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Protein control of photochemistry and transient intermediates in phytochromes. Nat Commun 2022; 13:6838. [PMID: 36369284 PMCID: PMC9652276 DOI: 10.1038/s41467-022-34640-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Accepted: 11/01/2022] [Indexed: 11/13/2022] Open
Abstract
Phytochromes are ubiquitous photoreceptors responsible for sensing light in plants, fungi and bacteria. Their photoactivation is initiated by the photoisomerization of the embedded chromophore, triggering large conformational changes in the protein. Despite numerous experimental and computational studies, the role of chromophore-protein interactions in controlling the mechanism and timescale of the process remains elusive. Here, we combine nonadiabatic surface hopping trajectories and adiabatic molecular dynamics simulations to reveal the molecular details of such control for the Deinococcus radiodurans bacteriophytochrome. Our simulations reveal that chromophore photoisomerization proceeds through a hula-twist mechanism whose kinetics is mainly determined by the hydrogen bond of the chromophore with a close-by histidine. The resulting photoproduct relaxes to an early intermediate stabilized by a tyrosine, and finally evolves into a late intermediate, featuring a more disordered binding pocket and a weakening of the aspartate-to-arginine salt-bridge interaction, whose cleavage is essential to interconvert the phytochrome to the active state.
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2
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Zeps M, Kondratovičs T, Grigžde E, Jansons Ā, Zeltiņš P, Samsone I, Matisons R. Plantlet Anatomy of Silver Birch (Betula pendula Roth.) and Hybrid Aspen (Populus tremuloides Michx. × Populus tremula L.) Shows Intraspecific Reactions to Illumination In Vitro. PLANTS 2022; 11:plants11081097. [PMID: 35448825 PMCID: PMC9024933 DOI: 10.3390/plants11081097] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Revised: 04/11/2022] [Accepted: 04/15/2022] [Indexed: 11/24/2022]
Abstract
Micropropagation of forest reproductive material is becoming an increasingly important tool of climate-smart forest management, whose efficiency is depending on artificial illumination, which in turn can have species-specific effects. To improve the energy-efficiency of micropropagation, light emitting diodes (LED) are becoming more popular; however, they emit light of narrow spectral composition, synergic effects of which can alter plantlet development. Regarding the in vitro cultures of trees, such effects have been scarcely studied. In this study, three clones of silver birch (Betula pendula Roth.) and three clones of hybrid aspen (Populus tremuloides Michx. × Populus tremula L.) from the eastern Baltic region were tested. The responses of leaf and stem anatomy of in vitro cultures to three LED light illumination treatments differing by spectral composition and to illumination by fluorescent tubes were estimated by linear (mixed) models. The studied light treatments had non-interacted effects on stomata density and on the secondary xylem cell wall in the stem of silver birch and in the stomata length, stem radius, and phloem width of hybrid aspen. Furthermore, clone-specific responses to illumination were observed for number of chloroplasts and phloem width of silver birch and for leaf thickness and xylem cell wall thickness of hybrid aspen, implying different mechanisms of shade avoidance. In general, the responses of plantlet anatomy differed according to the width of the light spectrum in case of LED, as well as for fluorescent tubes. Considering the legacy effects of early development of plantlets, adaptability of illumination in terms of spectral composition according to the requirements of genotypes appear highly beneficial for micropropagation of sustainable forest reproductive material.
