1
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Sirimatayanant S, Andruniów T. Tuning Two-Photon Absorption in Rhodopsin Chromophore via Backbone Modification: The Story Told by CC2 and TD-DFT. J Chem Theory Comput 2024. [PMID: 39269133 DOI: 10.1021/acs.jctc.4c00675] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/15/2024]
Abstract
We investigate here a systematic way to tune two-photon transition strengths (δ2PA) and two-photon absorption (2PA) cross sections (σ2PA) of the rhodopsin's chromophore 11-cis-retinal protonated Schiff base (RPSB) via the modulation of the methyl groups pattern along its polyene chain. Our team employed the resolution of identity, coupled cluster approximate second order (RI-CC2) method with Dunning's aug-cc-pVDZ basis set, to determine the structural impact on δ2PA, as well as its correlation to both transition dipole moments and permanent electric dipole moments. Seven structures were probed in vacuo, including five-double-bond-conjugated model of the native chromophore, shortened by the β-ionone ring (RPSB5), and its de/methylated analogues: 9-methyl, 13-methyl, planar and twisted models of 9,10-dimethyl and 9,10,13-trimethyl. Our results demonstrate that the magnitude of δ2PA is dictated by both the position and number of methylated groups attached to its polyene chain as well as the degree of dihedral twist that is introduced due to the de/methylation. In fact, a strong correlation between δ2PA enhancement and the presence of a C13-methyl group in the planar RPSB5 species is found. Trends in δ2PA values follow the trends observed in their corresponding changes in the permanent dipole moment upon the S0-S1 excitation nearly exactly. The assessment of four DFT functionals, i.e., M11, MN15, CAM-B3LYP, and BHandHLYP, previously found most successful in predicting 2PA properties in biological chromophores, points to a long-range-corrected hybrid meta-GGA M11 as the top-performing functional, albeit still delivering underestimated δ2PA and σ2PA values by a factor of 3.3-5.3 with respect to the CC2 results. In the case of global-hybrid meta-NGA (MN15), as well as CAM-B3LYP and BHandHLYP functionals, this factor deteriorates significantly to 6.7-20.9 and is mostly related to significantly lower quality of the ground- and excited-state dipole moments.
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Affiliation(s)
- Saruti Sirimatayanant
- Institute of Advanced Materials, Department of Chemistry, Wroclaw University of Science and Technology, Wyb. Wyspiańskiego 27, Wrocław 50-370, Poland
| | - Tadeusz Andruniów
- Institute of Advanced Materials, Department of Chemistry, Wroclaw University of Science and Technology, Wyb. Wyspiańskiego 27, Wrocław 50-370, Poland
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2
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Santillo S, De Petrocellis L, Musio C. Diurnal and circadian regulation of opsin-like transcripts in the eyeless cnidarian Hydra. Biomol Concepts 2024; 15:bmc-2022-0044. [PMID: 38502542 DOI: 10.1515/bmc-2022-0044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Accepted: 02/28/2024] [Indexed: 03/21/2024] Open
Abstract
Opsins play a key role in the ability to sense light both in image-forming vision and in non-visual photoreception (NVP). These modalities, in most animal phyla, share the photoreceptor protein: an opsin-based protein binding a light-sensitive chromophore by a lysine (Lys) residue. So far, visual and non-visual opsins have been discovered throughout the Metazoa phyla, including the photoresponsive Hydra, an eyeless cnidarian considered the evolutionary sister species to bilaterians. To verify whether light influences and modulates opsin gene expression in Hydra, we utilized four expression sequence tags, similar to two classic opsins (SW rhodopsin and SW blue-sensitive opsin) and two non-visual opsins (melanopsin and peropsin), in investigating the expression patterns during both diurnal and circadian time, by means of a quantitative RT-PCR. The expression levels of all four genes fluctuated along the light hours of diurnal cycle with respect to the darkness one and, in constant dark condition of the circadian cycle, they increased. The monophasic behavior in the L12:D12 cycle turned into a triphasic expression profile during the continuous darkness condition. Consequently, while the diurnal opsin-like expression revealed a close dependence on light hours, the highest transcript levels were found in darkness, leading us to novel hypothesis that in Hydra, an "internal" biological rhythm autonomously supplies the opsins expression during the circadian time. In conclusion, in Hydra, both diurnal and circadian rhythms apparently regulate the expression of the so-called visual and non-visual opsins, as already demonstrated in higher invertebrate and vertebrate species. Our data confirm that Hydra is a suitable model for studying ancestral precursor of both visual and NVP, providing useful hints on the evolution of visual and photosensory systems.
