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Castiglione GM, Chiu YLI, Gutierrez EDA, Van Nynatten A, Hauser FE, Preston M, Bhattacharyya N, Schott RK, Chang BSW. Convergent evolution of dim light vision in owls and deep-diving whales. Curr Biol 2023; 33:4733-4740.e4. [PMID: 37776863 DOI: 10.1016/j.cub.2023.09.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2023] [Revised: 08/21/2023] [Accepted: 09/05/2023] [Indexed: 10/02/2023]
Abstract
Animals with enhanced dim-light sensitivity are at higher risk of light-induced retinal degeneration when exposed to bright light conditions.1,2,3,4 This trade-off is mediated by the rod photoreceptor sensory protein, rhodopsin (RHO), and its toxic vitamin A chromophore by-product, all-trans retinal.5,6,7,8 Rod arrestin (Arr-1) binds to RHO and promotes sequestration of excess all-trans retinal,9,10 which has recently been suggested as a protective mechanism against photoreceptor cell death.2,11 We investigated Arr-1 evolution in animals at high risk of retinal damage due to periodic bright-light exposure of rod-dominated retinas. Here, we find the convergent evolution of enhanced Arr-1/RHO all-trans-retinal sequestration in owls and deep-diving whales. Statistical analyses reveal a parallel acceleration of Arr-1 evolutionary rates in these lineages, which is associated with the introduction of a rare Arr-1 mutation (Q69R) into the RHO-Arr-1 binding interface. Using in vitro assays, we find that this single mutation significantly enhances RHO-all-trans-retinal sequestration by ∼30%. This functional convergence across 300 million years of evolutionary divergence suggests that Arr-1 and RHO may play an underappreciated role in the photoprotection of the eye, with potentially vast clinical significance.
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Affiliation(s)
- Gianni M Castiglione
- Department of Biological Sciences, Vanderbilt University, Nashville, TN 37232, USA; Department of Ophthalmology & Visual Sciences, Vanderbilt University, Nashville, TN 37232, USA; Department of Cell & Systems Biology, University of Toronto, Toronto, ON M5S 3G5, Canada; Department of Ecology & Evolutionary Biology, University of Toronto, Toronto, ON M5S 3B2, Canada; Evolutionary Studies, Vanderbilt University, Nashville, TN 37235, USA.
| | - Yan L I Chiu
- Department of Cell & Systems Biology, University of Toronto, Toronto, ON M5S 3G5, Canada
| | - Eduardo de A Gutierrez
- Department of Ecology & Evolutionary Biology, University of Toronto, Toronto, ON M5S 3B2, Canada
| | - Alexander Van Nynatten
- Department of Cell & Systems Biology, University of Toronto, Toronto, ON M5S 3G5, Canada; Department of Biological Sciences, University of Toronto Scarborough, Toronto, ON M1C 1A4, Canada
| | - Frances E Hauser
- Department of Ecology & Evolutionary Biology, University of Toronto, Toronto, ON M5S 3B2, Canada; Department of Biological Sciences, University of Toronto Scarborough, Toronto, ON M1C 1A4, Canada
| | - Matthew Preston
- Department of Cell & Systems Biology, University of Toronto, Toronto, ON M5S 3G5, Canada
| | - Nihar Bhattacharyya
- Department of Cell & Systems Biology, University of Toronto, Toronto, ON M5S 3G5, Canada; Institute of Ophthalmology, University College London, London EC1V 2PD, UK
| | - Ryan K Schott
- Department of Ecology & Evolutionary Biology, University of Toronto, Toronto, ON M5S 3B2, Canada; Department of Biology and Centre for Vision Research, York University, Toronto, ON M3J 1P3, Canada; Department of Vertebrate Zoology, National Museum of Natural History, Smithsonian Institution, Washington, DC 20560, USA
| | - Belinda S W Chang
- Department of Cell & Systems Biology, University of Toronto, Toronto, ON M5S 3G5, Canada; Department of Ecology & Evolutionary Biology, University of Toronto, Toronto, ON M5S 3B2, Canada.
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2
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Zheng C, Weinstein LD, Nguyen KK, Grewal A, Gurevich EV, Gurevich VV. GPCR Binding and JNK3 Activation by Arrestin-3 Have Different Structural Requirements. Cells 2023; 12:1563. [PMID: 37371033 DOI: 10.3390/cells12121563] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Revised: 05/30/2023] [Accepted: 06/01/2023] [Indexed: 06/29/2023] Open
Abstract
Arrestins bind active phosphorylated G protein-coupled receptors (GPCRs). Among the four mammalian subtypes, only arrestin-3 facilitates the activation of JNK3 in cells. In available structures, Lys-295 in the lariat loop of arrestin-3 and its homologue Lys-294 in arrestin-2 directly interact with the activator-attached phosphates. We compared the roles of arrestin-3 conformational equilibrium and Lys-295 in GPCR binding and JNK3 activation. Several mutants with enhanced ability to bind GPCRs showed much lower activity towards JNK3, whereas a mutant that does not bind GPCRs was more active. The subcellular distribution of mutants did not correlate with GPCR recruitment or JNK3 activation. Charge neutralization and reversal mutations of Lys-295 differentially affected receptor binding on different backgrounds but had virtually no effect on JNK3 activation. Thus, GPCR binding and arrestin-3-assisted JNK3 activation have distinct structural requirements, suggesting that facilitation of JNK3 activation is the function of arrestin-3 that is not bound to a GPCR.
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Affiliation(s)
- Chen Zheng
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, USA
| | - Liana D Weinstein
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, USA
| | - Kevin K Nguyen
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, USA
| | - Abhijeet Grewal
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, USA
| | - Eugenia V Gurevich
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, USA
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3
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Zheng C, Weinstein LD, Nguyen KK, Grewal A, Gurevich EV, Gurevich VV. GPCR binding and JNK3 activation by arrestin-3 have different structural requirements. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.01.538990. [PMID: 37205393 PMCID: PMC10187157 DOI: 10.1101/2023.05.01.538990] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Arrestins bind active phosphorylated G protein-coupled receptors (GPCRs). Among the four mammalian subtypes, only arrestin-3 facilitates the activation of JNK3 in cells. In available structures, Lys-295 in the lariat loop of arrestin-3 and its homologue Lys-294 in arrestin-2 directly interact with the activator-attached phosphates. We compared the role of arrestin-3 conformational equilibrium and of Lys-295 in GPCR binding and JNK3 activation. Several mutants with enhanced ability to bind GPCRs showed much lower activity towards JNK3, whereas a mutant that does not bind GPCRs was more active. Subcellular distribution of mutants did not correlate with GPCR recruitment or JNK3 activation. Charge neutralization and reversal mutations of Lys-295 differentially affected receptor binding on different backgrounds, but had virtually no effect on JNK3 activation. Thus, GPCR binding and arrestin-3-assisted JNK3 activation have distinct structural requirements, suggesting that facilitation of JNK3 activation is the function of arrestin-3 that is not bound to a GPCR.
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4
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Hofmann KP, Lamb TD. Rhodopsin, light-sensor of vision. Prog Retin Eye Res 2023; 93:101116. [PMID: 36273969 DOI: 10.1016/j.preteyeres.2022.101116] [Citation(s) in RCA: 21] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2022] [Revised: 08/20/2022] [Accepted: 08/22/2022] [Indexed: 11/06/2022]
Abstract
The light sensor of vertebrate scotopic (low-light) vision, rhodopsin, is a G-protein-coupled receptor comprising a polypeptide chain with bound chromophore, 11-cis-retinal, that exhibits remarkable physicochemical properties. This photopigment is extremely stable in the dark, yet its chromophore isomerises upon photon absorption with 70% efficiency, enabling the activation of its G-protein, transducin, with high efficiency. Rhodopsin's photochemical and biochemical activities occur over very different time-scales: the energy of retinaldehyde's excited state is stored in <1 ps in retinal-protein interactions, but it takes milliseconds for the catalytically active state to form, and many tens of minutes for the resting state to be restored. In this review, we describe the properties of rhodopsin and its role in rod phototransduction. We first introduce rhodopsin's gross structural features, its evolution, and the basic mechanisms of its activation. We then discuss light absorption and spectral sensitivity, photoreceptor electrical responses that result from the activity of individual rhodopsin molecules, and recovery of rhodopsin and the visual system from intense bleaching exposures. We then provide a detailed examination of rhodopsin's molecular structure and function, first in its dark state, and then in the active Meta states that govern its interactions with transducin, rhodopsin kinase and arrestin. While it is clear that rhodopsin's molecular properties are exquisitely honed for phototransduction, from starlight to dawn/dusk intensity levels, our understanding of how its molecular interactions determine the properties of scotopic vision remains incomplete. We describe potential future directions of research, and outline several major problems that remain to be solved.