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3
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Cavallaro V, Pellegrino A, Muleo R, Forgione I. Light and Plant Growth Regulators on In Vitro Proliferation. PLANTS (BASEL, SWITZERLAND) 2022; 11:plants11070844. [PMID: 35406824 PMCID: PMC9002540 DOI: 10.3390/plants11070844] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 03/09/2022] [Accepted: 03/17/2022] [Indexed: 05/17/2023]
Abstract
Plant tissue cultures depend entirely upon artificial light sources for illumination. The illumination should provide light in the appropriate regions of the electromagnetic spectrum for photomorphogenic responses and photosynthetic metabolism. Controlling light quality, irradiances and photoperiod enables the production of plants with desired characteristics. Moreover, significant money savings may be achieved using both more appropriate and less consuming energy lamps. In this review, the attention will be focused on the effects of light characteristics and plant growth regulators on shoot proliferation, the main process in in vitro propagation. The effects of the light spectrum on the balance of endogenous growth regulators will also be presented. For each light spectrum, the effects on proliferation but also on plantlet quality, i.e., shoot length, fresh and dry weight and photosynthesis, have been also analyzed. Even if a huge amount of literature is available on the effects of light on in vitro proliferation, the results are often conflicting. In fact, a lot of exogenous and endogenous factors, but also the lack of a common protocol, make it difficult to choose the most effective light spectrum for each of the large number of species. However, some general issues derived from the analysis of the literature are discussed.
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Affiliation(s)
- Valeria Cavallaro
- Institute of BioEconomy (IBE), National Research Council of Italy, 95126 Catania, Italy;
- Correspondence: (V.C.); (R.M.)
| | - Alessandra Pellegrino
- Institute of BioEconomy (IBE), National Research Council of Italy, 95126 Catania, Italy;
| | - Rosario Muleo
- Tree Physiology and Fruit Crop Biotechnology Laboratory, Department of Agriculture and Forest Sciences (DAFNE), University of Tuscia, 01100 Viterbo, Italy;
- Correspondence: (V.C.); (R.M.)
| | - Ivano Forgione
- Tree Physiology and Fruit Crop Biotechnology Laboratory, Department of Agriculture and Forest Sciences (DAFNE), University of Tuscia, 01100 Viterbo, Italy;
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4
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Jung JH, Jeong S, Im S, Kim MK, Seo HS, Lim S. Lack of the Bacterial Phytochrome Protein Decreases Deinococcus radiodurans Resistance to Mitomycin C. Front Microbiol 2021; 12:659233. [PMID: 34394020 PMCID: PMC8363230 DOI: 10.3389/fmicb.2021.659233] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Accepted: 07/12/2021] [Indexed: 11/13/2022] Open
Abstract
Deinococcus radiodurans known for its extraordinary resistance to ionizing radiation contains bacterial phytochrome (BphP), a member of the family of red/far-red light-sensing proteins. In this study, we constructed a bphP mutant strain (ΔbphP) to investigate the role of D. radiodurans BphP (DrBphP) in the DNA damage response. When cells were incubated under light and dark conditions following exposure to DNA damaging agents, such as γ- and UV-radiation and mitomycin C (MMC), no significant difference in cell survival was observed between the wild-type D. radiodurans strain (WT) and ΔbphP. However, when continuously exposed to MMC under light conditions, the WT strain notably exhibited increased survival compared to cells grown in the dark. The increased survival was not observed in the ΔbphP strain. These results are indicative of the protective role of light-activated DrBphP in the presence of MMC. Site-directed mutagenesis revealed that the conserved amino acids Cys-24 and His-532 involved in chromophore binding and signal transduction, respectively, were essential for the protective function of DrBphP. Inactivation of the cognate response regulator (RR; DrBphR) of DrBphP increased MMC resistance in the dark. In trans complementation of the bphP bphR double mutant strain (ΔbphPR) with DrBphR decreased MMC resistance. Considering that DrBphP acts as a light-activated phosphatase that dephosphorylates DrBphR, it appears that phosphorylated DrBphR exerts a negative effect on cell survival in the presence of MMC. DrBphP overexpression resulted in an increase in MMC resistance of ΔbphPR, implying that other RRs might be involved in the DrBphP-mediated signaling pathway. A mutant lacking the dr_0781 gene (Δdr_0781) demonstrated the same MMC phenotype as ΔbphR. Survival was further increased in the bphR dr_0781 double mutant strain compared to each single mutant ΔbphR or Δdr_0781, suggesting that DR_0781 is also involved in the DrBphP-dependent MMC sensitivity. This study uncovered a previously unknown phenomenon of red/far-red light-dependent DNA damage survival mediated by BphP by identifying the conditions under which DrBphP exhibits a fitness advantage.