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Affiliation(s)
- Silvia Santillo
- Institute of Applied Sciences and Intelligent Systems "Eduardo Caianiello" (ISASI), National Research Council (CNR), Via Campi Flegrei 34, 80078 Pozzuoli (Naples), Italy
| | - Luciano De Petrocellis
- Institute of Biomolecular Chemistry (ICB), National Research Council (CNR), 80078 Pozzuoli (Naples), Italy
| | - Carlo Musio
- Institute of Biophysics (IBF), Trento Unit, National Research Council (CNR), Via Sommarive 18, 38123 Trento, Italy
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3
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Mackintosh MJ, Hoischen D, Martin HD, Schapiro I, Gärtner W. Merocyanines form bacteriorhodopsins with strongly bathochromic absorption maxima. Photochem Photobiol Sci 2024; 23:31-53. [PMID: 38070056 DOI: 10.1007/s43630-023-00496-0] [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: 07/26/2023] [Accepted: 10/13/2023] [Indexed: 02/02/2024]
Abstract
There is a need to shift the absorbance of biomolecules to the optical transparency window of tissue for applications in optogenetics and photo-pharmacology. There are a few strategies to achieve the so-called red shift of the absorption maxima. Herein, a series of 11 merocyanine dyes were synthesized and employed as chromophores in place of retinal in bacteriorhodopsin (bR) to achieve a bathochromic shift of the absorption maxima relative to bR's [Formula: see text] of 568 nm. Assembly with the apoprotein bacterioopsin (bO) led to stable, covalently bound chromoproteins with strongly bathochromic absorbance bands, except for three compounds. Maximal red shifts were observed for molecules 9, 2, and 8 in bR where the [Formula: see text] was 766, 755, and 736 nm, respectively. While these three merocyanines have different end groups, they share a similar structural feature, namely, a methyl group which is located at the retinal equivalent position 13 of the polyene chain. The absorption and fluorescence data are also presented for the retinal derivatives in their aldehyde, Schiff base (SB), and protonated SB (PSB) forms in solution. According to their hemicyanine character, the PSBs and their analogue bRs exhibited fluorescence quantum yields (Φf) several orders of magnitude greater than native bR (Φf 0.02 to 0.18 versus 1.5 × 10-5 in bR) while also exhibiting much smaller Stokes shifts than bR (400 to 1000 cm-1 versus 4030 cm-1 in bR). The experimental results are complemented by quantum chemical calculations where excellent agreement between the experimental [Formula: see text] and the calculated [Formula: see text] was achieved with the second-order algebraic-diagrammatic construction [ADC(2)] method. In addition, quantum mechanics/molecular mechanics (QM/MM) calculations were employed to shed light on the origin of the bathochromic shift of merocyanine 2 in bR compared with native bR.
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Affiliation(s)
- Megan J Mackintosh
- Fritz Haber Center for Molecular Dynamics, Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Dorothee Hoischen
- Institute for Organic Chemistry and Macromolecular Chemistry, University of Düsseldorf, 40225, Düsseldorf, Germany
- ISK Biosciences Europe N.V., 1831, Diegem, Belgium
| | - Hans-Dieter Martin
- Institute for Organic Chemistry and Macromolecular Chemistry, University of Düsseldorf, 40225, Düsseldorf, Germany
| | - Igor Schapiro
- Fritz Haber Center for Molecular Dynamics, Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem, Israel.
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4
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Nikolaev DM, Shtyrov AA, Vyazmin SY, Vasin AV, Panov MS, Ryazantsev MN. Fluorescence of the Retinal Chromophore in Microbial and Animal Rhodopsins. Int J Mol Sci 2023; 24:17269. [PMID: 38139098 PMCID: PMC10743670 DOI: 10.3390/ijms242417269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Revised: 11/30/2023] [Accepted: 12/06/2023] [Indexed: 12/24/2023] Open
Abstract
Fluorescence of the vast majority of natural opsin-based photoactive proteins is extremely low, in accordance with their functions that depend on efficient transduction of absorbed light energy. However, several recently proposed classes of engineered rhodopsins with enhanced fluorescence, along with the discovery of a new natural highly fluorescent rhodopsin, NeoR, opened a way to exploit these transmembrane proteins as fluorescent sensors and draw more attention to studies on this untypical rhodopsin property. Here, we review the available data on the fluorescence of the retinal chromophore in microbial and animal rhodopsins and their photocycle intermediates, as well as different isomers of the protonated retinal Schiff base in various solvents and the gas phase.
