1
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Jarrin M, Kalligeraki AA, Uwineza A, Cawood CS, Brown AP, Ward EN, Le K, Freitag-Pohl S, Pohl E, Kiss B, Tapodi A, Quinlan RA. Independent Membrane Binding Properties of the Caspase Generated Fragments of the Beaded Filament Structural Protein 1 (BFSP1) Involves an Amphipathic Helix. Cells 2023; 12:1580. [PMID: 37371051 DOI: 10.3390/cells12121580] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Revised: 06/04/2023] [Accepted: 06/05/2023] [Indexed: 06/29/2023] Open
Abstract
BACKGROUND BFSP1 (beaded filament structural protein 1) is a plasma membrane, Aquaporin 0 (AQP0/MIP)-associated intermediate filament protein expressed in the eye lens. BFSP1 is myristoylated, a post-translation modification that requires caspase cleavage at D433. Bioinformatic analyses suggested that the sequences 434-452 were α-helical and amphipathic. METHODS AND RESULTS By CD spectroscopy, we show that the addition of trifluoroethanol induced a switch from an intrinsically disordered to a more α-helical conformation for the residues 434-467. Recombinantly produced BFSP1 fragments containing this amphipathic helix bind to lens lipid bilayers as determined by surface plasmon resonance (SPR). Lastly, we demonstrate by transient transfection of non-lens MCF7 cells that these same BFSP1 C-terminal sequences localise to plasma membranes and to cytoplasmic vesicles. These can be co-labelled with the vital dye, lysotracker, but other cell compartments, such as the nuclear and mitochondrial membranes, were negative. The N-terminal myristoylation of the amphipathic helix appeared not to change either the lipid affinity or membrane localisation of the BFSP1 polypeptides or fragments we assessed by SPR and transient transfection, but it did appear to enhance its helical content. CONCLUSIONS These data support the conclusion that C-terminal sequences of human BFSP1 distal to the caspase site at G433 have independent membrane binding properties via an adjacent amphipathic helix.
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Affiliation(s)
- Miguel Jarrin
- Department of Biosciences, Upper Mountjoy Science Site, The University of Durham, South Road, Durham DH1 3LE, UK
- Biophysical Sciences Institute, Durham University, Upper Mountjoy, South Road, Durham DH1 3LE, UK
| | - Alexia A Kalligeraki
- Department of Biosciences, Upper Mountjoy Science Site, The University of Durham, South Road, Durham DH1 3LE, UK
- Biophysical Sciences Institute, Durham University, Upper Mountjoy, South Road, Durham DH1 3LE, UK
| | - Alice Uwineza
- Department of Biosciences, Upper Mountjoy Science Site, The University of Durham, South Road, Durham DH1 3LE, UK
- Biophysical Sciences Institute, Durham University, Upper Mountjoy, South Road, Durham DH1 3LE, UK
| | - Chris S Cawood
- Department of Biosciences, Upper Mountjoy Science Site, The University of Durham, South Road, Durham DH1 3LE, UK
- Biophysical Sciences Institute, Durham University, Upper Mountjoy, South Road, Durham DH1 3LE, UK
| | - Adrian P Brown
- Department of Biosciences, Upper Mountjoy Science Site, The University of Durham, South Road, Durham DH1 3LE, UK
| | - Edward N Ward
- Department of Biosciences, Upper Mountjoy Science Site, The University of Durham, South Road, Durham DH1 3LE, UK
- Biophysical Sciences Institute, Durham University, Upper Mountjoy, South Road, Durham DH1 3LE, UK
| | - Khoa Le
- Biophysical Sciences Institute, Durham University, Upper Mountjoy, South Road, Durham DH1 3LE, UK
- Department of Biological Structure, University of Washington, Seattle, WA 98195, USA
| | - Stefanie Freitag-Pohl
- Department of Chemistry, Durham University, Lower Mountjoy, South Road, Durham DH1 3LE, UK
| | - Ehmke Pohl
- Biophysical Sciences Institute, Durham University, Upper Mountjoy, South Road, Durham DH1 3LE, UK
- Department of Chemistry, Durham University, Lower Mountjoy, South Road, Durham DH1 3LE, UK
| | - Bence Kiss
- Department of Biochemistry and Medical Chemistry, Medical School, University of Pécs, 7624 Pécs, Hungary
| | - Antal Tapodi
- Department of Biosciences, Upper Mountjoy Science Site, The University of Durham, South Road, Durham DH1 3LE, UK
- Biophysical Sciences Institute, Durham University, Upper Mountjoy, South Road, Durham DH1 3LE, UK
- Department of Biochemistry and Medical Chemistry, Medical School, University of Pécs, 7624 Pécs, Hungary
| | - Roy A Quinlan
- Department of Biosciences, Upper Mountjoy Science Site, The University of Durham, South Road, Durham DH1 3LE, UK
- Biophysical Sciences Institute, Durham University, Upper Mountjoy, South Road, Durham DH1 3LE, UK
- Department of Biological Structure, University of Washington, Seattle, WA 98195, USA
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2
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Gulati S, Palczewski K. Structural view of G protein-coupled receptor signaling in the retinal rod outer segment. Trends Biochem Sci 2023; 48:172-186. [PMID: 36163145 PMCID: PMC9868064 DOI: 10.1016/j.tibs.2022.08.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Revised: 08/26/2022] [Accepted: 08/29/2022] [Indexed: 01/26/2023]
Abstract
Visual phototransduction is the most extensively studied G protein-coupled receptor (GPCR) signaling pathway because of its quantifiable stimulus, non-redundancy of genes, and immense importance in vision. We summarize recent discoveries that have advanced our understanding of rod outer segment (ROS) morphology and the pathological basis of retinal diseases. We have combined recently published cryo-electron tomography (cryo-ET) data on the ROS with structural knowledge on individual proteins to define the precise spatial limitations under which phototransduction occurs. Although hypothetical, the reconstruction of the rod phototransduction system highlights the potential roles of phosphodiesterase 6 (PDE6) and guanylate cyclases (GCs) in maintaining the spacing between ROS discs, suggesting a plausible mechanism by which intrinsic optical signals are generated in the retina.
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Affiliation(s)
| | - Krzysztof Palczewski
- Gavin Herbert Eye Institute and the Department of Ophthalmology, Center for Translational Vision Research, Department of Physiology and Biophysics, Department of Chemistry, Molecular Biology, and Biochemistry, University of California Irvine, 850 Health Sciences Road, Irvine, CA 92697-4375, USA.
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3
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Jain S, Sekhar A. Elucidating the mechanisms underlying protein conformational switching using NMR spectroscopy. JOURNAL OF MAGNETIC RESONANCE OPEN 2022; 10-11:100034. [PMID: 35586549 PMCID: PMC7612731 DOI: 10.1016/j.jmro.2022.100034] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
How proteins switch between various ligand-free and ligand-bound structures has been a key biophysical question ever since the postulation of the Monod-Wyman-Changeux and Koshland-Nemethy-Filmer models over six decades ago. The ability of NMR spectroscopy to provide structural and kinetic information on biomolecular conformational exchange places it in a unique position as an analytical tool to interrogate the mechanisms of biological processes such as protein folding and biomolecular complex formation. In addition, recent methodological developments in the areas of saturation transfer and relaxation dispersion have expanded the scope of NMR for probing the mechanics of transitions in systems where one or more states constituting the exchange process are sparsely populated and 'invisible' in NMR spectra. In this review, we highlight some of the strategies available from NMR spectroscopy for examining the nature of multi-site conformational exchange, using five case studies that have employed NMR, either in isolation, or in conjunction with other biophysical tools.
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4
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Abbas S, Koch KW. Label-free Quantification of Direct Protein-protein Interactions with Backscattering Interferometry. Bio Protoc 2021; 11:e4256. [PMID: 35087916 DOI: 10.21769/bioprotoc.4256] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Revised: 10/04/2021] [Accepted: 10/07/2021] [Indexed: 12/25/2022] Open
Abstract
The functional performance of a cell depends on how macromolecules, in particular proteins, come together in a precise orientation, how they assemble into protein complexes and interact with each other. In order to study protein-protein interactions at a molecular level, a variety of methods to investigate these binding processes yield affinity constants and/or the identification of binding regions. There are several well-established biophysical techniques for biomolecular interaction studies, such as fluorescence spectroscopy and surface plasmon resonance. Although these techniques have been proven to be efficient, they either need labeling or immobilization of one interaction partner. Backscattering interferometry (BSI) is a label-free detection method, which allows label- and immobilization-free interaction analysis under physiologically relevant conditions with high sensitivity and in small volumes. We used BSI to measure the interaction of the neuronal calcium sensor recoverin with its target G protein-coupled receptor kinase 1 (GRK1) as a model system. Increasing concentrations of purified recoverin were mixed with a specific concentration of a GRK1 fusion protein. In this protocol, we provide a full description of the instrumental setup, data acquisition, and evaluation. Equilibrium dissociation constants of recoverin-GRK1 interaction determined by the BSI instrumental setup are in full agreement with affinity constants obtained by different methods as described in the literature.