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Affiliation(s)
- Jong-Hyun Jung
- Radiation Research Division, Korea Atomic Energy Research Institute, Jeongeup, South Korea.,Department of Radiation Science and Technology, University of Science and Technology, Daejeon, South Korea
| | - Soyoung Jeong
- Radiation Research Division, Korea Atomic Energy Research Institute, Jeongeup, South Korea.,Department of Food and Animal Biotechnology, Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul, South Korea
| | - Seonghun Im
- Radiation Research Division, Korea Atomic Energy Research Institute, Jeongeup, South Korea
| | - Min-Kyu Kim
- Radiation Research Division, Korea Atomic Energy Research Institute, Jeongeup, South Korea
| | - Ho Seong Seo
- Radiation Research Division, Korea Atomic Energy Research Institute, Jeongeup, South Korea.,Department of Radiation Science and Technology, University of Science and Technology, Daejeon, South Korea
| | - Sangyong Lim
- Radiation Research Division, Korea Atomic Energy Research Institute, Jeongeup, South Korea.,Department of Radiation Science and Technology, University of Science and Technology, Daejeon, South Korea
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5
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Streng C, Hartmann J, Leister K, Krauß N, Lamparter T, Frankenberg-Dinkel N, Weth F, Bastmeyer M, Yu Z, Fischer R. Fungal phytochrome chromophore biosynthesis at mitochondria. EMBO J 2021; 40:e108083. [PMID: 34254350 PMCID: PMC8447599 DOI: 10.15252/embj.2021108083] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Revised: 06/18/2021] [Accepted: 06/21/2021] [Indexed: 12/16/2022] Open
Abstract
Mitochondria are essential organelles because of their function in energy conservation. Here, we show an involvement of mitochondria in phytochrome‐dependent light sensing in fungi. Phytochrome photoreceptors are found in plants, bacteria, and fungi and contain a linear, heme‐derived tetrapyrrole as chromophore. Linearization of heme requires heme oxygenases (HOs) which reside inside chloroplasts in planta. Despite the poor degree of conservation of HOs, we identified two candidates in the fungus Alternaria alternata. Deletion of either one phenocopied phytochrome deletion. The two enzymes had a cooperative effect and physically interacted with phytochrome, suggesting metabolon formation. The metabolon was attached to the surface of mitochondria with a C‐terminal anchor (CTA) sequence in HoxA. The CTA was necessary and sufficient for mitochondrial targeting. The affinity of phytochrome apoprotein to HoxA was 57,000‐fold higher than the affinity of the holoprotein, suggesting a “kiss‐and‐go” mechanism for chromophore loading and a function of mitochondria as assembly platforms for functional phytochrome. Hence, two alternative approaches for chromophore biosynthesis and insertion into phytochrome evolved in plants and fungi.