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Affiliation(s)
- Dmitrii M. Nikolaev
- Institute of Chemistry, Saint Petersburg State University, 26 Universitetskii pr, 198504 St. Petersburg, Russia
| | - Andrey A. Shtyrov
- Institute of Chemistry, Saint Petersburg State University, 26 Universitetskii pr, 198504 St. Petersburg, Russia
| | - Sergey Yu. Vyazmin
- Nanotechnology Research and Education Centre RAS, Saint Petersburg Academic University, 8/3 Khlopina Street, 194021 St. Petersburg, Russia
| | - Andrey V. Vasin
- Institute of Biomedical Systems and Biotechnologies, Peter the Great St. Petersburg Polytechnic University, 29 Polytechnicheskaya Str., 195251 St. Petersburg, Russia
| | - Maxim S. Panov
- Institute of Chemistry, Saint Petersburg State University, 26 Universitetskii pr, 198504 St. Petersburg, Russia
- Center for Biophysical Studies, St. Petersburg State Chemical Pharmaceutical University, Professor Popov str. 14, lit. A, 197022 St. Petersburg, Russia
| | - Mikhail N. Ryazantsev
- Institute of Chemistry, Saint Petersburg State University, 26 Universitetskii pr, 198504 St. Petersburg, Russia
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5
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Lin F, Tang R, Zhang C, Scholz N, Nagel G, Gao S. Combining different ion-selective channelrhodopsins to control water flux by light. Pflugers Arch 2023; 475:1375-1385. [PMID: 37670155 PMCID: PMC10730689 DOI: 10.1007/s00424-023-02853-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2023] [Revised: 08/03/2023] [Accepted: 08/21/2023] [Indexed: 09/07/2023]
Abstract
Water transport through water channels, aquaporins (AQPs), is vital for many physiological processes including epithelial fluid secretion, cell migration and adipocyte metabolism. Water flux through AQPs is driven by the osmotic gradient that results from concentration differences of solutes including ions. Here, we developed a novel optogenetic toolkit that combines the light-gated anion channel GtACR1 either with the light-gated K+ channel HcKCR1 or the new Na+ channelrhodopsin HcNCR1 with high Na+ permeability, to manipulate water transport in Xenopus oocytes non-invasively. Water efflux through AQP was achieved by light-activating K+ and Cl- efflux through HcKCR1 and GtACR1. Contrarily, when GtACR1 was co-expressed with HcNCR1, inward movement of Na+ and Cl- was light-triggered, and the resulting osmotic gradient led to water influx through AQP1. In sum, we demonstrate a novel optogenetic strategy to manipulate water movement into or out of Xenopus oocytes non-invasively. This approach provides a new avenue to interfere with water homeostasis as a means to study related biological phenomena across cell types and organisms.
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Affiliation(s)
- Fei Lin
- Department of Neurophysiology, Institute of Physiology, Biocenter, Julius-Maximilians-University of Würzburg, Würzburg, Germany
| | - Ruijing Tang
- Department of Neurophysiology, Institute of Physiology, Biocenter, Julius-Maximilians-University of Würzburg, Würzburg, Germany
- The United Innovation of Mengchao Hepatobiliary Technology Key Laboratory of Fujian Province, Mengchao Hepatobiliary Hospital of Fujian Medical University, Fuzhou, China
| | - Chong Zhang
- Department of Neurophysiology, Institute of Physiology, Biocenter, Julius-Maximilians-University of Würzburg, Würzburg, Germany
| | - Nicole Scholz
- Rudolf Schönheimer Institute of Biochemistry, Division of General Biochemistry, Medical Faculty, Leipzig University, Johannisallee 30, 04103, Leipzig, Germany
| | - Georg Nagel
- Department of Neurophysiology, Institute of Physiology, Biocenter, Julius-Maximilians-University of Würzburg, Würzburg, Germany
| | - Shiqiang Gao
- Department of Neurophysiology, Institute of Physiology, Biocenter, Julius-Maximilians-University of Würzburg, Würzburg, Germany.