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Affiliation(s)
- Seher Abbas
- Department of Neuroscience, University of Oldenburg, Oldenburg D-26129, Germany
| | - Karl-Wilhelm Koch
- Department of Neuroscience, University of Oldenburg, Oldenburg D-26129, Germany
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5
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Sulon SM, Benovic JL. Targeting G protein-coupled receptor kinases (GRKs) to G protein-coupled receptors. ACTA ACUST UNITED AC 2021; 16:56-65. [PMID: 33718657 DOI: 10.1016/j.coemr.2020.09.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
G protein-coupled receptors (GPCRs) interact with three protein families following agonist binding: heterotrimeric G proteins, G protein-coupled receptor kinases (GRKs) and arrestins. GRK-mediated phosphorylation of GPCRs promotes arrestin binding to uncouple the receptor from G protein, a process called desensitization, and for many GPCRs, arrestin binding also promotes receptor endocytosis and intracellular signaling. Thus, GRKs play a central role in modulating GPCR signaling and localization. Here we review recent advances in this field which include additional insight into how GRKs target GPCRs and bias signaling, and the development of specific inhibitors to dissect GRK function in model systems.
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Affiliation(s)
- Sarah M Sulon
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Jeffrey L Benovic
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, PA 19107, USA
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6
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Marino V, Riva M, Zamboni D, Koch KW, Dell'Orco D. Bringing the Ca 2+ sensitivity of myristoylated recoverin into the physiological range. Open Biol 2021; 11:200346. [PMID: 33401992 PMCID: PMC7881174 DOI: 10.1098/rsob.200346] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The prototypical Ca2+-sensor protein recoverin (Rec) is thought to regulate the activity of rhodopsin kinase (GRK1) in photoreceptors by switching from a relaxed (R) disc membrane-bound conformation in the dark to a more compact, cytosol-diffusing tense (T) conformation upon cell illumination. However, the apparent affinity for Ca2+ of its physiologically relevant form (myristoylated recoverin) is almost two orders of magnitude too low to support this mechanism in vivo. In this work, we compared the individual and synergistic roles of the myristic moiety, the GRK1 target and the disc membrane in modulating the calcium sensitivity of Rec. We show that the sole presence of the target or the disc membrane alone are not sufficient to achieve a physiological response to changes in intracellular [Ca2+]. Instead, the simultaneous presence of GRK1 and membrane allows the T to R transition to occur in a physiological range of [Ca2+] with high cooperativity via a conformational selection mechanism that drives the structural transitions of Rec in the presence of multiple ligands. Our conclusions may apply to other sensory transduction systems involving protein complexes and biological membranes.
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Affiliation(s)
- Valerio Marino
- Department of Neurosciences, Biomedicine and Movement Sciences, Section of Biological Chemistry, University of Verona, 37134 Verona, Italy
| | - Matteo Riva
- Department of Neurosciences, Biomedicine and Movement Sciences, Section of Biological Chemistry, University of Verona, 37134 Verona, Italy.,Department of Neuroscience, Division of Biochemistry, University of Oldenburg, 26111 Oldenburg, Germany
| | - Davide Zamboni
- Department of Neurosciences, Biomedicine and Movement Sciences, Section of Biological Chemistry, University of Verona, 37134 Verona, Italy.,Department of Neuroscience, Division of Biochemistry, University of Oldenburg, 26111 Oldenburg, Germany
| | - Karl-Wilhelm Koch
- Department of Neuroscience, Division of Biochemistry, University of Oldenburg, 26111 Oldenburg, Germany
| | - Daniele Dell'Orco
- Department of Neurosciences, Biomedicine and Movement Sciences, Section of Biological Chemistry, University of Verona, 37134 Verona, Italy
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7
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Ahrens N, Elbers D, Greb H, Janssen-Bienhold U, Koch KW. Interaction of G protein-coupled receptor kinases and recoverin isoforms is determined by localization in zebrafish photoreceptors. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2020; 1868:118946. [PMID: 33385424 DOI: 10.1016/j.bbamcr.2020.118946] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 12/22/2020] [Accepted: 12/23/2020] [Indexed: 12/14/2022]
Abstract
The zebrafish retina expresses four recoverin genes (rcv1a, rcv1b, rcv2a and rcv2b) and four opsin kinase genes (grk1a, grk1b, grk7a and grk7b) coding for recoverin and G protein-coupled receptor kinase (opsin kinase) paralogs, respectively. Both protein groups are suggested to form regulatory complexes in rod and cone outer segments, but at present, we lack information about co-localization of recoverin and opsin kinases in zebrafish retinae and which protein-protein interacting pairs form. We analyzed the distribution and co-localization of recoverin and opsin kinase expression in the zebrafish retina. For this purpose, we used custom-tailored monospecific antibodies revealing that the amount of recoverin paralogs in a zebrafish retina can differ by more than one order of magnitude with the highest amount for recoverin 1a and 2b. Further, immunohistochemical labelling showed presence of recoverin 1a in all rod cell compartments, but it only co-localized with opsin kinase 1a in rod outer segments. In contrast, recoverin 2b was only detected in double cones and co-localized with opsin kinases 1b, 7a and 7b. Further, we investigated the interaction between recoverin and opsin kinase variants by surface plasmon resonance spectroscopy indicating interaction of recoverin 1a and recoverin 2b with all opsin kinases. However, binding kinetics for recoverin 1a differed from those observed with recoverin 2b that showed slower association and dissociation processes. Our results indicate diverse recoverin and opsin kinase properties due to differential expression and interaction profiles.
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Affiliation(s)
- Nicole Ahrens
- Department of Neuroscience, Division of Biochemistry, University of Oldenburg, 26111 Oldenburg, Germany
| | - Dana Elbers
- Department of Neuroscience, Division of Biochemistry, University of Oldenburg, 26111 Oldenburg, Germany
| | - Helena Greb
- Department of Neuroscience, Division of Biochemistry, University of Oldenburg, 26111 Oldenburg, Germany
| | - Ulrike Janssen-Bienhold
- Department of Neuroscience, Division of Neurobiology, University of Oldenburg, 26111 Oldenburg, Germany
| | - Karl-Wilhelm Koch
- Department of Neuroscience, Division of Biochemistry, University of Oldenburg, 26111 Oldenburg, Germany.
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8
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Komolov KE, Sulon SM, Bhardwaj A, van Keulen SC, Duc NM, Laurinavichyute DK, Lou HJ, Turk BE, Chung KY, Dror RO, Benovic JL. Structure of a GRK5-Calmodulin Complex Reveals Molecular Mechanism of GRK Activation and Substrate Targeting. Mol Cell 2020; 81:323-339.e11. [PMID: 33321095 DOI: 10.1016/j.molcel.2020.11.026] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2020] [Revised: 09/15/2020] [Accepted: 11/12/2020] [Indexed: 10/22/2022]
Abstract
The phosphorylation of G protein-coupled receptors (GPCRs) by GPCR kinases (GRKs) facilitates arrestin binding and receptor desensitization. Although this process can be regulated by Ca2+-binding proteins such as calmodulin (CaM) and recoverin, the molecular mechanisms are poorly understood. Here, we report structural, computational, and biochemical analysis of a CaM complex with GRK5, revealing how CaM shapes GRK5 response to calcium. The CaM N and C domains bind independently to two helical regions at the GRK5 N and C termini to inhibit GPCR phosphorylation, though only the C domain interaction disrupts GRK5 membrane association, thereby facilitating cytoplasmic translocation. The CaM N domain strongly activates GRK5 via ordering of the amphipathic αN-helix of GRK5 and allosteric disruption of kinase-RH domain interaction for phosphorylation of cytoplasmic GRK5 substrates. These results provide a framework for understanding how two functional effects, GRK5 activation and localization, can cooperate under control of CaM for selective substrate targeting by GRK5.
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Affiliation(s)
- Konstantin E Komolov
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Sarah M Sulon
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Anshul Bhardwaj
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Siri C van Keulen
- Department of Computer Science, Department of Molecular and Cellular Physiology, Department of Structural Biology, and Institute for Computational and Mathematical Engineering, Stanford University, Stanford, CA 94305, USA
| | - Nguyen Minh Duc
- School of Pharmacy, Sungkyunkwan University, Suwon 16419, South Korea; Division of Precision Medicine, Research Institute, National Cancer Center, Goyang, South Korea
| | - Daniela K Laurinavichyute
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Hua Jane Lou
- Department of Pharmacology, Yale School of Medicine, New Haven, CT 06520, USA
| | - Benjamin E Turk
- Department of Pharmacology, Yale School of Medicine, New Haven, CT 06520, USA
| | - Ka Young Chung
- School of Pharmacy, Sungkyunkwan University, Suwon 16419, South Korea
| | - Ron O Dror
- Department of Computer Science, Department of Molecular and Cellular Physiology, Department of Structural Biology, and Institute for Computational and Mathematical Engineering, Stanford University, Stanford, CA 94305, USA; Biophysics Program, Stanford University, Stanford, CA 94305, USA
| | - Jeffrey L Benovic
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, PA 19107, USA.