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Affiliation(s)
- Christian Streng
- Department of Microbiology, Karlsruhe Institute of Technology (KIT) - South Campus, Institute for Applied Biosciences, Karlsruhe, Germany
| | - Jana Hartmann
- Department of Microbiology, University of Kaiserslautern, Kaiserslautern, Germany
| | - Kai Leister
- Department of Microbiology, Karlsruhe Institute of Technology (KIT) - South Campus, Institute for Applied Biosciences, Karlsruhe, Germany
| | - Norbert Krauß
- Karlsruhe Institute of Technology (KIT) - South Campus, Botanical Institute, Karlsruhe, Germany
| | - Tilman Lamparter
- Karlsruhe Institute of Technology (KIT) - South Campus, Botanical Institute, Karlsruhe, Germany
| | | | - Franco Weth
- Karlsruhe Institute of Technology (KIT) - South Campus, Zoological Institute, Karlsruhe, Germany
| | - Martin Bastmeyer
- Karlsruhe Institute of Technology (KIT) - South Campus, Zoological Institute, Karlsruhe, Germany
| | - Zhenzhong Yu
- The Key Laboratory of Plant Immunity, Jiangsu Provincial Key Lab of Organic Solid Waste Utilization, Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, National Engineering Research Center for Organic-based Fertilizers, Nanjing Agricultural University, Nanjing, China
| | - Reinhard Fischer
- Department of Microbiology, Karlsruhe Institute of Technology (KIT) - South Campus, Institute for Applied Biosciences, Karlsruhe, Germany
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6
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Takala H, Edlund P, Ihalainen JA, Westenhoff S. Tips and turns of bacteriophytochrome photoactivation. Photochem Photobiol Sci 2021; 19:1488-1510. [PMID: 33107538 DOI: 10.1039/d0pp00117a] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Phytochromes are ubiquitous photosensor proteins, which control the growth, reproduction and movement in plants, fungi and bacteria. Phytochromes switch between two photophysical states depending on the light conditions. In analogy to molecular machines, light absorption induces a series of structural changes that are transduced from the bilin chromophore, through the protein, and to the output domains. Recent progress towards understanding this structural mechanism of signal transduction has been manifold. We describe this progress with a focus on bacteriophytochromes. We describe the mechanism along three structural tiers, which are the chromophore-binding pocket, the photosensory module, and the output domains. We discuss possible interconnections between the tiers and conclude by presenting future directions and open questions. We hope that this review may serve as a compendium to guide future structural and spectroscopic studies designed to understand structural signaling in phytochromes.
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Affiliation(s)
- Heikki Takala
- Department of Biological and Environmental Science, Nanoscience Center, University of Jyvaskyla, Box 35, 40014 Jyvaskyla, Finland. and Department of Anatomy, Faculty of Medicine, University of Helsinki, Box 63, 00014 Helsinki, Finland
| | - Petra Edlund
- Department of Chemistry and Molecular Biology, University of Gothenburg, Box 462, 40530 Gothenburg, Sweden.
| | - Janne A Ihalainen
- Department of Biological and Environmental Science, Nanoscience Center, University of Jyvaskyla, Box 35, 40014 Jyvaskyla, Finland.
| | - Sebastian Westenhoff
- Department of Chemistry and Molecular Biology, University of Gothenburg, Box 462, 40530 Gothenburg, Sweden.
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7
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Ultrafast proton release reaction and primary photochemistry of phycocyanobilin in solution observed with fs-time-resolved mid-IR and UV/Vis spectroscopy. Photochem Photobiol Sci 2021; 20:715-732. [PMID: 34002345 DOI: 10.1007/s43630-021-00045-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Accepted: 04/16/2021] [Indexed: 12/27/2022]
Abstract
Deactivation processes of photoexcited (λex = 580 nm) phycocyanobilin (PCB) in methanol were investigated by means of UV/Vis and mid-IR femtosecond (fs) transient absorption (TA) as well as static fluorescence spectroscopy, supported by density-functional-theory calculations of three relevant ground state conformers, PCBA, PCBB and PCBC, their relative electronic state energies and normal mode vibrational analysis. UV/Vis fs-TA reveals time constants of 2.0, 18 and 67 ps, describing decay of PCBB*, of PCBA* and thermal re-equilibration of PCBA, PCBB and PCBC, respectively, in line with the model by Dietzek et al. (Chem Phys Lett 515:163, 2011) and predecessors. Significant substantiation and extension of this model is achieved first via mid-IR fs-TA, i.e. identification of molecular structures and their dynamics, with time constants of 2.6, 21 and 40 ps, respectively. Second, transient IR continuum absorption (CA) is observed in the region above 1755 cm-1 (CA1) and between 1550 and 1450 cm-1 (CA2), indicative for the IR absorption of highly polarizable protons in hydrogen bonding networks (X-H…Y). This allows to characterize chromophore protonation/deprotonation processes, associated with the electronic and structural dynamics, on a molecular level. The PCB photocycle is suggested to be closed via a long living (> 1 ns), PCBC-like (i.e. deprotonated), fluorescent species.