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Affiliation(s)
- Klaus Peter Hofmann
- Institut für Medizinische Physik und Biophysik (CC2), Charité, and, Zentrum für Biophysik und Bioinformatik, Humboldt-Unversität zu Berlin, Berlin, 10117, Germany.
| | - Trevor D Lamb
- Eccles Institute of Neuroscience, John Curtin School of Medical Research, The Australian National University, Canberra, ACT 2600, Australia.
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5
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Phosphorylated peptide of G protein-coupled receptor induces dimerization in activated arrestin. Sci Rep 2020; 10:10938. [PMID: 32616825 PMCID: PMC7331637 DOI: 10.1038/s41598-020-67944-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2020] [Accepted: 06/16/2020] [Indexed: 11/08/2022] Open
Abstract
Termination of the G-protein-coupled receptor signaling involves phosphorylation of its C-terminus and subsequent binding of the regulatory protein arrestin. In the visual system, arrestin-1 preferentially binds to photoactivated and phosphorylated rhodopsin and inactivates phototransduction. Here, we have investigated binding of a synthetic phosphopeptide of bovine rhodopsin (residues 323-348) to the active variants of visual arrestin-1: splice variant p44, and the mutant R175E. Unlike the wild type arrestin-1, both these arrestins are monomeric in solution. Solution structure analysis using small angle X-ray scattering supported by size exclusion chromatography results reveal dimerization in both the arrestins in the presence of phosphopeptide. Our results are the first report, to our knowledge, on receptor-induced oligomerization in arrestin, suggesting possible roles for the cellular function of arrestin oligomers. Given high structural homology and the similarities in their activation mechanism, these results are expected to have implications for all arrestin isoforms.
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6
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Park JY, Qu CX, Li RR, Yang F, Yu X, Tian ZM, Shen YM, Cai BY, Yun Y, Sun JP, Chung KY. Structural Mechanism of the Arrestin-3/JNK3 Interaction. Structure 2019; 27:1162-1170.e3. [PMID: 31080119 DOI: 10.1016/j.str.2019.04.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2018] [Revised: 02/25/2019] [Accepted: 04/03/2019] [Indexed: 01/14/2023]
Abstract
Arrestins, in addition to desensitizing GPCR-induced G protein activation, also mediate G protein-independent signaling by interacting with various signaling proteins. Among these, arrestins regulate MAPK signal transduction by scaffolding mitogen-activated protein kinase (MAPK) signaling components such as MAPKKK, MAPKK, and MAPK. In this study, we investigated the binding mode and interfaces between arrestin-3 and JNK3 using hydrogen/deuterium exchange mass spectrometry, 19F-NMR, and tryptophan-induced Atto 655 fluorescence-quenching techniques. Results suggested that the β1 strand of arrestin-3 is the major and potentially only interaction site with JNK3. The results also suggested that C-lobe regions near the activation loop of JNK3 form the potential binding interface, which is variable depending on the ATP binding status. Because the β1 strand of arrestin-3 is buried by the C-terminal strand in its basal state, C-terminal truncation (i.e., pre-activation) of arrestin-3 facilitates the arrestin-3/JNK3 interaction.
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Affiliation(s)
- Ji Young Park
- School of Pharmacy, Sungkyunkwan University, 2066 Seobu-ro, Jangan-gu, Suwon 16419, Republic of Korea
| | - Chang-Xiu Qu
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University, Key Laboratory of Molecular Cardiovascular Science, Ministry of Education, Beijing 100191, China; Key Laboratory Experimental Teratology of the Ministry of Education and Department of Biochemistry and Molecular Biology, Shandong University School of Medicine, 44 Wenhua Xi Road, Jinan, Shandong 250012, China
| | - Rui-Rui Li
- Key Laboratory Experimental Teratology of the Ministry of Education and Department of Biochemistry and Molecular Biology, Shandong University School of Medicine, 44 Wenhua Xi Road, Jinan, Shandong 250012, China
| | - Fan Yang
- Key Laboratory of Infection and Immunity of Shandong Province, Department of Pharmacology, School of Basic Medical Science, Shandong University, Jinan 250012, China
| | - Xiao Yu
- Key Laboratory Experimental Teratology of the Ministry of Education and Department of Physiology, Shandong University School of Medicine, 44 Wenhua Xi Road, Jinan, Shandong 250012, China
| | - Zhao-Mei Tian
- Key Laboratory Experimental Teratology of the Ministry of Education and Department of Biochemistry and Molecular Biology, Shandong University School of Medicine, 44 Wenhua Xi Road, Jinan, Shandong 250012, China
| | - Yue-Mao Shen
- Key Laboratory of Chemical Biology, (Ministry of Education), School of Pharmaceutical Science, Shandong University, Jinan, Shandong 250012, China
| | - Bo-Yang Cai
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University, Key Laboratory of Molecular Cardiovascular Science, Ministry of Education, Beijing 100191, China
| | - Youngjoo Yun
- School of Pharmacy, Sungkyunkwan University, 2066 Seobu-ro, Jangan-gu, Suwon 16419, Republic of Korea
| | - Jin-Peng Sun
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University, Key Laboratory of Molecular Cardiovascular Science, Ministry of Education, Beijing 100191, China; Key Laboratory Experimental Teratology of the Ministry of Education and Department of Biochemistry and Molecular Biology, Shandong University School of Medicine, 44 Wenhua Xi Road, Jinan, Shandong 250012, China.
| | - Ka Young Chung
- School of Pharmacy, Sungkyunkwan University, 2066 Seobu-ro, Jangan-gu, Suwon 16419, Republic of Korea.
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7
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Mayer D, Damberger FF, Samarasimhareddy M, Feldmueller M, Vuckovic Z, Flock T, Bauer B, Mutt E, Zosel F, Allain FHT, Standfuss J, Schertler GFX, Deupi X, Sommer ME, Hurevich M, Friedler A, Veprintsev DB. Distinct G protein-coupled receptor phosphorylation motifs modulate arrestin affinity and activation and global conformation. Nat Commun 2019; 10:1261. [PMID: 30890705 PMCID: PMC6424980 DOI: 10.1038/s41467-019-09204-y] [Citation(s) in RCA: 71] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Accepted: 02/22/2019] [Indexed: 12/15/2022] Open
Abstract
Cellular functions of arrestins are determined in part by the pattern of phosphorylation on the G protein-coupled receptors (GPCRs) to which arrestins bind. Despite high-resolution structural data of arrestins bound to phosphorylated receptor C-termini, the functional role of each phosphorylation site remains obscure. Here, we employ a library of synthetic phosphopeptide analogues of the GPCR rhodopsin C-terminus and determine the ability of these peptides to bind and activate arrestins using a variety of biochemical and biophysical methods. We further characterize how these peptides modulate the conformation of arrestin-1 by nuclear magnetic resonance (NMR). Our results indicate different functional classes of phosphorylation sites: 'key sites' required for arrestin binding and activation, an 'inhibitory site' that abrogates arrestin binding, and 'modulator sites' that influence the global conformation of arrestin. These functional motifs allow a better understanding of how different GPCR phosphorylation patterns might control how arrestin functions in the cell.
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Affiliation(s)
- Daniel Mayer
- Laboratory of Biomolecular Research, Paul Scherrer Institute, 5232, Villigen, Switzerland.
- Department of Biology, ETH Zürich, 8093, Zürich, Switzerland.