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9
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Lankford CK, Laird JG, Inamdar SM, Baker SA. A Comparison of the Primary Sensory Neurons Used in Olfaction and Vision. Front Cell Neurosci 2020; 14:595523. [PMID: 33250719 PMCID: PMC7676898 DOI: 10.3389/fncel.2020.595523] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2020] [Accepted: 10/06/2020] [Indexed: 12/18/2022] Open
Abstract
Vision, hearing, smell, taste, and touch are the tools used to perceive and navigate the world. They enable us to obtain essential resources such as food and highly desired resources such as mates. Thanks to the investments in biomedical research the molecular unpinning’s of human sensation are rivaled only by our knowledge of sensation in the laboratory mouse. Humans rely heavily on vision whereas mice use smell as their dominant sense. Both modalities have many features in common, starting with signal detection by highly specialized primary sensory neurons—rod and cone photoreceptors (PR) for vision, and olfactory sensory neurons (OSN) for the smell. In this chapter, we provide an overview of how these two types of primary sensory neurons operate while highlighting the similarities and distinctions.
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Affiliation(s)
- Colten K Lankford
- Department of Biochemistry, University of Iowa, Iowa City, IA, United States
| | - Joseph G Laird
- Department of Biochemistry, University of Iowa, Iowa City, IA, United States
| | - Shivangi M Inamdar
- Department of Biochemistry, University of Iowa, Iowa City, IA, United States
| | - Sheila A Baker
- Department of Biochemistry, University of Iowa, Iowa City, IA, United States.,Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City, IA, United States
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10
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Abbas S, Marino V, Dell’Orco D, Koch KW. Molecular Recognition of Rhodopsin Kinase GRK1 and Recoverin Is Tuned by Switching Intra- and Intermolecular Electrostatic Interactions. Biochemistry 2019; 58:4374-4385. [DOI: 10.1021/acs.biochem.9b00846] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Seher Abbas
- Department of Neuroscience, Division of Biochemistry, University of Oldenburg, 26111 Oldenburg, Germany
| | - Valerio Marino
- Department of Neurosciences, Biomedicine and Movement Sciences, Section of Biological Chemistry, University of Verona, 37134 Verona, Italy
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, 56126 Pisa, Italy
| | - Daniele Dell’Orco
- Department of Neurosciences, Biomedicine and Movement Sciences, Section of Biological Chemistry, University of Verona, 37134 Verona, Italy
| | - Karl-Wilhelm Koch
- Department of Neuroscience, Division of Biochemistry, University of Oldenburg, 26111 Oldenburg, Germany
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11
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Zang J, Neuhauss SCF. The Binding Properties and Physiological Functions of Recoverin. Front Mol Neurosci 2018; 11:473. [PMID: 30618620 PMCID: PMC6306944 DOI: 10.3389/fnmol.2018.00473] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Accepted: 12/04/2018] [Indexed: 12/14/2022] Open
Abstract
Recoverin (Rcv) is a low molecular-weight, neuronal calcium sensor (NCS) primarily located in photoreceptor outer segments of the vertebrate retina. Calcium ions (Ca2+)-bound Rcv has been proposed to inhibit G-protein-coupled receptor kinase (GRKs) in darkness. During the light response, the Ca2+-free Rcv releases GRK, which in turn phosphorylates visual pigment, ultimately leading to the cessation of the visual transduction cascade. Technological advances over the last decade have contributed significantly to a deeper understanding of Rcv function. These include both biophysical and biochemical approaches that will be discussed in this review article. Furthermore, electrophysiological experiments uncovered additional functions of Rcv, such as regulation of the lifetime of Phosphodiesterase-Transducin complex. Recently, attention has been drawn to different roles in rod and cone photoreceptors.This review article focuses on Rcv binding properties to Ca2+, disc membrane and GRK, and its physiological functions in phototransduction and signal transmission.
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Affiliation(s)
- Jingjing Zang
- Institute of Molecular Life Sciences, University of Zurich, Zurich, Switzerland
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12
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Christoffers J. Diaminoterephthalate Fluorescence Dyes - Versatile Tools for Life Sciences and Materials Science. European J Org Chem 2018. [DOI: 10.1002/ejoc.201701447] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Jens Christoffers
- Institut für Chemie; Carl von Ossietzky Universität Oldenburg; 26111 Oldenburg Germany
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13
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Wallisch M, Sulmann S, Koch KW, Christoffers J. Bifunctional Diaminoterephthalate Fluorescent Dye as Probe for Cross-Linking Proteins. Chemistry 2017; 23:6535-6543. [DOI: 10.1002/chem.201700774] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Indexed: 01/05/2023]
Affiliation(s)
- Melanie Wallisch
- Institut für Chemie; Carl von Ossietzky-Universität Oldenburg; 26111 Oldenburg Germany
| | - Stefan Sulmann
- Biochemistry Group, Department of Neuroscience; Carl von Ossietzky-Universität Oldenburg; 26111 Oldenburg Germany
| | - Karl-Wilhelm Koch
- Biochemistry Group, Department of Neuroscience; Carl von Ossietzky-Universität Oldenburg; 26111 Oldenburg Germany
| | - Jens Christoffers
- Institut für Chemie; Carl von Ossietzky-Universität Oldenburg; 26111 Oldenburg Germany
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14
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Label-free quantification of calcium-sensor targeting to photoreceptor guanylate cyclase and rhodopsin kinase by backscattering interferometry. Sci Rep 2017; 7:45515. [PMID: 28361875 PMCID: PMC5374524 DOI: 10.1038/srep45515] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Accepted: 02/28/2017] [Indexed: 01/26/2023] Open
Abstract
Quantification of protein binding to membrane proteins is challenging and a limited set of methods is available to study such systems. Here we employed backscattering interferometry (BSI), a free-solution label-free method with high sensitivity, to quantify the interaction of neuronal Ca2+-Sensor proteins with their targets operating in phototransduction. We tested direct binding of guanylate cyclase–activating proteins (GCAP1 and GCAP2) to their membrane target guanylate cyclase 1. The regulatory mechanism of GCAPs including their binding interface in the target is unresolved. Here we used a label-free, free-solution assay method based on BSI to determine binding constants of GCAP1 and GCAP2 to the full-length membrane-bound guanylate cyclase type 1. GCAP1 and GCAP2 bound to different regions on the target guanylate cyclase with submicromolar affinity (apparent KD-values of 663 ± 121 nM and 231 ± 63 nM for Ca2+-free GCAP1 and GCAP2, respectively). A guanylate cyclase construct containing the juxta-membrane and kinase homology domain harbored an exclusive binding site for GCAP1 with similar affinities as the full-length protein, whereas GCAP2 did not bind to this region. We provide a model in which GCAP1 and GCAP2 do not share a single binding site to the target, thus cannot exchange upon fluctuating Ca2+ levels.
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15
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16
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Jones Brunette AM, Sinha A, David L, Farrens DL. Evidence that the Rhodopsin Kinase (GRK1) N-Terminus and the Transducin Gα C-Terminus Interact with the Same "Hydrophobic Patch" on Rhodopsin TM5. Biochemistry 2016; 55:3123-35. [PMID: 27078130 DOI: 10.1021/acs.biochem.6b00328] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Phosphorylation of G protein-coupled receptors (GPCRs) terminates their ability to couple with and activate G proteins by increasing their affinity for arrestins. Unfortunately, detailed information regarding how GPCRs interact with the kinases responsible for their phosphorylation is still limited. Here, we purified fully functional GPCR kinase 1 (GRK1) using a rapid method and used it to gain insights into how this important kinase interacts with the GPCR rhodopsin. Specifically, we find that GRK1 uses the same site on rhodopsin as the transducin (Gt) Gtα C-terminal tail and the arrestin "finger loop", a cleft formed in the cytoplasmic face of the receptor upon activation. Our studies also show GRK1 requires two conserved residues located in this cleft (L226 and V230) that have been shown to be required for Gt activation due to their direct interactions with hydrophobic residues on the Gα C-terminal tail. Our data and modeling studies are consistent with the idea that all three proteins (Gt, GRK1, and visual arrestin) bind, at least in part, in the same site on rhodopsin and interact with the receptor through a similar hydrophobic contact-driven mechanism.
