1
|
Sharma K, Sizova I, Sanyal SK, Pandey GK, Hegemann P, Kateriya S. Deciphering the role of cytoplasmic domain of Channelrhodopsin in modulating the interactome and SUMOylome of Chlamydomonas reinhardtii. Int J Biol Macromol 2023:125135. [PMID: 37247713 DOI: 10.1016/j.ijbiomac.2023.125135] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2022] [Revised: 05/25/2023] [Accepted: 05/26/2023] [Indexed: 05/31/2023]
Abstract
Translocation of channelrhodopsins (ChRs) is mediated by the intraflagellar transport (IFT) machinery. However, the functional role of the network involving photoreceptors, IFT and other proteins in controlling algal ciliary motility is still not fully delineated. In the current study, we have identified two important motifs at the C-terminus of ChR1, VXPX and LKNE. VXPX is a known ciliary targeting sequence in animals, and LKNE is a well-known SUMOylation motif. To the best of our knowledge, this study gives prima facie insight into the role of SUMOylation in Chlamydomonas. We prove that VMPS of ChR1 is important for interaction with GTPase CrARL11. We show that SUMO motifs are present in the C-terminus of putative ChR1s from green algae. Performing experiments with n-Ethylmaleimide (NEM) and Ubiquitin-like protease 1 (ULP-1) we show that SUMOylation may modulate ChR1 protein in Chlamydomonas. Experiments with 2D08, a known sumoylation blocker, increased the concentration of ChR1 protein. Finally, we show the endogenous SUMOylated proteins (SUMOylome) of C. reinhardtii, identified by using immunoprecipitation followed by nano-LC-MS/MS detection. This report establishes a link between evolutionarily conserved SUMOylation, and ciliary machinery for the maintenance and functioning of cilia across the eukaryotes. Our enriched SUMOylome of C. reinhardtii comprehends the proteins related to ciliary development and, photo-signaling, along with orthologue(s) associated to human ciliopathies as SUMO targets.
Collapse
Affiliation(s)
- Komal Sharma
- Department of Plant Molecular Biology, University of Delhi South Campus, New Delhi 110021, India; Laboratory of Optobiology, School of Biotechnology, Jawaharlal Nehru University, New Delhi 110067, India
| | - Irina Sizova
- Petersburg Nuclear Physics Institute named by B.P. Konstantinov of National Research Centre, «Kurchatov Institute», St. Petersburg, Gatchina 1 188300, Russia
| | - Sibaji K Sanyal
- Department of Plant Molecular Biology, University of Delhi South Campus, New Delhi 110021, India; Laboratory of Optobiology, School of Biotechnology, Jawaharlal Nehru University, New Delhi 110067, India
| | - Girdhar K Pandey
- Department of Plant Molecular Biology, University of Delhi South Campus, New Delhi 110021, India
| | - Peter Hegemann
- Institut für Biologie, Experimentelle Biophysik, Humboldt-Universität zu Berlin, Invalidenstrasse 42, 10115 Berlin, Germany.
| | - Suneel Kateriya
- Laboratory of Optobiology, School of Biotechnology, Jawaharlal Nehru University, New Delhi 110067, India.
| |
Collapse
|
2
|
Tesson SVM. Physiological responses to pH in the freshwater microalga Limnomonas gaiensis. J Basic Microbiol 2023. [PMID: 37229780 DOI: 10.1002/jobm.202300107] [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: 03/03/2023] [Revised: 04/26/2023] [Accepted: 05/13/2023] [Indexed: 05/27/2023]
Abstract
The ecological niche of the recently described limnic microalga Limnomonas gaiensis (Chlamydomonadales) in Northern Europe remains unknown. To decipher the species tolerance capacity to pH, the effects of hydrogen ions on the physiological response of L. gaiensis were investigated. Results showed that L. gaiensis could tolerate exposure from pH 3 up to pH 11, with an optimal survival at pH 5-8. Its physiological response to pH was strain specific. Globally the southernmost strain was more alkaliphilic, had a slightly rounder shape, a slowest growth rate, and a lowest carrying capacity. Despite strain discrepancies among lakes, Swedish strains exhibited similar growth rates, faster at more acidic conditions. The extreme pH conditions affected its morphological features such as the eye spot and papilla shape, especially at acidic pH, and the cell wall integrity, at more alkaline pH. The wide range tolerance of L. gaiensis to pH would not be a hindrance to its dispersal in Swedish lakes (pH 4-8). Notably, the storage of high-energetic reserves over a wide range of pH conditions, as numerous starch grains and oil droplets, makes L. gaiensis a good candidate for bioethanol/fuel industrial production and a key resource to sustain aquatic food chain and microbial loop.
Collapse
Affiliation(s)
- Sylvie V M Tesson
- Aarhus Institute of Advanced Studies, Aarhus University, Aarhus, Denmark
| |
Collapse
|
3
|
Gating and ion selectivity of Channelrhodopsins are critical for photo-activated orientation of Chlamydomonas as shown by in vivo point mutation. Nat Commun 2022; 13:7253. [PMID: 36433995 PMCID: PMC9700795 DOI: 10.1038/s41467-022-35018-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Accepted: 11/15/2022] [Indexed: 11/26/2022] Open
Abstract
The green unicellular alga Chlamydomonas reinhardtii with two photoreceptors called channelrhodopsins is a model organism that gave birth to a new scientific field of biomedical studies, optogenetics. Although channelrhodopsins are helping to decipher the activity of the human brain, their functionality has never been extensively studied in the organism of origin, mainly due to the difficulties connected to reverse genetic interventions. In this study, we present a CRISPR-Cas9-based technique that enables a precise in vivo exchange of single amino acids in a selected gene. To shed light on the function of channelrhodopsins ChR1 (C1) and ChR2 (C2) in vivo, we deleted both channelrhodopsins independently in the wild-type strain and introduced point mutations in the remaining channel, causing modified photocycle kinetics and ion selectivity. The mutated strains, ΔC1C2-E123T, ΔC1C2-E90R and ΔC1C2-E90Q, showed about 100-fold decrease in photosensitivity, a reduced photophobic response and faster light adaptation rates due to accelerated photocycle kinetics and reduced Ca2+ conductance. Moreover, the ΔC1C2-E90Q with an additionally reduced H+ permeability produced an electrical response only in the presence of Na+ ions, highlighting a contribution and importance of H+ conductance to photocurrents in the wild-type algae. Finally, in the ΔC1C2-E90R strain with the channelrhodopsin selectivity converted to anions, no photo-responses were detected. We conclude that the precise photocycle kinetics and the particular ion selectivity of channelrhodopsins are the key parameters for efficient phototaxis in low light conditions.