- Department of Pharmacology, University of California San Diego School of Medicine, La Jolla, 92093-0636, California, USA.
| | | | | | - Miki Feldmueller
- Laboratory of Biomolecular Research, Paul Scherrer Institute, 5232, Villigen, Switzerland
- Department of Biology, ETH Zürich, 8093, Zürich, Switzerland
| | - Ziva Vuckovic
- Laboratory of Biomolecular Research, Paul Scherrer Institute, 5232, Villigen, Switzerland
- Department of Biology, ETH Zürich, 8093, Zürich, Switzerland
| | - Tilman Flock
- Laboratory of Biomolecular Research, Paul Scherrer Institute, 5232, Villigen, Switzerland
- Department of Biology, ETH Zürich, 8093, Zürich, Switzerland
- Fitzwilliam College, Cambridge, CB3 0DG, UK
| | - Brian Bauer
- Institut für Medizinische Physik und Biophysik, Charité-Universitätsmedizin Berlin, Berlin, 10117, Germany
| | - Eshita Mutt
- Laboratory of Biomolecular Research, Paul Scherrer Institute, 5232, Villigen, Switzerland
| | | | | | - Jörg Standfuss
- Laboratory of Biomolecular Research, Paul Scherrer Institute, 5232, Villigen, Switzerland
| | - Gebhard F X Schertler
- Laboratory of Biomolecular Research, Paul Scherrer Institute, 5232, Villigen, Switzerland
- Department of Biology, ETH Zürich, 8093, Zürich, Switzerland
| | - Xavier Deupi
- Laboratory of Biomolecular Research, Paul Scherrer Institute, 5232, Villigen, Switzerland
- Condensed Matter Theory, Paul Scherrer Institute, 5232, Villigen, Switzerland
| | - Martha E Sommer
- Institut für Medizinische Physik und Biophysik, Charité-Universitätsmedizin Berlin, Berlin, 10117, Germany
| | - Mattan Hurevich
- Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Assaf Friedler
- Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Dmitry B Veprintsev
- Laboratory of Biomolecular Research, Paul Scherrer Institute, 5232, Villigen, Switzerland.
- Department of Biology, ETH Zürich, 8093, Zürich, Switzerland.
- Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, Midlands, NG7 2RD, UK.
- Division of Physiology, Pharmacology & Neuroscience, School of Life Sciences, University of Nottingham, Nottingham, NG7 2UH, UK.
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8
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Peterson YK, Luttrell LM. The Diverse Roles of Arrestin Scaffolds in G Protein-Coupled Receptor Signaling. Pharmacol Rev 2017. [PMID: 28626043 DOI: 10.1124/pr.116.013367] [Citation(s) in RCA: 299] [Impact Index Per Article: 42.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The visual/β-arrestins, a small family of proteins originally described for their role in the desensitization and intracellular trafficking of G protein-coupled receptors (GPCRs), have emerged as key regulators of multiple signaling pathways. Evolutionarily related to a larger group of regulatory scaffolds that share a common arrestin fold, the visual/β-arrestins acquired the capacity to detect and bind activated GPCRs on the plasma membrane, which enables them to control GPCR desensitization, internalization, and intracellular trafficking. By acting as scaffolds that bind key pathway intermediates, visual/β-arrestins both influence the tonic level of pathway activity in cells and, in some cases, serve as ligand-regulated scaffolds for GPCR-mediated signaling. Growing evidence supports the physiologic and pathophysiologic roles of arrestins and underscores their potential as therapeutic targets. Circumventing arrestin-dependent GPCR desensitization may alleviate the problem of tachyphylaxis to drugs that target GPCRs, and find application in the management of chronic pain, asthma, and psychiatric illness. As signaling scaffolds, arrestins are also central regulators of pathways controlling cell growth, migration, and survival, suggesting that manipulating their scaffolding functions may be beneficial in inflammatory diseases, fibrosis, and cancer. In this review we examine the structure-function relationships that enable arrestins to perform their diverse roles, addressing arrestin structure at the molecular level, the relationship between arrestin conformation and function, and sites of interaction between arrestins, GPCRs, and nonreceptor-binding partners. We conclude with a discussion of arrestins as therapeutic targets and the settings in which manipulating arrestin function might be of clinical benefit.
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Affiliation(s)
- Yuri K Peterson
- Department of Drug Discovery and Biomedical Sciences, College of Pharmacy (Y.K.P.), and Departments of Medicine and Biochemistry and Molecular Biology (L.M.L.), Medical University of South Carolina, Charleston, South Carolina; and Ralph H. Johnson Veterans Affairs Medical Center, Charleston, South Carolina (L.M.L.)
| | - Louis M Luttrell
- Department of Drug Discovery and Biomedical Sciences, College of Pharmacy (Y.K.P.), and Departments of Medicine and Biochemistry and Molecular Biology (L.M.L.), Medical University of South Carolina, Charleston, South Carolina; and Ralph H. Johnson Veterans Affairs Medical Center, Charleston, South Carolina (L.M.L.)
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9
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Scheerer P, Sommer ME. Structural mechanism of arrestin activation. Curr Opin Struct Biol 2017; 45:160-169. [PMID: 28600951 DOI: 10.1016/j.sbi.2017.05.001] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Revised: 04/24/2017] [Accepted: 05/01/2017] [Indexed: 01/14/2023]
Abstract
The large and multifunctional family of G protein-coupled receptors (GPCRs) are regulated by a small family of structurally conserved arrestin proteins. In order to bind an active GPCR, arrestin must first be activated by interaction with the phosphorylated receptor C-terminus. Recent years have witnessed major developments in high-resolution crystal structures of pre-active arrestins and arrestin or arrestin-derived peptides in complex with an active GPCR. Although each structure individually offers only a limited snapshot, taken together and interpreted in light of recent complementary functional data, they offer valuable insight into how arrestin is activated by and couples to a phosphorylated active GPCR.
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Affiliation(s)
- Patrick Scheerer
- Institute of Medical Physics and Biophysics (CC2), Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany; Group Protein X-ray Crystallography & Signal Transduction, Germany.
| | - Martha E Sommer
- Institute of Medical Physics and Biophysics (CC2), Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany.
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10
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Understanding the GPCR biased signaling through G protein and arrestin complex structures. Curr Opin Struct Biol 2017; 45:150-159. [PMID: 28558341 DOI: 10.1016/j.sbi.2017.05.004] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Revised: 05/05/2017] [Accepted: 05/05/2017] [Indexed: 12/30/2022]
Abstract
G protein-coupled receptors (GPCRs) are the largest family of cell surface receptors and are important drug targets for many human diseases. The determination of the 3-D structure of GPCRs and their signaling complexes has promoted our understanding of GPCR biology and provided templates for structure-based drug discovery. In this review, we focus on the recent structure work on GPCR signaling complexes, the β2-adrenoreceptor-Gs and the rhodopsin-arrestin complexes in particular, and highlight the structural features of GPCR complexes involved in G protein- and arrestin-mediated signal transduction. The crystal structures reveal distinct structural mechanisms by which GPCRs recruit a G protein and an arrestin. A comparison of the two complex structures provides insight into the molecular mechanism of functionally selective GPCR signaling, and a structural basis for the discovery of G protein- and arrestin-biased treatments of human diseases related to GPCR signal transduction.
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11
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Lally CCM, Bauer B, Selent J, Sommer ME. C-edge loops of arrestin function as a membrane anchor. Nat Commun 2017; 8:14258. [PMID: 28220785 PMCID: PMC5321764 DOI: 10.1038/ncomms14258] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Accepted: 12/13/2016] [Indexed: 01/14/2023] Open
Abstract
G-protein-coupled receptors are membrane proteins that are regulated by a small family of arrestin proteins. During formation of the arrestin-receptor complex, arrestin first interacts with the phosphorylated receptor C terminus in a pre-complex, which activates arrestin for tight receptor binding. Currently, little is known about the structure of the pre-complex and its transition to a high-affinity complex. Here we present molecular dynamics simulations and site-directed fluorescence experiments on arrestin-1 interactions with rhodopsin, showing that loops within the C-edge of arrestin function as a membrane anchor. Activation of arrestin by receptor-attached phosphates is necessary for C-edge engagement of the membrane, and we show that these interactions are distinct in the pre-complex and high-affinity complex in regard to their conformation and orientation. Our results expand current knowledge of C-edge structure and further illuminate the conformational transitions that occur in arrestin along the pathway to tight receptor binding.
