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Carrau A, Tano J, Moyano L, Ripa MB, Petrocelli S, Piskulic L, Moreira LM, Patané JSL, Setubal JC, Orellano EG. A novel BLUF photoreceptor modulates the Xanthomonas citri subsp. citri-host plant interaction. Photochem Photobiol Sci 2023; 22:1901-1918. [PMID: 37209300 DOI: 10.1007/s43630-023-00420-6] [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: 01/02/2023] [Accepted: 04/05/2023] [Indexed: 05/22/2023]
Abstract
Plant-pathogen interaction is influenced by multiple environmental factors, including temperature and light. Recent works have shown that light modulates not only the defense response of plants but also the pathogens virulence. Xanthomonas citri subsp. citri (Xcc) is the bacterium responsible for citrus canker, an important plant disease worldwide. The Xcc genome presents four genes encoding putative photoreceptors: one bacteriophytochrome and three blue light photoreceptors, one LOV and two BLUFs (bluf1: XAC2120 and bluf2: XAC3278). The presence of two BLUFs proteins is an outstanding feature of Xcc. In this work we show that the bluf2 gene is functional. The mutant strain, XccΔbluf2, was constructed demonstrating that BLUF2 regulates swimming-type motility, adhesion to leaves, exopolysaccharide production and biofilm formation, features involved in the Xcc virulence processes. An important aspect during the plant-pathogen interaction is the oxidative response of the host and the consequent reaction of the pathogen. We observed that ROS detoxification is regulated by Xcc bluf2 gene. The phenotypes of disease in orange plants produced by WT and XccΔbluf2 strains were evaluated, observing different phenotypes. Altogether, these results show that BLUF2 negatively regulates virulence during citrus canker. This work constitutes the first report on BLUF-like receptors in plant pathogenic bacteria.
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Affiliation(s)
- Analía Carrau
- Instituto de Biología Molecular y Celular de Rosario, Consejo Nacional de Investigaciones Científicas y Técnicas, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, S2002LRK, Rosario, Argentina
| | - Josefina Tano
- Instituto de Biología Molecular y Celular de Rosario, Consejo Nacional de Investigaciones Científicas y Técnicas, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, S2002LRK, Rosario, Argentina
| | - Laura Moyano
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Biodiversidad y Biología Experimental, Buenos Aires, Argentina
- Instituto de Biodiversidad y Biología Experimental y Aplicada, Consejo Nacional de Investigaciones Científicas y Técnicas-Universidad de Buenos Aires (IBBEA, CONICET-UBA), Buenos Aires, Argentina
| | - María Belén Ripa
- Instituto de Biología Molecular y Celular de Rosario, Consejo Nacional de Investigaciones Científicas y Técnicas, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, S2002LRK, Rosario, Argentina
| | - Silvana Petrocelli
- Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, S2002LRK, Rosario, Argentina
| | - Laura Piskulic
- Área Estadística y Procesamiento de Datos, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
| | - Leandro Marcio Moreira
- Programa de Pós-Graduação em Biotecnologia, Núcleo de Pesquisas em Ciências Biológicas, Universidade Federal de Ouro Preto, Ouro Preto, MG, Brazil
- Departamento de Ciências Biológicas, Instituto de Ciências Exatas e Biológicas, Universidade Federal de Ouro Preto, Ouro Preto, MG, Brazil
| | | | | | - Elena Graciela Orellano
- Instituto de Biología Molecular y Celular de Rosario, Consejo Nacional de Investigaciones Científicas y Técnicas, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, S2002LRK, Rosario, Argentina.
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Karlsson ME, Hellström M, Flöhr A, Bergstrand KJ, Alsanius BW. The power of light: Impact on the performance of biocontrol agents under minimal nutrient conditions. Front Microbiol 2023; 14:1087639. [PMID: 36819051 PMCID: PMC9932321 DOI: 10.3389/fmicb.2023.1087639] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Accepted: 01/17/2023] [Indexed: 02/05/2023] Open
Abstract
Background The spectral distribution of light (different wavelength) has recently been identified as an important factor in the dynamics and function of leaf-associated microbes. This study investigated the impact of different wavelength on three commercial biocontrol agents (BCA): Bacillus amyloliquefaciens (BA), Pseudomonas chlororaphis (PC), and Streptomyces griseoviridis (SG). Methods The impact of light exposure on sole carbon source utilization, biofilm formation, and biosurfactant production by the selected BCA was studied using phenotypic microarray (PM) including 190 sole carbon sources (OmniLog®, PM panels 1 and 2). The BCA were exposed to five monochromatic light conditions (420, 460, 530, 630, and 660 nm) and darkness during incubation, at an intensity of 50 μmol m-2 s-1. Results Light exposure together with specific carbon source increased respiration in all three BCA. Different wavelengths of light influenced sole carbon utilization for the different BCA, with BA and PC showing increased respiration when exposed to wavelengths within the blue spectrum (420 and 460 nm) while respiration of selected carbon sources by SG increased in the presence of red light (630 and 660 nm). Only one carbon source (capric acid) generated biosurfactant production in all three BCA. A combination of specific wavelength of light and sole carbon source increased biofilm formation in all three BCA. BA showed significantly higher biofilm formation when exposed to blue (460 nm) and green (530 nm) light and propagated in D-sucrose, D-fructose, and dulcitol. PC showed higher biofilm formation when exposed to blue light. Biofilm formation by SG increased when exposed to red light (630 nm) and propagated in citraconic acid. Conclusion To increase attachment and success in BCA introduced into the phyllosphere, a suitable combination of light quality and nutrient conditions could be used.