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Affiliation(s)
- Amber M Jones Brunette
- Department of Biochemistry and Molecular Biology, Oregon Health and Science University , Portland, Oregon 97239-3098, United States
| | - Abhinav Sinha
- Department of Biochemistry and Molecular Biology, Oregon Health and Science University , Portland, Oregon 97239-3098, United States
| | - Larry David
- Department of Biochemistry and Molecular Biology, Oregon Health and Science University , Portland, Oregon 97239-3098, United States
| | - David L Farrens
- Department of Biochemistry and Molecular Biology, Oregon Health and Science University , Portland, Oregon 97239-3098, United States
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17
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Chakrabarti KS, Agafonov RV, Pontiggia F, Otten R, Higgins MK, Schertler GFX, Oprian DD, Kern D. Conformational Selection in a Protein-Protein Interaction Revealed by Dynamic Pathway Analysis. Cell Rep 2015; 14:32-42. [PMID: 26725117 DOI: 10.1016/j.celrep.2015.12.010] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Revised: 10/17/2015] [Accepted: 11/20/2015] [Indexed: 11/28/2022] Open
Abstract
Molecular recognition plays a central role in biology, and protein dynamics has been acknowledged to be important in this process. However, it is highly debated whether conformational changes happen before ligand binding to produce a binding-competent state (conformational selection) or are caused in response to ligand binding (induced fit). Proposals for both mechanisms in protein/protein recognition have been primarily based on structural arguments. However, the distinction between them is a question of the probabilities of going via these two opposing pathways. Here, we present a direct demonstration of exclusive conformational selection in protein/protein recognition by measuring the flux for rhodopsin kinase binding to its regulator recoverin, an important molecular recognition in the vision system. Using nuclear magnetic resonance (NMR) spectroscopy, stopped-flow kinetics, and isothermal titration calorimetry, we show that recoverin populates a minor conformation in solution that exposes a hydrophobic binding pocket responsible for binding rhodopsin kinase. Protein dynamics in free recoverin limits the overall rate of binding.
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Affiliation(s)
- Kalyan S Chakrabarti
- Howard Hughes Medical Institute, Brandeis University, 415 South Street, Waltham, MA 02454; Department of Biochemistry, Brandeis University, 415 South Street, Waltham, MA 02454
| | - Roman V Agafonov
- Howard Hughes Medical Institute, Brandeis University, 415 South Street, Waltham, MA 02454; Department of Biochemistry, Brandeis University, 415 South Street, Waltham, MA 02454
| | - Francesco Pontiggia
- Howard Hughes Medical Institute, Brandeis University, 415 South Street, Waltham, MA 02454; Department of Biochemistry, Brandeis University, 415 South Street, Waltham, MA 02454
| | - Renee Otten
- Howard Hughes Medical Institute, Brandeis University, 415 South Street, Waltham, MA 02454; Department of Biochemistry, Brandeis University, 415 South Street, Waltham, MA 02454
| | - Matthew K Higgins
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | | | - Daniel D Oprian
- Department of Biochemistry, Brandeis University, 415 South Street, Waltham, MA 02454.
| | - Dorothee Kern
- Howard Hughes Medical Institute, Brandeis University, 415 South Street, Waltham, MA 02454; Department of Biochemistry, Brandeis University, 415 South Street, Waltham, MA 02454.
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18
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Kumar RP, Ranaghan MJ, Ganjei AY, Oprian DD. Crystal Structure of Recoverin with Calcium Ions Bound to Both Functional EF Hands. Biochemistry 2015; 54:7222-8. [PMID: 26584024 DOI: 10.1021/acs.biochem.5b01160] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Recoverin (Rv), a small Ca(2+)-binding protein that inhibits rhodopsin kinase (RK), has four EF hands, two of which are functional (EF2 and EF3). Activation requires Ca(2+) in both EF hands, but crystal structures have never been observed with Ca(2+) ions in both sites; all previous structures have Ca(2+) bound to only EF3. We suspected that this was due to an intermolecular crystal contact between T80 and a surface glutamate (E153) that precluded coordination of a Ca(2+) ion in EF2. We constructed the E153A mutant, determined its X-ray crystal structure to 1.2 Å resolution, and showed that two Ca(2+) ions are bound, one in EF3 and one in EF2. Additionally, several other residues are shown to adopt conformations in the 2Ca(2+) structure not seen previously and not seen in a second structure of the E153A mutant containing Na(+) instead of Ca(2+) in the EF2 site. The side-chain rearrangements in these residues form a 28 Å allosteric cascade along the surface of the protein connecting the Ca(2+)-binding site of EF2 with the active-site pocket responsible for binding RK.
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Affiliation(s)
- Ramasamy P Kumar
- Department of Biochemistry, Brandeis University , Waltham, Massachusetts 02454, United States
| | - Matthew J Ranaghan
- Department of Biochemistry, Brandeis University , Waltham, Massachusetts 02454, United States
| | - Allen Y Ganjei
- Department of Biochemistry, Brandeis University , Waltham, Massachusetts 02454, United States
| | - Daniel D Oprian
- Department of Biochemistry, Brandeis University , Waltham, Massachusetts 02454, United States
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19
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Koch KW, Dell'Orco D. Protein and Signaling Networks in Vertebrate Photoreceptor Cells. Front Mol Neurosci 2015; 8:67. [PMID: 26635520 PMCID: PMC4646965 DOI: 10.3389/fnmol.2015.00067] [Citation(s) in RCA: 74] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Accepted: 10/26/2015] [Indexed: 01/10/2023] Open
Abstract
Vertebrate photoreceptor cells are exquisite light detectors operating under very dim and bright illumination. The photoexcitation and adaptation machinery in photoreceptor cells consists of protein complexes that can form highly ordered supramolecular structures and control the homeostasis and mutual dependence of the secondary messengers cyclic guanosine monophosphate (cGMP) and Ca2+. The visual pigment in rod photoreceptors, the G protein-coupled receptor rhodopsin is organized in tracks of dimers thereby providing a signaling platform for the dynamic scaffolding of the G protein transducin. Illuminated rhodopsin is turned off by phosphorylation catalyzed by rhodopsin kinase (GRK1) under control of Ca2+-recoverin. The GRK1 protein complex partly assembles in lipid raft structures, where shutting off rhodopsin seems to be more effective. Re-synthesis of cGMP is another crucial step in the recovery of the photoresponse after illumination. It is catalyzed by membrane bound sensory guanylate cyclases (GCs) and is regulated by specific neuronal Ca2+-sensor proteins called guanylate cyclase-activating proteins (GCAPs). At least one GC (ROS-GC1) was shown to be part of a multiprotein complex having strong interactions with the cytoskeleton and being controlled in a multimodal Ca2+-dependent fashion. The final target of the cGMP signaling cascade is a cyclic nucleotide-gated (CNG) channel that is a hetero-oligomeric protein located in the plasma membrane and interacting with accessory proteins in highly organized microdomains. We summarize results and interpretations of findings related to the inhomogeneous organization of signaling units in photoreceptor outer segments.
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Affiliation(s)
- Karl-Wilhelm Koch
- Department of Neurosciences, Biochemistry Group, University of Oldenburg Oldenburg, Germany
| | - Daniele Dell'Orco
- Department of Neurological, Biomedical and Movement Sciences, Section of Biological Chemistry and Center for BioMedical Computing (CBMC), University of Verona Verona, Italy
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20
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Zernii EY, Grigoriev II, Nazipova AA, Scholten A, Kolpakova TV, Zinchenko DV, Kazakov AS, Senin II, Permyakov SE, Dell'Orco D, Philippov PP, Koch KW. Regulatory function of the C-terminal segment of guanylate cyclase-activating protein 2. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2015; 1854:1325-37. [PMID: 26001899 DOI: 10.1016/j.bbapap.2015.05.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2015] [Revised: 04/22/2015] [Accepted: 05/13/2015] [Indexed: 12/13/2022]
Abstract
Neuronal responses to Ca2+-signals are provided by EF-hand-type neuronal Ca2+-sensor (NCS) proteins, which have similar core domains containing Ca2+-binding and target-recognizing sites. NCS proteins vary in functional specificity, probably depending on the structure and conformation of their non-conserved C-terminal segments. Here, we investigated the role of the C-terminal segment in guanylate cyclase activating protein-2, GCAP2, an NCS protein controlling the Ca2+-dependent regulation of photoreceptor guanylate cyclases. We obtained two chimeric proteins by exchanging C-terminal segments between GCAP2 and its photoreceptor homolog recoverin, a Ca2+-sensor controlling rhodopsin kinase (RK) activity. The exchange affected neither the structural integrity of GCAP2 and recoverin nor the Ca2+-sensitivity of GCAP2. Intrinsic fluorescence, circular dichroism, biochemical studies and hydrophobic dye probing revealed Ca2+-dependent conformational transition of the C-terminal segment of GCAP2 occurring in the molecular environment of both proteins. In Ca2+-GCAP2, the C-terminal segment was constrained and its replacement provided the protein with approximately two-fold inhibitory activity towards RK, suggesting that the segment contributes to specific target recognition by interfering with RK-binding. Upon Ca2+-release, it became less constrained and more available for phosphorylation by cyclic nucleotide-dependent protein kinase. The transition from the Ca2+-bound to the apo-state exposed hydrophobic sites in GCAP2, and was associated with its activating function without affecting its dimerization. The released C-terminal segment participated further in photoreceptor membrane binding making it sensitive to phosphorylation. Thus, the C-terminal segment in GCAP2 confers target selectivity, facilitates membrane binding and provides sensitivity of the membrane localization of the protein to phosphorylation by signaling kinases.