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Affiliation(s)
- Ciara C M. Lally
- Institute of Medical Physics and Biophysics (CC2), Charité Medical University, Charitéplatz 1, Berlin 10117, Germany
| | - Brian Bauer
- Institute of Medical Physics and Biophysics (CC2), Charité Medical University, Charitéplatz 1, Berlin 10117, Germany
| | - Jana Selent
- Research Programme on Biomedical Informatics, Department of Experimental and Health Sciences, Pompeu Fabra University, Hospital del Mar Medical Research Institute, Carrer del Dr. Aiguader, 88, Barcelona 08003, Spain
| | - Martha E Sommer
- Institute of Medical Physics and Biophysics (CC2), Charité Medical University, Charitéplatz 1, Berlin 10117, Germany
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12
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Peterhans C, Lally CCM, Ostermaier MK, Sommer ME, Standfuss J. Functional map of arrestin binding to phosphorylated opsin, with and without agonist. Sci Rep 2016; 6:28686. [PMID: 27350090 PMCID: PMC4923902 DOI: 10.1038/srep28686] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Accepted: 06/01/2016] [Indexed: 01/06/2023] Open
Abstract
Arrestins desensitize G protein-coupled receptors (GPCRs) and act as mediators of signalling. Here we investigated the interactions of arrestin-1 with two functionally distinct forms of the dim-light photoreceptor rhodopsin. Using unbiased scanning mutagenesis we probed the individual contribution of each arrestin residue to the interaction with the phosphorylated apo-receptor (Ops-P) and the agonist-bound form (Meta II-P). Disruption of the polar core or displacement of the C-tail strengthened binding to both receptor forms. In contrast, mutations of phosphate-binding residues (phosphosensors) suggest the phosphorylated receptor C-terminus binds arrestin differently for Meta II-P and Ops-P. Likewise, mutations within the inter-domain interface, variations in the receptor-binding loops and the C-edge of arrestin reveal different binding modes. In summary, our results indicate that arrestin-1 binding to Meta II-P and Ops-P is similarly dependent on arrestin activation, although the complexes formed with these two receptor forms are structurally distinct.
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Affiliation(s)
- Christian Peterhans
- Paul Scherrer Institute, Laboratory for Biomolecular Research, CH-5323, Villigen, Switzerland
| | - Ciara C M Lally
- Institut für Medizinische Physik und Biophysik (CC2), Charité-Universitätsmedizin Berlin, Charitéplatz 1, D-10117, Berlin, Germany
| | - Martin K Ostermaier
- Institut für Medizinische Physik und Biophysik (CC2), Charité-Universitätsmedizin Berlin, Charitéplatz 1, D-10117, Berlin, Germany
| | - Martha E Sommer
- Institut für Medizinische Physik und Biophysik (CC2), Charité-Universitätsmedizin Berlin, Charitéplatz 1, D-10117, Berlin, Germany
| | - Jörg Standfuss
- Paul Scherrer Institute, Laboratory for Biomolecular Research, CH-5323, Villigen, Switzerland
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Chatterjee D, Eckert CE, Slavov C, Saxena K, Fürtig B, Sanders CR, Gurevich VV, Wachtveitl J, Schwalbe H. Influence of Arrestin on the Photodecay of Bovine Rhodopsin. Angew Chem Int Ed Engl 2015; 54:13555-60. [PMID: 26383645 PMCID: PMC4685475 DOI: 10.1002/anie.201505798] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Revised: 08/11/2015] [Indexed: 11/07/2022]
Abstract
Continued activation of the photocycle of the dim-light receptor rhodopsin leads to the accumulation of all-trans-retinal in the rod outer segments (ROS). This accumulation can damage the photoreceptor cell. For retinal homeostasis, deactivation processes are initiated in which the release of retinal is delayed. One of these processes involves the binding of arrestin to rhodopsin. Here, the interaction of pre-activated truncated bovine visual arrestin (Arr(Tr)) with rhodopsin in 1,2-diheptanoyl-sn-glycero-3-phosphocholine (DHPC) micelles is investigated by solution NMR techniques and flash photolysis spectroscopy. Our results show that formation of the rhodopsin-arrestin complex markedly influences partitioning in the decay kinetics of rhodopsin, which involves the simultaneous formation of a meta II and a meta III state from the meta I state. Binding of Arr(Tr) leads to an increase in the population of the meta III state and consequently to an approximately twofold slower release of all-trans-retinal from rhodopsin.
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Affiliation(s)
- Deep Chatterjee
- Institute of Organic Chemistry and Chemical Biology, Center of Biomolecular Magnetic Resonance (BMRZ), Goethe University Frankfurt/Main, Max-von-Laue-Strasse 7, 60438 Frankfurt am Main (Germany)
| | - Carl Elias Eckert
- Institute of Physical and Theoretical Chemistry, Goethe University Frankfurt/Main, Max-von-Laue-Strasse 7, 60438 Frankfurt am Main (Germany)
| | - Chavdar Slavov
- Institute of Physical and Theoretical Chemistry, Goethe University Frankfurt/Main, Max-von-Laue-Strasse 7, 60438 Frankfurt am Main (Germany)
| | - Krishna Saxena
- Institute of Organic Chemistry and Chemical Biology, Center of Biomolecular Magnetic Resonance (BMRZ), Goethe University Frankfurt/Main, Max-von-Laue-Strasse 7, 60438 Frankfurt am Main (Germany)
| | - Boris Fürtig
- Institute of Organic Chemistry and Chemical Biology, Center of Biomolecular Magnetic Resonance (BMRZ), Goethe University Frankfurt/Main, Max-von-Laue-Strasse 7, 60438 Frankfurt am Main (Germany)
| | - Charles R Sanders
- Department of Biochemistry, Center for Structural Biology, Institute of Chemical Biology, Vanderbilt University School of Medicine, Nashville, TN 37232 (USA)
| | - Vsevolod V Gurevich
- Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, TN 37232 (USA)
| | - Josef Wachtveitl
- Institute of Physical and Theoretical Chemistry, Goethe University Frankfurt/Main, Max-von-Laue-Strasse 7, 60438 Frankfurt am Main (Germany).
| | - Harald Schwalbe
- Institute of Organic Chemistry and Chemical Biology, Center of Biomolecular Magnetic Resonance (BMRZ), Goethe University Frankfurt/Main, Max-von-Laue-Strasse 7, 60438 Frankfurt am Main (Germany).
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14
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Chatterjee D, Eckert CE, Slavov C, Saxena K, Fürtig B, Sanders CR, Gurevich VV, Wachtveitl J, Schwalbe H. Influence of Arrestin on the Photodecay of Bovine Rhodopsin. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201505798] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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15
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Beyrière F, Sommer ME, Szczepek M, Bartl FJ, Hofmann KP, Heck M, Ritter E. Formation and decay of the arrestin·rhodopsin complex in native disc membranes. J Biol Chem 2015; 290:12919-28. [PMID: 25847250 DOI: 10.1074/jbc.m114.620898] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2014] [Indexed: 01/05/2023] Open
Abstract
In the G protein-coupled receptor rhodopsin, light-induced cis/trans isomerization of the retinal ligand triggers a series of distinct receptor states culminating in the active Metarhodopsin II (Meta II) state, which binds and activates the G protein transducin (Gt). Long before Meta II decays into the aporeceptor opsin and free all-trans-retinal, its signaling is quenched by receptor phosphorylation and binding of the protein arrestin-1, which blocks further access of Gt to Meta II. Although recent crystal structures of arrestin indicate how it might look in a precomplex with the phosphorylated receptor, the transition into the high affinity complex is not understood. Here we applied Fourier transform infrared spectroscopy to monitor the interaction of arrestin-1 and phosphorylated rhodopsin in native disc membranes. By isolating the unique infrared signature of arrestin binding, we directly observed the structural alterations in both reaction partners. In the high affinity complex, rhodopsin adopts a structure similar to Gt-bound Meta II. In arrestin, a modest loss of β-sheet structure indicates an increase in flexibility but is inconsistent with a large scale structural change. During Meta II decay, the arrestin-rhodopsin stoichiometry shifts from 1:1 to 1:2. Arrestin stabilizes half of the receptor population in a specific Meta II protein conformation, whereas the other half decays to inactive opsin. Altogether these results illustrate the distinct binding modes used by arrestin to interact with different functional forms of the receptor.