Collapse
|
4
|
Rozenberg A, Kaczmarczyk I, Matzov D, Vierock J, Nagata T, Sugiura M, Katayama K, Kawasaki Y, Konno M, Nagasaka Y, Aoyama M, Das I, Pahima E, Church J, Adam S, Borin VA, Chazan A, Augustin S, Wietek J, Dine J, Peleg Y, Kawanabe A, Fujiwara Y, Yizhar O, Sheves M, Schapiro I, Furutani Y, Kandori H, Inoue K, Hegemann P, Béjà O, Shalev-Benami M. Rhodopsin-bestrophin fusion proteins from unicellular algae form gigantic pentameric ion channels. Nat Struct Mol Biol 2022; 29:592-603. [PMID: 35710843 DOI: 10.1038/s41594-022-00783-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Accepted: 04/27/2022] [Indexed: 11/09/2022]
Abstract
Many organisms sense light using rhodopsins, photoreceptive proteins containing a retinal chromophore. Here we report the discovery, structure and biophysical characterization of bestrhodopsins, a microbial rhodopsin subfamily from marine unicellular algae, in which one rhodopsin domain of eight transmembrane helices or, more often, two such domains in tandem, are C-terminally fused to a bestrophin channel. Cryo-EM analysis of a rhodopsin-rhodopsin-bestrophin fusion revealed that it forms a pentameric megacomplex (~700 kDa) with five rhodopsin pseudodimers surrounding the channel in the center. Bestrhodopsins are metastable and undergo photoconversion between red- and green-absorbing or green- and UVA-absorbing forms in the different variants. The retinal chromophore, in a unique binding pocket, photoisomerizes from all-trans to 11-cis form. Heterologously expressed bestrhodopsin behaves as a light-modulated anion channel.
Collapse
Affiliation(s)
- Andrey Rozenberg
- Faculty of Biology, Technion - Israel Institute of Technology, Haifa, Israel
| | - Igor Kaczmarczyk
- Department of Chemical and Structural Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Donna Matzov
- Department of Chemical and Structural Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Johannes Vierock
- Institute for Biology, Experimental Biophysics, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Takashi Nagata
- The Institute for Solid State Physics, The University of Tokyo, Kashiwa, Japan.,PRESTO, Japan Science and Technology Agency, Kawaguchi, Japan
| | - Masahiro Sugiura
- Department of Life Science and Applied Chemistry, Nagoya Institute of Technology, Showa-ku, Japan
| | - Kota Katayama
- PRESTO, Japan Science and Technology Agency, Kawaguchi, Japan.,Department of Life Science and Applied Chemistry, Nagoya Institute of Technology, Showa-ku, Japan.,OptoBioTechnology Research Center, Nagoya Institute of Technology, Showa-ku, Japan
| | - Yuma Kawasaki
- The Institute for Solid State Physics, The University of Tokyo, Kashiwa, Japan
| | - Masae Konno
- The Institute for Solid State Physics, The University of Tokyo, Kashiwa, Japan.,PRESTO, Japan Science and Technology Agency, Kawaguchi, Japan
| | - Yujiro Nagasaka
- The Institute for Solid State Physics, The University of Tokyo, Kashiwa, Japan
| | - Mako Aoyama
- Department of Life Science and Applied Chemistry, Nagoya Institute of Technology, Showa-ku, Japan
| | - Ishita Das
- Department of Molecular Chemistry and Materials Science, Weizmann Institute of Science, Rehovot, Israel
| | - Efrat Pahima
- Fritz Haber Center for Molecular Dynamics Research Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Jonathan Church
- Fritz Haber Center for Molecular Dynamics Research Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Suliman Adam
- Fritz Haber Center for Molecular Dynamics Research Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Veniamin A Borin
- Fritz Haber Center for Molecular Dynamics Research Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Ariel Chazan
- Faculty of Biology, Technion - Israel Institute of Technology, Haifa, Israel
| | - Sandra Augustin
- Institute for Biology, Experimental Biophysics, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Jonas Wietek
- Department of Neurobiology, Weizmann Institute of Science, Rehovot, Israel
| | - Julien Dine
- Department of Neurobiology, Weizmann Institute of Science, Rehovot, Israel
| | - Yoav Peleg
- Structural Proteomics Unit (SPU), Life Sciences Core Facilities (LSCF), Weizmann Institute of Science, Rehovot, Israel
| | - Akira Kawanabe
- Laboratory of Molecular Physiology & Biophysics, Faculty of Medicine, Kagawa University, Miki-cho, Japan
| | - Yuichiro Fujiwara
- Laboratory of Molecular Physiology & Biophysics, Faculty of Medicine, Kagawa University, Miki-cho, Japan
| | - Ofer Yizhar
- Department of Neurobiology, Weizmann Institute of Science, Rehovot, Israel
| | - Mordechai Sheves
- Department of Molecular Chemistry and Materials Science, Weizmann Institute of Science, Rehovot, Israel
| | - Igor Schapiro
- Fritz Haber Center for Molecular Dynamics Research Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Yuji Furutani
- Department of Life Science and Applied Chemistry, Nagoya Institute of Technology, Showa-ku, Japan.,OptoBioTechnology Research Center, Nagoya Institute of Technology, Showa-ku, Japan
| | - Hideki Kandori
- Department of Life Science and Applied Chemistry, Nagoya Institute of Technology, Showa-ku, Japan.,OptoBioTechnology Research Center, Nagoya Institute of Technology, Showa-ku, Japan
| | - Keiichi Inoue
- The Institute for Solid State Physics, The University of Tokyo, Kashiwa, Japan
| | - Peter Hegemann
- Institute for Biology, Experimental Biophysics, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Oded Béjà
- Faculty of Biology, Technion - Israel Institute of Technology, Haifa, Israel.
| | - Moran Shalev-Benami
- Department of Chemical and Structural Biology, Weizmann Institute of Science, Rehovot, Israel.
| |
Collapse
|
5
|
Gordeliy V, Kovalev K, Bamberg E, Rodriguez-Valera F, Zinovev E, Zabelskii D, Alekseev A, Rosselli R, Gushchin I, Okhrimenko I. Microbial Rhodopsins. Methods Mol Biol 2022; 2501:1-52. [PMID: 35857221 DOI: 10.1007/978-1-0716-2329-9_1] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The first microbial rhodopsin, a light-driven proton pump bacteriorhodopsin from Halobacterium salinarum (HsBR), was discovered in 1971. Since then, this seven-α-helical protein, comprising a retinal molecule as a cofactor, became a major driver of groundbreaking developments in membrane protein research. However, until 1999 only a few archaeal rhodopsins, acting as light-driven proton and chloride pumps and also photosensors, were known. A new microbial rhodopsin era started in 2000 when the first bacterial rhodopsin, a proton pump, was discovered. Later it became clear that there are unexpectedly many rhodopsins, and they are present in all the domains of life and even in viruses. It turned out that they execute such a diversity of functions while being "nearly the same." The incredible evolution of the research area of rhodopsins and the scientific and technological potential of the proteins is described in the review with a focus on their function-structure relationships.