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Insights into Molecular Structure of Pterins Suitable for Biomedical Applications. Int J Mol Sci 2022; 23:ijms232315222. [PMID: 36499560 PMCID: PMC9737128 DOI: 10.3390/ijms232315222] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Revised: 11/22/2022] [Accepted: 11/30/2022] [Indexed: 12/07/2022] Open
Abstract
Pterins are an inseparable part of living organisms. Pterins participate in metabolic reactions mostly as tetrahydropterins. Dihydropterins are usually intermediates of these reactions, whereas oxidized pterins can be biomarkers of diseases. In this review, we analyze the available data on the quantum chemistry of unconjugated pterins as well as their photonics. This gives a comprehensive overview about the electronic structure of pterins and offers some benefits for biomedicine applications: (1) one can affect the enzymatic reactions of aromatic amino acid hydroxylases, NO synthases, and alkylglycerol monooxygenase through UV irradiation of H4pterins since UV provokes electron donor reactions of H4pterins; (2) the emission properties of H2pterins and oxidized pterins can be used in fluorescence diagnostics; (3) two-photon absorption (TPA) should be used in such pterin-related infrared therapy because single-photon absorption in the UV range is inefficient and scatters in vivo; (4) one can affect pathogen organisms through TPA excitation of H4pterin cofactors, such as the molybdenum cofactor, leading to its detachment from proteins and subsequent oxidation; (5) metal nanostructures can be used for the UV-vis, fluorescence, and Raman spectroscopy detection of pterin biomarkers. Therefore, we investigated both the biochemistry and physical chemistry of pterins and suggested some potential prospects for pterin-related biomedicine.
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Dwijayanti A, Zhang C, Poh CL, Lautier T. Toward Multiplexed Optogenetic Circuits. Front Bioeng Biotechnol 2022; 9:804563. [PMID: 35071213 PMCID: PMC8766309 DOI: 10.3389/fbioe.2021.804563] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Accepted: 12/06/2021] [Indexed: 11/25/2022] Open
Abstract
Owing to its ubiquity and easy availability in nature, light has been widely employed to control complex cellular behaviors. Light-sensitive proteins are the foundation to such diverse and multilevel adaptive regulations in a large range of organisms. Due to their remarkable properties and potential applications in engineered systems, exploration and engineering of natural light-sensitive proteins have significantly contributed to expand optogenetic toolboxes with tailor-made performances in synthetic genetic circuits. Progressively, more complex systems have been designed in which multiple photoreceptors, each sensing its dedicated wavelength, are combined to simultaneously coordinate cellular responses in a single cell. In this review, we highlight recent works and challenges on multiplexed optogenetic circuits in natural and engineered systems for a dynamic regulation breakthrough in biotechnological applications.
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Affiliation(s)
| | - Congqiang Zhang
- Singapore Institute of Food and Biotechnology Innovation (SIFBI), Agency for Science, Technology and Research (A*STAR), Singapore, Singapore
| | - Chueh Loo Poh
- NUS Synthetic Biology for Clinical and Technological Innovation (SynCTI), Life Sciences Institute, National University of Singapore, Singapore, Singapore
| | - Thomas Lautier
- CNRS@CREATE, Singapore, Singapore
- Singapore Institute of Food and Biotechnology Innovation (SIFBI), Agency for Science, Technology and Research (A*STAR), Singapore, Singapore
- TBI, Université de Toulouse, CNRS, INRAE, INSA, Toulouse, France
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5
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Bioluminescence and Photoreception in Unicellular Organisms: Light-Signalling in a Bio-Communication Perspective. Int J Mol Sci 2021; 22:ijms222111311. [PMID: 34768741 PMCID: PMC8582858 DOI: 10.3390/ijms222111311] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 10/12/2021] [Accepted: 10/13/2021] [Indexed: 12/13/2022] Open
Abstract
Bioluminescence, the emission of light catalysed by luciferases, has evolved in many taxa from bacteria to vertebrates and is predominant in the marine environment. It is now well established that in animals possessing a nervous system capable of integrating light stimuli, bioluminescence triggers various behavioural responses and plays a role in intra- or interspecific visual communication. The function of light emission in unicellular organisms is less clear and it is currently thought that it has evolved in an ecological framework, to be perceived by visual animals. For example, while it is thought that bioluminescence allows bacteria to be ingested by zooplankton or fish, providing them with favourable conditions for growth and dispersal, the luminous flashes emitted by dinoflagellates may have evolved as an anti-predation system against copepods. In this short review, we re-examine this paradigm in light of recent findings in microorganism photoreception, signal integration and complex behaviours. Numerous studies show that on the one hand, bacteria and protists, whether autotrophs or heterotrophs, possess a variety of photoreceptors capable of perceiving and integrating light stimuli of different wavelengths. Single-cell light-perception produces responses ranging from phototaxis to more complex behaviours. On the other hand, there is growing evidence that unicellular prokaryotes and eukaryotes can perform complex tasks ranging from habituation and decision-making to associative learning, despite lacking a nervous system. Here, we focus our analysis on two taxa, bacteria and dinoflagellates, whose bioluminescence is well studied. We propose the hypothesis that similar to visual animals, the interplay between light-emission and reception could play multiple roles in intra- and interspecific communication and participate in complex behaviour in the unicellular world.
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Consiglieri E, Xu QZ, Zhao KH, Gärtner W, Losi A. The first molecular characterisation of blue- and red-light photoreceptors from Methylobacterium radiotolerans. Phys Chem Chem Phys 2020; 22:12434-12446. [PMID: 32458860 DOI: 10.1039/d0cp02014a] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Methylobacteria are facultative methylotrophic phytosymbionts of great industrial and agronomical interest, and they are considered as opportunistic pathogens posing a health threat to humans. So far only a few reports mention photoreceptor coding sequences in Methylobacteria genomes, but no investigation at the molecular level has been performed yet. We here present comprehensive in silico research into potential photoreceptors in this bacterial phylum and report the photophysical and photochemical characterisation of two representatives of the most widespread photoreceptor classes, a blue-light sensing LOV (light, oxygen, voltage) protein and a red/far red light sensing BphP (biliverdin-binding bacterial phytochrome) from M. radiotolerans JCM 2831. Overall, both proteins undergo the expected light-triggered reactions, but peculiar features were also identified. The LOV protein Mr4511 has an extremely long photocycle and lacks a tryptophan conserved in ca. 75% of LOV domains. Mutation I37V accelerates the photocycle by one order of magnitude, while the Q112W change underscores the ability of tryptophan in this position to perform efficient energy transfer to the flavin chromophore. Time-resolved photoacoustic experiments showed that Mr4511 has a higher triplet quantum yield than other LOV domains and that the formation of the photoproduct results in a volume expansion, in sharp contrast to other LOV proteins. Mr4511 was found to be astonishingly resistant to denaturation by urea, still showing light-triggered reactions after incubation in urea for more than 20 h. The phytochrome MrBphP1 exhibits the so far most red-shifted absorption maxima for its Pr- and Pfr forms (λmax = 707 nm and 764 nm for the Pr and Pfr forms). The light-driven conversions in both directions occur with relatively high quantum yields of 0.2. Transient ns absorption spectroscopy (μs-ms time range) identifies the decay of the instantaneously formed lumi-intermediate, followed by only one additional intermediate before the formation of the respective final photoproducts for Pr-to-Pfr or Pfr-to-Pr photoconversion, in contrast to other BphPs. The relatively simple photoconversion patterns suggest the absence of the shunt pathways reported for other bacterial phytochromes.