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Affiliation(s)
- Florent Beyrière
- From the Institut für Medizinische Physik und Biophysik, Charité-Universitätsmedizin Berlin, 10117 Berlin, Germany and
| | - Martha E Sommer
- From the Institut für Medizinische Physik und Biophysik, Charité-Universitätsmedizin Berlin, 10117 Berlin, Germany and
| | - Michal Szczepek
- From the Institut für Medizinische Physik und Biophysik, Charité-Universitätsmedizin Berlin, 10117 Berlin, Germany and
| | - Franz J Bartl
- From the Institut für Medizinische Physik und Biophysik, Charité-Universitätsmedizin Berlin, 10117 Berlin, Germany and Zentrum für Biophysik und Bioinformatik (BPI) and
| | - Klaus Peter Hofmann
- From the Institut für Medizinische Physik und Biophysik, Charité-Universitätsmedizin Berlin, 10117 Berlin, Germany and Zentrum für Biophysik und Bioinformatik (BPI) and
| | - Martin Heck
- From the Institut für Medizinische Physik und Biophysik, Charité-Universitätsmedizin Berlin, 10117 Berlin, Germany and
| | - Eglof Ritter
- Institut für Biologie, Experimentelle Biophysik, Humboldt-Universität zu Berlin, 10115 Berlin, Germany
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16
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Structure-Based Biophysical Analysis of the Interaction of Rhodopsin with G Protein and Arrestin. Methods Enzymol 2015; 556:563-608. [DOI: 10.1016/bs.mie.2014.12.014] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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17
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Sommer ME, Hofmann KP, Heck M. Not just signal shutoff: the protective role of arrestin-1 in rod cells. Handb Exp Pharmacol 2014; 219:101-16. [PMID: 24292826 DOI: 10.1007/978-3-642-41199-1_5] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The retinal rod cell is an exquisitely sensitive single-photon detector that primarily functions in dim light (e.g., moonlight). However, rod cells must routinely survive light intensities more than a billion times greater (e.g., bright daylight). One serious challenge to rod cell survival in daylight is the massive amount of all-trans-retinal that is released by Meta II, the light-activated form of the photoreceptor rhodopsin. All-trans-retinal is toxic, and its condensation products have been implicated in disease. Our recent work has developed the concept that rod arrestin (arrestin-1), which terminates Meta II signaling, has an additional role in protecting rod cells from the consequences of bright light by limiting free all-trans-retinal. In this chapter we will elaborate upon the molecular mechanisms by which arrestin-1 serves as both a single-photon response quencher as well as an instrument of rod cell survival in bright light. This discussion will take place within the framework of three distinct functional modules of vision: signal transduction, the retinoid cycle, and protein translocation.
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Affiliation(s)
- Martha E Sommer
- Institut für Medizinische Physik und Biophysik (CC2), Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117, Berlin, Germany,
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18
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Kim YJ, Hofmann KP, Ernst OP, Scheerer P, Choe HW, Sommer ME. Crystal structure of pre-activated arrestin p44. Nature 2013; 497:142-6. [PMID: 23604253 DOI: 10.1038/nature12133] [Citation(s) in RCA: 141] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2013] [Accepted: 04/02/2013] [Indexed: 12/21/2022]
Abstract
Arrestins interact with G-protein-coupled receptors (GPCRs) to block interaction with G proteins and initiate G-protein-independent signalling. Arrestins have a bi-lobed structure that is stabilized by a long carboxy-terminal tail (C-tail), and displacement of the C-tail by receptor-attached phosphates activates arrestins for binding active GPCRs. Structures of the inactive state of arrestin are available, but it is not known how C-tail displacement activates arrestin for receptor coupling. Here we present a 3.0 Å crystal structure of the bovine arrestin-1 splice variant p44, in which the activation step is mimicked by C-tail truncation. The structure of this pre-activated arrestin is profoundly different from the basal state and gives insight into the activation mechanism. p44 displays breakage of the central polar core and other interlobe hydrogen-bond networks, leading to a ∼21° rotation of the two lobes as compared to basal arrestin-1. Rearrangements in key receptor-binding loops in the central crest region include the finger loop, loop 139 (refs 8, 10, 11) and the sequence Asp 296-Asn 305 (or gate loop), here identified as controlling the polar core. We verified the role of these conformational alterations in arrestin activation and receptor binding by site-directed fluorescence spectroscopy. The data indicate a mechanism for arrestin activation in which C-tail displacement releases critical central-crest loops from restricted to extended receptor-interacting conformations. In parallel, increased flexibility between the two lobes facilitates a proper fitting of arrestin to the active receptor surface. Our results provide a snapshot of an arrestin ready to bind the active receptor, and give an insight into the role of naturally occurring truncated arrestins in the visual system.
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Affiliation(s)
- Yong Ju Kim
- Institut für Medizinische Physik und Biophysik (CC2), Charité-Universitätsmedizin Berlin, Charitéplatz 1, D-10117 Berlin, Germany
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19
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Smith WC. The role of arrestins in visual and disease processes of the eye. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2013; 118:243-65. [PMID: 23764057 DOI: 10.1016/b978-0-12-394440-5.00010-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Visual arrestins are well known for their function in quenching the phototransduction process in rods and cones. Perhaps not as well known is their participation in multiple other processes in the normal and disease states of the eye. This chapter covers the range of the known functions of the visual arrestins, beginning with their classical role in quenching light-activated visual pigments. The role of visual arrestins is also reviewed from the perspective of their dynamic mobility whereby they redistribute significantly between the compartments of highly polarized photoreceptor cells. Additional roles of the visual arrestins are also reviewed based on new interacting partners that have been discovered over the past decade. Finally, the contribution of the visual arrestins to diseases of the visual system is explored.
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Affiliation(s)
- W Clay Smith
- Department of Ophthalmology, University of Florida, Gainesville, Florida, USA
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20
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Granzin J, Cousin A, Weirauch M, Schlesinger R, Büldt G, Batra-Safferling R. Crystal structure of p44, a constitutively active splice variant of visual arrestin. J Mol Biol 2012; 416:611-8. [PMID: 22306737 DOI: 10.1016/j.jmb.2012.01.028] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2011] [Revised: 12/22/2011] [Accepted: 01/17/2012] [Indexed: 11/26/2022]
Abstract
Visual arrestin specifically binds to photoactivated and phosphorylated rhodopsin and inactivates phototransduction. In contrast, the p44 splice variant can terminate phototransduction by binding to nonphosphorylated light-activated rhodopsin. Here we report the crystal structure of bovine p44 at a resolution of 1.85 Å. Compared to native arrestin, the p44 structure reveals significant differences in regions crucial for receptor binding, namely flexible loop V-VI and polar core regions. Additionally, electrostatic potential is remarkably positive on the N-domain and the C-domain. The p44 structure represents an active conformation that serves as a model to explain the 'constitutive activity' found in arrestin variants.
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Affiliation(s)
- Joachim Granzin
- Institute of Complex Systems, ICS-6: Structural Biochemistry, Forschungszentrum Jülich, 52425 Jülich, Germany
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21
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Tsukamoto H, Sinha A, DeWitt M, Farrens DL. Monomeric rhodopsin is the minimal functional unit required for arrestin binding. J Mol Biol 2010; 399:501-11. [PMID: 20417217 DOI: 10.1016/j.jmb.2010.04.029] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2010] [Revised: 04/13/2010] [Accepted: 04/16/2010] [Indexed: 11/19/2022]
Abstract
We have tested whether arrestin binding requires the G-protein-coupled receptor be a dimer or a multimer. To do this, we encapsulated single-rhodopsin molecules into nanoscale phospholipid particles (so-called nanodiscs) and measured their ability to bind arrestin. Our data clearly show that both visual arrestin and beta-arrestin 1 can bind to monomeric rhodopsin and stabilize the active metarhodopsin II form. Interestingly, we find that the monomeric rhodopsin in nanodiscs has a higher affinity for wild-type arrestin binding than does oligomeric rhodopsin in liposomes or nanodiscs, as assessed by stabilization of metarhodopsin II. Together, these results establish that rhodopsin self-association is not required to enable arrestin binding.
