/07/2024] [Accepted: 07/08/2024] [Indexed: 07/18/2024]
Abstract
G protein-coupled receptors (GPCRs) are essential contributors to tumor growth and metastasis due to their roles in immune cell regulation. Therefore, GPCRs are potential targets for cancer immunotherapy. Here, we discuss the current understanding of the roles of GPCRs and their signaling pathways in tumor progression from an immunocellular perspective. Additionally, we focus on the roles of GPCRs in regulating immune checkpoint proteins involved in immune evasion. Finally, we review the progress of clinical trials of GPCR-targeted drugs for cancer treatment, which may be combined with immunotherapy to improve treatment efficacy. This expanded understanding of the role of GPCRs may shed light on the mechanisms underlying tumor progression and provide a novel perspective on cancer immunotherapy.
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Affiliation(s)
- Guang-Hong Qiu
- Department of Oncology, The First Affiliated Hospital, Jiangxi Medical College, Nanchang University, Nanchang, PR China
| | - Bin Yu
- Department of General Surgery, The First Affiliated Hospital, Jiangxi Medical College, Nanchang University, Nanchang, PR China
| | - Mei Ma
- Department of Oncology, The First Affiliated Hospital, Jiangxi Medical College, Nanchang University, Nanchang, PR China
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2
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Asido M, Wachtveitl J. Photochemistry of the Light-Driven Sodium Pump Krokinobacter eikastus Rhodopsin 2 and Its Implications on Microbial Rhodopsin Research: Retrospective and Perspective. J Phys Chem B 2023; 127:3766-3773. [PMID: 36919947 DOI: 10.1021/acs.jpcb.2c08933] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/16/2023]
Abstract
The discovery of the light-driven sodium pump Krokinobacter eikastus rhodopsin 2 (KR2) in 2013 has changed the paradigm that cation transport in microbial rhodopsins is restricted to the translocation of protons. Even though this finding is already remarkable by itself, it also reignited more general discussions about the functional mechanism of ion transport. The unique composition of the retinal binding pocket in KR2 with a tight interaction between the retinal Schiff base and its respective counterion D116 also has interesting implications on the photochemical pathway of the chromophore. Here, we discuss the most recent advances in our understanding of the KR2 functionality from the primary event of photon absorption by all-trans retinal up to the actual protein response in the later phases of the photocycle, mainly from the point of view of optical spectroscopy. In this context, we furthermore highlight some of the ongoing debates on the photochemistry of microbial rhodopsins and give some perspectives for promising future directions in this field of research.
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Affiliation(s)
- Marvin Asido
- Institute of Physical and Theoretical Chemistry, Goethe University Frankfurt, Max-von-Laue Straße 7, 60438 Frankfurt am Main, Germany
| | - Josef Wachtveitl
- Institute of Physical and Theoretical Chemistry, Goethe University Frankfurt, Max-von-Laue Straße 7, 60438 Frankfurt am Main, Germany
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3
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Su M, Zhu L, Zhang Y, Paknejad N, Dey R, Huang J, Lee MY, Williams D, Jordan KD, Eng ET, Ernst OP, Meyerson JR, Hite RK, Walz T, Liu W, Huang XY. Structural Basis of the Activation of Heterotrimeric Gs-Protein by Isoproterenol-Bound β 1-Adrenergic Receptor. Mol Cell 2020; 80:59-71.e4. [PMID: 32818430 PMCID: PMC7541785 DOI: 10.1016/j.molcel.2020.08.001] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Revised: 02/09/2020] [Accepted: 07/31/2020] [Indexed: 01/21/2023]
Abstract
Cardiac disease remains the leading cause of morbidity and mortality worldwide. The β1-adrenergic receptor (β1-AR) is a major regulator of cardiac functions and is downregulated in the majority of heart failure cases. A key physiological process is the activation of heterotrimeric G-protein Gs by β1-ARs, leading to increased heart rate and contractility. Here, we use cryo-electron microscopy and functional studies to investigate the molecular mechanism by which β1-AR activates Gs. We find that the tilting of α5-helix breaks a hydrogen bond between the sidechain of His373 in the C-terminal α5-helix and the backbone carbonyl of Arg38 in the N-terminal αN-helix of Gαs. Together with the disruption of another interacting network involving Gln59 in the α1-helix, Ala352 in the β6-α5 loop, and Thr355 in the α5-helix, these conformational changes might lead to the deformation of the GDP-binding pocket. Our data provide molecular insights into the activation of G-proteins by G-protein-coupled receptors.
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Affiliation(s)
- Minfei Su
- Department of Physiology and Biophysics, Weill Cornell Medical College of Cornell University, New York, NY 10065
| | - Lan Zhu
- School of Molecular Sciences and Biodesign Center for Applied Structural Discovery, Arizona State University, Tempe, AZ 85287
| | - Yixiao Zhang
- Laboratory of Molecular Electron Microscopy, The Rockefeller University, New York, NY 10065
| | - Navid Paknejad
- Structural Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065
| | - Raja Dey
- Department of Physiology and Biophysics, Weill Cornell Medical College of Cornell University, New York, NY 10065
| | - Jianyun Huang
- Department of Physiology and Biophysics, Weill Cornell Medical College of Cornell University, New York, NY 10065
| | - Ming-Yue Lee
- School of Molecular Sciences and Biodesign Center for Applied Structural Discovery, Arizona State University, Tempe, AZ 85287
| | - Dewight Williams
- School of Molecular Sciences and Biodesign Center for Applied Structural Discovery, Arizona State University, Tempe, AZ 85287
| | - Kelsey D. Jordan
- Department of Biochemistry, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Edward T. Eng
- Department of Biochemistry, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Oliver P. Ernst
- Simons Electron Microscopy Center, New York Structural Biology Center, New York, NY 10027,Department of Molecular Genetics, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Joel R. Meyerson
- Department of Physiology and Biophysics, Weill Cornell Medical College of Cornell University, New York, NY 10065
| | - Richard K. Hite
- Structural Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065
| | - Thomas Walz
- Laboratory of Molecular Electron Microscopy, The Rockefeller University, New York, NY 10065
| | - Wei Liu
- School of Molecular Sciences and Biodesign Center for Applied Structural Discovery, Arizona State University, Tempe, AZ 85287,To whom correspondence should be addressed. ;
| | - Xin-Yun Huang
- Department of Physiology and Biophysics, Weill Cornell Medical College of Cornell University, New York, NY 10065,Lead Contact,To whom correspondence should be addressed. ;
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4
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Delaney SL, Gendreau JL, D'Souza M, Feng AY, Ho AL. Optogenetic Modulation for the Treatment of Traumatic Brain Injury. Stem Cells Dev 2020; 29:187-197. [DOI: 10.1089/scd.2019.0187] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Affiliation(s)
| | | | | | - Austin Y. Feng
- Department of Neurosurgery, Stanford University School of Medicine, Stanford, Georgia
| | - Allen L. Ho
- Department of Neurosurgery, Stanford University School of Medicine, Stanford, Georgia
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5
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Hamouri F, Zhang W, Aujard I, Le Saux T, Ducos B, Vriz S, Jullien L, Bensimon D. Optical control of protein activity and gene expression by photoactivation of caged cyclofen. Methods Enzymol 2019; 624:1-23. [PMID: 31370925 DOI: 10.1016/bs.mie.2019.04.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The use of light to control the expression of genes and the activity of proteins is a rapidly expanding field. While many of these approaches use a fusion between a light activatable protein and the protein of interest to control the activity of the latter, it is also possible to control the activity of a protein by uncaging a specific ligand. In that context, controlling the activation of a protein fused to the modified estrogen receptor (ERT) by uncaging its ligand cyclofen-OH has emerged as a generic and versatile method to control the activation of proteins quantitatively, quickly and locally in a live organism. Here, we present the experimental details behind this approach.
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Affiliation(s)
- Fatima Hamouri
- Laboratoire de Physique de l'ENS, CNRS-UMR8023, PSL Research University, Paris, France; Institut de Biologie de l'ENS, CNRS-UMR8197, INSERM-U1024, PSL Research University, Paris, France
| | - Weiting Zhang
- Laboratoire de Physique de l'ENS, CNRS-UMR8023, PSL Research University, Paris, France; Institut de Biologie de l'ENS, CNRS-UMR8197, INSERM-U1024, PSL Research University, Paris, France
| | - Isabelle Aujard
- PASTEUR, Département de Chimie de l'ENS, CNRS, PSL Research University, Paris, France; Sorbonne Universités, UPMC Univ Paris 06, ENS, CNRS, PASTEUR, Paris, France
| | - Thomas Le Saux
- PASTEUR, Département de Chimie de l'ENS, CNRS, PSL Research University, Paris, France; Sorbonne Universités, UPMC Univ Paris 06, ENS, CNRS, PASTEUR, Paris, France
| | - Bertrand Ducos
- Laboratoire de Physique de l'ENS, CNRS-UMR8023, PSL Research University, Paris, France; Institut de Biologie de l'ENS, CNRS-UMR8197, INSERM-U1024, PSL Research University, Paris, France
| | - Sophie Vriz
- Center for Interdisciplinary Research in Biology (CIRB), College de France, CNRS UMR 7241, INSERM U1050, Paris, France; Department of Life Sciences, Paris-Diderot University, Sorbonne-Paris-Cité, Paris, France
| | - Ludovic Jullien
- PASTEUR, Département de Chimie de l'ENS, CNRS, PSL Research University, Paris, France; Sorbonne Universités, UPMC Univ Paris 06, ENS, CNRS, PASTEUR, Paris, France
| | - David Bensimon
- Laboratoire de Physique de l'ENS, CNRS-UMR8023, PSL Research University, Paris, France; Institut de Biologie de l'ENS, CNRS-UMR8197, INSERM-U1024, PSL Research University, Paris, France; Department of Chemistry and Biochemistry, University of California at Los Angeles, Los Angeles, CA, United States.