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Affiliation(s)
- Eleonora Consiglieri
- Department of Mathematical, Physical and Computer Sciences, University of Parma, Parco Area delle Scienze 7/A, 43124 Parma, Italy.
| | - Qian-Zhao Xu
- Institute for Analytical Chemistry, University of Leipzig, Linnéstrasse 3, 04103 Leipzig, Germany and State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China
| | - Kai-Hong Zhao
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China
| | - Wolfgang Gärtner
- Institute for Analytical Chemistry, University of Leipzig, Linnéstrasse 3, 04103 Leipzig, Germany
| | - Aba Losi
- Department of Mathematical, Physical and Computer Sciences, University of Parma, Parco Area delle Scienze 7/A, 43124 Parma, Italy.
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7
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Polverini E, Schackert FK, Losi A. Interplay among the “flipping” glutamine, a conserved phenylalanine, water and hydrogen bonds within a blue-light sensing LOV domain. Photochem Photobiol Sci 2020; 19:892-904. [DOI: 10.1039/d0pp00082e] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
A combined photoacoustics and molecular dynamics approach highlights the crucial role of a conserved phenyalanine in photosensing LOV domains.
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Affiliation(s)
- Eugenia Polverini
- Department of Mathematical
- Physical and Computer Sciences
- University of Parma
- 43124 Parma
- Italy
| | - Florian Karl Schackert
- Department of Mathematical
- Physical and Computer Sciences
- University of Parma
- 43124 Parma
- Italy
| | - Aba Losi
- Department of Mathematical
- Physical and Computer Sciences
- University of Parma
- 43124 Parma
- Italy
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8
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Pezza A, Tuttobene M, Abatedaga I, Valle L, Borsarelli CD, Mussi MA. Through the eyes of a pathogen: light perception and signal transduction in Acinetobacter baumannii. Photochem Photobiol Sci 2019; 18:2363-2373. [PMID: 31290528 DOI: 10.1039/c9pp00261h] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Sunlight is a ubiquitous environmental stimulus for the great majority of living organisms on Earth; therefore it is logical to expect the development of "seeing mechanisms" which lead them to successfully adapt to particular ecological niches. Although these mechanisms were recognized in photosynthetic organisms, it was not until recent years that the scientific community found out about light perception in chemotrophic ones. In this review we summarize the current knowledge about the mechanism of light sensing through the blue light receptor BlsA in Acinetobacter baumannii. We highlight its function as a global regulator that pleiotropically modulates a large number of physiological processes, many of which are linked to the ability of this opportunist pathogen to persist in adverse intrahospital environments. Moreover, we describe with some specific examples the molecular basis of how this photoregulator senses blue light and translates this physical signal by modulating gene expression of target regulons. Finally, we discuss the possible course of these investigations needed to dissect this complex regulatory network, which ultimately will help us better understand the A. baumannii physiology.
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Affiliation(s)
- Alejandro Pezza
- Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET), 2000, Rosario, Argentina
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9
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Santamaría-Hernando S, Rodríguez-Herva JJ, Martínez-García PM, Río-Álvarez I, González-Melendi P, Zamorano J, Tapia C, Rodríguez-Palenzuela P, López-Solanilla E. Pseudomonas syringae pv. tomato exploits light signals to optimize virulence and colonization of leaves. Environ Microbiol 2018; 20:4261-4280. [PMID: 30058114 DOI: 10.1111/1462-2920.14331] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Revised: 06/13/2018] [Accepted: 06/17/2018] [Indexed: 11/30/2022]
Abstract
Light is pervasive in the leaf environment, creating opportunities for both plants and pathogens to cue into light as a signal to regulate plant-microbe interactions. Light enhances plant defences and regulates opening of stomata, an entry point for foliar bacterial pathogens such as Pseudomonas syringae pv. tomato DC3000 (PsPto). The effect of light perception on gene expression and virulence was investigated in PsPto. Light induced genetic reprogramming in PsPto that entailed significant changes in stress tolerance and virulence. Blue light-mediated up-regulation of type three secretion system genes and red light-mediated down-regulation of coronatine biosynthesis genes. Cells exposed to white light, blue light or darkness before inoculation were more virulent when inoculated at dawn than dusk probably due to an enhanced entry through open stomata. Exposure to red light repressed coronatine biosynthesis genes which could lead to a reduced stomatal re-opening and PsPto entry. Photoreceptor were required for the greater virulence of light-treated and dark-treated PsPto inoculated at dawn as compared to dusk, indicating that these proteins sense the absence of light and contribute to priming of virulence in the dark. These results support a model in which PsPto exploits light changes to maximize survival, entry and virulence on plants.