Collapse
Affiliation(s)
- Valentin Gordeliy
- Institut de Biologie Structurale (IBS), Université Grenoble Alpes, CEA, CNRS, Grenoble, France.
| | - Kirill Kovalev
- Institut de Biologie Structurale (IBS), Université Grenoble Alpes, CEA, CNRS, Grenoble, France
- Institute of Biological Information Processing (IBI-7: Structural Biochemistry), Forschungszentrum Jülich GmbH, Jülich, Germany
- JuStruct: Jülich Center for Structural Biology, Forschungszentrum Jülich GmbH, Jülich, Germany
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology (National Research University), Dolgoprudny, Russia
- Institute of Crystallography, University of Aachen (RWTH), Aachen, Germany
| | - Ernst Bamberg
- Max Planck Institute of Biophysics, Frankfurt am Main, Germany
| | - Francisco Rodriguez-Valera
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology (National Research University), Dolgoprudny, Russia
- Evolutionary Genomics Group, Departamento de Producción Vegetal y Microbiología, Universidad Miguel Hernández, San Juan de Alicante, Alicante, Spain
| | - Egor Zinovev
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology (National Research University), Dolgoprudny, Russia
| | - Dmitrii Zabelskii
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology (National Research University), Dolgoprudny, Russia
| | - Alexey Alekseev
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology (National Research University), Dolgoprudny, Russia
| | - Riccardo Rosselli
- Departamento de Fisiología, Genetica y Microbiología. Facultad de Ciencias, Universidad de Alicante, Alicante, Spain
| | - Ivan Gushchin
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology (National Research University), Dolgoprudny, Russia
| | - Ivan Okhrimenko
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology (National Research University), Dolgoprudny, Russia
| |
Collapse
|
6
|
Abstract
Microbial rhodopsins are diverse photoreceptive proteins containing a retinal chromophore and are found in all domains of cellular life and are even encoded in genomes of viruses. These rhodopsins make up two families: type 1 rhodopsins and the recently discovered heliorhodopsins. These families have seven transmembrane helices with similar structures but opposing membrane orientation. Microbial rhodopsins participate in a portfolio of light-driven energy and sensory transduction processes. In this review we present data collected over the last two decades about these rhodopsins and describe their diversity, functions, and biological and ecological roles. Expected final online publication date for the Annual Review of Microbiology, Volume 75 is October 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
Collapse
Affiliation(s)
- Andrey Rozenberg
- Faculty of Biology, Technion-Israel Institute of Technology, Haifa 3200003, Israel; ,
| | - Keiichi Inoue
- The Institute for Solid State Physics, The University of Tokyo, Kashiwa 277-8581, Japan;
| | - Hideki Kandori
- Department of Life Science and Applied Chemistry, Nagoya Institute of Technology, Nagoya 466-8555, Japan;
| | - Oded Béjà
- Faculty of Biology, Technion-Israel Institute of Technology, Haifa 3200003, Israel; ,
| |
Collapse
|
7
|
Adam S, Wiebeler C, Schapiro I. Structural Factors Determining the Absorption Spectrum of Channelrhodopsins: A Case Study of the Chimera C1C2. J Chem Theory Comput 2021; 17:6302-6313. [PMID: 34255519 DOI: 10.1021/acs.jctc.1c00160] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Channelrhodopsins are photosensitive proteins that trigger flagella motion in single-cell algae and have been successfully utilized in optogenetic applications. In optogenetics, light is used to activate neural cells in living organisms, which can be achieved by exploiting the ion channel signaling of channelrhodopsins. Tailoring channelrhodopsins for such applications includes the tuning of the absorption maximum. In order to establish rational design and to obtain a desired spectral shift, a basic understanding of the absorption spectrum is required. We have studied the chimera C1C2 as a representative of this protein family and the first member with an available crystal structure. For this purpose, we sampled the conformations of C1C2 using quantum mechanical/molecular mechanical molecular dynamics and subjected the resulting snapshots of the trajectory to excitation energy calculations using ADC(2) and simplified time-dependent density functional theory. In contrast to previous reports, we found that different hydrogen-bonding networks-involving the retinal protonated Schiff base, the putative counterions E162 and D292, and water molecules-had only a small impact on the absorption spectrum. However, in the case of deprotonated E162, increasing the distance to the Schiff base hydrogen-bonding partner led to a systematic blue shift. The β-ionone ring rotation was identified as another important contributor. Yet the most important factors were found to be the bond length alternation and bond order alternation that were linearly correlated to the absorption maximum by up to 62 and 82%, respectively. We ascribe this novel insight into the structural basis of the absorption spectrum to our enhanced protein setup that includes membrane embedding as well as long and extensive sampling.
Collapse
Affiliation(s)
- Suliman Adam
- Fritz Haber Center for Molecular Dynamics, Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel
| | - Christian Wiebeler
- Fritz Haber Center for Molecular Dynamics, Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel
| | - Igor Schapiro
- Fritz Haber Center for Molecular Dynamics, Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel
| |
Collapse
|
8
|
Böhm M, Boness D, Fantisch E, Erhard H, Frauenholz J, Kowalzyk Z, Marcinkowski N, Kateriya S, Hegemann P, Kreimer G. Channelrhodopsin-1 Phosphorylation Changes with Phototactic Behavior and Responds to Physiological Stimuli in Chlamydomonas. THE PLANT CELL 2019; 31:886-910. [PMID: 30862615 PMCID: PMC6501600 DOI: 10.1105/tpc.18.00936] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Revised: 02/25/2019] [Accepted: 03/11/2019] [Indexed: 05/26/2023]
Abstract
The unicellular alga Chlamydomonas (Chlamydomonas reinhardtii) exhibits oriented movement responses (phototaxis) to light over more than three log units of intensity. Phototaxis thus depends on the cell's ability to adjust the sensitivity of its photoreceptors to ambient light conditions. In Chlamydomonas, the photoreceptors for phototaxis are the channelrhodopsins (ChR)1 and ChR2; these light-gated cation channels are located in the plasma membrane. Although ChRs are widely used in optogenetic studies, little is known about ChR signaling in algae. We characterized the in vivo phosphorylation of ChR1. Its reversible phosphorylation occurred within seconds as a graded response to changes in the light intensity and ionic composition of the medium and depended on an elevated cytosolic Ca2+ concentration. Changes in the phototactic sign were accompanied by alterations in the phosphorylation status of ChR1. Furthermore, compared with the wild type, a permanently negative phototactic mutant required higher light intensities to evoke ChR1 phosphorylation. C-terminal truncation of ChR1 disturbed its reversible phosphorylation, whereas it was normal in ChR2-knockout and eyespot-assembly mutants. The identification of phosphosites in regions important for ChR1 function points to their potential regulatory role(s). We propose that multiple ChR1 phosphorylation, regulated via a Ca2+-based feedback loop, is an important component in the adaptation of phototactic sensitivity in Chlamydomonas.