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Affiliation(s)
- Evgeni Yu Zernii
- Department of Cell Signaling, Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119992 Russia
| | - Ilya I Grigoriev
- Department of Cell Signaling, Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119992 Russia
| | - Aliya A Nazipova
- Protein Research Group, Institute for Biological Instrumentation of the Russian Academy of Sciences, Pushchino, Moscow region, 142290 Russia
| | - Alexander Scholten
- Department of Neurosciences, Biochemistry Group, University of Oldenburg, Oldenburg, 26111 Germany
| | - Tatiana V Kolpakova
- Department of Cell Signaling, Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119992 Russia
| | - Dmitry V Zinchenko
- Branch of Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry of the Russian Academy of Sciences, Pushchino, Moscow region, 142290 Russia
| | - Alexey S Kazakov
- Protein Research Group, Institute for Biological Instrumentation of the Russian Academy of Sciences, Pushchino, Moscow region, 142290 Russia
| | - Ivan I Senin
- Department of Cell Signaling, Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119992 Russia
| | - Sergei E Permyakov
- Protein Research Group, Institute for Biological Instrumentation of the Russian Academy of Sciences, Pushchino, Moscow region, 142290 Russia
| | - Daniele Dell'Orco
- Department of Life Sciences and Reproduction, Section of Biological Chemistry and Center for BioMedical Computing, University of Verona, Verona, 37134 Italy
| | - Pavel P Philippov
- Department of Cell Signaling, Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119992 Russia
| | - Karl-W Koch
- Department of Neurosciences, Biochemistry Group, University of Oldenburg, Oldenburg, 26111 Germany.
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21
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Ranaghan MJ, Kumar RP, Chakrabarti KS, Buosi V, Kern D, Oprian DD. A highly conserved cysteine of neuronal calcium-sensing proteins controls cooperative binding of Ca2+ to recoverin. J Biol Chem 2013; 288:36160-7. [PMID: 24189072 DOI: 10.1074/jbc.m113.524355] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Recoverin, a 23-kDa Ca(2+)-binding protein of the neuronal calcium sensing (NCS) family, inhibits rhodopsin kinase, a Ser/Thr kinase responsible for termination of photoactivated rhodopsin in rod photoreceptor cells. Recoverin has two functional EF hands and a myristoylated N terminus. The myristoyl chain imparts cooperativity to the Ca(2+)-binding sites through an allosteric mechanism involving a conformational equilibrium between R and T states of the protein. Ca(2+) binds preferentially to the R state; the myristoyl chain binds preferentially to the T state. In the absence of myristoylation, the R state predominates, and consequently, binding of Ca(2+) to the non-myristoylated protein is not cooperative. We show here that a mutation, C39A, of a highly conserved Cys residue among NCS proteins, increases the apparent cooperativity for binding of Ca(2+) to non-myristoylated recoverin. The binding data can be explained by an effect on the T/R equilibrium to favor the T state without affecting the intrinsic binding constants for the two Ca(2+) sites.
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22
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Invergo BM, Montanucci L, Koch KW, Bertranpetit J, Dell'orco D. Exploring the rate-limiting steps in visual phototransduction recovery by bottom-up kinetic modeling. Cell Commun Signal 2013; 11:36. [PMID: 23693153 PMCID: PMC3732082 DOI: 10.1186/1478-811x-11-36] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2013] [Accepted: 05/09/2013] [Indexed: 01/20/2023] Open
Abstract
Background Phototransduction in vertebrate photoreceptor cells represents a paradigm of signaling pathways mediated by G-protein-coupled receptors (GPCRs), which share common modules linking the initiation of the cascade to the final response of the cell. In this work, we focused on the recovery phase of the visual photoresponse, which is comprised of several interacting mechanisms. Results We employed current biochemical knowledge to investigate the response mechanisms of a comprehensive model of the visual phototransduction pathway. In particular, we have improved the model by implementing a more detailed representation of the recoverin (Rec)-mediated calcium feedback on rhodopsin kinase and including a dynamic arrestin (Arr) oligomerization mechanism. The model was successfully employed to investigate the rate limiting steps in the recovery of the rod photoreceptor cell after illumination. Simulation of experimental conditions in which the expression levels of rhodospin kinase (RK), of the regulator of the G-protein signaling (RGS), of Arr and of Rec were altered individually or in combination revealed severe kinetic constraints to the dynamics of the overall network. Conclusions Our simulations confirm that RGS-mediated effector shutdown is the rate-limiting step in the recovery of the photoreceptor and show that the dynamic formation and dissociation of Arr homodimers and homotetramers at different light intensities significantly affect the timing of rhodopsin shutdown. The transition of Arr from its oligomeric storage forms to its monomeric form serves to temper its availability in the functional state. Our results may explain the puzzling evidence that overexpressing RK does not influence the saturation time of rod cells at bright light stimuli. The approach presented here could be extended to the study of other GPCR signaling pathways.
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Affiliation(s)
- Brandon M Invergo
- Department of Life Sciences and Reproduction, Section of Biological Chemistry and Center for BioMedical Computing (CBMC), University of Verona, Strada le Grazie 8, 37134, Verona, Italy.
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23
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Conformational dynamics of activation for the pentameric complex of dimeric G protein-coupled receptor and heterotrimeric G protein. Structure 2012; 20:826-40. [PMID: 22579250 DOI: 10.1016/j.str.2012.03.017] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2012] [Revised: 03/05/2012] [Accepted: 03/05/2012] [Indexed: 01/08/2023]
Abstract
Photoactivation of rhodopsin (Rho), a G protein-coupled receptor, causes conformational changes that provide a specific binding site for the rod G protein, G(t). In this work we employed structural mass spectrometry techniques to elucidate the structural changes accompanying transition of ground state Rho to photoactivated Rho (Rho(∗)) and in the pentameric complex between dimeric Rho(∗) and heterotrimeric G(t). Observed differences in hydroxyl radical labeling and deuterium uptake between Rho(∗) and the (Rho(∗))(2)-G(t) complex suggest that photoactivation causes structural relaxation of Rho following its initial tightening upon G(t) coupling. In contrast, nucleotide-free G(t) in the complex is significantly more accessible to deuterium uptake allowing it to accept GTP and mediating complex dissociation. Thus, we provide direct evidence that in the critical step of signal amplification, Rho(∗) and G(t) exhibit dissimilar conformational changes when they are coupled in the (Rho(∗))(2)-G(t) complex.
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24
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Ames JB, Lim S. Molecular structure and target recognition of neuronal calcium sensor proteins. BIOCHIMICA ET BIOPHYSICA ACTA 2012; 1820:1205-13. [PMID: 22020049 PMCID: PMC3266469 DOI: 10.1016/j.bbagen.2011.10.003] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2011] [Revised: 10/06/2011] [Accepted: 10/07/2011] [Indexed: 02/06/2023]
Abstract
BACKGROUND Neuronal calcium sensor (NCS) proteins, a sub-branch of the calmodulin superfamily, are expressed in the brain and retina where they transduce calcium signals and are genetically linked to degenerative diseases. The amino acid sequences of NCS proteins are highly conserved but their physiological functions are quite distinct. Retinal recoverin and guanylate cyclase activating proteins (GCAPs) both serve as calcium sensors in retinal rod cells, neuronal frequenin (NCS1) modulate synaptic activity and neuronal secretion, K+ channel interacting proteins (KChIPs) regulate ion channels to control neuronal excitability, and DREAM (KChIP3) is a transcriptional repressor that regulates neuronal gene expression. SCOPE OF REVIEW Here we review the molecular structures of myristoylated forms of NCS1, recoverin, and GCAP1 that all look very different, suggesting that the sequestered myristoyl group helps to refold these highly homologous proteins into very different structures. The molecular structure of NCS target complexes have been solved for recoverin bound to rhodopsin kinase, NCS-1 bound to phosphatidylinositol 4-kinase, and KChIP1 bound to A-type K+ channels. MAJOR CONCLUSIONS We propose the idea that N-terminal myristoylation is critical for shaping each NCS family member into a unique structure, which upon Ca2+-induced extrusion of the myristoyl group exposes a unique set of previously masked residues, thereby exposing a distinctive ensemble of hydrophobic residues to associate specifically with a particular physiological target. This article is part of a Special Issue entitled Biochemical, biophysical and genetic approaches to intracellular calcium signaling.