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8
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Upadhyaya HP. Computational Characterization of “Dark” Intermediates in the Ultrafast Deactivation of Photoexcited Bilirubin. J Phys Chem A 2018; 122:9084-9092. [DOI: 10.1021/acs.jpca.8b09392] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Hari P. Upadhyaya
- Radiation & Photochemistry Division, Bhabha Atomic Research Centre, HBNI, Trombay, Mumbai-400 085, India
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9
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Viczián A, Klose C, Ádám É, Nagy F. New insights of red light-induced development. PLANT, CELL & ENVIRONMENT 2017; 40:2457-2468. [PMID: 27943362 DOI: 10.1111/pce.12880] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Revised: 12/04/2016] [Accepted: 12/05/2016] [Indexed: 05/14/2023]
Abstract
The red/far-red light absorbing photoreceptors phytochromes regulate development and growth and thus play an essential role in optimizing adaptation of the sessile plants to the ever-changing environment. Our understanding of how absorption of a red/far-red photon by phytochromes initiates/modifies diverse physiological responses has been steadily improving. Research performed in the last 5 years has been especially productive and led to significant conceptual changes about the mode of action of these photoreceptors. In this review, we focus on the phytochrome B photoreceptor, the major phytochrome species active in light-grown plants. We discuss how its light-independent inactivation (termed dark/thermal reversion), post-translational modification, including ubiquitination, phosphorylation and sumoylation, as well as heterodimerization with other phytochrome species modify red light-controlled physiological responses. Finally, we discuss how photobiological properties of phytochrome B enable this photoreceptor to function also as a thermosensor.
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Affiliation(s)
- András Viczián
- Institute of Plant Biology, Biological Research Centre, Hungarian Academy of Sciences, Temesvári krt. 62, H-6726, Szeged, Hungary
| | - Cornelia Klose
- Institute of Biology2/Botany, University of Freiburg, Schänzlestrasse 1, D-79104, Freiburg, Germany
| | - Éva Ádám
- Institute of Plant Biology, Biological Research Centre, Hungarian Academy of Sciences, Temesvári krt. 62, H-6726, Szeged, Hungary
| | - Ferenc Nagy
- Institute of Plant Biology, Biological Research Centre, Hungarian Academy of Sciences, Temesvári krt. 62, H-6726, Szeged, Hungary
- Institute of Molecular Plant Science, School of Biological Sciences, University of Edinburgh, Edinburgh, EH9 3JH, UK
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10
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Biological activity and dimerization state of modified phytochrome A proteins. PLoS One 2017; 12:e0186468. [PMID: 29049346 PMCID: PMC5648194 DOI: 10.1371/journal.pone.0186468] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Accepted: 10/02/2017] [Indexed: 11/29/2022] Open
Abstract
To assess potential physical interactions of type I phyA with the type II phyB-phyE phytochromes in vivo, transgenes expressing fusion gene forms of phyA were introduced into the Arabidopsis phyA mutant background. When a single c-Myc (myc) epitope is added to either the N- or C-terminus of phyA, the constructs completely complement phyA mutant phenotypes. However, addition of larger tags, such as six consecutive myc epitopes or the yellow fluorescent protein sequence, result in fusion proteins that show reduced activity. All the tagged phyA proteins migrate as dimers on native gels and co-immunoprecipitation reveals no binding interaction of phyA to any of the type II phys in the dark or under continuous far-red light. Dimers of the phyA 1–615 amino acid N-terminal photosensory domain (NphyA), generated in vivo with a yeast GAL4 dimerization domain and attached to a constitutive nuclear localization sequence, are expressed at a low level and, although they cause a cop phenotype in darkness and mediate a very low fluence response to pulses of FR, have no activity under continuous FR. It is concluded that type I phyA in its Pr form is present in plants predominantly or exclusively as a homodimer and does not stably interact with type II phys in a dimer-to-dimer manner. In addition, its activity in mediating response to continuous FR is sensitive to modification of its N- or C-terminus.