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Affiliation(s)
- Hisao Tsukamoto
- Department of Biochemistry and Molecular Biology, Oregon Health and Science University, 3181 SW Sam Jackson Park Road, Portland, OR 97239-3098, USA
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22
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Skegro D, Pulvermüller A, Krafft B, Granzin J, Hofmann KP, Büldt G, Schlesinger R. N-terminal and C-terminal domains of arrestin both contribute in binding to rhodopsin. Photochem Photobiol 2007; 83:385-92. [PMID: 17132044 DOI: 10.1562/2006-08-25-ra-1014] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Visual arrestin terminates the signal amplification cascade in photoreceptor cells by blocking the interaction of light activated phosphorylated rhodopsin with the G-protein transducin. Although crystal structures of arrestin and rhodopsin are available, it is still unknown how the complex of the two proteins is formed. To investigate the interaction sites of arrestin with rhodopsin various surface regions of recombinant arrestin were sterically blocked by different numbers of fluorophores (Alexa 633). The binding was recorded by time-resolved light scattering. To accomplish site-specific shielding of protein regions, in a first step all three wild-type cysteines were replaced by alanines. Nevertheless, regarding the magnitude and specificity of rhodopsin binding, the protein is still fully active. In a second step, new cysteines were introduced at selected sites to allow covalent binding of fluorophores. Upon attachment of Alexa 633 to the recombinant cysteines we observed that these bulky labels residing in the concave area of either the N- or the C-terminal domain do not perturb the activity of arrestin. By simultaneously modifying both domains with one Alexa 633 the binding capacity was reduced. The presence of two Alexa 633 molecules in each domain prevented binding of rhodopsin to arrestin. This observation indicates that both concave sites participate in binding.
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Affiliation(s)
- Darko Skegro
- Forschungszentrum Jülich, INB 2/Molekulare Biophysik, Jülich, Germany
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23
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Sommer ME, Farrens DL, McDowell JH, Weber LA, Smith WC. Dynamics of arrestin-rhodopsin interactions: loop movement is involved in arrestin activation and receptor binding. J Biol Chem 2007; 282:25560-8. [PMID: 17606620 DOI: 10.1074/jbc.m702155200] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In this study we investigate conformational changes in Loop V-VI of visual arrestin during binding to light-activated, phosphorylated rhodopsin (Rho*-P) using a combination of site-specific cysteine mutagenesis and intramolecular fluorescence quenching. Introduction of cysteines at positions in the N-domain at residues predicted to be in close proximity to Ile-72 in Loop V-VI of arrestin (i.e. Glu-148 and Lys-298) appear to form an intramolecular disulfide bond with I72C, significantly diminishing the binding of arrestin to Rho*-P. Using a fluorescence approach, we show that the steady-state emission from a monobromobimane fluorophore in Loop V-VI is quenched by tryptophan residues placed at 148 or 298. This quenching is relieved upon binding of arrestin to Rho*-P. These results suggest that arrestin Loop V-VI moves during binding to Rho*-P and that conformational flexibility of this loop is essential for arrestin to adopt a high affinity binding state.
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Affiliation(s)
- Martha E Sommer
- Department of Biochemistry and Molecular Biology, Oregon Health and Science University, Portland, Oregon 97239-3098, USA
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24
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Sommer ME, Farrens DL. Arrestin can act as a regulator of rhodopsin photochemistry. Vision Res 2006; 46:4532-46. [PMID: 17069872 PMCID: PMC2877124 DOI: 10.1016/j.visres.2006.08.031] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2006] [Revised: 08/11/2006] [Accepted: 08/16/2006] [Indexed: 11/24/2022]
Abstract
We report that visual arrestin can regulate retinal release and late photoproduct formation in rhodopsin. Our experiments, which employ a fluorescently labeled arrestin and rhodopsin solubilized in detergent/phospholipid micelles, indicate that arrestin can trap a population of retinal in the binding pocket with an absorbance characteristic of Meta II with the retinal Schiff-base intact. Furthermore, arrestin can convert Metarhodopsin III (formed either by thermal decay or blue-light irradiation) to a Meta II-like absorbing species. Together, our results suggest arrestin may be able to play a more complex role in the rod cell besides simply quenching transducin activity. This possibility may help explain why arrestin deficiency leads to problems like stationary night blindness (Oguchi disease) and retinal degeneration.
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Affiliation(s)
| | - David L. Farrens
- Corresponding author. Fax: +1 503 494 8393. E-mail address: (D.L. Farrens)
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25
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Rózanowska M, Sarna T. Light-induced damage to the retina: role of rhodopsin chromophore revisited. Photochem Photobiol 2006; 81:1305-30. [PMID: 16120006 DOI: 10.1562/2004-11-13-ir-371] [Citation(s) in RCA: 123] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The presence of the regenerable visual pigment rhodopsin has been shown to be primarily responsible for the acute photodamage to the retina. The photoexcitation of rhodopsin leads to isomerization of its chromophore 11-cis-retinal to all-trans-retinal (ATR). ATR is a potent photosensitizer and its role in mediating photodamage has been suspected for over two decades. However, there was lack of experimental evidence that free ATR exists in the retina in sufficient concentrations to impose a risk of photosensitized damage. Identification in the retina of a retinal dimer and a pyridinium bisretinoid, so called A2E, and determination of its biosynthetic pathway indicate that substantial amounts of ATR do accumulate in the retina. Both light damage and A2E accumulation are facilitated under conditions where efficient retinoid cycle operates. Efficient retinoid cycle leads to rapid regeneration of rhodopsin, which may result in ATR release from the opsin "exit site" before its enzymatic reduction to all-trans-retinol. Here we discuss photodamage to the retina where ATR could play a role as the main toxic and/or phototoxic agent. Moreover, we discuss secondary products of (photo)toxic properties accumulating within retinal lipofuscin as a result of ATR accumulation.
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Satoh AK, Ready DF. Arrestin1 mediates light-dependent rhodopsin endocytosis and cell survival. Curr Biol 2006; 15:1722-33. [PMID: 16213818 DOI: 10.1016/j.cub.2005.08.064] [Citation(s) in RCA: 107] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2005] [Revised: 08/29/2005] [Accepted: 08/31/2005] [Indexed: 11/23/2022]
Abstract
BACKGROUND Arrestins are pivotal, multifunctional organizers of cell responses to GPCR stimulation, including cell survival and cell death. In Drosophila norpA and rdgC mutants, endocytosis of abnormally stable complexes of rhodopsin (Rh1) and fly photoreceptor Arrestin2 (Arr2) triggers cell death, implicating Rh1/Arr2-bearing endosomes in pro-cell death signaling, potentially via arrestin-mediated GPCR activation of effector kinase pathways. In order to further investigate arrestin function in photoreceptor physiology and survival, we studied Arr2's partner photoreceptor arrestin, Arr1, in developing and adult Drosophila compound eyes. RESULTS We report that Arr1, but not Arr2, is essential for normal, light-induced rhodopsin endocytosis. Also distinct from Arr2, Arr1 is essential for light-independent photoreceptor survival. Photoreceptor cell death caused by loss of Arr1 is strongly suppressed by coordinate loss of Arr2. We further find that Rh1 C-terminal phosphorylation is essential for light-induced endocytosis and also for translocation of Arr1, but not Arr2, from dark-adapted photoreceptor cytoplasm to photosensory membrane rhabdomeres. In contrast to a previous report, we do not find a requirement for photoreceptor myosin kinase NINAC in Arr1 or Arr2 translocation. CONCLUSIONS The two Drosophila photoreceptor arrestins mediate distinct and essential cell pathways downstream of rhodopsin activation. We propose that Arr1 mediates an endocytotic cell-survival activity, scavenging phosphorylated rhodopsin and thereby countering toxic Arr2/Rh1 accumulation; elimination of toxic Arr2/Rh1 in double mutants could thus rescue arr1 mutant photoreceptor degeneration.