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6
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Mitchell J, Yanamala N, Tan YL, Gardner EE, Tirupula KC, Balem F, Sheves M, Nietlispach D, Klein‐Seetharaman J. Structural and Functional Consequences of the Weak Binding of Chlorin e6 to Bovine Rhodopsin. Photochem Photobiol 2019; 95:787-802. [DOI: 10.1111/php.13074] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2018] [Accepted: 12/07/2018] [Indexed: 12/14/2022]
Affiliation(s)
- James Mitchell
- Biomedical Sciences Division Warwick Medical School University of Warwick Coventry UK
| | - Naveena Yanamala
- Department of Structural Biology School of Medicine University of Pittsburgh Pittsburgh PA
| | - Yi Lei Tan
- Department of Biochemistry University of Cambridge Cambridge UK
| | - Eric E. Gardner
- Department of Structural Biology School of Medicine University of Pittsburgh Pittsburgh PA
| | - Kalyan C. Tirupula
- Department of Structural Biology School of Medicine University of Pittsburgh Pittsburgh PA
| | - Fernanda Balem
- Department of Structural Biology School of Medicine University of Pittsburgh Pittsburgh PA
| | - Mordechai Sheves
- Organic Chemistry Department Weizmann Institute of Science Rehovot Israel
| | | | - Judith Klein‐Seetharaman
- Biomedical Sciences Division Warwick Medical School University of Warwick Coventry UK
- Department of Structural Biology School of Medicine University of Pittsburgh Pittsburgh PA
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7
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A light in the dark: state of the art and perspectives in optogenetics and optopharmacology for restoring vision. Future Med Chem 2019; 11:463-487. [DOI: 10.4155/fmc-2018-0315] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
In the last decade, innovative therapeutic strategies against inherited retinal degenerations (IRDs) have emerged. In particular, chemical- and opto-genetics approaches or a combination of them have been identified for modulating neuronal/optical activity in order to restore vision in blinding diseases. The ‘chemical-genetics approach’ (optopharmacology) uses small molecules (exogenous photoswitches) for restoring light sensitivity by activating ion channels. The ‘opto-genetics approach’ employs light-activated photosensitive proteins (exogenous opsins), introduced by viral vectors in injured tissues, to restore light response. These approaches offer control of neuronal activities with spatial precision and limited invasiveness, although with some drawbacks. Currently, a combined therapeutic strategy (optogenetic pharmacology) is emerging. This review describes the state of the art and provides an overview of the future perspectives in vision restoration.
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8
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Zhang W, Hamouri F, Feng Z, Aujard I, Ducos B, Ye S, Weiss S, Volovitch M, Vriz S, Jullien L, Bensimon D. Control of Protein Activity and Gene Expression by Cyclofen-OH Uncaging. Chembiochem 2018; 19:1232-1238. [PMID: 29341391 DOI: 10.1002/cbic.201700630] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Indexed: 11/06/2022]
Abstract
The use of light to control the expression of genes and the activity of proteins is a rapidly expanding field. Whereas many of these approaches use fusion between a light-activable protein and the protein of interest to control the activity of the latter, it is also possible to control the activity of a protein by uncaging a specific ligand. In that context, controlling the activation of a protein fused to the modified estrogen receptor (ERT) by uncaging its ligand cyclofen-OH has emerged as a generic and versatile method to control the activation of proteins quantitatively, quickly, and locally in a live organism. We present that approach and its uses in a variety of physiological contexts.
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Affiliation(s)
- Weiting Zhang
- Laboratoire de Physique Statistique, Ecole Normale Supérieure, PSL Research University, 24 rue Lhomond, 75005, Paris, France.,IBENS, CNRS-UMR8197, INSERM-U1024, PSL Research University, 46 rue d'Ulm, 75005, Paris, France
| | - Fatima Hamouri
- Laboratoire de Physique Statistique, Ecole Normale Supérieure, PSL Research University, 24 rue Lhomond, 75005, Paris, France.,IBENS, CNRS-UMR8197, INSERM-U1024, PSL Research University, 46 rue d'Ulm, 75005, Paris, France
| | - Zhiping Feng
- Department of Chemical and Systems Biology, Stanford University, Stanford, CA, 94305, USA
| | - Isabelle Aujard
- PASTEUR, Département de Chimie, École Normale Supérieure, UPMC Univ Paris 06, CNRS, PSL Research University, 75005, Paris, France.,Sorbonne Universités, UPMC Univ Paris 06, École Normale Supérieure, CNRS, PASTEUR, 75005, Paris, France
| | - Bertrand Ducos
- Laboratoire de Physique Statistique, Ecole Normale Supérieure, PSL Research University, 24 rue Lhomond, 75005, Paris, France.,IBENS, CNRS-UMR8197, INSERM-U1024, PSL Research University, 46 rue d'Ulm, 75005, Paris, France
| | - Shixin Ye
- Sorbonne Universités, UPMC Univ Paris 06, 4 place Jussieu, 75005, Paris, France
| | - Shimon Weiss
- Department of Chemistry and Biochemistry, University of California at Los Angeles, Los Angeles, CA, 90024, USA
| | - Michel Volovitch
- Center for Interdisciplinary Research in Biology (CIRB), College de France, CNRS UMR 7241, INSERM U1050, 11 place Marcellin Berthelot, 75005, Paris, France.,Department of Biology, Ecole Normale Supérieure, PSL Research University, 46 rue d'Ulm, 75005, Paris, France
| | - Sophie Vriz
- Center for Interdisciplinary Research in Biology (CIRB), College de France, CNRS UMR 7241, INSERM U1050, 11 place Marcellin Berthelot, 75005, Paris, France.,Department of Life Sciences, Paris-Diderot University, Sorbonne-Paris-Cité, 5 rue Thomas Mann, 75013, Paris, France
| | - Ludovic Jullien
- PASTEUR, Département de Chimie, École Normale Supérieure, UPMC Univ Paris 06, CNRS, PSL Research University, 75005, Paris, France.,Sorbonne Universités, UPMC Univ Paris 06, École Normale Supérieure, CNRS, PASTEUR, 75005, Paris, France
| | - David Bensimon
- Laboratoire de Physique Statistique, Ecole Normale Supérieure, PSL Research University, 24 rue Lhomond, 75005, Paris, France.,IBENS, CNRS-UMR8197, INSERM-U1024, PSL Research University, 46 rue d'Ulm, 75005, Paris, France.,Department of Chemistry and Biochemistry, University of California at Los Angeles, Los Angeles, CA, 90024, USA
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9
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Li G, Ferrie AM, Fang Y. Label-Free Profiling of Ligands for Endogenous Gpcrs Using a Cell-Based High-Throughput Screening Technology. ACTA ACUST UNITED AC 2016. [DOI: 10.1016/j.jala.2006.06.001] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
This article reports the use of Corning Epic system— a label-free and noninvasive optical system that is centered on resonant waveguide grating biosensors—to profile endogenous G protein-coupled receptors (GPCRs) in living cells under physiologically relevant conditions. The endogenous GPCRs examined were bradykinin B2 receptor in A431 cells and protease-activated receptor subtype 1 (PAR1) in Chinese hamster ovary (CHO) cells. The activation of either receptor led to Gq-mediated signaling in the respective cells, as confirmed by Fluo-3 assays. Stimulation of CHO cells with thrombin, a PAR1 natural agonist, resulted in an optical response relating to dynamic mass redistribution that is similar to that induced by bradykinin in A431 cells. Based on the kinetics of agonist-mediated optical signatures, two time points, one before and another 5 min after the stimulation, were chosen to develop high-throughput (HT) screening assays. Results showed that such endpoint measurements enable not only HT screening of compounds using endogenous GPCRs, but also determining the efficacies of agonists. Those results suggested that the Corning Epic label-free system is an easily scaleable biosensor, amenable as an HTS platform for GPCR drug discovery and deorphanization. (JALA 2006;11:181–7)
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Affiliation(s)
| | | | - Ye Fang
- Corning Incorporated, Corning, NY
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10
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Moore AR, Ceraudo E, Sher JJ, Guan Y, Shoushtari AN, Chang MT, Zhang JQ, Walczak EG, Kazmi MA, Taylor BS, Huber T, Chi P, Sakmar TP, Chen Y. Recurrent activating mutations of G-protein-coupled receptor CYSLTR2 in uveal melanoma. Nat Genet 2016; 48:675-80. [PMID: 27089179 DOI: 10.1038/ng.3549] [Citation(s) in RCA: 203] [Impact Index Per Article: 25.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Accepted: 03/21/2016] [Indexed: 12/16/2022]
Abstract
Uveal melanomas are molecularly distinct from cutaneous melanomas and lack mutations in BRAF, NRAS, KIT, and NF1. Instead, they are characterized by activating mutations in GNAQ and GNA11, two highly homologous α subunits of Gαq/11 heterotrimeric G proteins, and in PLCB4 (phospholipase C β4), the downstream effector of Gαq signaling. We analyzed genomics data from 136 uveal melanoma samples and found a recurrent mutation in CYSLTR2 (cysteinyl leukotriene receptor 2) encoding a p.Leu129Gln substitution in 4 of 9 samples that lacked mutations in GNAQ, GNA11, and PLCB4 but in 0 of 127 samples that harbored mutations in these genes. The Leu129Gln CysLT2R mutant protein constitutively activates endogenous Gαq and is unresponsive to stimulation by leukotriene. Expression of Leu129Gln CysLT2R in melanocytes enforces expression of a melanocyte-lineage signature, drives phorbol ester-independent growth in vitro, and promotes tumorigenesis in vivo. Our findings implicate CYSLTR2 as a uveal melanoma oncogene and highlight the critical role of Gαq signaling in uveal melanoma pathogenesis.