Collapse
Affiliation(s)
- Michaela Böhm
- Department of Biology, Friedrich-Alexander University, 91058 Erlangen, Germany
| | - David Boness
- Department of Biology, Friedrich-Alexander University, 91058 Erlangen, Germany
| | - Elisabeth Fantisch
- Department of Biology, Friedrich-Alexander University, 91058 Erlangen, Germany
| | - Hanna Erhard
- Department of Biology, Friedrich-Alexander University, 91058 Erlangen, Germany
| | - Julia Frauenholz
- Department of Biology, Friedrich-Alexander University, 91058 Erlangen, Germany
| | - Zarah Kowalzyk
- Department of Biology, Friedrich-Alexander University, 91058 Erlangen, Germany
| | - Nadin Marcinkowski
- Department of Biology, Friedrich-Alexander University, 91058 Erlangen, Germany
| | - Suneel Kateriya
- School of Biotechnology, Jawaharlal Nehru University, 110067 New Delhi, India
| | - Peter Hegemann
- Institute for Experimental Biophysics, Humboldt University, 10115 Berlin, Germany
| | - Georg Kreimer
- Department of Biology, Friedrich-Alexander University, 91058 Erlangen, Germany
| |
Collapse
|
9
|
Dokukina I, Nenov A, Garavelli M, Marian CM, Weingart O. QM/MM Photodynamics of Retinal in the Channelrhodopsin Chimera C1C2 with OM3/MRCI. CHEMPHOTOCHEM 2019. [DOI: 10.1002/cptc.201800185] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Irina Dokukina
- Institut für Theoretische Chemie und ComputerchemieHeinrich-Heine-Universität Düsseldorf Universitätsstr. 1 40225 Düsseldorf Germany
| | - Artur Nenov
- Dipartimento di Chimica Industriale “Toso Montanari”Universitá degli Studi di Bologna Viale del Risorgimento, 4 40136 Bologna Italia
| | - Marco Garavelli
- Dipartimento di Chimica Industriale “Toso Montanari”Universitá degli Studi di Bologna Viale del Risorgimento, 4 40136 Bologna Italia
| | - Christel M. Marian
- Institut für Theoretische Chemie und ComputerchemieHeinrich-Heine-Universität Düsseldorf Universitätsstr. 1 40225 Düsseldorf Germany
| | - Oliver Weingart
- Institut für Theoretische Chemie und ComputerchemieHeinrich-Heine-Universität Düsseldorf Universitätsstr. 1 40225 Düsseldorf Germany
| |
Collapse
|
10
|
Deisseroth K, Hegemann P. The form and function of channelrhodopsin. Science 2018; 357:357/6356/eaan5544. [PMID: 28912215 PMCID: PMC5723383 DOI: 10.1126/science.aan5544] [Citation(s) in RCA: 155] [Impact Index Per Article: 25.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2017] [Accepted: 07/25/2017] [Indexed: 12/22/2022]
Abstract
Channelrhodopsins are light-gated ion channels that, via regulation of flagellar function, enable single-celled motile algae to seek ambient light conditions suitable for photosynthesis and survival. These plant behavioral responses were initially investigated more than 150 years ago. Recently, major principles of function for light-gated ion channels have been elucidated by creating channelrhodopsins with kinetics that are accelerated or slowed over orders of magnitude, by discovering and designing channelrhodopsins with altered spectral properties, by solving the high-resolution channelrhodopsin crystal structure, and by structural model-guided redesign of channelrhodopsins for altered ion selectivity. Each of these discoveries not only revealed basic principles governing the operation of light-gated ion channels, but also enabled the creation of new proteins for illuminating, via optogenetics, the fundamentals of brain function.
Collapse
Affiliation(s)
- Karl Deisseroth
- Department of Bioengineering, Stanford University, Stanford, CA, USA. .,Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA, USA.,Howard Hughes Medical Institute, Stanford University, Stanford, CA, USA
| | - Peter Hegemann
- Institute for Biology, Humboldt Universität zu Berlin, D-10115 Berlin, Germany. .,Experimental Biophysics, Humboldt Universität zu Berlin, D-10115 Berlin, Germany
| |
Collapse
|
11
|
Calcium-Dependent Signalling Processes in Chlamydomonas. CHLAMYDOMONAS: MOLECULAR GENETICS AND PHYSIOLOGY 2017. [DOI: 10.1007/978-3-319-66365-4_8] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
|
12
|
Construction and application of photoresponsive smart nanochannels. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY C-PHOTOCHEMISTRY REVIEWS 2016. [DOI: 10.1016/j.jphotochemrev.2015.12.002] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
|
13
|
Bruun S, Stoeppler D, Keidel A, Kuhlmann U, Luck M, Diehl A, Geiger MA, Woodmansee D, Trauner D, Hegemann P, Oschkinat H, Hildebrandt P, Stehfest K. Light-Dark Adaptation of Channelrhodopsin Involves Photoconversion between the all-trans and 13-cis Retinal Isomers. Biochemistry 2015; 54:5389-400. [PMID: 26237332 DOI: 10.1021/acs.biochem.5b00597] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Channelrhodopsins (ChR) are light-gated ion channels of green algae that are widely used to probe the function of neuronal cells with light. Most ChRs show a substantial reduction in photocurrents during illumination, a process named "light adaptation". The main objective of this spectroscopic study was to elucidate the molecular processes associated with light-dark adaptation. Here we show by liquid and solid-state nuclear magnetic resonance spectroscopy that the retinal chromophore of fully dark-adapted ChR is exclusively in an all-trans configuration. Resonance Raman (RR) spectroscopy, however, revealed that already low light intensities establish a photostationary equilibrium between all-trans,15-anti and 13-cis,15-syn configurations at a ratio of 3:1. The underlying photoreactions involve simultaneous isomerization of the C(13)═C(14) and C(15)═N bonds. Both isomers of this DAapp state may run through photoinduced reaction cycles initiated by photoisomerization of only the C(13)═C(14) bond. RR spectroscopic experiments further demonstrated that photoinduced conversion of the apparent dark-adapted (DAapp) state to the photocycle intermediates P500 and P390 is distinctly more efficient for the all-trans isomer than for the 13-cis isomer, possibly because of different chromophore-water interactions. Our data demonstrating two complementary photocycles of the DAapp isomers are fully consistent with the existence of two conducting states that vary in quantitative relation during light-dark adaptation, as suggested previously by electrical measurements.