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Affiliation(s)
- Akiko K Satoh
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907, USA
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27
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Burns ME, Mendez A, Chen CK, Almuete A, Quillinan N, Simon MI, Baylor DA, Chen J. Deactivation of phosphorylated and nonphosphorylated rhodopsin by arrestin splice variants. J Neurosci 2006; 26:1036-44. [PMID: 16421323 PMCID: PMC6675359 DOI: 10.1523/jneurosci.3301-05.2006] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Arrestins constitute a family of small cytoplasmic proteins that mediate deactivation of G-protein-coupled receptors (GPCRs) and are known to be essential for cascade inactivation and receptor desensitization. Alternative splicing produces an array of arrestin gene products that have widely different specificities for their cognate receptors in vitro, but the differential functions of these splice variants in vivo are essentially unknown. Bovine rod photoreceptors express two splice variants of visual arrestin (p44 and p48) that display different affinities for the GPCR rhodopsin. To determine the functions of these splice variants in intact cells, we expressed a transgene encoding either a truncated form of murine arrestin (mArr(1-369), or m44) or the long (p48) isoform in mouse rods lacking endogenous arrestin (Arr-/-). Morphological analysis showed that expression of either variant attenuated the light-induced degeneration that is thought to result from excessive cascade activity in Arr-/-rods. Suction electrode recordings from individual rods indicated that the expression of either m44 or p48 splice variants could restore normal kinetics to Arr-/- dim flash responses, indicating that both isoforms can bind to and quench phosphorylated rhodopsin rapidly. To our surprise, only the full-length variant was able to alter the kinetics of responses in rods lacking both arrestin and rhodopsin kinase, indicating that p48 can also quench the activity of nonphosphorylated rhodopsin.
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Affiliation(s)
- Marie E Burns
- Center for Neuroscience, Department of Psychiatry and Behavioral Sciences, University of California, Davis, California 95616, USA.
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28
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Hamer RD, Nicholas SC, Tranchina D, Lamb TD, Jarvinen JLP. Toward a unified model of vertebrate rod phototransduction. Vis Neurosci 2006; 22:417-36. [PMID: 16212700 PMCID: PMC1482458 DOI: 10.1017/s0952523805224045] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2004] [Accepted: 01/27/2005] [Indexed: 11/07/2022]
Abstract
Recently, we introduced a phototransduction model that was able to account for the reproducibility of vertebrate rod single-photon responses (SPRs) (Hamer et al., 2003). The model was able to reproduce SPR statistics by means of stochastic activation and inactivation of rhodopsin (R*), transducin (G alpha ), and phosphodiesterase (PDE). The features needed to capture the SPR statistics were (1) multiple steps of R* inactivation by means of multiple phosphorylations (followed by arrestin capping) and (2) phosphorylation dependence of the affinity between R* and the three molecules competing to bind with R* (G alpha, arrestin, and rhodopsin kinase). The model was also able to account for several other rod response features in the dim-flash regime, including SPRs obtained from rods in which various elements of the cascade have been genetically disabled or disrupted. However, the model was not tested under high light-level conditions. We sought to evaluate the extent to which the multiple phosphorylation model could simultaneously account for single-photon response behavior, as well as responses to high light levels causing complete response saturation and/or significant light adaptation (LA). To date no single model, with one set of parameters, has been able to do this. Dim-flash responses and statistics were simulated using a hybrid stochastic/deterministic model and Monte-Carlo methods as in Hamer et al. (2003). A dark-adapted flash series, and stimulus paradigms from the literature eliciting various degrees of light adaptation (LA), were simulated using a full differential equation version of the model that included the addition of Ca2+-feedback onto rhodopsin kinase via recoverin. With this model, using a single set of parameters, we attempted to account for (1) SPR waveforms and statistics (as in Hamer et al., 2003); (2) a full dark-adapted flash-response series, from dim flash to saturating, bright flash levels, from a toad rod; (3) steady-state LA responses, including LA circulating current (as in Koutalos et al., 1995) and LA flash sensitivity measured in rods from four species; (4) step responses from newt rods ( Forti et al., 1989) over a large dynamic range; (5) dynamic LA responses, such as the step-flash paradigm of Fain et al. (1989), and the two-flash paradigm of Murnick and Lamb (1996); and (6) the salient response features from four knockout rod preparations. The model was able to meet this stringent test, accounting for almost all the salient qualitative, and many quantitative features, of the responses across this broad array of stimulus conditions, including SPR reproducibility. The model promises to be useful in testing hypotheses regarding both normal and abnormal photoreceptor function, and is a good starting point for development of a full-range model of cone phototransduction. Informative limitations of the model are also discussed.
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Affiliation(s)
- R D Hamer
- Smith-Kettlewell Eye Research Institute, San Francisco, CA 94115, USA.
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Shearstone JR, Wang YE, Clement A, Allaire NE, Yang C, Worley DS, Carulli JP, Perrin S. Application of functional genomic technologies in a mouse model of retinal degeneration. Genomics 2005; 85:309-21. [PMID: 15718098 DOI: 10.1016/j.ygeno.2004.11.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2004] [Accepted: 11/01/2004] [Indexed: 02/03/2023]
Abstract
Generation of tissue-specific, normalized and subtracted cDNA libraries has the potential to characterize the expression of rare transcriptional units not represented on Affymetrix GeneChips. Initial sequence analysis of our murine cDNA clone collections showed that as much as 86, 45, and 30% of clones are not represented on the Affymetrix Mu11k, MG-U74, and MG-430 chip sets, respectively. A detailed study that compared EST sequences of a subtracted library generated from mouse retina to those of MG-430 consensus sequences was undertaken, using UniGene build 124 as the common reference. A set of 1111 nonredundant transcript regions, not represented on the commercial array, was identified. These clusters were used as the primary filter for analyzing a data set produced by assaying samples from the Pde6b(rd1) mouse model of retinal degeneration on a 12,325-feature retinal cDNA microarray. QRT-PCR validated eight unique transcripts identified by microarray. Seven of the transcripts showed retina-specific expression. Full-length cloning strategies were applied to two of the ESTs. The genes discovered by this approach are the full-length mouse homologue of guanylate cyclase 2F (GUCY2F) and a carboxy-truncated splice variant of retinal S-antigen (SAG), known as regulators of the visual phototransduction G-protein-coupled receptor-mediated signaling pathway. These sequences have been assigned GenBank Accession Nos. and , respectively.
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Affiliation(s)
- Jeffrey R Shearstone
- Research Molecular Discovery, Biogen Idec, Inc., 14 Cambridge Center, Cambridge, MA 02142, USA.
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Sommer ME, Smith WC, Farrens DL. Dynamics of arrestin-rhodopsin interactions: arrestin and retinal release are directly linked events. J Biol Chem 2004; 280:6861-71. [PMID: 15591052 DOI: 10.1074/jbc.m411341200] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In this study, we address the mechanism of visual arrestin release from light-activated rhodopsin using fluorescently labeled arrestin mutants. We find that two mutants, I72C and S251C, when labeled with the small, solvent-sensitive fluorophore monobromobimane, exhibit spectral changes only upon binding light-activated, phosphorylated rhodopsin. Our analysis indicates that these changes are probably due to a burying of the probes at these sites in the rhodopsin-arrestin or phospholipid-arrestin interface. Using a fluorescence approach based on this observation, we demonstrate that arrestin and retinal release are linked and are described by similar activation energies. However, at physiological temperatures, we find that arrestin slows the rate of retinal release approximately 2-fold and abolishes the pH dependence of retinal release. Using fluorescence, EPR, and biochemical approaches, we also find intriguing evidence that arrestin binds to a post-Meta II photodecay product, possibly Meta III. We speculate that arrestin regulates levels of free retinal in the rod cell to help limit the formation of damaging oxidative retinal adducts. Such adducts may contribute to diseases like atrophic age-related macular degeneration (AMD). Thus, arrestin may serve to both attenuate rhodopsin signaling and protect the cell from excessive retinal levels under bright light conditions.