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Affiliation(s)
- Saray Santamaría-Hernando
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM)-Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA) Campus Montegancedo UPM, Pozuelo de Alarcón, 28223, Madrid, Spain
| | - José J Rodríguez-Herva
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM)-Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA) Campus Montegancedo UPM, Pozuelo de Alarcón, 28223, Madrid, Spain.,Departamento de Biotecnología-Biología Vegetal, Escuela Técnica Superior de Ingeniería Agronómica, Alimentaria y de Biosistemas, UPM, Madrid, Spain
| | - Pedro M Martínez-García
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM)-Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA) Campus Montegancedo UPM, Pozuelo de Alarcón, 28223, Madrid, Spain
| | - Isabel Río-Álvarez
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM)-Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA) Campus Montegancedo UPM, Pozuelo de Alarcón, 28223, Madrid, Spain
| | - Pablo González-Melendi
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM)-Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA) Campus Montegancedo UPM, Pozuelo de Alarcón, 28223, Madrid, Spain.,Departamento de Biotecnología-Biología Vegetal, Escuela Técnica Superior de Ingeniería Agronómica, Alimentaria y de Biosistemas, UPM, Madrid, Spain
| | - Jaime Zamorano
- Departamento de Astrofísica y CC. de la Atmósfera, Universidad Complutense, Madrid, Spain
| | - Carlos Tapia
- Departamento de Astrofísica y CC. de la Atmósfera, Universidad Complutense, Madrid, Spain
| | - Pablo Rodríguez-Palenzuela
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM)-Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA) Campus Montegancedo UPM, Pozuelo de Alarcón, 28223, Madrid, Spain.,Departamento de Biotecnología-Biología Vegetal, Escuela Técnica Superior de Ingeniería Agronómica, Alimentaria y de Biosistemas, UPM, Madrid, Spain
| | - Emilia López-Solanilla
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM)-Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA) Campus Montegancedo UPM, Pozuelo de Alarcón, 28223, Madrid, Spain.,Departamento de Biotecnología-Biología Vegetal, Escuela Técnica Superior de Ingeniería Agronómica, Alimentaria y de Biosistemas, UPM, Madrid, Spain
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Abstract
Sensory photoreceptors underpin light-dependent adaptations of organismal physiology, development, and behavior in nature. Adapted for optogenetics, sensory photoreceptors become genetically encoded actuators and reporters to enable the noninvasive, spatiotemporally accurate and reversible control by light of cellular processes. Rooted in a mechanistic understanding of natural photoreceptors, artificial photoreceptors with customized light-gated function have been engineered that greatly expand the scope of optogenetics beyond the original application of light-controlled ion flow. As we survey presently, UV/blue-light-sensitive photoreceptors have particularly allowed optogenetics to transcend its initial neuroscience applications by unlocking numerous additional cellular processes and parameters for optogenetic intervention, including gene expression, DNA recombination, subcellular localization, cytoskeleton dynamics, intracellular protein stability, signal transduction cascades, apoptosis, and enzyme activity. The engineering of novel photoreceptors benefits from powerful and reusable design strategies, most importantly light-dependent protein association and (un)folding reactions. Additionally, modified versions of these same sensory photoreceptors serve as fluorescent proteins and generators of singlet oxygen, thereby further enriching the optogenetic toolkit. The available and upcoming UV/blue-light-sensitive actuators and reporters enable the detailed and quantitative interrogation of cellular signal networks and processes in increasingly more precise and illuminating manners.
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Affiliation(s)
- Aba Losi
- Department of Mathematical, Physical and Computer Sciences , University of Parma , Parco Area delle Scienze 7/A-43124 Parma , Italy
| | - Kevin H Gardner
- Structural Biology Initiative, CUNY Advanced Science Research Center , New York , New York 10031 , United States.,Department of Chemistry and Biochemistry, City College of New York , New York , New York 10031 , United States.,Ph.D. Programs in Biochemistry, Chemistry, and Biology , The Graduate Center of the City University of New York , New York , New York 10016 , United States
| | - Andreas Möglich
- Lehrstuhl für Biochemie , Universität Bayreuth , 95447 Bayreuth , Germany.,Research Center for Bio-Macromolecules , Universität Bayreuth , 95447 Bayreuth , Germany.,Bayreuth Center for Biochemistry & Molecular Biology , Universität Bayreuth , 95447 Bayreuth , Germany
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Gharaie S, Vaas LAI, Rosberg AK, Windstam ST, Karlsson ME, Bergstrand KJ, Khalil S, Wohanka W, Alsanius BW. Light spectrum modifies the utilization pattern of energy sources in Pseudomonas sp. DR 5-09. PLoS One 2017; 12:e0189862. [PMID: 29267321 PMCID: PMC5739431 DOI: 10.1371/journal.pone.0189862] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2016] [Accepted: 12/04/2017] [Indexed: 11/18/2022] Open
Abstract
Despite the overruling impact of light in the phyllosphere, little is known regarding the influence of light spectra on non-phototrophic bacteria colonizing the leaf surface. We developed an in vitro method to study phenotypic profile responses of bacterial pure cultures to different bands of the visible light spectrum using monochromatic (blue: 460 nm; red: 660 nm) and polychromatic (white: 350–990 nm) LEDs, by modification and optimization of a protocol for the Phenotype MicroArray™ technique (Biolog Inc., CA, USA). The new protocol revealed high reproducibility of substrate utilization under all conditions tested. Challenging the non-phototrophic bacterium Pseudomonas sp. DR 5–09 with white, blue, and red light demonstrated that all light treatments affected the respiratory profile differently, with blue LED having the most decisive impact on substrate utilization by impairing respiration of 140 substrates. The respiratory activity was decreased on 23 and 42 substrates under red and white LEDs, respectively, while utilization of one, 16, and 20 substrates increased in the presence of red, blue, and white LEDs, respectively. Interestingly, on four substrates contrasting utilization patterns were found when the bacterium was exposed to different light spectra. Although non-phototrophic bacteria do not rely directly on light as an energy source, Pseudomonas sp. DR 5–09 changed its respiratory activity on various substrates differently when exposed to different lights. Thus, ability to sense and distinguish between different wavelengths even within the visible light spectrum must exist, and leads to differential regulation of substrate usage. With these results, we hypothesize that different light spectra might be a hitherto neglected key stimulus for changes in microbial lifestyle and habits of substrate usage by non-phototrophic phyllospheric microbiota, and thus might essentially stratify leaf microbiota composition and diversity.