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11
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Kim JY, Song JT, Seo HS. COP1 regulates plant growth and development in response to light at the post-translational level. JOURNAL OF EXPERIMENTAL BOTANY 2017; 68:4737-4748. [PMID: 28992300 DOI: 10.1093/jxb/erx312] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Photoreceptors perceive different wavelengths of light and transduce light signals downstream via a range of proteins. COP1, an E3 ubiquitin ligase, regulates light signaling by mediating the ubiquitination and subsequent proteasomal degradation of photoreceptors such as phytochromes and cryptochromes, as well as various development-related proteins including other light-responsive proteins. COP1 is itself regulated by direct interactions with several signaling molecules that modulate its activity. The control of photomorphogenesis by COP1 is also regulated by its localization to the cytoplasm in response to light. COP1 thus acts as a tightly regulated switch that determines whether development is skotomorphogenic or photomorphogenic. In this review, we discuss the effects of COP1 on the abundance and activity of various development-related proteins, including photoreceptors, and summarize the regulatory mechanisms that influence COP1 activity and stability in plants.
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Affiliation(s)
- Joo Yong Kim
- Department of Plant Science and Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul 151-921, Korea
| | - Jong Tae Song
- School of Applied Biosciences, Kyungpook National University, Daegu 702-701, Korea
| | - Hak Soo Seo
- Department of Plant Science and Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul 151-921, Korea
- Plant Genomics and Breeding Institute, Seoul National University, Seoul 151-921, Korea
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12
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Mapping light-driven conformational changes within the photosensory module of plant phytochrome B. Sci Rep 2016; 6:34366. [PMID: 27694986 PMCID: PMC5046071 DOI: 10.1038/srep34366] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Accepted: 09/09/2016] [Indexed: 12/04/2022] Open
Abstract
Organisms developed different photoreceptors to be able to adapt to changing environmental light conditions. Phytochromes are red/far-red (r/fr) photochromic photoreceptors that belong to the classical photoreceptors along with cryptochromes and phototropins. They convert absorbed light into a biological signal by switching between two states in a light-dependent manner therefore enabling the light control downstream signalling. Their Pfr conformation is the biological active form in plants, but until now only a structure of the ground state (Pr) was solved. Here, the authors provide information about structural changes occurring during photoconversion within phytochrome B and identify possible interaction sites for its N-terminal extension (NTE) utilising hydrogen/deuterium exchange rate analyses of its amide backbone. Especially, the newly identified light-dependency of two regions in the NTE are of particular interest for understanding the involvement of the phytochrome’s NTE in the regulation of its downstream signalling.
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13
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Exploiting the cyanobacterial light-harvesting machinery for developing fluorescent probes. Nat Methods 2016; 13:729-30. [DOI: 10.1038/nmeth.3983] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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14
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Pacín M, Semmoloni M, Legris M, Finlayson SA, Casal JJ. Convergence of CONSTITUTIVE PHOTOMORPHOGENESIS 1 and PHYTOCHROME INTERACTING FACTOR signalling during shade avoidance. THE NEW PHYTOLOGIST 2016; 211:967-79. [PMID: 27105120 DOI: 10.1111/nph.13965] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2016] [Accepted: 03/04/2016] [Indexed: 05/22/2023]
Abstract
Shade-avoidance responses require CONSTITUTIVE PHOTOMORPHOGENESIS 1 (COP1) but the mechanisms of action of COP1 under shade have not been elucidated. Using simulated shade and control conditions, we analysed: the transcriptome and the auxin levels of cop1 and phytochrome interacting factor 1 (pif1) pif3 pif4 pif5 (pifq) mutants; the dynamics of ELONGATED HYPOCOTYL 5 (HY5) and LONG HYPOCOTYL IN FAR-RED (HFR1) proteins; and the epistatic relationships between cop1 and pif3, pif4, pif5, hy5 and hfr1 mutations in Arabidopsis thaliana. Despite severely impaired shade-avoidance responses, only a few genes that responded to shade in the wild-type failed to do so in cop1. Shade enhanced the convergence between cop1 and pifq transcriptomes, mainly on shade-avoidance marker genes. Shade failed to increase auxin levels in cop1. Residual shade avoidance in cop1 was not further reduced by the pif3, pif4 or pif5 mutations, suggesting convergent pathways. HFR1 stability decreased under shade in a COP1-dependent manner but shade increased HY5 stability. The cop1 mutant retains responses to shade and is more specifically impaired in shade avoidance. COP1 promotes the degradation of HFR1 under shade, thus increasing the ability of PIFs to control gene expression, increase auxin levels and promote stem growth.