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Affiliation(s)
- Amanda R Moore
- Human Oncology and Pathogenesis Program, Memorial Sloan Kettering Cancer Center, New York, New York, USA.,Weill Cornell Graduate School of Medical Sciences, Cornell University, New York, New York, USA
| | - Emilie Ceraudo
- Laboratory of Chemical Biology and Signal Transduction, Rockefeller University, New York, New York, USA
| | - Jessica J Sher
- Human Oncology and Pathogenesis Program, Memorial Sloan Kettering Cancer Center, New York, New York, USA
| | - Youxin Guan
- Human Oncology and Pathogenesis Program, Memorial Sloan Kettering Cancer Center, New York, New York, USA
| | - Alexander N Shoushtari
- Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, New York, USA.,Department of Medicine, Weill Cornell Medical College, New York, New York, USA
| | - Matthew T Chang
- Human Oncology and Pathogenesis Program, Memorial Sloan Kettering Cancer Center, New York, New York, USA.,Department of Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center, New York, New York, USA.,Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, California, USA
| | - Jenny Q Zhang
- Human Oncology and Pathogenesis Program, Memorial Sloan Kettering Cancer Center, New York, New York, USA
| | - Edward G Walczak
- Human Oncology and Pathogenesis Program, Memorial Sloan Kettering Cancer Center, New York, New York, USA
| | - Manija A Kazmi
- Laboratory of Chemical Biology and Signal Transduction, Rockefeller University, New York, New York, USA
| | - Barry S Taylor
- Human Oncology and Pathogenesis Program, Memorial Sloan Kettering Cancer Center, New York, New York, USA.,Department of Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center, New York, New York, USA.,Marie-Josée and Henry R. Kravis Center for Molecular Oncology, Memorial Sloan Kettering Cancer Center, New York, New York, USA
| | - Thomas Huber
- Laboratory of Chemical Biology and Signal Transduction, Rockefeller University, New York, New York, USA
| | - Ping Chi
- Human Oncology and Pathogenesis Program, Memorial Sloan Kettering Cancer Center, New York, New York, USA.,Weill Cornell Graduate School of Medical Sciences, Cornell University, New York, New York, USA.,Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, New York, USA.,Department of Medicine, Weill Cornell Medical College, New York, New York, USA
| | - Thomas P Sakmar
- Laboratory of Chemical Biology and Signal Transduction, Rockefeller University, New York, New York, USA.,Department of Neurobiology, Care Sciences and Society, Division for Neurogeriatrics, Center for Alzheimer Research, Karolinska Institutet, Huddinge, Sweden
| | - Yu Chen
- Human Oncology and Pathogenesis Program, Memorial Sloan Kettering Cancer Center, New York, New York, USA.,Weill Cornell Graduate School of Medical Sciences, Cornell University, New York, New York, USA.,Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, New York, USA.,Department of Medicine, Weill Cornell Medical College, New York, New York, USA
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11
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Liu Y, An S, Ward R, Yang Y, Guo XX, Li W, Xu TR. G protein-coupled receptors as promising cancer targets. Cancer Lett 2016; 376:226-39. [PMID: 27000991 DOI: 10.1016/j.canlet.2016.03.031] [Citation(s) in RCA: 85] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Revised: 03/14/2016] [Accepted: 03/14/2016] [Indexed: 02/07/2023]
Abstract
G protein-coupled receptors (GPCRs) regulate an array of fundamental biological processes, such as growth, metabolism and homeostasis. Specifically, GPCRs are involved in cancer initiation and progression. However, compared with the involvement of the epidermal growth factor receptor in cancer, that of GPCRs have been largely ignored. Recent findings have implicated many GPCRs in tumorigenesis, tumor progression, invasion and metastasis. Moreover, GPCRs contribute to the establishment and maintenance of a microenvironment which is permissive for tumor formation and growth, including effects upon surrounding blood vessels, signaling molecules and the extracellular matrix. Thus, GPCRs are considered to be among the most useful drug targets against many solid cancers. Development of selective ligands targeting GPCRs may provide novel and effective treatment strategies against cancer and some anticancer compounds are now in clinical trials. Here, we focus on tumor related GPCRs, such as G protein-coupled receptor 30, the lysophosphatidic acid receptor, angiotensin receptors 1 and 2, the sphingosine 1-phosphate receptors and gastrin releasing peptide receptor. We also summarize their tissue distributions, activation and roles in tumorigenesis and discuss the potential use of GPCR agonists and antagonists in cancer therapy.
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Affiliation(s)
- Ying Liu
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, Yunnan 650500, China
| | - Su An
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, Yunnan 650500, China
| | - Richard Ward
- Molecular Pharmacology Group, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, Scotland, United Kingdom
| | - Yang Yang
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, Yunnan 650500, China
| | - Xiao-Xi Guo
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, Yunnan 650500, China
| | - Wei Li
- Kidney Cancer Research, Diagnosis and Translational Technology Center of Yunnan Province, Department of Urology, The People's Hospital of Yunnan Province, Kunming, Yunnan 650032, China.
| | - Tian-Rui Xu
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, Yunnan 650500, China.
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12
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Functional genomics identifies regulators of the phototransduction machinery in the Drosophila larval eye and adult ocelli. Dev Biol 2016; 410:164-177. [PMID: 26769100 DOI: 10.1016/j.ydbio.2015.12.026] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Revised: 12/22/2015] [Accepted: 12/22/2015] [Indexed: 11/21/2022]
Abstract
Sensory perception of light is mediated by specialized Photoreceptor neurons (PRs) in the eye. During development all PRs are genetically determined to express a specific Rhodopsin (Rh) gene and genes mediating a functional phototransduction pathway. While the genetic and molecular mechanisms of PR development is well described in the adult compound eye, it remains unclear how the expression of Rhodopsins and the phototransduction cascade is regulated in other visual organs in Drosophila, such as the larval eye and adult ocelli. Using transcriptome analysis of larval PR-subtypes and ocellar PRs we identify and study new regulators required during PR differentiation or necessary for the expression of specific signaling molecules of the functional phototransduction pathway. We found that the transcription factor Krüppel (Kr) is enriched in the larval eye and controls PR differentiation by promoting Rh5 and Rh6 expression. We also identified Camta, Lola, Dve and Hazy as key genes acting during ocellar PR differentiation. Further we show that these transcriptional regulators control gene expression of the phototransduction cascade in both larval eye and adult ocelli. Our results show that PR cell type-specific transcriptome profiling is a powerful tool to identify key transcriptional regulators involved during several aspects of PR development and differentiation. Our findings greatly contribute to the understanding of how combinatorial action of key transcriptional regulators control PR development and the regulation of a functional phototransduction pathway in both larval eye and adult ocelli.
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13
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Zhao M, Alleva R, Ma H, Daniel AGS, Schwartz TH. Optogenetic tools for modulating and probing the epileptic network. Epilepsy Res 2015; 116:15-26. [PMID: 26354163 PMCID: PMC4567692 DOI: 10.1016/j.eplepsyres.2015.06.010] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2015] [Revised: 05/29/2015] [Accepted: 06/14/2015] [Indexed: 12/01/2022]
Abstract
Epilepsy affects roughly 1% of the population worldwide. Although effective treatments with antiepileptic drugs are available, more than 20% of patients have seizures that are refractory to medical therapy and many patients experience adverse effects. Hence, there is a continued need for novel therapies for those patients. A new technique called "optogenetics" may offer a new hope for these refractory patients. Optogenetics is a technology based on the combination of optics and genetics, which can control or record neural activity with light. Following delivery of light-sensitive opsin genes such as channelrhodopsin-2 (ChR2), halorhodopsin (NpHR), and others into brain, excitation or inhibition of specific neurons in precise brain areas can be controlled by illumination at different wavelengths with very high temporal and spatial resolution. Neuromodulation with the optogenetics toolbox have already been shown to be effective at treating seizures in animal models of epilepsy. This review will outline the most recent advances in epilepsy research with optogenetic techniques and discuss how this technology can contribute to our understanding and treatment of epilepsy in the future.
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Affiliation(s)
- Mingrui Zhao
- Department of Neurological Surgery, Weill Medical College of Cornell University, New York Presbyterian Hospital, New York, NY 10021, USA.
| | - Rose Alleva
- Department of Neurological Surgery, Weill Medical College of Cornell University, New York Presbyterian Hospital, New York, NY 10021, USA.
| | - Hongtao Ma
- Department of Neurological Surgery, Weill Medical College of Cornell University, New York Presbyterian Hospital, New York, NY 10021, USA.
| | - Andy G S Daniel
- Department of Neurological Surgery, Weill Medical College of Cornell University, New York Presbyterian Hospital, New York, NY 10021, USA.
| | - Theodore H Schwartz
- Department of Neurological Surgery, Weill Medical College of Cornell University, New York Presbyterian Hospital, New York, NY 10021, USA; Department of Otolaryngology, Weill Medical College of Cornell University, New York Presbyterian Hospital, New York, NY 10021, USA; Department of Neuroscience, Weill Medical College of Cornell University, New York Presbyterian Hospital, New York, NY 10021, USA.