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6
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Cárdenas G, Ledentu V, Huix-Rotllant M, Olivucci M, Ferré N. Automatic Rhodopsin Modeling with Multiple Protonation Microstates. J Phys Chem A 2023; 127:9365-9380. [PMID: 37877699 DOI: 10.1021/acs.jpca.3c05413] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2023]
Abstract
Automatic Rhodopsin Modeling (ARM) is a simulation protocol providing QM/MM models of rhodopsins capable of reproducing experimental electronic absorption and emission trends. Currently, ARM is restricted to a single protonation microstate for each rhodopsin model. Herein, we incorporate an extension of the minimal electrostatic model (MEM) into the ARM protocol to account for all relevant protonation microstates at a given pH. The new ARM+MEM protocol determines the most important microstates contributing to the description of the absorption spectrum. As a test case, we have applied this methodology to simulate the pH-dependent absorption spectrum of a toy model, showing that the single-microstate picture breaks down at certain pH values. Subsequently, we applied ARM+MEM toAnabaenasensory rhodopsin, confirming an improved description of its absorption spectrum when the titration of several key residues is considered.
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Affiliation(s)
| | | | | | - Massimo Olivucci
- Department of Chemistry, Bowling Green State University, Bowling Green, Ohio 43403, United States
- Dipartimento di Biotecnologie, Chimica e Farmacia, Università degli Studi di Siena, 53100 Siena, Italy
| | - Nicolas Ferré
- Aix-Marseille Univ, CNRS, ICR, 13013 Marseille, France
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7
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Strauss J, Deng L, Gao S, Toseland A, Bachy C, Zhang C, Kirkham A, Hopes A, Utting R, Joest EF, Tagliabue A, Löw C, Worden AZ, Nagel G, Mock T. Plastid-localized xanthorhodopsin increases diatom biomass and ecosystem productivity in iron-limited surface oceans. Nat Microbiol 2023; 8:2050-2066. [PMID: 37845316 PMCID: PMC10627834 DOI: 10.1038/s41564-023-01498-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Accepted: 09/12/2023] [Indexed: 10/18/2023]
Abstract
Microbial rhodopsins are photoreceptor proteins that convert light into biological signals or energy. Proteins of the xanthorhodopsin family are common in eukaryotic photosynthetic plankton including diatoms. However, their biological role in these organisms remains elusive. Here we report on a xanthorhodopsin variant (FcR1) isolated from the polar diatom Fragilariopsis cylindrus. Applying a combination of biophysical, biochemical and reverse genetics approaches, we demonstrate that FcR1 is a plastid-localized proton pump which binds the chromophore retinal and is activated by green light. Enhanced growth of a Thalassiora pseudonana gain-of-function mutant expressing FcR1 under iron limitation shows that the xanthorhodopsin proton pump supports growth when chlorophyll-based photosynthesis is iron-limited. The abundance of xanthorhodopsin transcripts in natural diatom communities of the surface oceans is anticorrelated with the availability of dissolved iron. Thus, we propose that these proton pumps convey a fitness advantage in regions where phytoplankton growth is limited by the availability of dissolved iron.
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Affiliation(s)
- Jan Strauss
- School of Environmental Sciences, University of East Anglia, Norwich Research Park, Norwich, UK.
- Ocean EcoSystems Biology Unit, RD3, GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany.
- European Molecular Biology Laboratory (EMBL), Hamburg Unit c/o Deutsches Elektronen Synchrotron (DESY), Hamburg, Germany.
- Centre for Structural Systems Biology (CSSB), Hamburg, Germany.
- German Maritime Centre, Hamburg, Germany.