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Affiliation(s)
- James B Ames
- University of California, Davis Department of Chemistry, Davis, CA 95616, USa.
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25
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Regulation of the methylation status of G protein-coupled receptor kinase 1 (rhodopsin kinase). Cell Signal 2012; 24:2259-67. [PMID: 22846544 DOI: 10.1016/j.cellsig.2012.07.020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2012] [Revised: 07/09/2012] [Accepted: 07/24/2012] [Indexed: 01/03/2023]
Abstract
Rhodopsin kinase (GRK1) is a member of G protein-coupled receptor kinase family and a key enzyme in the quenching of photolysed rhodopsin activity and desensitisation of the rod photoreceptor neurons. Like some other rod proteins involved in phototransduction, GRK1 is posttranslationally modified at the C terminus by isoprenylation (farnesylation), endoproteolysis and α-carboxymethylation. In this study, we examined the potential mechanisms of regulation of GRK1 methylation status, which have remained unexplored so far. We found that considerable fraction of GRK1 is endogenously methylated. In isolated rod outer segments, its methylation is inhibited and demethylation stimulated by low-affinity nucleotide binding. This effect is not specific for ATP and was observed in the presence of a non-hydrolysable ATP analogue AMP-PNP, GTP and other nucleotides, and thus may involve a site distinct from the active site of the kinase. GRK1 demethylation is inhibited in the presence of Ca(2+) by recoverin. This inhibition requires recoverin myristoylation and the presence of the membranes, and may be due to changes in GRK1 availability for processing enzymes upon its redistribution to the membranes induced by recoverin/Ca(2+). We hypothesise that increased GRK1 methylation in dark-adapted rods due to elevated cytoplasmic Ca(2+) levels would further increase its association with the membranes and recoverin, providing a positive feedback to efficiently suppress spurious phosphorylation of non-activated rhodopsin molecules and thus maximise senstivity of the photoreceptor. This study provides the first evidence for dynamic regulation of GRK1 α-carboxymethylation, which might play a role in the regulation of light sensitivity and adaptation in the rod photoreceptors.
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26
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Mushegian A, Gurevich VV, Gurevich EV. The origin and evolution of G protein-coupled receptor kinases. PLoS One 2012; 7:e33806. [PMID: 22442725 PMCID: PMC3307776 DOI: 10.1371/journal.pone.0033806] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2012] [Accepted: 02/22/2012] [Indexed: 01/25/2023] Open
Abstract
G protein-coupled receptor (GPCR) kinases (GRKs) play key role in homologous desensitization of GPCRs. GRKs phosphorylate activated receptors, promoting high affinity binding of arrestins, which precludes G protein coupling. Direct binding to active GPCRs activates GRKs, so that they selectively phosphorylate only the activated form of the receptor regardless of the accessibility of the substrate peptides within it and their Ser/Thr-containing sequence. Mammalian GRKs were classified into three main lineages, but earlier GRK evolution has not been studied. Here we show that GRKs emerged at the early stages of eukaryotic evolution via an insertion of a kinase similar to ribosomal protein S6 kinase into a loop in RGS domain. GRKs in Metazoa fall into two clades, one including GRK2 and GRK3, and the other consisting of all remaining GRKs, split into GRK1-GRK7 lineage and GRK4-GRK5-GRK6 lineage in vertebrates. One representative of each of the two ancient clades is found as early as placozoan Trichoplax adhaerens. Several protists, two oomycetes and unicellular brown algae have one GRK-like protein, suggesting that the insertion of a kinase domain into the RGS domain preceded the origin of Metazoa. The two GRK families acquired distinct structural units in the N- and C-termini responsible for membrane recruitment and receptor association. Thus, GRKs apparently emerged before animals and rapidly expanded in true Metazoa, most likely due to the need for rapid signalling adjustments in fast-moving animals.
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Affiliation(s)
- Arcady Mushegian
- Stowers Institute for Medical Research, Kansas City, Missouri, United States of America
- Department of Microbiology, Kansas University Medical Center, Kansas City, Kansas, United States of America
| | - Vsevolod V. Gurevich
- Department of Pharmacology, Vanderbilt University, Nashville, Tennessee, United States of America
| | - Eugenia V. Gurevich
- Department of Pharmacology, Vanderbilt University, Nashville, Tennessee, United States of America
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27
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Grigoriev II, Senin II, Tikhomirova NK, Komolov KE, Permyakov SE, Zernii EY, Koch KW, Philippov PP. Synergetic effect of recoverin and calmodulin on regulation of rhodopsin kinase. Front Mol Neurosci 2012; 5:28. [PMID: 22408603 PMCID: PMC3296934 DOI: 10.3389/fnmol.2012.00028] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2012] [Accepted: 02/17/2012] [Indexed: 01/24/2023] Open
Abstract
Phosphorylation of photoactivated rhodopsin by rhodopsin kinase (RK or GRK1), a first step of the phototransduction cascade turnoff, is under the control of Ca2+/recoverin. Here, we demonstrate that calmodulin, a ubiquitous Ca2+-sensor, can inhibit RK, though less effectively than recoverin does. We have utilized the surface plasmon resonance technology to map the calmodulin binding site in the RK molecule. Calmodulin does not interact with the recoverin-binding site within amino acid residues M1-S25 of the enzyme. Instead, the high affinity calmodulin binding site is localized within a stretch of amino acid residues V150-K175 in the N-terminal regulatory region of RK. Moreover, the inhibitory effect of calmodulin and recoverin on RK activity is synergetic, which is in agreement with the existence of separate binding sites for each Ca2+-sensing protein. The synergetic inhibition of RK by both Ca2+-sensors occurs over a broader range of Ca2+-concentration than by recoverin alone, indicating increased Ca2+-sensitivity of RK regulation in the presence of both Ca2+-sensors. Taken together, our data suggest that RK regulation by calmodulin in photoreceptor cells could complement the well-known inhibitory effect of recoverin on RK.
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Affiliation(s)
- Ilya I Grigoriev
- Department of Cell Signaling, A.N. Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University Moscow, Russia
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28
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Ames JB, Lim S, Ikura M. Molecular structure and target recognition of neuronal calcium sensor proteins. Front Mol Neurosci 2012; 5:10. [PMID: 22363261 PMCID: PMC3275791 DOI: 10.3389/fnmol.2012.00010] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2012] [Accepted: 01/26/2012] [Indexed: 01/19/2023] Open
Abstract
Neuronal calcium sensor (NCS) proteins, a sub-branch of the EF-hand superfamily, are expressed in the brain and retina where they transduce calcium signals and are genetically linked to degenerative diseases. The amino acid sequences of NCS proteins are highly conserved but their physiological functions are quite distinct. Retinal recoverin and guanylate cyclase activating proteins (GCAPs) both serve as calcium sensors in retinal rod cells, neuronal frequenin (NCS1) modulates synaptic activity and neuronal secretion, K+ channel interacting proteins (KChIPs) regulate ion channels to control neuronal excitability, and DREAM (KChIP3) is a transcriptional repressor that regulates neuronal gene expression. Here we review the molecular structures of myristoylated forms of NCS1, recoverin, and GCAP1 that all look very different, suggesting that the sequestered myristoyl group helps to refold these highly homologous proteins into very different structures. The molecular structure of NCS target complexes have been solved for recoverin bound to rhodopsin kinase (RK), NCS-1 bound to phosphatidylinositol 4-kinase, and KChIP1 bound to A-type K+ channels. We propose that N-terminal myristoylation is critical for shaping each NCS family member into a different structure, which upon Ca2+-induced extrusion of the myristoyl group exposes a unique set of previously masked residues that interact with a particular physiological target.
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Affiliation(s)
- James B Ames
- Department of Chemistry, University of California, Davis CA, USA
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29
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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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30
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Gurevich EV, Tesmer JJG, Mushegian A, Gurevich VV. G protein-coupled receptor kinases: more than just kinases and not only for GPCRs. Pharmacol Ther 2011; 133:40-69. [PMID: 21903131 DOI: 10.1016/j.pharmthera.2011.08.001] [Citation(s) in RCA: 319] [Impact Index Per Article: 24.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2011] [Accepted: 08/01/2011] [Indexed: 12/24/2022]
Abstract
G protein-coupled receptor (GPCR) kinases (GRKs) are best known for their role in homologous desensitization of GPCRs. GRKs phosphorylate activated receptors and promote high affinity binding of arrestins, which precludes G protein coupling. GRKs have a multidomain structure, with the kinase domain inserted into a loop of a regulator of G protein signaling homology domain. Unlike many other kinases, GRKs do not need to be phosphorylated in their activation loop to achieve an activated state. Instead, they are directly activated by docking with active GPCRs. In this manner they are able to selectively phosphorylate Ser/Thr residues on only the activated form of the receptor, unlike related kinases such as protein kinase A. GRKs also phosphorylate a variety of non-GPCR substrates and regulate several signaling pathways via direct interactions with other proteins in a phosphorylation-independent manner. Multiple GRK subtypes are present in virtually every animal cell, with the highest expression levels found in neurons, with their extensive and complex signal regulation. Insufficient or excessive GRK activity was implicated in a variety of human disorders, ranging from heart failure to depression to Parkinson's disease. As key regulators of GPCR-dependent and -independent signaling pathways, GRKs are emerging drug targets and promising molecular tools for therapy. Targeted modulation of expression and/or of activity of several GRK isoforms for therapeutic purposes was recently validated in cardiac disorders and Parkinson's disease.