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14
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Henriksen BS, Marc RE, Bernstein PS. Optogenetics for retinal disorders. J Ophthalmic Vis Res 2015; 9:374-82. [PMID: 25667740 PMCID: PMC4307663 DOI: 10.4103/2008-322x.143379] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2014] [Accepted: 05/10/2014] [Indexed: 12/26/2022] Open
Abstract
Optogenetics is the use of genetic methods combined with optical technology to achieve gain or loss of function within neuronal circuits. The field of optogenetics has been rapidly expanding in efforts to restore visual function to blinding diseases such as retinitis pigmentosa (RP). Most work in the field includes a group of light-sensitive retinaldehyde-binding proteins known as opsins. Opsins couple photon absorption to molecular signaling chains that control cellular ion currents. Targeting of opsin genes to surviving retinal cells is fundamental to the success of optogenetic therapy. Viral delivery, primarily adeno-associated virus, using intravitreal injection for inner retinal cells and subretinal injection for outer retinal cells, has proven successful in many models. Challenges in bioengineering remain for optogenetics including relative insensitivity of opsins to physiologic light levels of stimulation and difficulty with viral delivery in primate models. However, targeting optogenetic therapy may present an even greater challenge. Neural and glial remodeling seen in advanced stages of RP result in reorganization of remaining neural retina, and optogenetic therapy may not yield functional results. Remodeling also poses a challenge to the selection of cellular targets, with bipolar, amacrine and ganglion cells all playing distinct physiologic roles, and affected by remodeling differently. Although optogenetics has drawn closer to clinical utility, advances in opsin engineering, therapeutic targeting and ultimately in molecular inhibition of remodeling will play critical roles in the continued clinical advancement of optogenetic therapy.
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Affiliation(s)
- Bradley S Henriksen
- Department of Ophthalmology and Visual Sciences, Moran Eye Center, University of Utah School of Medicine, Salt Lake City, Utah, USA
| | - Robert E Marc
- Department of Ophthalmology and Visual Sciences, Moran Eye Center, University of Utah School of Medicine, Salt Lake City, Utah, USA
| | - Paul S Bernstein
- Department of Ophthalmology and Visual Sciences, Moran Eye Center, University of Utah School of Medicine, Salt Lake City, Utah, USA
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15
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Affiliation(s)
| | | | - Krzysztof Palczewski
- Department of Pharmacology, School of Medicine, Case
Western Reserve University, 2109 Adelbert Road, Cleveland, Ohio 44106-4965,
United States
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16
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Gil-Mast S, Kortagere S, Kota K, Kuzhikandathil EV. An amino acid residue in the second extracellular loop determines the agonist-dependent tolerance property of the human D3 dopamine receptor. ACS Chem Neurosci 2013; 4:940-51. [PMID: 23477444 DOI: 10.1021/cn3002202] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
The D3 dopamine receptor is a therapeutic target for treating various nervous system disorders such as schizophrenia, Parkinson's disease, depression, and addictive behaviors. The crystal structure of the D3 receptor bound to an antagonist was recently described; however, the structural features that contribute to agonist-induced conformational changes and signaling properties are not well understood. We have previously described the conformation-dependent tolerance and slow response termination (SRT) signaling properties of the D3 receptor and identified the C147 residue in the second intracellular loop (IL2) of the D3 receptor as important for the tolerance property. Interestingly, while IL2 and the C147 residue, in particular, were important for dopamine- and quinpirole-induced tolerance, this residue did not affect the severe tolerance induced by the high affinity, D3 receptor-selective agonist, PD128907. Here, we used D2/D3 receptor chimeras and site-specific D3 receptor mutants to identify another residue, D187, in the second extracellular loop (EC2) of the human D3 receptor that mediates the tolerance property induced by PD128907, quinpirole, pramipexole, and dopamine. Molecular dynamics simulations confirmed the distinct conformation adopted by D3 receptor during tolerance and suggested that in the tolerant D3 receptor the D187 residue in EC2 forms a salt bridge with the H354 residue in EC3. Indeed, site-directed mutation of the H354 residue resulted in loss of PD1287907-induced tolerance. The mapping of specific amino acid residues that contribute to agonist-dependent conformation changes and D3 receptor signaling properties refines the agonist-bound D3 receptor pharmacophore model which will help develop novel D3 receptor agonists.
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Affiliation(s)
- Sara Gil-Mast
- Department of Pharmacology and Physiology, UMDNJ-New Jersey Medical School, Newark, New Jersey
07103, United States
| | - Sandhya Kortagere
- Department
of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania 19129, United
States
| | - Kokila Kota
- Department of Pharmacology and Physiology, UMDNJ-New Jersey Medical School, Newark, New Jersey
07103, United States
| | - Eldo V. Kuzhikandathil
- Department of Pharmacology and Physiology, UMDNJ-New Jersey Medical School, Newark, New Jersey
07103, United States
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17
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Crystal structure of oligomeric β1-adrenergic G protein-coupled receptors in ligand-free basal state. Nat Struct Mol Biol 2013; 20:419-25. [PMID: 23435379 PMCID: PMC3618578 DOI: 10.1038/nsmb.2504] [Citation(s) in RCA: 215] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2012] [Accepted: 01/03/2013] [Indexed: 01/23/2023]
Abstract
G protein-coupled receptors (GPCRs) mediate transmembrane signaling. Before ligand binding, GPCRs exist in a basal state. Crystal structures of several GPCRs bound with antagonists or agonists have been solved. However, the crystal structure of the ligand-free basal state of a GPCR, the starting point of GPCR activation and function, has not been determined. Here we report the X-ray crystal structure of the first ligand-free basal state of a GPCR in a lipid membrane-like environment. Oligomeric turkey β1-adrenergic receptors display two alternating dimer interfaces. One interface involves the transmembrane domain (TM) 1, TM2, the C-terminal H8, and the extracellular loop 1. The other interface engages residues from TM4, TM5, the intracellular loop 2 and the extracellular loop 2. Structural comparisons show that this ligand-free state is in an inactive conformation. This provides the structural information regarding GPCR dimerization and oligomerization.
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18
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Weadick CJ, Loew ER, Rodd FH, Chang BSW. Visual Pigment Molecular Evolution in the Trinidadian Pike Cichlid (Crenicichla frenata): A Less Colorful World for Neotropical Cichlids? Mol Biol Evol 2012; 29:3045-60. [DOI: 10.1093/molbev/mss115] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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19
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Zhang F, Vierock J, Yizhar O, Fenno LE, Tsunoda S, Kianianmomeni A, Prigge M, Berndt A, Cushman J, Polle J, Magnuson J, Hegemann P, Deisseroth K. The microbial opsin family of optogenetic tools. Cell 2012; 147:1446-57. [PMID: 22196724 PMCID: PMC4166436 DOI: 10.1016/j.cell.2011.12.004] [Citation(s) in RCA: 374] [Impact Index Per Article: 31.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2011] [Revised: 11/17/2011] [Accepted: 12/05/2011] [Indexed: 11/24/2022]
Abstract
The capture and utilization of light is an exquisitely evolved process. The single-component microbial opsins, although more limited than multicomponent cascades in processing, display unparalleled compactness and speed. Recent advances in understanding microbial opsins have been driven by molecular engineering for optogenetics and by comparative genomics. Here we provide a Primer on these light-activated ion channels and pumps, describe a group of opsins bridging prior categories, and explore the convergence of molecular engineering and genomic discovery for the utilization and understanding of these remarkable molecular machines.
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Affiliation(s)
- Feng Zhang
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA.
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20
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Yanamala N, Gardner E, Riciutti A, Klein-Seetharaman J. The cytoplasmic rhodopsin-protein interface: potential for drug discovery. Curr Drug Targets 2012; 13:3-14. [PMID: 21777183 PMCID: PMC3275648 DOI: 10.2174/138945012798868461] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2010] [Revised: 02/08/2011] [Accepted: 02/10/2011] [Indexed: 01/20/2023]
Abstract
The mammalian dim-light photoreceptor rhodopsin is a prototypic G protein coupled receptor (GPCR), interacting with the G protein, transducin, rhodopsin kinase, and arrestin. All of these proteins interact with rhodopsin at its cytoplasmic surface. Structural and modeling studies have provided in-depth descriptions of the respective interfaces. Overlap and thus competition for binding surfaces is a major regulatory mechanism for signal processing. Recently, it was found that the same surface is also targeted by small molecules. These ligands can directly interfere with the binding and activation of the proteins of the signal transduction cascade, but they can also allosterically modulate the retinal ligand binding pocket. Because the pocket that is targeted contains residues that are highly conserved across Class A GPCRs, these findings imply that it may be possible to target multiple GPCRs with the same ligand(s). This is desirable for example in complex diseases such as cancer where multiple GPCRs participate in the disease networks.