Collapse
Affiliation(s)
- Sara Bruun
- Technische Universität Berlin , Institut für Chemie, Sekr. PC14, Straße des 17. Juni 135, D-10623 Berlin, Germany
| | - Daniel Stoeppler
- Leibniz-Institut für Molekulare Pharmakologie (FMP) , Robert-Rössle-Strasse 10, 13125 Berlin, Germany
| | - Anke Keidel
- Technische Universität Berlin , Institut für Chemie, Sekr. PC14, Straße des 17. Juni 135, D-10623 Berlin, Germany
| | - Uwe Kuhlmann
- Technische Universität Berlin , Institut für Chemie, Sekr. PC14, Straße des 17. Juni 135, D-10623 Berlin, Germany
| | - Meike Luck
- Humboldt-Universität zu Berlin , Institut für Biologie, Invalidenstrasse 42, D-10115 Berlin, Germany
| | - Anne Diehl
- Leibniz-Institut für Molekulare Pharmakologie (FMP) , Robert-Rössle-Strasse 10, 13125 Berlin, Germany
| | - Michel-Andreas Geiger
- Leibniz-Institut für Molekulare Pharmakologie (FMP) , Robert-Rössle-Strasse 10, 13125 Berlin, Germany
| | - David Woodmansee
- Department of Chemistry, Ludwig-Maximilians-Universität München , Butenandtstraße 5-13, 81377 München, Germany
| | - Dirk Trauner
- Department of Chemistry, Ludwig-Maximilians-Universität München , Butenandtstraße 5-13, 81377 München, Germany
| | - Peter Hegemann
- Humboldt-Universität zu Berlin , Institut für Biologie, Invalidenstrasse 42, D-10115 Berlin, Germany
| | - Hartmut Oschkinat
- Leibniz-Institut für Molekulare Pharmakologie (FMP) , Robert-Rössle-Strasse 10, 13125 Berlin, Germany
| | - Peter Hildebrandt
- Technische Universität Berlin , Institut für Chemie, Sekr. PC14, Straße des 17. Juni 135, D-10623 Berlin, Germany
| | - Katja Stehfest
- Humboldt-Universität zu Berlin , Institut für Biologie, Invalidenstrasse 42, D-10115 Berlin, Germany
| |
Collapse
|
14
|
Lee KA, Lee SS, Kim SY, Choi AR, Lee JH, Jung KH. Mistic-fused expression of algal rhodopsins in Escherichia coli and its photochemical properties. Biochim Biophys Acta Gen Subj 2015; 1850:1694-703. [PMID: 25869488 DOI: 10.1016/j.bbagen.2015.04.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Revised: 03/10/2015] [Accepted: 04/03/2015] [Indexed: 01/29/2023]
Abstract
BACKGROUND Since algal rhodopsins, the eukaryotic seven-transmembrane proteins, are generally difficult to express in Escherichia coli, eukaryotic cells have been used for heterologous expression. Mistic, a membrane-associated protein that was originally discovered in Bacillus subtilis, has been shown to improve the expression levels of many foreign integral membrane proteins in E. coli when used as a fusion partner linked to the N-terminus of cargo proteins. METHODS Here, we expressed two algal rhodopsins with N- and C-terminal Mistic domains in E. coli-Acetabularia rhodopsin I (ARI) and Chlamydomonas sensory rhodopsin B (CSRB, channel rhodopsin 2). UV/VIS spectroscopy, pH titration of proton acceptor residue, laser-induced photolysis and electrophysiological measurement were used for investigating important residues in proton transport and spectroscopic characters of the proteins. RESULTS Protein yield of two algal rhodopsins was enhanced, obtaining 0.12mg of Mistic-ARI and 0.04mg of Mistic-CSRB per liter of culture. Spheroplast expression Mistic-ARI had outward proton-pumping activity, indicating protein functionality. Asp89 of ARI changed its protonation state by light absorption, and Asp100 was important for O(600) formation. Electrophysiology revealed that both residues took part in proton transport. The spectroscopic analyses of Mistic-CSRB revealed its characteristics. CONCLUSIONS Fusion to the membrane-integrating protein Mistic can enhance overexpression of eukaryotic type I rhodopsins in E. coli. GENERAL SIGNIFICANCE These findings indicate that Mistic fusion and E. coli expression method could be an effective, low cost technique for studying eukaryotic membrane proteins. This may have useful implications, for example, in studying structural characteristics and optogenetics for rhodopsins.
Collapse
Affiliation(s)
- Keon Ah Lee
- Department of Life Science and Interdisciplinary Program of Integrated Biotechnology, Sogang University, Shinsu-Dong 1, Mapo-Gu, Seoul 121-742, Republic of Korea
| | - Sang-Soo Lee
- Department of Life Science and Interdisciplinary Program of Integrated Biotechnology, Sogang University, Shinsu-Dong 1, Mapo-Gu, Seoul 121-742, Republic of Korea
| | - So Young Kim
- Department of Life Science and Interdisciplinary Program of Integrated Biotechnology, Sogang University, Shinsu-Dong 1, Mapo-Gu, Seoul 121-742, Republic of Korea
| | - Ah Reum Choi
- Department of Life Science and Interdisciplinary Program of Integrated Biotechnology, Sogang University, Shinsu-Dong 1, Mapo-Gu, Seoul 121-742, Republic of Korea
| | - Jung-Ha Lee
- Department of Life Science and Interdisciplinary Program of Integrated Biotechnology, Sogang University, Shinsu-Dong 1, Mapo-Gu, Seoul 121-742, Republic of Korea
| | - Kwang-Hwan Jung
- Department of Life Science and Interdisciplinary Program of Integrated Biotechnology, Sogang University, Shinsu-Dong 1, Mapo-Gu, Seoul 121-742, Republic of Korea.
| |
Collapse
|
15
|
Dokukina I, Weingart O. Spectral properties and isomerisation path of retinal in C1C2 channelrhodopsin. Phys Chem Chem Phys 2015; 17:25142-50. [DOI: 10.1039/c5cp02650d] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Computed torsion profiles along the reactive coordinate in S1reveal a two-path deactivation mechanism for retinal in C1C2 channelrhodopsin.
Collapse
Affiliation(s)
- I. Dokukina
- Institut für Theoretische Chemie und Computerchemie
- Heinrich-Heine-Universität Düsseldorf
- 40225 Düsseldorf
- Germany
| | - O. Weingart
- Institut für Theoretische Chemie und Computerchemie
- Heinrich-Heine-Universität Düsseldorf
- 40225 Düsseldorf
- Germany
| |
Collapse
|
16
|
Richards R, Dempski RE. Re-introduction of transmembrane serine residues reduce the minimum pore diameter of channelrhodopsin-2. PLoS One 2012; 7:e50018. [PMID: 23185520 PMCID: PMC3501483 DOI: 10.1371/journal.pone.0050018] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2012] [Accepted: 10/17/2012] [Indexed: 11/18/2022] Open
Abstract
Channelrhodopsin-2 (ChR2) is a microbial-type rhodopsin found in the green algae Chlamydomonas reinhardtii. Under physiological conditions, ChR2 is an inwardly rectifying cation channel that permeates a wide range of mono- and divalent cations. Although this protein shares a high sequence homology with other microbial-type rhodopsins, which are ion pumps, ChR2 is an ion channel. A sequence alignment of ChR2 with bacteriorhodopsin, a proton pump, reveals that ChR2 lacks specific motifs and residues, such as serine and threonine, known to contribute to non-covalent interactions within transmembrane domains. We hypothesized that reintroduction of the eight transmembrane serine residues present in bacteriorhodopsin, but not in ChR2, will restrict the conformational flexibility and reduce the pore diameter of ChR2. In this work, eight single serine mutations were created at homologous positions in ChR2. Additionally, an endogenous transmembrane serine was replaced with alanine. We measured kinetics, changes in reversal potential, and permeability ratios in different alkali metal solutions using two-electrode voltage clamp. Applying excluded volume theory, we calculated the minimum pore diameter of ChR2 constructs. An analysis of the results from our experiments show that reintroducing serine residues into the transmembrane domain of ChR2 can restrict the minimum pore diameter through inter- and intrahelical hydrogen bonds while the removal of a transmembrane serine results in a larger pore diameter. Therefore, multiple positions along the intracellular side of the transmembrane domains contribute to the cation permeability of ChR2.