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Affiliation(s)
- Samareh Gharaie
- Swedish University of Agricultural Sciences, Department of Biosystems and Technology, Microbial Horticulture Unit, Alnarp, Sweden
| | | | - Anna Karin Rosberg
- Swedish University of Agricultural Sciences, Department of Biosystems and Technology, Microbial Horticulture Unit, Alnarp, Sweden
| | - Sofia T. Windstam
- Swedish University of Agricultural Sciences, Department of Biosystems and Technology, Microbial Horticulture Unit, Alnarp, Sweden
- State University of New York, Department of Biological Sciences, Oswego, New York, United States of America
| | - Maria E. Karlsson
- Swedish University of Agricultural Sciences, Department of Biosystems and Technology, Microbial Horticulture Unit, Alnarp, Sweden
| | - Karl-Johan Bergstrand
- Swedish University of Agricultural Sciences, Department of Biosystems and Technology, Microbial Horticulture Unit, Alnarp, Sweden
| | - Sammar Khalil
- Swedish University of Agricultural Sciences, Department of Biosystems and Technology, Microbial Horticulture Unit, Alnarp, Sweden
| | - Walter Wohanka
- Geisenheim University, Department of Phytomedicine, Geisenheim, Germany
| | - Beatrix W. Alsanius
- Swedish University of Agricultural Sciences, Department of Biosystems and Technology, Microbial Horticulture Unit, Alnarp, Sweden
- * E-mail:
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12
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Optogenetic Module for Dichromatic Control of c-di-GMP Signaling. J Bacteriol 2017; 199:JB.00014-17. [PMID: 28320886 DOI: 10.1128/jb.00014-17] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2017] [Accepted: 03/15/2017] [Indexed: 02/08/2023] Open
Abstract
Many aspects of bacterial physiology and behavior, including motility, surface attachment, and the cell cycle, are controlled by cyclic di-GMP (c-di-GMP)-dependent signaling pathways on the scale of seconds to minutes. Interrogation of such processes in real time requires tools for introducing rapid and reversible changes in intracellular c-di-GMP levels. Inducing the expression of genes encoding c-di-GMP-synthetic (diguanylate cyclases) and -degrading (c-di-GMP phosphodiesterase) enzymes by chemicals may not provide adequate temporal control. In contrast, light-controlled diguanylate cyclases and phosphodiesterases can be quickly activated and inactivated. A red/near-infrared-light-regulated diguanylate cyclase, BphS, was engineered previously, yet a complementary light-activated c-di-GMP phosphodiesterase has been lacking. In search of such a phosphodiesterase, we investigated two homologous proteins from Allochromatium vinosum and Magnetococcus marinus, designated BldP, which contain C-terminal EAL-BLUF modules, where EAL is a c-di-GMP phosphodiesterase domain and BLUF is a blue light sensory domain. Characterization of the BldP proteins in Escherichia coli and in vitro showed that they possess light-activated c-di-GMP phosphodiesterase activities. Interestingly, light activation in both enzymes was dependent on oxygen levels. The truncated EAL-BLUF fragment from A. vinosum BldP lacked phosphodiesterase activity, whereas a similar fragment from M. marinus BldP, designated EB1, possessed such activity that was highly (>30-fold) upregulated by light. Following light withdrawal, EB1 reverted to the inactive ground state with a half-life of ∼6 min. Therefore, the blue-light-activated phosphodiesterase EB1 can be used in combination with the red/near-infrared-light-regulated diguanylate cyclase BphS for the bidirectional regulation of c-di-GMP-dependent processes in E. coli as well as other bacterial and nonbacterial cells.IMPORTANCE Regulation of motility, attachment to surfaces, the cell cycle, and other bacterial processes controlled by the c-di-GMP signaling pathways occur at a fast (seconds-to-minutes) pace. Interrogation of these processes at high temporal and spatial resolution using chemicals is difficult or impossible, while optogenetic approaches may prove useful. We identified and characterized a robust, blue-light-activated c-di-GMP phosphodiesterase (hydrolase) that complements a previously engineered red/near-infrared-light-regulated diguanylate cyclase (c-di-GMP synthase). These two enzymes form a dichromatic module for manipulating intracellular c-di-GMP levels in bacterial and nonbacterial cells.
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Losi A, Gärtner W. Solving Blue Light Riddles: New Lessons from Flavin-binding LOV Photoreceptors. Photochem Photobiol 2017; 93:141-158. [PMID: 27861974 DOI: 10.1111/php.12674] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2016] [Accepted: 10/22/2016] [Indexed: 12/15/2022]
Abstract
Detection of blue light (BL) via flavin-binding photoreceptors (Fl-Blues) has evolved throughout all three domains of life. Although the main BL players, that is light, oxygen and voltage (LOV), blue light sensing using flavins (BLUF) and Cry (cryptochrome) proteins, have been characterized in great detail with respect to structure and function, still several unresolved issues at different levels of complexity remain and novel unexpected findings were reported. Here, we review the most prevailing riddles of LOV-based photoreceptors, for example: the relevance of water and/or small metabolites for the dynamics of the photocycle; molecular details of light-to-signal transduction events; the interplay of BL sensing by LOV domains with other environmental stimuli, such as BL plus oxygen-mediating photodamage and its impact on microbial lifestyles; the importance of the cell or chromophore redox state in determining the fate of BL-driven reactions; the evolutionary pathways of LOV-based BL sensing and associated functions through the diverse phyla. We will discuss major novelties emerged during the last few years on these intriguing aspects of LOV proteins by presenting paradigmatic examples from prokaryotic photosensors that exhibit the largest complexity and richness in associated functions.
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Affiliation(s)
- Aba Losi
- Department of Physics and Earth Sciences, University of Parma, Parma, Italy
| | - Wolfgang Gärtner
- Max-Planck-Institute for Chemical Energy Conversion, Mülheim, Germany
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Banerjee A, Herman E, Serif M, Maestre-Reyna M, Hepp S, Pokorny R, Kroth PG, Essen LO, Kottke T. Allosteric communication between DNA-binding and light-responsive domains of diatom class I aureochromes. Nucleic Acids Res 2016; 44:5957-70. [PMID: 27179025 PMCID: PMC4937327 DOI: 10.1093/nar/gkw420] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Accepted: 05/04/2016] [Indexed: 12/20/2022] Open
Abstract
The modular architecture of aureochrome blue light receptors, found in several algal groups including diatoms, is unique by having the LOV-type photoreceptor domain fused to the C-terminus of its putative effector, an N-terminal DNA-binding bZIP module. The structural and functional understanding of aureochromes’ light-dependent signaling mechanism is limited, despite their promise as an optogenetic tool. We show that class I aureochromes 1a and 1c from the diatom Phaeodactylum tricornutum are regulated in a light-independent circadian rhythm. These aureochromes are capable to form functional homo- and heterodimers, which recognize the ACGT core sequence within the canonical ‘aureo box’, TGACGT, in a light-independent manner. The bZIP domain holds a more folded and less flexible but extended conformation in the duplex DNA-bound state. FT-IR spectroscopy in the absence and the presence of DNA shows light-dependent helix unfolding in the LOV domain, which leads to conformational changes in the bZIP region. The solution structure of DNA bound to aureochrome points to a tilted orientation that was further validated by molecular dynamics simulations. We propose that aureochrome signaling relies on an allosteric pathway from LOV to bZIP that results in conformational changes near the bZIP-DNA interface without major effects on the binding affinity.