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Affiliation(s)
- Eugenia V Gurevich
- Department of Pharmacology, Vanderbilt University, 2200 Pierce Avenue, Preston Research Building, Rm. 454, Nashville, TN 37232, United States.
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Involvement of the recoverin C-terminal segment in recognition of the target enzyme rhodopsin kinase. Biochem J 2011; 435:441-50. [DOI: 10.1042/bj20110013] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
NCS (neuronal Ca2+ sensor) proteins belong to a family of calmodulin-related EF-hand Ca2+-binding proteins which, in spite of a high degree of structural similarity, are able to selectively recognize and regulate individual effector enzymes in a Ca2+-dependent manner. NCS proteins vary at their C-termini, which could therefore serve as structural control elements providing specific functions such as target recognition or Ca2+ sensitivity. Recoverin, an NCS protein operating in vision, regulates the activity of rhodopsin kinase, GRK1, in a Ca2+-dependent manner. In the present study, we investigated a series of recoverin forms that were mutated at the C-terminus. Using pull-down assays, surface plasmon resonance spectroscopy and rhodopsin phosphorylation assays, we demonstrated that truncation of recoverin at the C-terminus significantly reduced the affinity of recoverin for rhodopsin kinase. Site-directed mutagenesis of single amino acids in combination with structural analysis and computational modelling of the recoverin–kinase complex provided insight into the protein–protein interface between the kinase and the C-terminus of recoverin. Based on these results we suggest that Phe3 from the N-terminal helix of rhodopsin kinase and Lys192 from the C-terminal segment of recoverin form a cation–π interaction pair which is essential for target recognition by recoverin. Taken together, the results of the present study reveal a novel rhodopsin-kinase-binding site within the C-terminal region of recoverin, and highlights its significance for target recognition and regulation.
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Arinobu D, Tachibanaki S, Kawamura S. Larger inhibition of visual pigment kinase in cones than in rods. J Neurochem 2010; 115:259-68. [PMID: 20649847 DOI: 10.1111/j.1471-4159.2010.06925.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
In the carp retina, visual pigment kinase, GRK1 (G-protein coupled receptor kinase 1) in rods and GRK7 in cones, is inhibited by a photoreceptor neuronal Ca(2+)-sensor protein, S-modulin (or recoverin) in rods and visinin (formerly named s26) in cones. Here, we compared Ca(2+)-dependent inhibition of GRK1 by S-modulin and that of GRK7 by visinin. First, the concentrations of S-modulin and visinin in the outer segment were estimated: the concentration of visinin (1.2 mM) was 20 times higher than that of S-modulin (53 μM). Based on the determined concentrations of the Ca(2+)-sensor proteins and the known dark Ca(2+) concentrations, we estimated that in situ Ca(2+)-dependent inhibition on GRK in cones would be 2.5 times higher than that in rods at the Ca(2+) concentration in the dark. Because GRK activity is approximately 100 times higher in cones than in rods [Proc. Natl Acad. Sci. USA 102 (2005) 21359], the range of Ca(2+)-dependent inhibition on GRK activity is more than 100 times wider in cones than in rods. The inhibitory effects of S-modulin and visinin on photoreceptor GRKs were indistinguishable, although these Ca(2+)-sensor proteins are expressed in a cell-type specific manner. The inhibition by these Ca(2+)-sensor proteins was slightly higher on GRK7 than GRK1 probably because of a characteristic specific to GRK7.
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Affiliation(s)
- Daisuke Arinobu
- Graduate School of Frontier Biosciences, Osaka University, Suita, Osaka, Japan
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Background light produces a recoverin-dependent modulation of activated-rhodopsin lifetime in mouse rods. J Neurosci 2010; 30:1213-20. [PMID: 20107049 DOI: 10.1523/jneurosci.4353-09.2010] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The Ca(2+)-binding protein recoverin is thought to regulate rhodopsin kinase and to modulate the lifetime of the photoexcited state of rhodopsin (Rh*), the visual pigment of vertebrate rods. Recoverin has been postulated to inhibit the kinase in darkness, when Ca(2+) is high, and to be released from the disk membrane in light when Ca(2+) is low, accelerating rhodopsin phosphorylation and shortening the lifetime of Rh*. This proposal has remained controversial, in part because the normally rapid turnoff of Rh* has made Rh* modulation difficult to study in an intact rod. To circumvent this problem, we have made mice that underexpress rhodopsin kinase so that Rh* turnoff is rate limiting for the decay of the rod light response. We show that background light speeds the decay of Rh* turnoff, and that this no longer occurs in mice that have had recoverin knocked out. This is the first demonstration in an intact rod that light accelerates Rh* inactivation and that the Ca(2+)-binding protein recoverin may be required for the light-dependent modulation of Rh* lifetime.
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Fries R, Reddy PP, Mikhaylova M, Haverkamp S, Wei T, Müller M, Kreutz MR, Koch KW. Dynamic cellular translocation of caldendrin is facilitated by the Ca2+-myristoyl switch of recoverin. J Neurochem 2010; 113:1150-62. [PMID: 20236386 DOI: 10.1111/j.1471-4159.2010.06676.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Caldendrin and recoverin are Ca(2+)-sensor proteins operating in neuronal systems. In a search for novel binding partners of recoverin, we employed an affinity column and identified caldendrin as a possible interaction partner. Caldendrin and recoverin co-localized in the retina in a subset of bipolar cells and in the pineal gland as revealed by immunofluorescence studies. The binding process was controlled by Ca(2+) as revealed by pull-down assays, and surface plasmon resonance studies. Importantly, caldendrin existed as a Ca(2+)-independent homodimer whereas a complex of recoverin and caldendrin formed with low to moderate affinity in the presence of Ca(2+). Co-transfection of COS-7 cells with plasmids harboring the gene for fluorescently labeled recoverin and caldendrin was used to study the cellular distribution by time-lapse fluorescence microscopy. Apparently, the increase of intracellular Ca(2+) facilitates the translocation of caldendrin to intracellular membranes, which is under control of complex formation with recoverin.
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Affiliation(s)
- Ramona Fries
- Biochemistry group, Institute of Biology and Environmental Science, Faculty V, Carl von Ossietzky University Oldenburg, Oldenburg, Germany
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Pao CS, Barker BL, Benovic JL. Role of the amino terminus of G protein-coupled receptor kinase 2 in receptor phosphorylation. Biochemistry 2009; 48:7325-33. [PMID: 19715378 DOI: 10.1021/bi900408g] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
G protein-coupled receptor kinases (GRKs) specifically phosphorylate activated G protein-coupled receptors. While the X-ray crystal structures of several GRKs have been determined, the mechanism of interaction of GRK with GPCRs is currently unknown. To further characterize the role of the GRK2 amino terminus in receptor interaction and phosphorylation, we generated a series of point mutations within the first 10 amino acids of GRK2 and tested their ability to phosphorylate receptor and nonreceptor substrates. Although all mutants exhibited some impairment in receptor phosphorylation, three of the mutants, D3K, L4A, and D10A, were the most severely affected. Using the beta2-adrenergic receptor and rhodopsin as receptor substrates and tubulin as a nonreceptor substrate, we demonstrated that the kinase activity toward the receptors was severely decreased in the mutants, while they fully retained their ability to phosphorylate tubulin. Moreover, the amino-terminal mutants were able to bind to the receptor but, in contrast to wild-type GRK2, were not activated by receptor binding. A synthetic peptide containing residues 1-14 of GRK2 served as a noncompetitive inhibitor of receptor phosphorylation by GRK2, while a comparable peptide from GRK5 had no effect on GRK2 activity. Secondary structure prediction and circular dichroism suggest that the GRK2 amino-terminal peptide forms an amphipathic alpha-helix. Taken together, we propose a mechanism whereby the extreme amino terminus of GRK2 forms an intramolecular interaction that selectively enhances the catalytic activity of the kinase toward receptor substrates.