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Affiliation(s)
- Manuel Pacín
- IFEVA, Facultad de Agronomía, Universidad de Buenos Aires and CONICET, Av. San Martın 4453, 1417, Buenos Aires, Argentina
| | - Mariana Semmoloni
- IFEVA, Facultad de Agronomía, Universidad de Buenos Aires and CONICET, Av. San Martın 4453, 1417, Buenos Aires, Argentina
| | - Martina Legris
- Fundación Instituto Leloir, Instituto de Investigaciones Bioquímicas de Buenos Aires-CONICET, 1405, Buenos Aires, Argentina
| | - Scott A Finlayson
- Department of Soil and Crop Sciences, Texas A & M University, College Station, TX, 77843, USA
- Faculty of Molecular and Environmental Plant Sciences, Texas A&M University, College Station, TX, 77843, USA
| | - Jorge J Casal
- IFEVA, Facultad de Agronomía, Universidad de Buenos Aires and CONICET, Av. San Martın 4453, 1417, Buenos Aires, Argentina
- Fundación Instituto Leloir, Instituto de Investigaciones Bioquímicas de Buenos Aires-CONICET, 1405, Buenos Aires, Argentina
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15
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Björling A, Berntsson O, Lehtivuori H, Takala H, Hughes AJ, Panman M, Hoernke M, Niebling S, Henry L, Henning R, Kosheleva I, Chukharev V, Tkachenko NV, Menzel A, Newby G, Khakhulin D, Wulff M, Ihalainen JA, Westenhoff S. Structural photoactivation of a full-length bacterial phytochrome. SCIENCE ADVANCES 2016; 2:e1600920. [PMID: 27536728 PMCID: PMC4982709 DOI: 10.1126/sciadv.1600920] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Accepted: 07/13/2016] [Indexed: 05/11/2023]
Abstract
Phytochromes are light sensor proteins found in plants, bacteria, and fungi. They function by converting a photon absorption event into a conformational signal that propagates from the chromophore through the entire protein. However, the structure of the photoactivated state and the conformational changes that lead to it are not known. We report time-resolved x-ray scattering of the full-length phytochrome from Deinococcus radiodurans on micro- and millisecond time scales. We identify a twist of the histidine kinase output domains with respect to the chromophore-binding domains as the dominant change between the photoactivated and resting states. The time-resolved data further show that the structural changes up to the microsecond time scales are small and localized in the chromophore-binding domains. The global structural change occurs within a few milliseconds, coinciding with the formation of the spectroscopic meta-Rc state. Our findings establish key elements of the signaling mechanism of full-length bacterial phytochromes.