Collapse
Affiliation(s)
- Ryan Richards
- Department of Chemistry and Biochemistry, Worcester Polytechnic Institute, Worcester, Massachusetts, United States of America
| | - Robert E. Dempski
- Department of Chemistry and Biochemistry, Worcester Polytechnic Institute, Worcester, Massachusetts, United States of America
| |
Collapse
|
17
|
Foutz TJ, Arlow RL, McIntyre CC. Theoretical principles underlying optical stimulation of a channelrhodopsin-2 positive pyramidal neuron. J Neurophysiol 2012; 107:3235-45. [PMID: 22442566 DOI: 10.1152/jn.00501.2011] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Optogenetics is an emerging field of neuromodulation that permits scaled, millisecond temporal control of the membrane dynamics of genetically targeted cells using light. Optogenetic technology has revolutionized neuroscience research; however, numerous biophysical questions remain on the optical and neuronal factors impacting the modulation of neural activity with photon-sensitive ion channels. To begin to address such questions, we developed a computational tool to explore the underlying principles of optogenetic neural stimulation. This "light-neuron" model consists of theoretical representations of the light dynamics generated by a fiber optic in brain tissue, coupled to a multicompartment cable model of a cortical pyramidal neuron embedded with channelrhodopsin-2 (ChR2) membrane dynamics. Simulations revealed that the large energies required to generate an action potential are primarily due to the limited conductivity of ChR2, and that the major determinants of stimulation threshold are the surface area of illuminated cell membrane and proximity to the light source. Our results predict that the activation threshold is sensitive to many of the properties of ChR2 (density, conductivity, and kinetics), tissue medium (scattering and absorbance), and the fiber-optic light source (diameter and numerical aperture). We also illustrate the impact of redistributing the ChR2 expression density (uniform vs. nonuniform) on the activation threshold. The model system developed in this study represents a scientific instrument to characterize the effects of optogenetic neuromodulation, as well as an engineering design tool to help guide future development of optogenetic technology.
Collapse
Affiliation(s)
- Thomas J Foutz
- Cleveland Clinic Foundation, Dept. of Biomedical Engineering, Cleveland, OH 44195, USA.
| | | | | |
Collapse
|
18
|
Zhang F, Vierock J, Yizhar O, Fenno LE, Tsunoda S, Kianianmomeni A, Prigge M, Berndt A, Cushman J, Polle J, Magnuson J, Hegemann P, Deisseroth K. The microbial opsin family of optogenetic tools. Cell 2012; 147:1446-57. [PMID: 22196724 PMCID: PMC4166436 DOI: 10.1016/j.cell.2011.12.004] [Citation(s) in RCA: 403] [Impact Index Per Article: 33.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2011] [Revised: 11/17/2011] [Accepted: 12/05/2011] [Indexed: 11/24/2022]
Abstract
The capture and utilization of light is an exquisitely evolved process. The single-component microbial opsins, although more limited than multicomponent cascades in processing, display unparalleled compactness and speed. Recent advances in understanding microbial opsins have been driven by molecular engineering for optogenetics and by comparative genomics. Here we provide a Primer on these light-activated ion channels and pumps, describe a group of opsins bridging prior categories, and explore the convergence of molecular engineering and genomic discovery for the utilization and understanding of these remarkable molecular machines.
Collapse
Affiliation(s)
- Feng Zhang
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA.
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
19
|
Del Bene F, Wyart C. Optogenetics: A new enlightenment age for zebrafish neurobiology. Dev Neurobiol 2012; 72:404-14. [DOI: 10.1002/dneu.20914] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
|
20
|
Abstract
The absorption of light by bound or diffusible chromophores causes conformational rearrangements in natural and artificial photoreceptor proteins. These rearrangements are coupled to the opening or closing of ion transport pathways, the association or dissociation of binding partners, the enhancement or suppression of catalytic activity, or the transcription or repression of genetic information. Illumination of cells, tissues, or organisms engineered genetically to express photoreceptor proteins can thus be used to perturb biochemical and electrical signaling with exquisite cellular and molecular specificity. First demonstrated in 2002, this principle of optogenetic control has had a profound impact on neuroscience, where it provides a direct and stringent means of probing the organization of neural circuits and of identifying the neural substrates of behavior. The impact of optogenetic control is also beginning to be felt in other areas of cell and organismal biology.
Collapse
Affiliation(s)
- Gero Miesenböck
- Centre for Neural Circuits and Behaviour, Department of Physiology, Anatomy, and Genetics, University of Oxford, Oxford OX1 3TA, United Kingdom.
| |
Collapse
|
21
|
Wyart C, Del Bene F. Let there be light: zebrafish neurobiology and the optogenetic revolution. Rev Neurosci 2011; 22:121-30. [PMID: 21615266 DOI: 10.1515/rns.2011.013] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Optogenetics has revolutionized the toolbox arsenal that neuroscientists now possess to investigate neuronal circuit function in intact and living animals. With a combination of light emitting 'sensors' and light activated 'actuators', we can monitor and control neuronal activity with minimal perturbation and unprecedented spatiotemporal resolution. Zebrafish neuronal circuits represent an ideal system to apply an optogenetic based analysis owing to its transparency, relatively small size and amenability to genetic manipulation. In this review, we describe some of the most recent advances in the development and applications of optogenetic sensors (i.e., genetically encoded calcium indicators and voltage sensors) and actuators (i.e., light activated ion channels and ion pumps). We focus mostly on the tools that have already been successfully applied in zebrafish and on those that show the greatest potential for the future. We also describe crucial technical aspects to implement optogenetics in zebrafish including strategies to drive a high level of transgene expression in defined neuronal populations, and recent optical advances that allow the precise spatiotemporal control of sample illumination.
Collapse
Affiliation(s)
- Claire Wyart
- Institut du Cerveau et de la Moelle epiniere, Centre de Recherche, CHU Pitié-Salpétrière, Paris, France.
| | | |
Collapse
|
22
|
Abstract
Many processes in green algae are under control of rhodopsin-type photoreceptors, but only a few have been studied at least in some detail in the past. Up to now, functionally and biochemically only the channelrhodpsins ChR1 and ChR2 are characterized. Thus, this short review reports on channelrhodopsin properties with a strong focus on the knowledge about the photoreaction cycle(s).
Collapse
Affiliation(s)
- Katja Stehfest
- Institute of Biology, Experimental Biophysics, Humboldt-Universität zu Berlin, Invalidenstrasse 42, 10115 Berlin, Germany.
| | | |
Collapse
|
23
|
Sineshchekov OA, Govorunova EG, Spudich JL. Photosensory functions of channelrhodopsins in native algal cells. Photochem Photobiol 2009; 85:556-63. [PMID: 19222796 DOI: 10.1111/j.1751-1097.2008.00524.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Photomotility responses in flagellate alga are mediated by two types of sensory rhodopsins (A and B). Upon photoexcitation they trigger a cascade of transmembrane currents which provide sensory transduction of light stimuli. Both types of algal sensory rhodopsins demonstrate light-gated ion channel activities when heterologously expressed in animal cells, and therefore they have been given the alternative names channelrhodopsin 1 and 2. In recent publications their channel activity has been assumed to initiate the transduction chain in the native algal cells. Here we present data showing that: (1) the modes of action of both types of sensory rhodopsins are different in native cells such as Chlamydomonas reinhardtii than in heterologous expression systems, and also differ between the two types of rhodopsins; (2) the primary function of Type B sensory rhodopsin (channelrhodopsin-2) is biochemical activation of secondary Ca(2+)-channels with evidence for amplification and a diffusible messenger, sufficient for mediating phototaxis and photophobic responses; (3) Type A sensory rhodopsin (channelrhodopsin-1) mediates avoidance responses by direct channel activity under high light intensities and exhibits low-efficiency amplification. These dual functions of algal sensory rhodopsins enable the highly sophisticated photobehavior of algal cells.