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Affiliation(s)
- Ankan Banerjee
- Structural Biochemistry - Department of Chemistry, Philipps University Marburg, Hans-Meerwein Straße 4, 35032 Marburg, Germany
| | - Elena Herman
- Physical and Biophysical Chemistry - Department of Chemistry, Bielefeld University, Universitätsstraße 25, 33615 Bielefeld, Germany
| | - Manuel Serif
- Plant Ecophysiology - Department of Biology, University of Konstanz, 78457 Konstanz, Germany
| | - Manuel Maestre-Reyna
- Institute of Biological Chemistry, Academia Sinica, 128 Academia Road, Sec. 2 Nankang, Taipei 11529, Taiwan
| | - Sebastian Hepp
- Structural Biochemistry - Department of Chemistry, Philipps University Marburg, Hans-Meerwein Straße 4, 35032 Marburg, Germany
| | - Richard Pokorny
- Faculty of Biology, Department of Plant Physiology and Photobiology, Philipps-University Marburg, 35043 Marburg, Germany
| | - Peter G Kroth
- Plant Ecophysiology - Department of Biology, University of Konstanz, 78457 Konstanz, Germany
| | - Lars-Oliver Essen
- Structural Biochemistry - Department of Chemistry, Philipps University Marburg, Hans-Meerwein Straße 4, 35032 Marburg, Germany
| | - Tilman Kottke
- Physical and Biophysical Chemistry - Department of Chemistry, Bielefeld University, Universitätsstraße 25, 33615 Bielefeld, Germany
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15
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Glantz ST, Carpenter EJ, Melkonian M, Gardner KH, Boyden ES, Wong GKS, Chow BY. Functional and topological diversity of LOV domain photoreceptors. Proc Natl Acad Sci U S A 2016; 113:E1442-51. [PMID: 26929367 PMCID: PMC4801262 DOI: 10.1073/pnas.1509428113] [Citation(s) in RCA: 107] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Light-oxygen-voltage sensitive (LOV) flavoproteins are ubiquitous photoreceptors that mediate responses to environmental cues. Photosensory inputs are transduced into signaling outputs via structural rearrangements in sensor domains that consequently modulate the activity of an effector domain or multidomain clusters. Establishing the diversity in effector function and sensor-effector topology will inform what signaling mechanisms govern light-responsive behaviors across multiple kingdoms of life and how these signals are transduced. Here, we report the bioinformatics identification of over 6,700 candidate LOV domains (including over 4,000 previously unidentified sequences from plants and protists), and insights from their annotations for ontological function and structural arrangements. Motif analysis identified the sensors from ∼42 million ORFs, with strong statistical separation from other flavoproteins and non-LOV members of the structurally related Per-aryl hydrocarbon receptor nuclear translocator (ARNT)-Sim family. Conserved-domain analysis determined putative light-regulated function and multidomain topologies. We found that for certain effectors, sensor-effector linker length is discretized based on both phylogeny and the preservation of α-helical heptad repeats within an extended coiled-coil linker structure. This finding suggests that preserving sensor-effector orientation is a key determinant of linker length, in addition to ancestry, in LOV signaling structure-function. We found a surprisingly high prevalence of effectors with functions previously thought to be rare among LOV proteins, such as regulators of G protein signaling, and discovered several previously unidentified effectors, such as lipases. This work highlights the value of applying genomic and transcriptomic technologies to diverse organisms to capture the structural and functional variation in photosensory proteins that are vastly important in adaptation, photobiology, and optogenetics.
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Affiliation(s)
- Spencer T Glantz
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104
| | - Eric J Carpenter
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada T6G 2E9
| | - Michael Melkonian
- Institute of Botany, Cologne Biocenter, University of Cologne, 50674 Cologne, Germany
| | - Kevin H Gardner
- Structural Biology Initiative, CUNY Advanced Science Research Center, City College of New York, New York, NY 10031; Department of Chemistry and Biochemistry, City College of New York, New York, NY 10031; Biochemistry, Chemistry and Biology Programs, Graduate Center, The City University of New York, New York, NY 10031
| | - Edward S Boyden
- The Media Laboratory, Massachusetts Institute of Technology, Cambridge, MA 02139; Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139; Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139; McGovern Institute for Brain Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139
| | - Gane Ka-Shu Wong
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada T6G 2E9; Department of Medicine, University of Alberta, Edmonton, AB, Canada T6G 2E1; BGI-Shenzhen, Beishan Industrial Zone, Yantian District, Shenzhen 518083, China
| | - Brian Y Chow
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104;
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Ramírez MS, Müller GL, Pérez JF, Golic AE, Mussi MA. More Than Just Light: Clinical Relevance of Light Perception in the Nosocomial PathogenAcinetobacter baumanniiand Other Members of the GenusAcinetobacter. Photochem Photobiol 2015; 91:1291-301. [DOI: 10.1111/php.12523] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Accepted: 07/21/2015] [Indexed: 12/31/2022]
Affiliation(s)
- María Soledad Ramírez
- Facultad de Ciencias Médicas; Instituto de Investigaciones en Microbiología y Parasitología Médica (IMPaM-CONICET); Universidad de Buenos Aires; Buenos Aires Argentina
- Department of Biological Science; Center for Applied Biotechnology Studies; California State University Fullerton; Fullerton CA
| | - Gabriela Leticia Müller
- Facultad de Ciencias Bioquímicas y Farmacéuticas; Universidad Nacional de Rosario; Rosario Argentina
- Centro de Estudios Fotosintéticos y Bioquímicos (CEFOBI-CONICET); Rosario Argentina
| | - Jorgelina Fernanda Pérez
- Facultad de Ciencias Bioquímicas y Farmacéuticas; Universidad Nacional de Rosario; Rosario Argentina
| | | | - María Alejandra Mussi
- Facultad de Ciencias Bioquímicas y Farmacéuticas; Universidad Nacional de Rosario; Rosario Argentina
- Centro de Estudios Fotosintéticos y Bioquímicos (CEFOBI-CONICET); Rosario Argentina
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17