| | - Longji Deng
- School of Environmental Sciences, University of East Anglia, Norwich Research Park, Norwich, UK
| | - Shiqiang Gao
- Department of Neurophysiology, Institute of Physiology, University of Würzburg, Wuerzburg, Germany
| | - Andrew Toseland
- School of Environmental Sciences, University of East Anglia, Norwich Research Park, Norwich, UK
| | - Charles Bachy
- Ocean EcoSystems Biology Unit, RD3, GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany
- Sorbonne Université, CNRS, FR2424, Station biologique de Roscoff, Roscoff, France
| | - Chong Zhang
- Department of Neurophysiology, Institute of Physiology, University of Würzburg, Wuerzburg, Germany
| | - Amy Kirkham
- School of Environmental Sciences, University of East Anglia, Norwich Research Park, Norwich, UK
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, UK
| | - Amanda Hopes
- School of Environmental Sciences, University of East Anglia, Norwich Research Park, Norwich, UK
| | - Robert Utting
- School of Environmental Sciences, University of East Anglia, Norwich Research Park, Norwich, UK
| | - Eike F Joest
- Department of Biology, Biocenter, University of Würzburg, Wuerzburg, Germany
| | | | - Christian Löw
- European Molecular Biology Laboratory (EMBL), Hamburg Unit c/o Deutsches Elektronen Synchrotron (DESY), Hamburg, Germany
- Centre for Structural Systems Biology (CSSB), Hamburg, Germany
| | - Alexandra Z Worden
- Ocean EcoSystems Biology Unit, RD3, GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany
- Max Planck Institute for Evolutionary Biology, Plön, Germany
- Marine Biological Laboratory, Woods Hole, MA, USA
| | - Georg Nagel
- Department of Neurophysiology, Institute of Physiology, University of Würzburg, Wuerzburg, Germany
| | - Thomas Mock
- School of Environmental Sciences, University of East Anglia, Norwich Research Park, Norwich, UK.
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8
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Petrovskaya LE, Siletsky SA, Mamedov MD, Lukashev EP, Balashov SP, Dolgikh DA, Kirpichnikov MP. Features of the Mechanism of Proton Transport in ESR, Retinal Protein from Exiguobacterium sibiricum. BIOCHEMISTRY. BIOKHIMIIA 2023; 88:1544-1554. [PMID: 38105023 DOI: 10.1134/s0006297923100103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Revised: 07/11/2023] [Accepted: 07/11/2023] [Indexed: 12/19/2023]
Abstract
Retinal-containing light-sensitive proteins - rhodopsins - are found in many microorganisms. Interest in them is largely explained by their role in light energy storage and photoregulation in microorganisms, as well as the prospects for their use in optogenetics to control neuronal activity, including treatment of various diseases. One of the representatives of microbial rhodopsins is ESR, the retinal protein of Exiguobacterium sibiricum. What distinguishes ESR from homologous proteins is the presence of a lysine residue (Lys96) as a proton donor for the Schiff base. This feature, along with the hydrogen bond of the proton acceptor Asp85 with the His57 residue, determines functional characteristics of ESR as a proton pump. This review examines the results of ESR studies conducted using various methods, including direct electrometry. Comparison of the obtained data with the results of structural studies and with other retinal proteins allows us to draw conclusions about the mechanisms of transport of hydrogen ions in ESR and similar retinal proteins.
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Affiliation(s)
- Lada E Petrovskaya
- Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, 117997, Russia.
| | - Sergei A Siletsky
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119992, Russia
| | - Mahir D Mamedov
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119992, Russia
| | - Eugene P Lukashev
- Faculty of Biology, Lomonosov Moscow State University, Moscow, 119234, Russia
| | - Sergei P Balashov
- Department of Physiology and Biophysics, University of California, Irvine, CA 92697
| | - Dmitry A Dolgikh
- Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, 117997, Russia
- Faculty of Biology, Lomonosov Moscow State University, Moscow, 119234, Russia
| | - Mikhail P Kirpichnikov
- Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, 117997, Russia
- Faculty of Biology, Lomonosov Moscow State University, Moscow, 119234, Russia
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9
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Saliminasab M, Yamazaki Y, Palmateer A, Harris A, Schubert L, Langner P, Heberle J, Bondar AN, Brown LS. A Proteorhodopsin-Related Photosensor Expands the Repertoire of Structural Motifs Employed by Sensory Rhodopsins. J Phys Chem B 2023; 127:7872-7886. [PMID: 37694950 PMCID: PMC10519204 DOI: 10.1021/acs.jpcb.3c04032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Revised: 08/09/2023] [Indexed: 09/12/2023]
Abstract
Microbial rhodopsins are light-activated retinal-binding membrane proteins that perform a variety of ion transport and photosensory functions. They display several cases of convergent evolution where the same function is present in unrelated or very distant protein groups. Here we report another possible case of such convergent evolution, describing the biophysical properties of a new group of sensory rhodopsins. The first representative of this group was identified in 2004 but none of the members had been expressed and characterized. The well-studied haloarchaeal sensory rhodopsins interacting with methyl-accepting Htr transducers are close relatives of the halobacterial proton pump bacteriorhodopsin. In contrast, the sensory rhodopsins we describe here are relatives of proteobacterial proton pumps, proteorhodopsins, but appear to interact with Htr-like transducers likewise, even though they do not conserve the residues important for the interaction of haloarchaeal sensory rhodopsins with their transducers. The new sensory rhodopsins display many unusual amino acid residues, including those around the retinal chromophore; most strikingly, a tyrosine in place of a carboxyl counterion of the retinal Schiff base on helix C. To characterize their unique sequence motifs, we augment the spectroscopy and biochemistry data by structural modeling of the wild-type and three mutants. Taken together, the experimental data, bioinformatics sequence analyses, and structural modeling suggest that the tyrosine/aspartate complex counterion contributes to a complex water-mediated hydrogen-bonding network that couples the protonated retinal Schiff base to an extracellular carboxylic dyad.