Collapse
Affiliation(s)
- Oleg A Sineshchekov
- Department of Biochemistry and Molecular Biology, University of Texas Medical School, Houston, TX, USA.
| | | | | |
Collapse
|
24
|
Berthold P, Tsunoda SP, Ernst OP, Mages W, Gradmann D, Hegemann P. Channelrhodopsin-1 initiates phototaxis and photophobic responses in chlamydomonas by immediate light-induced depolarization. THE PLANT CELL 2008; 20:1665-77. [PMID: 18552201 PMCID: PMC2483371 DOI: 10.1105/tpc.108.057919] [Citation(s) in RCA: 120] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2008] [Revised: 04/25/2008] [Accepted: 05/24/2008] [Indexed: 05/24/2023]
Abstract
Channelrhodopsins (CHR1 and CHR2) are light-gated ion channels acting as sensory photoreceptors in Chlamydomonas reinhardtii. In neuroscience, they are used to trigger action potentials by light in neuronal cells, tissues, or living animals. Here, we demonstrate that Chlamydomonas cells with low CHR2 content exhibit photophobic and phototactic responses that strictly depend on the availability of CHR1. Since CHR1 was described as a H+-channel, the ion specificity of CHR1 was reinvestigated in Xenopus laevis oocytes. Our experiments show that, in addition to H+, CHR1 also conducts Na+, K+, and Ca2+. The kinetic selectivity analysis demonstrates that H+ selectivity is not due to specific translocation but due to selective ion binding. Purified recombinant CHR1 consists of two isoforms with different absorption maxima, CHR1505 and CHR1463, that are in pH-dependent equilibrium. Thus, CHR1 is a photochromic and protochromic sensory photoreceptor that functions as a light-activated cation channel mediating phototactic and photophobic responses via depolarizing currents in a wide range of ionic conditions.
Collapse
Affiliation(s)
- Peter Berthold
- Institute for Biology, Experimental Biophysics, Humboldt-Universität, 10115 Berlin, Germany
| | | | | | | | | | | |
Collapse
|
25
|
Ernst OP, Murcia PAS, Daldrop P, Tsunoda SP, Kateriya S, Hegemann P. Photoactivation of Channelrhodopsin. J Biol Chem 2008; 283:1637-1643. [DOI: 10.1074/jbc.m708039200] [Citation(s) in RCA: 135] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
|
26
|
Fabczak H, Sobierajska K, Fabczak S. A rhodopsin immunoanalog in the related photosensitive protozoans Blepharisma japonicum and Stentor coeruleus. Photochem Photobiol Sci 2008; 7:1041-5. [DOI: 10.1039/b717280j] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
27
|
Abstract
Only five major types of sensory photoreceptors (BLUF-proteins, cryptochromes, phototropins, phytochromes, and rhodopsins) are used in nature to regulate developmental processes, photosynthesis, photoorientation, and control of the circadian clock. Sensory photoreceptors of algae and protists are exceptionally rich in structure and function; light-gated ion channels and photoactivated adenylate cyclases are unique examples. During the past ten years major progress has been made with respect to understanding the function, photochemistry, and structure of key sensory players of the algal kingdom.
Collapse
Affiliation(s)
- Peter Hegemann
- Institute of Biology, Experimental Biophysics, Humboldt Universität zu Berlin, 10115 Berlin, Germany.
| |
Collapse
|
28
|
Herlitze S, Landmesser LT. New optical tools for controlling neuronal activity. Curr Opin Neurobiol 2006; 17:87-94. [PMID: 17174547 DOI: 10.1016/j.conb.2006.12.002] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2006] [Accepted: 12/06/2006] [Indexed: 11/26/2022]
Abstract
A major challenge in understanding the relationship between neural activity and development, and ultimately behavior, is to control simultaneously the activity of either many neurons belonging to specific subsets or specific regions within individual neurons. Optimally, such a technique should be capable of both switching nerve cells on and off within milliseconds in a non-invasive manner, and inducing depolarizations or hyperpolarizations for periods lasting from milliseconds to many seconds. Specific ion conductances in subcellular compartments must also be controlled to bypass signaling cascades in order to regulate precisely cellular events such as synaptic transmission. Light-activated G-protein-coupled receptors and ion channels, which can be genetically manipulated and targeted to neuronal circuits, have the greatest potential to fulfill these requirements.
Collapse
Affiliation(s)
- Stefan Herlitze
- Department of Neurosciences, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, Ohio 44106-4975, USA.
| | | |
Collapse
|
29
|
Okita N, Isogai N, Hirono M, Kamiya R, Yoshimura K. Phototactic activity inChlamydomonas'non-phototactic' mutants deficient in Ca2+-dependent control of flagellar dominance or in inner-arm dynein. J Cell Sci 2005; 118:529-37. [PMID: 15657081 DOI: 10.1242/jcs.01633] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In the mechanism underlying the phototactic behavior of Chlamydomonas, Ca2+ has been thought to control the dominance between the two flagella so as to steer the cell to correct directions. A newly isolated mutant, lsp1, that displays weak phototaxis was found to be defective in this Ca2+-dependent shift in flagellar dominance; in demembranated and reactivated cell models, the trans flagellum (the flagellum farthest from the eyespot) beat more strongly than the other (the cis flagellum) in about half of the cells regardless of the Ca2+ concentration between <10-9 M and 10-6 M, a range over which wild-type cell models display switching of flagellar dominance. This is unexpected because ptx1, another mutant that is also deficient in flagellar dominance control, has been reported to lack phototactic ability. We therefore re-examined ptx1 and another reportedly non-phototactic mutant, ida1, which lacks inner arm dynein subspecies f (also called I1). Both were found to retain reduced phototactic abilities. These results indicate that both Ca2+-dependent flagellar dominance control and inner-arm dynein subspecies f are important for phototaxis, but are not absolutely necessary. Analysis of the flagellar beat frequency in lsp1 cell models showed that both of the flagella beat at the frequency of the cis flagellum in wild type. In addition, lsp1 and ptx1 were found to be deficient in determining the sign of phototactic migration. Hence, the Ca2+-dependent flagellar dominance control detected in demembranated cells might be involved in the determination of the sign of phototaxis. The gene responsible for the lsp1 mutation was identified by phenotype rescue experiments and found to have sequences for phosphorylation.
Collapse
Affiliation(s)
- Noriko Okita
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, Hongo, Tokyo 113-0063, Japan
| | | | | | | | | |
Collapse
|
30
|
Abstract
Photosynthetic unicellular algae have a unique visual system. In Chlamydomonas reinhardtii, the pigmented eye comprises the optical system and at least five different rhodopsin photoreceptors. Two of them, the channelrhodopsins, are rhodopsin-ion channel hybrids switched between closed and open states by photoisomerization of the attached retinal chromophore. They promise to become a useful tool for noninvasive control of membrane potential and intracellular ion concentrations.