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Affiliation(s)
- Naveena Yanamala
- Department of Structural Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15260, USA
| | - Eric Gardner
- Department of Structural Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15260, USA
| | - Alec Riciutti
- Department of Structural Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15260, USA
| | - Judith Klein-Seetharaman
- Department of Structural Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15260, USA
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21
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Fanelli F, De Benedetti PG. Update 1 of: computational modeling approaches to structure-function analysis of G protein-coupled receptors. Chem Rev 2011; 111:PR438-535. [PMID: 22165845 DOI: 10.1021/cr100437t] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Francesca Fanelli
- Dulbecco Telethon Institute, University of Modena and Reggio Emilia, via Campi 183, 41125 Modena, Italy.
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22
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Corley SC, Sprangers P, Albert AD. The bilayer enhances rhodopsin kinetic stability in bovine rod outer segment disk membranes. Biophys J 2011; 100:2946-54. [PMID: 21689528 DOI: 10.1016/j.bpj.2011.05.015] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2010] [Revised: 05/04/2011] [Accepted: 05/09/2011] [Indexed: 10/18/2022] Open
Abstract
Rhodopsin is a kinetically stable protein constituting >90% of rod outer segment disk membrane protein. To investigate the bilayer contribution to rhodopsin kinetic stability, disk membranes were systematically disrupted by octyl-β-D-glucopyranoside. Rhodopsin kinetic stability was examined under subsolubilizing (rhodopsin in a bilayer environment perturbed by octyl-β-D-glucopyranoside) and under fully solubilizing conditions (rhodopsin in a micelle with cosolubilized phospholipids). As determined by DSC, rhodopsin exhibited a scan-rate-dependent irreversible endothermic transition at all stages of solubilization. The transition temperature (T(m)) decreased in the subsolubilizing stage. However, once the rhodopsin was in a micelle environment there was little change of the T(m) as the phospholipid/rhodopsin ratio in the mixed micelles decreased during the fully solubilized stage. Rhodopsin thermal denaturation is consistent with the two-state irreversible model at all stages of solubilization. The activation energy of denaturation (E(act)) was calculated from the scan rate dependence of the T(m) and from the rate of rhodopsin thermal bleaching at all stages of solubilization. The E(act) as determined by both techniques decreased in the subsolubilizing stage, but remained constant once fully solubilized. These results indicate the bilayer structure increases the E(act) to rhodopsin denaturation.
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Affiliation(s)
- Scott C Corley
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut, USA
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23
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Conformational dynamics of helix 8 in the GPCR rhodopsin controls arrestin activation in the desensitization process. Proc Natl Acad Sci U S A 2011; 108:18690-5. [PMID: 22039220 DOI: 10.1073/pnas.1015461108] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Arrestins are regulatory molecules for G-protein coupled receptor function. In visual rhodopsin, selective binding of arrestin to the cytoplasmic side of light-activated, phosphorylated rhodopsin (P-Rh*) terminates signaling via the G-protein transducin. While the "phosphate-sensor" of arrestin for the recognition of receptor-attached phosphates is identified, the molecular mechanism of arrestin binding and the involvement of receptor conformations in this process are still largely hypothetic. Here we used fluorescence pump-probe and time-resolved fluorescence depolarization measurements to investigate the kinetics of arrestin conformational changes and the corresponding nanosecond dynamical changes at the receptor surface. We show that at least two sequential conformational changes of arrestin occur upon interaction with P-Rh*, thus providing a kinetic proof for the suggested multistep nature of arrestin binding. At the cytoplasmic surface of P-Rh*, the structural dynamics of the amphipathic helix 8 (H8), connecting transmembrane helix 7 and the phosphorylated C-terminal tail, depends on the arrestin interaction state. We find that a high mobility of H8 is required in the low-affinity (prebinding) but not in the high-affinity binding state. High-affinity arrestin binding is inhibited when a bulky, inflexible group is bound to H8, indicating close interaction. We further show that this close steric interaction of H8 with arrestin is mandatory for the transition from prebinding to high-affinity binding; i.e., for arrestin activation. This finding implies a regulatory role for H8 in activation of visual arrestin, which shows high selectivity to P-Rh* in contrast to the broad receptor specificity displayed by the two nonvisual arrestins.
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Abstract
Genetically encoded, single-component optogenetic tools have made a significant impact on neuroscience, enabling specific modulation of selected cells within complex neural tissues. As the optogenetic toolbox contents grow and diversify, the opportunities for neuroscience continue to grow. In this review, we outline the development of currently available single-component optogenetic tools and summarize the application of various optogenetic tools in diverse model organisms.
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Affiliation(s)
- Lief Fenno
- Department of Bioengineering, Stanford University, Stanford, California 94305, USA
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25
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Kim TY, Schlieter T, Haase S, Alexiev U. Activation and molecular recognition of the GPCR rhodopsin--insights from time-resolved fluorescence depolarisation and single molecule experiments. Eur J Cell Biol 2011; 91:300-10. [PMID: 21803442 DOI: 10.1016/j.ejcb.2011.03.009] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2010] [Revised: 03/29/2011] [Accepted: 03/29/2011] [Indexed: 10/18/2022] Open
Abstract
The cytoplasmic surface of the G-protein coupled receptor (GPCR) rhodopsin is a key element in membrane receptor activation, molecular recognition by signalling molecules, and receptor deactivation. Understanding of the coupling between conformational changes in the intramembrane domain and the membrane-exposed surface of the photoreceptor rhodopsin is crucial for the elucidation of the molecular mechanism in GPCR activation. As little is known about protein dynamics, particularly the conformational dynamics of the cytoplasmic surface elements on the nanoseconds timescale, we utilised time-resolved fluorescence anisotropy experiments and site-directed fluorescence labelling to provide information on both, conformational space and motion. We summarise our recent advances in understanding rhodopsin dynamics and function using time-resolved fluorescence depolarisation and single molecule fluorescence experiments, with particular focus on the amphipathic helix 8, lying parallel to the cytoplasmic membrane surface and connecting transmembrane helix 7 with the long C-terminal tail.
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Affiliation(s)
- Tai-Yang Kim
- Physics Department, Freie Universität Berlin, Arnimallee 14, D-14195 Berlin, Germany
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26
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Yizhar O, Fenno L, Zhang F, Hegemann P, Diesseroth K. Microbial opsins: a family of single-component tools for optical control of neural activity. Cold Spring Harb Protoc 2011; 2011:top102. [PMID: 21363959 DOI: 10.1101/pdb.top102] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
INTRODUCTIONMembers of the microbial opsin gene family have emerged recently as crucial tools for “optogenetics,” a new neuroscience technology. “Optogenetics” can be defined as the integration of optics and genetics to control well-defined events (such as action potentials) within specified cells (such as a targeted class of projection neurons) in living tissues (such as the brains of freely behaving mammals). In this article, we focus on the diversity of the microbial opsin genes and the structure–function properties of their corresponding proteins.
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27
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Schey KL, Gutierrez DB, Wang Z, Wei J, Grey AC. Novel fatty acid acylation of lens integral membrane protein aquaporin-0. Biochemistry 2010; 49:9858-65. [PMID: 20942504 DOI: 10.1021/bi101415w] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Fatty acid acylation of proteins is a well-studied co- or posttranslational modification typically conferring membrane trafficking signals or membrane anchoring properties to proteins. Commonly observed examples of protein acylation include N-terminal myristoylation and palmitoylation of cysteine residues. In the present study, direct tissue profiling mass spectrometry of bovine and human lens sections revealed an abundant signal tentatively assigned as a lipid-modified form of aquaporin-0. LC/MS/MS proteomic analysis of hydrophobic tryptic peptides from lens membrane proteins revealed both N-terminal and C-terminal peptides modified by 238 and 264 Da which were subsequently assigned by accurate mass measurement as palmitoylation and oleoylation, respectively. Specific sites of modification were the N-terminal methionine residue and lysine 238 revealing, for the first time, an oleic acid modification via an amide linkage to a lysine residue. The specific fatty acids involved reflect their abundance in the lens fiber cell plasma membrane. Imaging mass spectrometry indicated abundant acylated AQP0 in the inner cortical region of both bovine and human lenses and acylated truncation products in the lens nucleus. Additional analyses revealed that the lipid-modified forms partitioned exclusively to a detergent-resistant membrane fraction, suggesting a role in membrane domain targeting.
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Affiliation(s)
- Kevin L Schey
- Department of Biochemistry, Vanderbilt University, Nashville, Tennessee 37232, United States.
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28
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Richardson V. Divergent and Synergistic Regulation of Matrix Metalloprotease Production by Cytokines in Combination with C-C Chemokines. Int J Immunopathol Pharmacol 2010; 23:715-26. [DOI: 10.1177/039463201002300305] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
The chemotactic effects of chemokines on cells has long been known, but it is now clear that chemokines also have much broader activities and are also involved in a number of disease pathologies, such as rheumatoid arthritis, cancer metastasis and other inflammatory processes. This study investigates the effects of four C-C chemokines, CCL2, CCL3, CCL4 and CCL5 either alone or in the presence of two regulatory cytokines TNF-α and TGF-β and their effect on secretion of two matrix metalloproteases MMP, MMP-2 and MMP-9, and the expression of one membrane bound MMP, MMP-14, by a monocytic human cell line, MonoMac6. All four C-C chemokines were shown to be chemotactic, but only CCL2 and CCL4 had any significant stimulatory effect on MMP-9 and MMP-2, respectively. Both TNF-α and TGF-β were found to divergently enhance MMP-9 and MMP-2 secretion respectively, with stimulation indexes of two and five respectively. Simultaneous treatment with TNF-α and chemokine resulted in up to a fifteen-fold stimulation of MMP-9 secretion and treatment with TGF-β and chemokine resulted in up to a fifteen-fold stimulation of MMP-2 secretion, while TNF-α in combination with CCL4 stimulated MMP-14 expression five-fold. Chemokine receptor expression was also investigated using a calcium-sensitive dye and FACS analysis. CCL2, CCL3, and CCL5 all resulted in a detectable enhancement of cytoplasmic Ca2+concentration. CCL4 was unable to activate Ca2+ mobilization, despite the presence of CCR5, the receptor for CCL4. There appeared to be no correlation between MMP production and chemotaxis. The strong synergy between chemokines and cytokines and the enhanced production of MMP may signify the differential regulatory mechanisms of the two cytokines and chemokines in disease pathology.