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Affiliation(s)
- Maryam Saliminasab
- Department
of Physics and Biophysics Interdepartmental Group, University of Guelph, Guelph, Ontario N1G 2W1, Canada
| | - Yoichi Yamazaki
- Division
of Materials Science, Graduate School of Science and Technology, Nara Institute of Science and Technology, Ikoma, Nara 630-0192, Japan
| | - Alyssa Palmateer
- Department
of Physics and Biophysics Interdepartmental Group, University of Guelph, Guelph, Ontario N1G 2W1, Canada
| | - Andrew Harris
- Department
of Physics and Biophysics Interdepartmental Group, University of Guelph, Guelph, Ontario N1G 2W1, Canada
| | - Luiz Schubert
- Experimental
Molecular Biophysics Group, Department of Physics, Freie Universität Berlin, D-14195 Berlin, Germany
| | - Pit Langner
- Experimental
Molecular Biophysics Group, Department of Physics, Freie Universität Berlin, D-14195 Berlin, Germany
| | - Joachim Heberle
- Experimental
Molecular Biophysics Group, Department of Physics, Freie Universität Berlin, D-14195 Berlin, Germany
| | - Ana-Nicoleta Bondar
- University
of Bucharest, Faculty of Physics, Atomiştilor 405, Măgurele 077125, Romania
- Forschungszentrum
Jülich, Institute for Neuroscience and Medicine and Institute
for Advanced Simulations (IAS-5/INM-9), Computational Biomedicine, Wilhelm-Johnen Straße, 52428 Jülich, Germany
| | - Leonid S. Brown
- Department
of Physics and Biophysics Interdepartmental Group, University of Guelph, Guelph, Ontario N1G 2W1, Canada
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10
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Meng X, Ganapathy S, van Roemburg L, Post M, Brinks D. Voltage Imaging with Engineered Proton-Pumping Rhodopsins: Insights from the Proton Transfer Pathway. ACS PHYSICAL CHEMISTRY AU 2023; 3:320-333. [PMID: 37520318 PMCID: PMC10375888 DOI: 10.1021/acsphyschemau.3c00003] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Revised: 04/13/2023] [Accepted: 04/13/2023] [Indexed: 08/01/2023]
Abstract
Voltage imaging using genetically encoded voltage indicators (GEVIs) has taken the field of neuroscience by storm in the past decade. Its ability to create subcellular and network level readouts of electrical dynamics depends critically on the kinetics of the response to voltage of the indicator used. Engineered microbial rhodopsins form a GEVI subclass known for their high voltage sensitivity and fast response kinetics. Here we review the essential aspects of microbial rhodopsin photocycles that are critical to understanding the mechanisms of voltage sensitivity in these proteins and link them to insights from efforts to create faster, brighter and more sensitive microbial rhodopsin-based GEVIs.