Collapse
Affiliation(s)
- Suneel Kateriya
- Institut für Biochemie, Universität Regensburg, 93040 Regensburg, Germany
| | | | | | | |
Collapse
|
31
|
Nagel G, Szellas T, Huhn W, Kateriya S, Adeishvili N, Berthold P, Ollig D, Hegemann P, Bamberg E. Channelrhodopsin-2, a directly light-gated cation-selective membrane channel. Proc Natl Acad Sci U S A 2003; 100:13940-5. [PMID: 14615590 PMCID: PMC283525 DOI: 10.1073/pnas.1936192100] [Citation(s) in RCA: 1780] [Impact Index Per Article: 84.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Microbial-type rhodopsins are found in archaea, prokaryotes, and eukaryotes. Some of them represent membrane ion transport proteins such as bacteriorhodopsin, a light-driven proton pump, or channelrhodopsin-1 (ChR1), a recently identified light-gated proton channel from the green alga Chlamydomonas reinhardtii. ChR1 and ChR2, a related microbial-type rhodopsin from C. reinhardtii, were shown to be involved in generation of photocurrents of this green alga. We demonstrate by functional expression, both in oocytes of Xenopus laevis and mammalian cells, that ChR2 is a directly light-switched cation-selective ion channel. This channel opens rapidly after absorption of a photon to generate a large permeability for monovalent and divalent cations. ChR2 desensitizes in continuous light to a smaller steady-state conductance. Recovery from desensitization is accelerated by extracellular H+ and negative membrane potential, whereas closing of the ChR2 ion channel is decelerated by intracellular H+. ChR2 is expressed mainly in C. reinhardtii under low-light conditions, suggesting involvement in photoreception in dark-adapted cells. The predicted seven-transmembrane alpha helices of ChR2 are characteristic for G protein-coupled receptors but reflect a different motif for a cation-selective ion channel. Finally, we demonstrate that ChR2 may be used to depolarize small or large cells, simply by illumination.
Collapse
Affiliation(s)
- Georg Nagel
- Max-Planck-Institut für Biophysik, Marie-Curie-Strasse 15, 60439 Frankfurt, Germany.
| | | | | | | | | | | | | | | | | |
Collapse
|
32
|
Abstract
The eyespot organelle of the green alga Chlamydomonas allows the cell to phototax toward (or away) from light to maximize the light intensity for photosynthesis and minimize photo-damage. At cytokinesis, the eyespot is resorbed at the cleavage furrow and two new eyespots form in the daughter cells 180 degrees from each other. The eyespots are positioned asymmetrically with respect to the microtubule cytoskeleton. Eyespots are assembled from all three chloroplast membranes and carotenoid-filled granules, which form a sandwich structure overlaid by the tightly apposed plasma membrane. This review describes (1) my interest in cellular asymmetry and organelle biology, (2) isolation of mutations that describe four genes governing eyespot placement and assembly, (3) the characterization of the EYE2 gene, which encodes a thioredoxin superfamily member, and (4) the characterization of the MIN1 gene, which is required for the layered organization of granules and membranes in the eyespot. BioEssays 25:410-416, 2003.
Collapse
Affiliation(s)
- Carol L Dieckmann
- Department of Biochemistry and Molecular Biophysics, University of Arizona, P. O. Box 210106, Tucson, AZ 85721-0106, USA.
| |
Collapse
|
33
|
Abstract
Proton channels exist in a wide variety of membrane proteins where they transport protons rapidly and efficiently. Usually the proton pathway is formed mainly by water molecules present in the protein, but its function is regulated by titratable groups on critical amino acid residues in the pathway. All proton channels conduct protons by a hydrogen-bonded chain mechanism in which the proton hops from one water or titratable group to the next. Voltage-gated proton channels represent a specific subset of proton channels that have voltage- and time-dependent gating like other ion channels. However, they differ from most ion channels in their extraordinarily high selectivity, tiny conductance, strong temperature and deuterium isotope effects on conductance and gating kinetics, and insensitivity to block by steric occlusion. Gating of H(+) channels is regulated tightly by pH and voltage, ensuring that they open only when the electrochemical gradient is outward. Thus they function to extrude acid from cells. H(+) channels are expressed in many cells. During the respiratory burst in phagocytes, H(+) current compensates for electron extrusion by NADPH oxidase. Most evidence indicates that the H(+) channel is not part of the NADPH oxidase complex, but rather is a distinct and as yet unidentified molecule.
Collapse
Affiliation(s)
- Thomas E Decoursey
- Department of Molecular Biophysics and Physiology, Rush Presbyterian St. Luke's Medical Center, Chicago, Illinois 60612, USA.
| |
Collapse
|
34
|
Nagel G, Ollig D, Fuhrmann M, Kateriya S, Musti AM, Bamberg E, Hegemann P. Channelrhodopsin-1: a light-gated proton channel in green algae. Science 2002; 296:2395-8. [PMID: 12089443 DOI: 10.1126/science.1072068] [Citation(s) in RCA: 735] [Impact Index Per Article: 33.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Phototaxis and photophobic responses of green algae are mediated by rhodopsins with microbial-type chromophores. We report a complementary DNA sequence in the green alga Chlamydomonas reinhardtii that encodes a microbial opsin-related protein, which we term Channelopsin-1. The hydrophobic core region of the protein shows homology to the light-activated proton pump bacteriorhodopsin. Expression of Channelopsin-1, or only the hydrophobic core, in Xenopus laevis oocytes in the presence of all-trans retinal produces a light-gated conductance that shows characteristics of a channel selectively permeable for protons. We suggest that Channelrhodopsins are involved in phototaxis of green algae.
Collapse
Affiliation(s)
- Georg Nagel
- Max-Planck-Institut für Biophysik, Kennedyallee 70, 60596 Frankfurt am Main, Germany.
| | | | | | | | | | | | | |
Collapse
|
35
|
Sineshchekov OA, Jung KH, Spudich JL. Two rhodopsins mediate phototaxis to low- and high-intensity light in Chlamydomonas reinhardtii. Proc Natl Acad Sci U S A 2002; 99:8689-94. [PMID: 12060707 PMCID: PMC124360 DOI: 10.1073/pnas.122243399] [Citation(s) in RCA: 366] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
We demonstrate that two rhodopsins, identified from cDNA sequences, function as low- and high-light-intensity phototaxis receptors in the eukaryotic alga Chlamydomonas reinhardtii. Each of the receptors consists of an approximately 300-residue seven-transmembrane helix domain with a retinal-binding pocket homologous to that of archaeal rhodopsins, followed by approximately 400 residues of additional membrane-associated portion. The function of the two rhodopsins, Chlamydomonas sensory rhodopsins A and B (CSRA and CSRB), as phototaxis receptors is demonstrated by in vivo analysis of photoreceptor electrical currents and motility responses in transformants with RNA interference (RNAi) directed against each of the rhodopsin genes. The kinetics, fluence dependencies, and action spectra of the photoreceptor currents differ greatly in transformants in accord with the relative amounts of photoreceptor pigments expressed. The data show that CSRA has an absorption maximum near 510 nm and mediates a fast photoreceptor current that saturates at high light intensity. In contrast, CSRB absorbs maximally at 470 nm and generates a slow photoreceptor current saturating at low light intensity. The relative wavelength dependence of CSRA and CSRB activity in producing phototaxis responses matches precisely the wavelength dependence of the CSRA- and CSRB-generated currents, demonstrating that each receptor mediates phototaxis. The saturation of the two photoreceptor currents at different light fluence levels extends the range of light intensity to which the organism can respond. Further, at intensities where both operate, their light signals are integrated at the level of membrane depolarization caused by the two photoreceptor currents.
Collapse
Affiliation(s)
- Oleg A Sineshchekov
- Department of Microbiology and Molecular Genetics, and Center for Membrane Biology, University of Texas Medical School, Houston, TX 77030, USA
| | | | | |
Collapse
|