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Ricci A, Dramis L, Shah R, Gärtner W, Losi A. Visualizing the relevance of bacterial blue- and red-light receptors during plant-pathogen interaction. ENVIRONMENTAL MICROBIOLOGY REPORTS 2015; 7:795-802. [PMID: 26147514 DOI: 10.1111/1758-2229.12320] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2015] [Revised: 06/26/2015] [Accepted: 06/29/2015] [Indexed: 06/04/2023]
Abstract
The foliar pathogen Pseudomonas syringae pv. tomato DC3000 (Pst) leads to consistent losses in tomato crops, urging to multiply investigations on the physiological bases for its infectiveness. As other P. syringae pathovars, Pst is equipped with photoreceptors for blue and red light, mimicking the photosensing ability of host plants. In this work we have investigated Pst strains lacking the genes for a blue-light sensing protein (PstLOV), for a bacteriophytochrome (PstBph1) or for heme-oxygenase-1. When grown in culturing medium, all deletion mutants presented a larger growth than wild-type (WT) Pst under all other light conditions, with the exception of blue light which, under our experimental conditions (photon fluence rate = 40 μmol m(-2) s(-1)), completely suppressed the growth of the deletion mutants. Each of the knockout mutants shows stronger virulence towards Arabidopsis thaliana than PstWT, as evidenced by macroscopic damages in the host tissues of infected leaves. Mutated bacteria were also identified in districts distant from the infection site using scanning electron microscopy. These results underscore the importance of Pst photoreceptors in responding to environmental light inputs and the partial protective role that they exert towards host plants during infection, diminishing virulence and invasiveness.
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Affiliation(s)
- Ada Ricci
- Department of Life Sciences, University of Parma, 43124, Parma, Italy
| | - Lucia Dramis
- Department of Life Sciences, University of Parma, 43124, Parma, Italy
| | - Rashmi Shah
- Max-Planck-Institute for Chemical Energy Conversion, 45470, Mülheim, Germany
| | - Wolfgang Gärtner
- Max-Planck-Institute for Chemical Energy Conversion, 45470, Mülheim, Germany
| | - Aba Losi
- Department of Physics and Earth Sciences, University of Parma, 43124, Parma, Italy
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18
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Kraiselburd I, Gutt A, Losi A, Gärtner W, Orellano EG. Functional Characterization of a LOV-Histidine Kinase Photoreceptor from Xanthomonas citri subsp. citri. Photochem Photobiol 2015; 91:1123-32. [PMID: 26172037 DOI: 10.1111/php.12493] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Accepted: 06/18/2015] [Indexed: 01/30/2023]
Abstract
The blue-light (BL) absorbing protein Xcc-LOV from Xanthomonas citri subsp. citri is composed of a LOV-domain, a histidine kinase (HK) and a response regulator. Spectroscopic characterization of Xcc-LOV identified intermediates and kinetics of the protein's photocycle. Measurements of steady state and time-resolved fluorescence allowed determination of quantum yields for triplet (ΦT = 0.68 ± 0.03) and photoproduct formation (Φ390 = 0.46 ± 0.05). The lifetime for triplet decay was determined as τT = 2.4-2.8 μs. Fluorescence of tryptophan and tyrosine residues was unchanged upon light-to-dark conversion, emphasizing the absence of significant conformational changes. Photochemistry was blocked upon cysteine C76 (C76S) mutation, causing a seven-fold longer lifetime of the triplet state (τT = 16-18.5 μs). Optoacoustic spectroscopy yielded the energy content of the triplet state. Interestingly, Xcc-LOV did not undergo the volume contraction reported for other LOV domains within the observation time window, although the back-conversion into the dark state was accompanied by a volume expansion. A radioactivity-based enzyme function assay revealed a larger HK activity in the lit than in the dark state. The C76S mutant showed a still lower enzyme function, indicating the dark state activity being corrupted by a remaining portion of the long-lived lit state.
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Affiliation(s)
- Ivana Kraiselburd
- Facultad de Ciencias Bioquímicas y Farmacéuticas, Instituto de Biología Molecular y Celular de Rosario (IBR), CONICET, Universidad Nacional de Rosario, Rosario, Argentina
| | - Alexander Gutt
- Max-Planck-Institute for Chemical Energy Conversion, Mülheim, Germany
| | - Aba Losi
- Department of Physics and Earth Sciences, University of Parma, Parma, Italy
| | - Wolfgang Gärtner
- Max-Planck-Institute for Chemical Energy Conversion, Mülheim, Germany
| | - Elena G Orellano
- Facultad de Ciencias Bioquímicas y Farmacéuticas, Instituto de Biología Molecular y Celular de Rosario (IBR), CONICET, Universidad Nacional de Rosario, Rosario, Argentina
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Losi A, Mandalari C, Gärtner W. The Evolution and Functional Role of Flavin-based Prokaryotic Photoreceptors. Photochem Photobiol 2015; 91:1021-31. [DOI: 10.1111/php.12489] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Accepted: 06/15/2015] [Indexed: 12/12/2022]
Affiliation(s)
- Aba Losi
- Department of Physics and Earth Sciences; University of Parma; Parma Italy
| | - Carmen Mandalari
- Department of Physics and Earth Sciences; University of Parma; Parma Italy
| | - Wolfgang Gärtner
- Max-Planck-Institute for Chemical Energy Conversion; Mülheim Germany
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20
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Nudel CB, Hellingwerf KJ. Photoreceptors in Chemotrophic Prokaryotes: The Case of Acinetobacter spp. Revisited. Photochem Photobiol 2015; 91:1012-20. [PMID: 26147719 DOI: 10.1111/php.12491] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Accepted: 06/08/2015] [Indexed: 12/23/2022]
Abstract
A comprehensive description of blue light using flavin (BLUF) photosensory proteins, including preferred domain architectures and the molecular mechanism of their light activation and signal generation, among chemotrophic prokaryotes is presented. Light-regulated physiological responses in Acinetobacter spp. from environmental and clinically relevant strains are discussed. The twitching motility response in A. baylyi sp. ADP1 and the joint involvement of three of the four putative BLUF-domain-containing proteins in this response, in this species, is presented as an example of remarkable photoreceptor redundancy.