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Affiliation(s)
- Xin Meng
- Department
of Imaging Physics, Delft University of
Technology, 2628 CJ Delft, The
Netherlands
| | - Srividya Ganapathy
- Department
of Imaging Physics, Delft University of
Technology, 2628 CJ Delft, The
Netherlands
- Department
of Pediatrics & Cellular and Molecular Medicine, UCSD School of Medicine, La Jolla, California 92093, United States
| | - Lars van Roemburg
- Department
of Imaging Physics, Delft University of
Technology, 2628 CJ Delft, The
Netherlands
| | - Marco Post
- Department
of Imaging Physics, Delft University of
Technology, 2628 CJ Delft, The
Netherlands
| | - Daan Brinks
- Department
of Imaging Physics, Delft University of
Technology, 2628 CJ Delft, The
Netherlands
- Department
of Molecular Genetics, Erasmus University
Medical Center, 3015 GD Rotterdam, The Netherlands
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11
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Kishi KE, Kato HE. Pump-like channelrhodopsins: Not just bridging the gap between ion pumps and ion channels. Curr Opin Struct Biol 2023; 79:102562. [PMID: 36871323 DOI: 10.1016/j.sbi.2023.102562] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2022] [Revised: 01/25/2023] [Accepted: 01/29/2023] [Indexed: 03/06/2023]
Abstract
Channelrhodopsins are microbial rhodopsins that work as light-gated ion channels. Their importance has become increasingly recognized due to their ability to control the membrane potential of specific cells in a light-dependent manner. This technology, termed optogenetics, has revolutionized neuroscience, and numerous channelrhodopsin variants have been isolated or engineered to expand the utility of optogenetics. Pump-like channelrhodopsins (PLCRs), one of the recently discovered channelrhodopsin subfamilies, have attracted broad attention due to their high sequence similarity to ion-pumping rhodopsins and their distinct properties, such as high light sensitivity and ion selectivity. In this review, we summarize the current understanding of the structure-function relationships of PLCRs and discuss the challenges and opportunities of channelrhodopsin research.
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Affiliation(s)
- Koichiro E Kishi
- Komaba Institute for Science, The University of Tokyo, Meguro, Tokyo, Japan. https://twitter.com/K_E_Kishi
| | - Hideaki E Kato
- Komaba Institute for Science, The University of Tokyo, Meguro, Tokyo, Japan; Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Bunkyo, Tokyo, Japan; FOREST, Japan Science and Technology Agency, Kawaguchi, Saitama, Japan.
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12
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Marín MDC, Jaffe AL, West PT, Konno M, Banfield JF, Inoue K. Biophysical characterization of microbial rhodopsins with DSE motif. Biophys Physicobiol 2023; 20:e201023. [PMID: 38362324 PMCID: PMC10865882 DOI: 10.2142/biophysico.bppb-v20.s023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Accepted: 03/07/2023] [Indexed: 03/09/2023] Open
Abstract
Microbial rhodopsins are photoreceptive transmembrane proteins that transport ions or regulate other intracellular biological processes. Recent genomic and metagenomic analyses found many microbial rhodopsins with unique sequences distinct from known ones. Functional characterization of these new types of microbial rhodopsins is expected to expand our understanding of their physiological roles. Here, we found microbial rhodopsins having a DSE motif in the third transmembrane helix from members of the Actinobacteria. Although the expressed proteins exhibited blue-green light absorption, either no or extremely small outward H+ pump activity was observed. The turnover rate of the photocycle reaction of the purified proteins was extremely slow compared to typical H+ pumps, suggesting these rhodopsins would work as photosensors or H+ pumps whose activities are enhanced by an unknown regulatory system in the hosts. The discovery of this rhodopsin group with the unique motif and functionality expands our understanding of the biological role of microbial rhodopsins.
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Affiliation(s)
- María del Carmen Marín
- The Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba 277-8581, Japan
| | - Alexander L. Jaffe
- Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720-3102, USA
- Department of Earth System Science, Stanford University, Stanford, CA 94305-4216, USA
| | - Patrick T. West
- Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720-3102, USA
| | - Masae Konno
- The Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba 277-8581, Japan
- PRESTO, Japan Science and Technology Agency, Kawaguchi, Saitama 332-0012, Japan
| | - Jillian F. Banfield
- Innovative Genomics Institute, University of California, Berkeley, CA 94720-2151, USA
- Department of Earth and Planetary Science, University of California, Berkeley, CA 94720-4767, USA
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, CA 94720-3114, USA
| | - Keiichi Inoue
- The Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba 277-8581, Japan
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13
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Hofmann KP, Lamb TD. Rhodopsin, light-sensor of vision. Prog Retin Eye Res 2023; 93:101116. [PMID: 36273969 DOI: 10.1016/j.preteyeres.2022.101116] [Citation(s) in RCA: 21] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2022] [Revised: 08/20/2022] [Accepted: 08/22/2022] [Indexed: 11/06/2022]
Abstract
The light sensor of vertebrate scotopic (low-light) vision, rhodopsin, is a G-protein-coupled receptor comprising a polypeptide chain with bound chromophore, 11-cis-retinal, that exhibits remarkable physicochemical properties. This photopigment is extremely stable in the dark, yet its chromophore isomerises upon photon absorption with 70% efficiency, enabling the activation of its G-protein, transducin, with high efficiency. Rhodopsin's photochemical and biochemical activities occur over very different time-scales: the energy of retinaldehyde's excited state is stored in <1 ps in retinal-protein interactions, but it takes milliseconds for the catalytically active state to form, and many tens of minutes for the resting state to be restored. In this review, we describe the properties of rhodopsin and its role in rod phototransduction. We first introduce rhodopsin's gross structural features, its evolution, and the basic mechanisms of its activation. We then discuss light absorption and spectral sensitivity, photoreceptor electrical responses that result from the activity of individual rhodopsin molecules, and recovery of rhodopsin and the visual system from intense bleaching exposures. We then provide a detailed examination of rhodopsin's molecular structure and function, first in its dark state, and then in the active Meta states that govern its interactions with transducin, rhodopsin kinase and arrestin. While it is clear that rhodopsin's molecular properties are exquisitely honed for phototransduction, from starlight to dawn/dusk intensity levels, our understanding of how its molecular interactions determine the properties of scotopic vision remains incomplete. We describe potential future directions of research, and outline several major problems that remain to be solved.