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Affiliation(s)
- V.J. Richardson
- Division of BioMedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St John's, NL, Canada
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29
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Protein-protein interaction changes in an archaeal light-signal transduction. J Biomed Biotechnol 2010; 2010:424760. [PMID: 20671933 PMCID: PMC2910557 DOI: 10.1155/2010/424760] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2009] [Accepted: 05/05/2010] [Indexed: 11/18/2022] Open
Abstract
Negative phototaxis in Natronomonas pharaonis is initiated by transient interaction changes between photoreceptor and transducer. pharaonis phoborhodopsin (ppR; also called pharaonis sensory rhodopsin II, psR-II) and the cognate transducer protein, pHtrII, form a tight 2 : 2 complex in the unphotolyzed state, and the interaction is somehow altered during the photocycle of ppR. We have studied the signal transduction mechanism in the ppR/pHtrII system by means of low-temperature Fourier-transform infrared (FTIR) spectroscopy. In the paper, spectral comparison in the absence and presence of pHtrII provided fruitful information in atomic details, where vibrational bands were identified by the use of isotope-labeling and site-directed mutagenesis. From these studies, we established the two pathways of light-signal conversion from the receptor to the transducer; (i) from Lys205 (retinal) of ppR to Asn74 of pHtrII through Thr204 and Tyr199, and (ii) from Lys205 of ppR to the cytoplasmic loop region of pHtrII that links Gly83.
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30
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SIVASUNDAR A, PALUMBI SR. Parallel amino acid replacements in the rhodopsins of the rockfishes (Sebastes spp.) associated with shifts in habitat depth. J Evol Biol 2010; 23:1159-69. [DOI: 10.1111/j.1420-9101.2010.01977.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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31
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Ahuja S, Eilers M, Hirshfeld A, Yan ECY, Ziliox M, Sakmar TP, Sheves M, Smith SO. 6-s-cis Conformation and polar binding pocket of the retinal chromophore in the photoactivated state of rhodopsin. J Am Chem Soc 2010; 131:15160-9. [PMID: 19795853 DOI: 10.1021/ja9034768] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The visual pigment rhodopsin is unique among the G protein-coupled receptors in having an 11-cis retinal chromophore covalently bound to the protein through a protonated Schiff base linkage. The chromophore locks the visual receptor in an inactive conformation through specific steric and electrostatic interactions. This efficient inverse agonist is rapidly converted to an agonist, the unprotonated Schiff base of all-trans retinal, upon light activation. Here, we use magic angle spinning NMR spectroscopy to obtain the (13)C chemical shifts (C5-C20) of the all-trans retinylidene chromophore and the (15)N chemical shift of the Schiff base nitrogen in the active metarhodopsin II intermediate. The retinal chemical shifts are sensitive to the conformation of the chromophore and its molecular interactions within the protein-binding site. Comparison of the retinal chemical shifts in metarhodopsin II with those of retinal model compounds reveals that the Schiff base environment is polar. In particular, the (13)C15 and (15)Nepsilon chemical shifts indicate that the C horizontal lineN bond is highly polarized in a manner that would facilitate Schiff base hydrolysis. We show that a strong perturbation of the retinal (13)C12 chemical shift observed in rhodopsin is reduced in wild-type metarhodopsin II and in the E181Q mutant of rhodopsin. On the basis of the T(1) relaxation time of the retinal (13)C18 methyl group and the conjugated retinal (13)C5 and (13)C8 chemical shifts, we have determined that the conformation of the retinal C6-C7 single bond connecting the beta-ionone ring and the retinylidene chain is 6-s-cis in both the inactive and the active states of rhodopsin. These results are discussed within the general framework of ligand-activated G protein-coupled receptors.
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Affiliation(s)
- Shivani Ahuja
- Department of Physics and Astronomy, Stony Brook University, Stony Brook, New York 11794-5215, USA
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32
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Kirchberg K, Kim TY, Haase S, Alexiev U. Functional interaction structures of the photochromic retinal protein rhodopsin. Photochem Photobiol Sci 2010; 9:226-33. [PMID: 20126799 DOI: 10.1039/b9pp00134d] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We studied functional interaction structures of the vertebrate membrane photoreceptor rhodopsin containing retinal as a chromophore. Using time-resolved fluorescence depolarization we analyzed real-time dynamics and conformational changes of the cytoplasmic helix 8 (H8) preceding the long C-terminal tail of rhodopsin. H8 runs parallel to the membrane surface and extends from transmembrane helix 7 whose highly conserved NPxxY(x)F motif connects that region of rhodopsin with the retinal binding pocket. Our measurements indicate that photo-induced retinal isomerization from 11-cis to all-trans provokes conformational changes of H8, including slower motion and reduced flexibility, that are specific for the active metarhodopsin-II photo-intermediate. These conformational changes are absent in the retinal-devoid state opsin and in the phosphorylated metarhodopsin-II state upon receptor deactivation. Furthermore we show that membrane rim effects can influence interfacial reactions at the cytoplasmic rhodopsin surface such as proton transfer reactions between surface and aqueous bulk phase or binding of the signaling protein transducin visualized with single-molecule widefield microscopy. These findings are important for an understanding of the effects of membrane structure on the photo-transduction mechanism.
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Affiliation(s)
- Kristina Kirchberg
- Freie Universität Berlin, Inst. für. Experimentalphysik, Arnimallee 14, D-14195 Berlin, Germany
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Lupieri P, Nguyen CHH, Bafghi ZG, Giorgetti A, Carloni P. Computational molecular biology approaches to ligand-target interactions. HFSP JOURNAL 2009; 3:228-39. [PMID: 20119480 DOI: 10.2976/1.3092784] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2008] [Accepted: 02/11/2009] [Indexed: 11/19/2022]
Abstract
Binding of small molecules to their targets triggers complex pathways. Computational approaches are keys for predictions of the molecular events involved in such cascades. Here we review current efforts at characterizing the molecular determinants in the largest membrane-bound receptor family, the G-protein-coupled receptors (GPCRs). We focus on odorant receptors, which constitute more than half GPCRs. The work presented in this review uncovers structural and energetic aspects of components of the cellular cascade. Finally, a computational approach in the context of radioactive boron-based antitumoral therapies is briefly described.
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Yuzlenko O, Kieć-Kononowicz K. Molecular modeling of A1 and A2A adenosine receptors: comparison of rhodopsin- and beta2-adrenergic-based homology models through the docking studies. J Comput Chem 2008; 30:14-32. [PMID: 18496794 DOI: 10.1002/jcc.21001] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Adenosine receptors (ARs) are members of the superfamily of G protein-coupled receptors. The homology models of adenosine A1 and A2A receptors were constructed. The high-resolution X-ray structure of bovine rhodopsin and crystal structure of beta2-adrenergic receptor were used as templates. The binding sites of the A1 and A2A ARs were constructed by using data obtained from mutagenesis experiments as well as docking simulations of the respective AR antagonsists DPCPX and XAC. To compare rhodopsin- and beta2-adrenergic-based models, the binding mode of A1 (KW-3902, LUF-5437) and A2A (KW-6002, ZM-241385) ARs antagonists were also examined. The differences in the binding ability of both models were noted during the study. The beta2-adrenergic-based A2A AR model was much more capable to stabilize the ligand in the binding site cavity than the corresponding rhodopsin-based A2A AR model, however, such differences were not so clear in case of A1 AR models. It was suggested that for the A1 AR it is possible to use the crystal structure of rhodopsin as a template as well as beta2-adrenergic receptor, but for A2A AR, with the now available beta2-adrenergic receptor X-ray structure, docking studies should be avoided on the rhodopsin-based model. However, taking into account that the beta2AR shares about 31% of the residues with the AR in comparison to 21% in case of bRho, we suggest using beta2-adrenergic-based models for the A1 and A2A ARs for further in silico ligand screening also because of their generally better ability to stabilize ligands inside the binding pocket.