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Affiliation(s)
- Clara B Nudel
- Nanobiotec Institute, Faculty of Pharmacy and Biochemistry, University of Buenos Aires, Ciudad de Buenos Aires, Argentina
| | - Klaas J Hellingwerf
- Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, The Netherlands
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21
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Endres S, Granzin J, Circolone F, Stadler A, Krauss U, Drepper T, Svensson V, Knieps-Grünhagen E, Wirtz A, Cousin A, Tielen P, Willbold D, Jaeger KE, Batra-Safferling R. Structure and function of a short LOV protein from the marine phototrophic bacterium Dinoroseobacter shibae. BMC Microbiol 2015; 15:30. [PMID: 25887755 PMCID: PMC4335406 DOI: 10.1186/s12866-015-0365-0] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2014] [Accepted: 01/29/2015] [Indexed: 12/29/2022] Open
Abstract
Background Light, oxygen, voltage (LOV) domains are widely distributed in plants, algae, fungi, bacteria, and represent the photo-responsive domains of various blue-light photoreceptor proteins. Their photocycle involves the blue-light triggered adduct formation between the C(4a) atom of a non-covalently bound flavin chromophore and the sulfur atom of a conserved cysteine in the LOV sensor domain. LOV proteins show considerable variation in the structure of N- and C-terminal elements which flank the LOV core domain, as well as in the lifetime of the adduct state. Results Here, we report the photochemical, structural and functional characterization of DsLOV, a LOV protein from the photoheterotrophic marine α-proteobacterium Dinoroseobacter shibae which exhibits an average adduct state lifetime of 9.6 s at 20°C, and thus represents the fastest reverting bacterial LOV protein reported so far. Mutational analysis in D. shibae revealed a unique role of DsLOV in controlling the induction of photopigment synthesis in the absence of blue-light. The dark state crystal structure of DsLOV determined at 1.5 Å resolution reveals a conserved core domain with an extended N-terminal cap. The dimer interface in the crystal structure forms a unique network of hydrogen bonds involving residues of the N-terminus and the β-scaffold of the core domain. The structure of photoexcited DsLOV suggests increased flexibility in the N-cap region and a significant shift in the Cα backbone of β strands in the N- and C-terminal ends of the LOV core domain. Conclusions The results presented here cover the characterization of the unusual short LOV protein DsLOV from Dinoroseobacter shibae including its regulatory function, extremely fast dark recovery and an N-terminus mediated dimer interface. Due to its unique photophysical, structural and regulatory properties, DsLOV might thus serve as an alternative model system for studying light perception by LOV proteins and physiological responses in bacteria. Electronic supplementary material The online version of this article (doi:10.1186/s12866-015-0365-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Stephan Endres
- Institute of Molecular Enzyme Technology, Heinrich-Heine-Universität Düsseldorf, Forschungszentrum Jülich, D-52425, Jülich, Germany.
| | - Joachim Granzin
- Institute of Complex Systems, ICS-6: Structural Biochemistry, Forschungszentrum Jülich, D-52425, Jülich, Germany.
| | - Franco Circolone
- Institute of Molecular Enzyme Technology, Heinrich-Heine-Universität Düsseldorf, Forschungszentrum Jülich, D-52425, Jülich, Germany.
| | - Andreas Stadler
- Juelich Centre for Neutron Science JCNS (JCNS-1) & Institute for Complex Systems (ICS-1), Forschungszentrum Jülich, D-52425, Jülich, Germany.
| | - Ulrich Krauss
- Institute of Molecular Enzyme Technology, Heinrich-Heine-Universität Düsseldorf, Forschungszentrum Jülich, D-52425, Jülich, Germany.
| | - Thomas Drepper
- Institute of Molecular Enzyme Technology, Heinrich-Heine-Universität Düsseldorf, Forschungszentrum Jülich, D-52425, Jülich, Germany.
| | - Vera Svensson
- Institute of Molecular Enzyme Technology, Heinrich-Heine-Universität Düsseldorf, Forschungszentrum Jülich, D-52425, Jülich, Germany.
| | - Esther Knieps-Grünhagen
- Institute of Molecular Enzyme Technology, Heinrich-Heine-Universität Düsseldorf, Forschungszentrum Jülich, D-52425, Jülich, Germany.
| | - Astrid Wirtz
- Institute of Molecular Enzyme Technology, Heinrich-Heine-Universität Düsseldorf, Forschungszentrum Jülich, D-52425, Jülich, Germany.
| | - Anneliese Cousin
- Institute of Complex Systems, ICS-6: Structural Biochemistry, Forschungszentrum Jülich, D-52425, Jülich, Germany.
| | - Petra Tielen
- Institute for Microbiology, Technische Universität Braunschweig, D-38106, Braunschweig, Germany.
| | - Dieter Willbold
- Institute of Complex Systems, ICS-6: Structural Biochemistry, Forschungszentrum Jülich, D-52425, Jülich, Germany. .,Institute of Physical Biology, Heinrich-Heine-Universität Düsseldorf, D-40225, Düsseldorf, Germany.
| | - Karl-Erich Jaeger
- Institute of Molecular Enzyme Technology, Heinrich-Heine-Universität Düsseldorf, Forschungszentrum Jülich, D-52425, Jülich, Germany. .,Institute of Bio- and Geosciences, IBG-1: Biotechnology, Forschungszentrum Jülich, D-52425, Jülich, Germany.
| | - Renu Batra-Safferling
- Institute of Complex Systems, ICS-6: Structural Biochemistry, Forschungszentrum Jülich, D-52425, Jülich, Germany.
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