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Affiliation(s)
- Martha E Sommer
- Department of Biochemistry and Molecular Biology, Oregon Health and Science University, Portland, Oregon 97239-3098, USA
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Giessl A, Pulvermüller A, Trojan P, Park JH, Choe HW, Ernst OP, Hofmann KP, Wolfrum U. Differential expression and interaction with the visual G-protein transducin of centrin isoforms in mammalian photoreceptor cells. J Biol Chem 2004; 279:51472-81. [PMID: 15347651 DOI: 10.1074/jbc.m406770200] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Photoisomerization of rhodopsin activates a heterotrimeric G-protein cascade leading to closure of cGMP-gated channels and hyperpolarization of photoreceptor cells. Massive translocation of the visual G-protein transducin, Gt, between subcellular compartments contributes to long term adaptation of photoreceptor cells. Ca(2+)-triggered assembly of a centrin-transducin complex in the connecting cilium of photoreceptor cells may regulate these transducin translocations. Here we demonstrate expression of all four known, closely related centrin isoforms in the mammalian retina. Interaction assays revealed binding potential of the four centrin isoforms to Gtbetagamma heterodimers. High affinity binding to Gtbetagamma and subcellular localization of the centrin isoforms Cen1 and Cen2 in the connecting cilium indicated that these isoforms contribute to the centrin-transducin complex and potentially participate in the regulation of transducin translocation through the photoreceptor cilium. Binding of Cen2 and Cen4 to Gbetagamma of non-visual G-proteins may additionally regulate G-proteins involved in centrosome and basal body functions.
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Affiliation(s)
- Andreas Giessl
- Institut für Zoologie, Johannes Gutenberg-Universität Mainz, 55099 Mainz, Germany
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Nair KS, Hanson SM, Kennedy MJ, Hurley JB, Gurevich VV, Slepak VZ. Direct binding of visual arrestin to microtubules determines the differential subcellular localization of its splice variants in rod photoreceptors. J Biol Chem 2004; 279:41240-8. [PMID: 15272005 DOI: 10.1074/jbc.m406768200] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Proper function of visual arrestin is indispensable for rapid signal shut-off in rod photoreceptors. Dramatic light-dependent changes in its subcellular localization are believed to play an important role in light adaptation of photoreceptor cells. Here we show that visual arrestin binds microtubules. The truncated splice variant of visual arrestin, p44, demonstrates dramatically higher affinity for microtubules than the full-length protein (p48). Enhanced microtubule binding of p44 underlies its earlier reported preferential localization to detergent-resistant membranes, where it is anchored via membrane-associated microtubules in a rhodopsin-independent fashion. Experiments with purified proteins demonstrate that arrestin interaction with microtubules is direct and does not require any additional protein partners. Most importantly, arrestin interactions with microtubules and light-activated phosphorylated rhodopsin are mutually exclusive, suggesting that microtubule interaction may play a role in keeping p44 arrestin away from rhodopsin in dark-adapted photoreceptors.
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Affiliation(s)
- K Saidas Nair
- Department of Molecular and Cellular Pharmacology and Neuroscience Program, University of Miami, Miami, Florida 33136, USA
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Chabre M, Cone R, Saibil H. Biophysics: is rhodopsin dimeric in native retinal rods? Nature 2003; 426:30-1; discussion 31. [PMID: 14603306 DOI: 10.1038/426030b] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Marc Chabre
- Institut de Pharmacologie, CNRS-Université de Nice-Sophia Antipolis, 06560 Valbonne, France.
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Heck M, Schädel SA, Maretzki D, Hofmann KP. Secondary binding sites of retinoids in opsin: characterization and role in regeneration. Vision Res 2003; 43:3003-10. [PMID: 14611936 DOI: 10.1016/j.visres.2003.08.011] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
To regenerate light-sensitive rhodopsin in rods from active metarhodopsin II (Meta II), all-trans-retinal must be removed from the retinal binding pocket and metabolically supplied 11-cis-retinal has to form a new retinylidene bond in the active site. Recent work from this laboratory has focused on Meta II decay and release and uptake of retinals in opsin employing intrinsic protein fluorescence. Here we summarize the results in the retinal channeling hypothesis, which describes a passage of the chromophore through the protein. 11-cis-retinal is taken up into an entrance site, and photolyzed all-trans-retinal is released from the active site into an exit site.
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Affiliation(s)
- Martin Heck
- Institut für Medizinische Physik und Biophysik, Universitätsklinikum Charité, Humboldt Universität zu Berlin, Schumannstr. 20-21, 10098 Berlin, Germany
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Vishnivetskiy SA, Hosey MM, Benovic JL, Gurevich VV. Mapping the arrestin-receptor interface. Structural elements responsible for receptor specificity of arrestin proteins. J Biol Chem 2003; 279:1262-8. [PMID: 14530255 DOI: 10.1074/jbc.m308834200] [Citation(s) in RCA: 107] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Arrestins selectively bind to phosphorylated activated forms of their cognate G protein-coupled receptors. Arrestin binding prevents further G protein activation and often redirects signaling to other pathways. The comparison of the high-resolution crystal structures of arrestin2, visual arrestin, and rhodopsin as well as earlier mutagenesis and peptide inhibition data collectively suggest that the elements on the concave sides of both arrestin domains most likely participate in receptor binding directly, thereby dictating its receptor preference. Using comparative binding of visual arrestin/arrestin2 chimeras to the preferred target of visual arrestin, light-activated phosphorylated rhodopsin (PRh*), and to the arrestin2 target, phosphorylated activated m2 muscarinic receptor (P-m2 mAChR*), we identified the elements that determine the receptor specificity of arrestins. We found that residues 49-90 (beta-strands V and VI and adjacent loops in the N-domain) and 237-268 (beta-strands XV and XVI in the C-domain) in visual arrestin and homologous regions in arrestin2 are largely responsible for their receptor preference. Only 35 amino acids (22 of which are nonconservative substitutions) in the two elements are different. Simultaneous exchange of both elements between visual arrestin and arrestin2 fully reverses their receptor specificity, demonstrating that these two elements in the two domains of arrestin are necessary and sufficient to determine their preferred receptor targets.
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Affiliation(s)
- Sergey A Vishnivetskiy
- Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, USA
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Imamoto Y, Tamura C, Kamikubo H, Kataoka M. Concentration-dependent tetramerization of bovine visual arrestin. Biophys J 2003; 85:1186-95. [PMID: 12885662 PMCID: PMC1303236 DOI: 10.1016/s0006-3495(03)74554-8] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The oligomeric states of bovine visual arrestin in solution were studied by small-angle x-ray scattering. The Guinier plot of arrestin at the concentration ranging from 0.4 mg/ml to 11.1 mg/ml was approximated with a straight line, and the apparent molecular weight was evaluated by the concentration-normalized intensity at zero angle (I(0)/conc). Using ovalbumin as a molecular weight standard, it was found that arrestin varied from monomer to tetramer depending on the concentration. The I(0)/conc decreased at high-salt concentration, but was independent of temperature. The simulation analysis of the concentration-dependent increase of I(0)/conc demonstrated that the tetramerization is highly cooperative, and arrestin at the physiological concentration is virtually in the equilibrium between monomer and tetramer. The concentration of arrestin monomer, which is considered to be an active form, remains at an almost constant level even if the total concentration of arrestin fluctuates within the physiological range. The scattering profile of arrestin tetramer in solution was in good agreement with that in the crystal, indicating that the quaternary structure in solution is essentially identical to that in crystal. Small-angle x-ray scattering was applied to a binding assay of phosphorylated rhodopsin and arrestin in the detergent system, and we directly observed their association as the increase of I(0)/conc.
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Affiliation(s)
- Yasushi Imamoto
- Graduate School of Materials Science, Nara Institute of Science and Technology, Ikoma, Nara 630-0192, Japan.
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