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Affiliation(s)
- Olga Yuzlenko
- Department of Technology and Biotechnology of Drugs, Medical College, Jagiellonian University, Kraków, Poland
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Receptor mosaics of neural and immune communication: Possible implications for basal ganglia functions. ACTA ACUST UNITED AC 2008; 58:400-14. [DOI: 10.1016/j.brainresrev.2007.10.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2007] [Revised: 10/09/2007] [Accepted: 10/10/2007] [Indexed: 12/22/2022]
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Witt M, Ślusarz M, Ciarkowski J. Molecular Modeling of Vasopressin V2 Receptor Tetramer in Hydrated Lipid Membrane. ACTA ACUST UNITED AC 2008. [DOI: 10.1002/qsar.200730082] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Tastan O, Yu E, Ganapathiraju M, Aref A, Rader AJ, Klein-Seetharaman J. Comparison of stability predictions and simulated unfolding of rhodopsin structures. Photochem Photobiol 2007; 83:351-62. [PMID: 17576347 DOI: 10.1562/2006-06-20-ra-942] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Developing a better mechanistic understanding of membrane protein folding is urgently needed because of the discovery of an increasing number of human diseases, where membrane protein instability and misfolding is involved. Towards this goal, we investigated folding and stability of 7-transmembrane (TM) helical bundles by computational methods. We compared the results of three different algorithms for predicting changes in stability of proteins against an experimental mutation dataset obtained for bacteriorhodopsin (BR) and mammalian rhodopsin and find that 61.6% and 70.6% of the mutation results can potentially be explained by known local contributors to the stability of the folded state of BR and mammalian rhodopsin, respectively. To obtain further information on the predicted folding pathway of 7-TM proteins, we conducted simulated thermal unfolding experiments of all available rhodopsin structures with resolution better than 3 angstroms using the Floppy Inclusions and Rigid Substructure Topography (FIRST) method (Jacobs, D. J., A. J. Rader, L. A. Kuhn and M. F. Thorpe [2001] Proteins 44, 150) described previously for a single mammalian rhodopsin structure (Rader et al. [2004] PNAS 101, 7246). In statistical comparison we found that structures of mammalian rhodopsin have a stability core that is characterized by long-range interactions involving amino acids close in space but distant in sequence comprising positions from both extracellular loop and TM regions. In contrast, BR-simulated unfolding does not reveal such a core but is dominated by interactions within individual and groups of TM helices, consistent with the two-stage hypothesis of membrane protein folding. Similar results were obtained for halo- and sensory rhodopsins as for BRs. However, the average folding core energies of sensory rhodopsins were in between those observed for mammalian rhodopsins and BRs hinting at a possible evolution of these structures toward a rhodopsin-like behavior. These results support the conclusion that although the two-stage model can explain the mechanisms of folding and stability of BR, it fails to account for the folding and stability of mammalian rhodopsin, even though the two proteins are structurally related.
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Affiliation(s)
- Oznur Tastan
- Language Technologies Institute, School of Computer Science, Carnegie Mellon University, Pittsburgh, PA, USA
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Epps J, Lewis JW, Szundi I, Kliger DS. Lumi I --> Lumi II: the last detergent independent process in rhodopsin photoexcitationt. Photochem Photobiol 2007; 82:1436-41. [PMID: 16553464 DOI: 10.1562/2006-02-01-ra-792] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Time-resolved absorbance difference spectra were collected at delays from 1 to 128 micros after photolysis of membrane and detergent suspensions of rhodopsin at 20 degrees C. Fitting both sets of data with two exponential decays plus a constant showed a similar fast process (lifetime 11 micros in membrane, 12 micros in 5% dodecyl maltoside) with a small but similar spectral change. This demonstrates that the Lumi I - Lumi II process, previously characterized in detergent suspensions, has similar properties in membrane without significant effect of detergent. The slower exponential process detected in the data is quite different in membrane compared to detergent solubilized samples, showing that the pronounced effect of detergent on the later rhodopsin photointermediates begins fairly abruptly near 20 micros. Besides affecting the late processes, the data collected here shows that detergent induces a small blue shift in the 1 micros difference spectrum (the Lumi I minus rhodopsin difference spectrum). The blue shift is similar to one induced by chloride ion in the E181Q rhodopsin mutant and may indicate that the ionization state of Glu181 in rhodopsin is affected by detergent.
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Affiliation(s)
- Jacqueline Epps
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, Santa Cruz, California 95064, USA
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40
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Crozier PS, Stevens MJ, Woolf TB. How a small change in retinal leads to G-protein activation: initial events suggested by molecular dynamics calculations. Proteins 2007; 66:559-74. [PMID: 17109408 PMCID: PMC2848121 DOI: 10.1002/prot.21175] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Rhodopsin is the prototypical G-protein coupled receptor, coupling light activation with high efficiency to signaling molecules. The dark-state X-ray structures of the protein provide a starting point for consideration of the relaxation from initial light activation to conformational changes that may lead to signaling. In this study we create an energetically unstable retinal in the light activated state and then use molecular dynamics simulations to examine the types of compensation, relaxation, and conformational changes that occur following the cis-trans light activation. The results suggest that changes occur throughout the protein, with changes in the orientation of Helices 5 and 6, a closer interaction between Ala 169 on Helix 4 and retinal, and a shift in the Schiff base counterion that also reflects changes in sidechain interactions with the retinal. Taken together, the simulation is suggestive of the types of changes that lead from local conformational change to light-activated signaling in this prototypical system.
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Affiliation(s)
- Paul S Crozier
- Sandia National Laboratories, MS 1322, Albuquerque, New Mexico 87185-1322, USA.
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41
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Abstract
The rhodopsin crystal structure provides a structural basis for understanding the function of this and other G protein-coupled receptors (GPCRs). The major structural motifs observed for rhodopsin are expected to carry over to other GPCRs, and the mechanism of transformation of the receptor from inactive to active forms is thus likely conserved. Moreover, the high expression level of rhodopsin in the retina, its specific localization in the internal disks of the photoreceptor structures [termed rod outer segments (ROS)], and the lack of other highly abundant membrane proteins allow rhodopsin to be examined in the native disk membranes by a number of methods. The results of these investigations provide evidence of the propensity of rhodopsin and, most likely, other GPCRs to dimerize, a property that may be pertinent to their function.
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Affiliation(s)
- Krzysztof Palczewski
- Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, Ohio 44106-4965, USA.
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Abstract
G protein-coupled receptors (GPCRs) mediate responses to hormones and neurotransmitters, as well as the senses of sight, smell, and taste. These remarkably versatile signaling molecules respond to structurally diverse ligands. Many GPCRs couple to multiple G protein subtypes, and several have been shown to activate G protein-independent signaling pathways. Drugs acting on GPCRs exhibit efficacy profiles that may differ for different signaling cascades. The functional plasticity exhibited by GPCRs can be attributed to structural flexibility and the existence of multiple ligand-specific conformational states. This chapter will review our current understanding of the mechanism by which agonists bind and activate GPCRs.
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Affiliation(s)
- Xavier Deupi
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, California 94305, USA
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43
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Kobilka BK. G protein coupled receptor structure and activation. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2006; 1768:794-807. [PMID: 17188232 PMCID: PMC1876727 DOI: 10.1016/j.bbamem.2006.10.021] [Citation(s) in RCA: 403] [Impact Index Per Article: 22.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2006] [Accepted: 10/23/2006] [Indexed: 11/25/2022]
Abstract
G protein coupled receptors (GPCRs) are remarkably versatile signaling molecules. The members of this large family of membrane proteins are activated by a spectrum of structurally diverse ligands, and have been shown to modulate the activity of different signaling pathways in a ligand specific manner. In this manuscript I will review what is known about the structure and mechanism of activation of GPCRs focusing primarily on two model systems, rhodopsin and the beta(2) adrenoceptor.
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Affiliation(s)
- Brian K Kobilka
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305, USA.
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44
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Epps J, Lewis JW, Szundi I, Kliger DS. Lumi I → Lumi II: The Last Detergent Independent Process in Rhodopsin Photoexcitation. Photochem Photobiol 2006. [DOI: 10.1111/j.1751-1097.2006.tb09796.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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45
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Thiagaraj HV, Ortiz TC, Devereaux MC, Seaver B, Hall B, Parker KK. Regulation of G proteins by human 5-HT1a receptor TM3/i2 and TM5/i3 loop peptides. Neurochem Int 2006; 50:109-18. [PMID: 16973243 DOI: 10.1016/j.neuint.2006.07.017] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2006] [Accepted: 07/11/2006] [Indexed: 12/15/2022]
Abstract
A bioactive synthetic 11 amino acid peptide probe (P11) was constructed according to the published sequence of the human 5HT1a receptor. The probe was used to enhance understanding of cytoplasmic loop 2/G protein coupling and activation. Additionally, two peptides (P8, P9) from the cytoplasmic loop 3 region were synthesized and studied. These probes were tested in a model system of human 5HT1a receptor stably expressed in Chinese Hamster Ovary cells. In agonist inhibition studies, P11 was active in all three receptor preparations tested: whole cells, membrane bound, and solubilized. In analyses of the membrane bound receptor system, P11 demonstrated uncompetitive inhibition characteristics. When forskolin-stimulated cAMP levels were measured, P11 was inactive in this negatively coupled system. Utilizing a [35S]gamma-S-GTP incorporation assay, P11 was unable to stimulate G protein incorporation of GTP. While P8 and P9 were also broadly active as non-competitive agonist inhibitors, their characteristics differed in the signal transduction system. P8 and P9 did not significantly change forskolin-stimulated cAMP levels. However, P8 increased [35S]gamma-S-GTP incorporation, while P9 decreased incorporation. Thus, P11, a synthetic peptide from the TM3/i2 region of the receptor, provides suggestive evidence that this receptor region is involved in G protein coupling but not activation. On the other hand, P8 and P9 activities suggest that the TM5/i3 region is involved in both coupling to and regulation of G protein activity. The current evidence from these cytoplasmic loop regions is discussed in the overall context of an emerging model for human 5HT1a receptor-G protein interactions.