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Affiliation(s)
- Klaus Peter Hofmann
- Institut für Medizinische Physik und Biophysik (CC2), Charité, and, Zentrum für Biophysik und Bioinformatik, Humboldt-Unversität zu Berlin, Berlin, 10117, Germany.
| | - Trevor D Lamb
- Eccles Institute of Neuroscience, John Curtin School of Medical Research, The Australian National University, Canberra, ACT 2600, Australia.
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14
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Pedraza-González L, Barneschi L, Marszałek M, Padula D, De Vico L, Olivucci M. Automated QM/MM Screening of Rhodopsin Variants with Enhanced Fluorescence. J Chem Theory Comput 2023; 19:293-310. [PMID: 36516450 DOI: 10.1021/acs.jctc.2c00928] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
We present a computational protocol for the fast and automated screening of excited-state hybrid quantum mechanics/molecular mechanics (QM/MM) models of rhodopsins to be used as fluorescent probes based on the automatic rhodopsin modeling protocol (a-ARM). Such "a-ARM fluorescence screening protocol" is implemented through a general Python-based driver, PyARM, that is also proposed here. The implementation and performance of the protocol are benchmarked using different sets of rhodopsin variants whose absorption and, more relevantly, emission spectra have been experimentally measured. We show that, despite important limitations that make unsafe to use it as a black-box tool, the protocol reproduces the observed trends in fluorescence and it is capable of selecting novel potentially fluorescent rhodopsins. We also show that the protocol can be used in mechanistic investigations to discern fluorescence enhancement effects associated with a near degeneracy of the S1/S2 states or, alternatively, with a barrier generated via coupling of the S0/S1 wave functions.
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Affiliation(s)
- Laura Pedraza-González
- Department of Biotechnology, Chemistry and Pharmacy, Università degli Studi di Siena, Via A. Moro 2, I-53100 Siena, Italy
| | - Leonardo Barneschi
- Department of Biotechnology, Chemistry and Pharmacy, Università degli Studi di Siena, Via A. Moro 2, I-53100 Siena, Italy
| | - Michał Marszałek
- Department of Biotechnology, Chemistry and Pharmacy, Università degli Studi di Siena, Via A. Moro 2, I-53100 Siena, Italy.,Faculty of Chemistry, Wrocław University of Science and Technology, Wybrzeże Wyspiaǹskiego 27, 50-370 Wrocław, Poland
| | - Daniele Padula
- Department of Biotechnology, Chemistry and Pharmacy, Università degli Studi di Siena, Via A. Moro 2, I-53100 Siena, Italy
| | - Luca De Vico
- Department of Biotechnology, Chemistry and Pharmacy, Università degli Studi di Siena, Via A. Moro 2, I-53100 Siena, Italy
| | - Massimo Olivucci
- Department of Biotechnology, Chemistry and Pharmacy, Università degli Studi di Siena, Via A. Moro 2, I-53100 Siena, Italy.,Department of Chemistry, Bowling Green State University, Bowling Green, Ohio 43403, United States
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15
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Penzkofer A, Silapetere A, Hegemann P. Theoretical Investigation of the Photocycle Dynamics of the Archaerhodopsin 3 Based Fluorescent Voltage Sensor Archon2. J Photochem Photobiol A Chem 2022. [DOI: 10.1016/j.jphotochem.2022.114366] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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