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Affiliation(s)
- Christina S Pao
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, USA
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Li JL, Geng CY, Bu Y, Huang XR, Sun CC. Conformational transition pathway in the allosteric process of calcium-induced recoverin: Molecular dynamics simulations. J Comput Chem 2009; 30:1135-45. [DOI: 10.1002/jcc.21144] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Komolov KE, Senin II, Kovaleva NA, Christoph MP, Churumova VA, Grigoriev II, Akhtar M, Philippov PP, Koch KW. Mechanism of rhodopsin kinase regulation by recoverin. J Neurochem 2009; 110:72-9. [PMID: 19457073 DOI: 10.1111/j.1471-4159.2009.06118.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Recoverin is suggested to inhibit rhodopsin kinase (GRK1) at high [Ca(2+)] in the dark state of the photoreceptor cell. Decreasing [Ca(2+)] terminates inhibition and facilitates phosphorylation of illuminated rhodopsin (Rh*). When recoverin formed a complex with GRK1, it did not interfere with the phosphorylation of a C-terminal peptide of rhodopsin (S338-A348) by GRK1. Furthermore, while GRK1 competed with transducin on interaction with rhodopsin and thereby suppressed GTPase activity of transducin, recoverin in the complex with GRK1 did not influence this competition. Constructs of GRK1 that encompass its N-terminal, catalytic or C-terminal domains were used in pull-down assays and surface plasmon resonance analysis to monitor interaction. Ca(2+)-recoverin bound to the N-terminus of GRK1, but did not bind to the other constructs. GRK1 interacted with rhodopsin also by its N-terminus in a light-dependent manner. No interaction was observed with the C-terminus. We conclude that inhibition of GRK1 by recoverin is not the result of their direct competition for the same docking site on Rh*, although the interaction sites of GRK1/Rh* and GRK1/recoverin partially overlap. The N-terminus of GRK1 is recognized by Rh* leading to a conformational change which moves the C-terminus of Rh* into the catalytic kinase groove. Ca(2+)-recoverin interacting with the N-terminus of GRK1 prevents this conformational change and thus blocks Rh* phosphorylation by GRK1.
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Singh P, Wang B, Maeda T, Palczewski K, Tesmer JJG. Structures of rhodopsin kinase in different ligand states reveal key elements involved in G protein-coupled receptor kinase activation. J Biol Chem 2008; 283:14053-62. [PMID: 18339619 PMCID: PMC2376226 DOI: 10.1074/jbc.m708974200] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2007] [Revised: 02/04/2008] [Indexed: 12/27/2022] Open
Abstract
G protein-coupled receptor (GPCR) kinases (GRKs) phosphorylate activated heptahelical receptors, leading to their uncoupling from G proteins. Here we report six crystal structures of rhodopsin kinase (GRK1), revealing not only three distinct nucleotide-binding states of a GRK but also two key structural elements believed to be involved in the recognition of activated GPCRs. The first is the C-terminal extension of the kinase domain, which was observed in all nucleotide-bound GRK1 structures. The second is residues 5-30 of the N terminus, observed in one of the GRK1.(Mg2+)2.ATP structures. The N terminus was also clearly phosphorylated, leading to the identification of two novel phosphorylation sites by mass spectral analysis. Co-localization of the N terminus and the C-terminal extension near the hinge of the kinase domain suggests that activated GPCRs stimulate kinase activity by binding to this region to facilitate full closure of the kinase domain.
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Affiliation(s)
- Puja Singh
- Life Sciences Institute, Department of Pharmacology, University of Michigan, Ann Arbor, Michigan 48109-2216, USA
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Torisawa A, Arinobu D, Tachibanaki S, Kawamura S. Amino acid residues in GRK1/GRK7 responsible for interaction with S-modulin/recoverin. Photochem Photobiol 2008; 84:823-30. [PMID: 18266817 DOI: 10.1111/j.1751-1097.2007.00292.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
GRK1 is a visual pigment kinase in rods and is essential for inactivation of light-activated rhodopsin. The GRK1 activity is inhibited by binding of the Ca(2+)-bound form of S-modulin/recoverin. We previously identified the S-modulin/recoverin site to interact with GRK1. In the present study, we identified its counterpart in GRK1. We synthesized 29 of GRK1 or GRK7 partial peptides that cover the entire sequence of GRK1/GRK7, and examined whether these peptides inhibit S-modulin/recoverin activity most probably by preoccupying the binding site for GRK1. The inhibition was the greatest with the N-terminal peptide (p1, aa 3-23 in GRK7). On mutation of each of eight amino acid residues highly conserved in the p1 region of more than 10 orthologs, the inhibition was significantly reduced in the mutation of Leu(6), Asn(12) and Tyr(15). We further examined the binding of the peptides, including mutated ones, to S-modulin/recoverin with a resonance mirror biosensor. The binding correlated well with the degree of the inhibition by a peptide. The inhibition, therefore, seemed to be due to a direct binding of the kinase peptide to the binding site of active S-modulin/recoverin. A GRK1 region close to its C-terminus also seemed to be the binding site for S-modulin/recoverin.
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Affiliation(s)
- Aya Torisawa
- Graduate School of Frontier Biosciences, Osaka University, Osaka, Japan
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Rich RL, Myszka DG. Survey of the year 2006 commercial optical biosensor literature. J Mol Recognit 2007; 20:300-66. [DOI: 10.1002/jmr.862] [Citation(s) in RCA: 97] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Ames JB, Levay K, Wingard JN, Lusin JD, Slepak VZ. Structural basis for calcium-induced inhibition of rhodopsin kinase by recoverin. J Biol Chem 2006; 281:37237-45. [PMID: 17020884 DOI: 10.1074/jbc.m606913200] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Recoverin, a member of the neuronal calcium sensor branch of the EF-hand superfamily, serves as a calcium sensor that regulates rhodopsin kinase (RK) activity in retinal rod cells. We report here the NMR structure of Ca(2+)-bound recoverin bound to a functional N-terminal fragment of rhodopsin kinase (residues 1-25, called RK25). The overall main-chain structure of recoverin in the complex is similar to structures of Ca(2+)-bound recoverin in the absence of target (<1.8A root-mean-square deviation). The first eight residues of recoverin at the N terminus are solvent-exposed, enabling the N-terminal myristoyl group to interact with target membranes, and Ca(2+) is bound at the second and third EF-hands of the protein. RK25 in the complex forms an amphipathic helix (residues 4-16). The hydrophobic face of the RK25 helix (Val-9, Val-10, Ala-11, Ala-14, and Phe-15) interacts with an exposed hydrophobic groove on the surface of recoverin lined by side-chain atoms of Trp-31, Phe-35, Phe-49, Ile-52, Tyr-53, Phe-56, Phe-57, Tyr-86, and Leu-90. Residues of recoverin that contact RK25 are highly conserved, suggesting a similar target binding site structure in all neuronal calcium sensor proteins. Site-specific mutagenesis and deletion analysis confirm that the hydrophobic residues at the interface are necessary and sufficient for binding. The recoverin-RK25 complex exhibits Ca(2+)-induced binding to rhodopsin immobilized on concanavalin-A resin. We propose that Ca(2+)-bound recoverin is bound between rhodopsin and RK in a ternary complex on rod outer segment disk membranes, thereby blocking RK interaction with rhodopsin at high Ca(2+).
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Affiliation(s)
- James B Ames
- Center for Advanced Research in Biotechnology, University of Maryland Biotechnology Institute, Rockville, Maryland 20850, USA.
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Senin II, Bosch L, Ramon E, Zernii EY, Manyosa J, Philippov PP, Garriga P. Ca2+/recoverin dependent regulation of phosphorylation of the rhodopsin mutant R135L associated with retinitis pigmentosa. Biochem Biophys Res Commun 2006; 349:345-52. [PMID: 16934219 DOI: 10.1016/j.bbrc.2006.08.048] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2006] [Accepted: 08/11/2006] [Indexed: 11/19/2022]
Abstract
No single molecular mechanism accounts for the effect of mutations in rhodopsin associated with retinitis pigmentosa. Here we report on the specific effect of a Ca2+/recoverin upon phosphorylation of the autosomal dominant retinitis pigmentosa R135L rhodopsin mutant. This mutant shows specific features like impaired G-protein signaling but enhanced phosphorylation in the shut-off process. We now report that R135L hyperphosphorylation by rhodopsin kinase is less efficiently inhibited by Ca2+/recoverin than wild-type rhodopsin. This suggests an involvement of Ca2+/recoverin into the molecular pathogenic effect of the mutation in retinitis pigmentosa which is the cause of rod photoreceptor cell degeneration. This new proposed role of Ca2+/recoverin may be one of the specific features of the proposed new Type III class or rhodopsin mutations associated with retinitis pigmentosa.
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Affiliation(s)
- Ivan I Senin
- Department of Cell Signalling, A. N. Belozersky Institute of Physico-Chemical Biology, M.V. Lomonosov Moscow State University, Russia
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