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Affiliation(s)
- Harish V Thiagaraj
- Department of Biomedical and Pharmaceutical Sciences (MPH I02), Skaggs School of Pharmacy, The University of Montana, 32 Campus Drive #1552, Missoula, MT 59812-1552, United States
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46
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Slusarz MJ, Giełdoń A, Slusarz R, Ciarkowski J. Analysis of interactions responsible for vasopressin binding to human neurohypophyseal hormone receptors-molecular dynamics study of the activated receptor-vasopressin-G(alpha) systems. J Pept Sci 2006; 12:180-9. [PMID: 16114100 DOI: 10.1002/psc.714] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Vasopressin (CYFQNCPRG-NH(2), AVP) is a semicyclic endogenous peptide, which exerts a variety of biological effects in mammals. The main physiological roles of AVP are the regulation of water balance and the control of blood pressure and adrenocorticotropin hormone (ACTH) secretion, mediated via three different subtypes of vasopressin receptors: V1a, V1b and V2 receptors (V1aR, V1bR and V2R, respectively). They are the members of the class A, G-protein-coupled receptors (GPCRs). AVP also modulates several behavioral and social functions. In this study, the interactions responsible for AVP binding to vasopressin V1a and V2 receptors versus the closely related oxytocin ([I3,L8]AVP, OT) receptor (OTR) have been investigated. Three-dimensional models of the activated receptors were constructed using multiple sequence alignment, followed by homology modeling using the complex of activated rhodopsin with Gt(alpha) C-terminal peptide of transducin MII-Gt(338-350) prototype as a template. AVP was docked into the receptor-G(alpha) systems. The three lowest-energy pairs of receptor-AVP-G(alpha) (two complexes per each receptor) were selected. The 1-ns unconstrained molecular dynamics (MD) of complexes embedded into the fully hydrated 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphatidylcholine (POPC) lipid bilayer was conducted in the AMBER 7.0 force field. Six relaxed receptor-AVP-G(alpha) models were obtained. The residues responsible for AVP binding to vasopressin receptors have been identified and a different mechanism of AVP binding to V2R than to V1aR has been proposed.
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Affiliation(s)
- Magdalena J Slusarz
- Faculty of Chemistry, University of Gdańsk, Sobieskiego 18, 80-952 Gdańsk, Poland.
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Slusarz MJ, Slusarz R, Ciarkowski J. Molecular dynamics simulation of human neurohypophyseal hormone receptors complexed with oxytocin-modeling of an activated state. J Pept Sci 2006; 12:171-9. [PMID: 16114099 DOI: 10.1002/psc.713] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The neurohypophyseal hormone oxytocin (CYIQNCPLG-NH(2), OT) is involved in the control of labor, secretion of milk and many social and behavioral functions via interaction with its receptors (OTR) located in the uterus, mammary glands and peripheral tissues, respectively. In this paper we propose the interactions responsible for OT binding and selectivity to OTR versus vasopressin ([F3,R8]OT, AVP) receptors: V1aR and V2R, all three belonging to the Class A G protein-coupled receptors (GPCRs). Three-dimensional models of the activated receptors were constructed using a multiple sequence alignment and the activated rhodopsin-transducin (MII-Gt) prototype [Slusarz and Ciarkowski, 2004] as a template. The 1 ns unconstrained molecular dynamics (MD) of three pairs of receptor-OT complexes (two complexes per each receptor) immersed in the fully hydrated 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphatidylcholine (POPC) lipid bilayer was conducted in the AMBER 7.0 force field. The relaxed models of ligand-receptor complexes were used to identify the putative binding sites of OT. The stabilizing interactions with conserved Gln residues in all complexes were identified. The nonconserved hydrophobic residues were proposed as responsible for OTR-OT selectivity and ligand recognition. These results provide guidelines for experimental site-directed mutagenesis and if confirmed, they may be helpful in designing new selective OT analogs with both agonistic or antagonistic properties.
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Affiliation(s)
- Magdalena J Slusarz
- Faculty of Chemistry, University of Gdańsk, Sobieskiego 18, 80-952 Gdańsk, Poland.
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48
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Matsumoto SC, Labovsky V, Roncoroni M, Guida MC, Giménez L, Mitelman J, Gori H, Jurgelevicius R, Grillo A, Manfredi P, Levin MJ, Paveto C. Retinal dysfunction in patients with chronic Chagas' disease is associated to anti‐Trypanosoma cruziantibodies that cross‐react with rhodopsin. FASEB J 2006; 20:550-2. [PMID: 16423878 DOI: 10.1096/fj.05-4654fje] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
To investigate retinal involvement in chronic Chagas' disease, we performed electroretinography and retinal fluorescein angiography studies in chagasic patients. Our results demonstrated a dissociated electrophysiological response characterized by both an abnormal reduction of the electroretinographic b-wave amplitude and a delayed latency, under the dark-adaptated condition. These alterations are compatible with a selective dysfunction of the rods. Antibodies raised against Trypanosoma cruzi that also interact with beta1-adrenergic receptor blocked light stimulation of cGMP-phosphodiesterase in bovine rod membranes. The specificity from the antibody-rhodopsin interaction was confirmed by Western blot analysis and antigenic competition experiments. Our results suggest an immunomediated rhodopsin blockade. T. cruzi infection probably induces an autoimmune response against rhodopsin in the chronic phase of Chagas' disease through a molecular mimicry mechanism similar to that described previously on cardiac human beta1-adrenergic and M2-cholinergic receptors, all related to the same subfamily of G-protein-coupled receptors.
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Affiliation(s)
- Silvia C Matsumoto
- Department of Neurology, Hospital Dr. Teodoro Alvarez, Buenos Aires, Argentina
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49
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Slusarz MJ, Slusarz R, Ciarkowski J. Investigation of mechanism of desmopressin binding in vasopressin V2 receptor versus vasopressin V1a and oxytocin receptors: Molecular dynamics simulation of the agonist-bound state in the membrane–aqueous system. Biopolymers 2006; 81:321-38. [PMID: 16333859 DOI: 10.1002/bip.20420] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The vasopressin V2 receptor (V2R) belongs to the Class A G protein-coupled receptors (GPCRs). V2R is expressed in the renal collecting duct (CD), where it mediates the antidiuretic action of the neurohypophyseal hormone arginine vasopressin (CYFQNCPRG-NH2, AVP). Desmopressin ([1-deamino, 8-D]AVP, dDAVP) is strong selective V2R agonist with negligible pressor and uterotonic activity. In this paper, the interactions responsible for binding of dDAVP to vasopressin V2 receptor versus vasopressin V1a and oxytocin receptors has been examined. Three-dimensional activated models of the receptors were constructed using the multiple sequence alignment and the complex of activated rhodopsin with Gt(alpha) C-terminal peptide of transducin MII-Gt(alpha) (338-350) prototype (Slusarz, R.; Ciarkowski, J. Acta Biochim Pol 2004 51, 129-136) as a template. The 1-ns unconstrained molecular dynamics (MD) of receptor-dDAVP complexes immersed in the fully hydrated 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphatidylcholine (POPC) membrane model was conducted in an Amber 7.0 force field. Highly conserved transmembrane residues have been proposed as being responsible for V2R activation and G protein coupling. Molecular mechanism of the dDAVP binding has been suggested. The internal water molecules involved in an intricate network of the hydrogen bonds inside the receptor cavity have been identified and their role in the stabilization of the agonist-bound state proposed.
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Affiliation(s)
- Magdalena J Slusarz
- Faculty of Chemistry, University of Gdańsk, Sobieskiego 18,80-952 Gdańsk,Poland.
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50
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Kratochwil NA, Malherbe P, Lindemann L, Ebeling M, Hoener MC, Mühlemann A, Porter RHP, Stahl M, Gerber PR. An automated system for the analysis of G protein-coupled receptor transmembrane binding pockets: alignment, receptor-based pharmacophores, and their application. J Chem Inf Model 2005; 45:1324-36. [PMID: 16180909 DOI: 10.1021/ci050221u] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
G protein-coupled receptors (GPCRs) share a common architecture consisting of seven transmembrane (TM) domains. Various lines of evidence suggest that this fold provides a generic binding pocket within the TM region for hosting agonists, antagonists, and allosteric modulators. Here, a comprehensive and automated method allowing fast analysis and comparison of these putative binding pockets across the entire GPCR family is presented. The method relies on a robust alignment algorithm based on conservation indices, focusing on pharmacophore-like relationships between amino acids. Analysis of conservation patterns across the GPCR family and alignment to the rhodopsin X-ray structure allows the extraction of the amino acids lining the TM binding pocket in a so-called ligand binding pocket vector (LPV). In a second step, LPVs are translated to simple 3D receptor pharmacophore models, where each amino acid is represented by a single spherical pharmacophore feature and all atomic detail is omitted. Applications of the method include the assessment of selectivity issues, support of mutagenesis studies, and the derivation of rules for focused screening to identify chemical starting points in early drug discovery projects. Because of the coarseness of this 3D receptor pharmacophore model, however, meaningful scoring and ranking procedures of large sets of molecules are not justified. The LPV analysis of the trace amine-associated receptor family and its experimental validation is discussed as an example. The value of the 3D receptor model is demonstrated for a class C GPCR family, the metabotropic glutamate receptors.
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Affiliation(s)
- Nicole A Kratochwil
- Pharmaceuticals Division, F. Hoffmann-La Roche Ltd, CH-4070 Basel, Switzerland.
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