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Affiliation(s)
| | | | | | - Heikki Takala
- University of Gothenburg, 40530 Gothenburg, Sweden
- University of Jyväskylä, 40014 Jyväskylä, Finland
| | | | | | | | | | | | | | | | | | | | - Andreas Menzel
- Paul Scherrer Institut, Villigen, 5232 Villigen PSI, Switzerland
| | - Gemma Newby
- European Synchrotron Radiation Facility, 38000 Grenoble, France
| | | | - Michael Wulff
- European Synchrotron Radiation Facility, 38000 Grenoble, France
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16
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Nagano S, Scheerer P, Zubow K, Michael N, Inomata K, Lamparter T, Krauß N. The Crystal Structures of the N-terminal Photosensory Core Module of Agrobacterium Phytochrome Agp1 as Parallel and Anti-parallel Dimers. J Biol Chem 2016; 291:20674-91. [PMID: 27466363 DOI: 10.1074/jbc.m116.739136] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Indexed: 11/06/2022] Open
Abstract
Agp1 is a canonical biliverdin-binding bacteriophytochrome from the soil bacterium Agrobacterium fabrum that acts as a light-regulated histidine kinase. Crystal structures of the photosensory core modules (PCMs) of homologous phytochromes have provided a consistent picture of the structural changes that these proteins undergo during photoconversion between the parent red light-absorbing state (Pr) and the far-red light-absorbing state (Pfr). These changes include secondary structure rearrangements in the so-called tongue of the phytochrome-specific (PHY) domain and structural rearrangements within the long α-helix that connects the cGMP-specific phosphodiesterase, adenylyl cyclase, and FhlA (GAF) and the PHY domains. We present the crystal structures of the PCM of Agp1 at 2.70 Å resolution and of a surface-engineered mutant of this PCM at 1.85 Å resolution in the dark-adapted Pr states. Whereas in the mutant structure the dimer subunits are in anti-parallel orientation, the wild-type structure contains parallel subunits. The relative orientations between the PAS-GAF bidomain and the PHY domain are different in the two structures, due to movement involving two hinge regions in the GAF-PHY connecting α-helix and the tongue, indicating pronounced structural flexibility that may give rise to a dynamic Pr state. The resolution of the mutant structure enabled us to detect a sterically strained conformation of the chromophore at ring A that we attribute to the tight interaction with Pro-461 of the conserved PRXSF motif in the tongue. Based on this observation and on data from mutants where residues in the tongue region were replaced by alanine, we discuss the crucial roles of those residues in Pr-to-Pfr photoconversion.
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Affiliation(s)
- Soshichiro Nagano
- From the School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, United Kingdom
| | - Patrick Scheerer
- the Institute of Medical Physics and Biophysics (CC2), Group Protein X-ray Crystallography and Signal Transduction, Charité-Universitätsmedizin Berlin, Charitéplatz 1, D-10117 Berlin, Germany
| | - Kristina Zubow
- From the School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, United Kingdom
| | - Norbert Michael
- the Institut für Chemie, Technische Universität Berlin, Sekretariat PC 14, Straße des 17. Juni 135, D-10623 Berlin, Germany
| | - Katsuhiko Inomata
- the Division of Material Sciences, Graduate School of Natural Science and Technology, Kanazawa University, Kakuma, Kanazawa, Ishikawa, 920-1192, Japan, and
| | - Tilman Lamparter
- the Botanical Institute, Karlsruhe Institute of Technology (KIT), Kaiserstraße 2, D-76131 Karlsruhe, Germany
| | - Norbert Krauß
- From the School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, United Kingdom, the Botanical Institute, Karlsruhe Institute of Technology (KIT), Kaiserstraße 2, D-76131 Karlsruhe, Germany
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17
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Otero LH, Klinke S, Rinaldi J, Velázquez-Escobar F, Mroginski MA, Fernández López M, Malamud F, Vojnov AA, Hildebrandt P, Goldbaum FA, Bonomi HR. Structure of the Full-Length Bacteriophytochrome from the Plant Pathogen Xanthomonas campestris Provides Clues to its Long-Range Signaling Mechanism. J Mol Biol 2016; 428:3702-20. [PMID: 27107635 DOI: 10.1016/j.jmb.2016.04.012] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Revised: 04/06/2016] [Accepted: 04/08/2016] [Indexed: 11/25/2022]
Abstract
Phytochromes constitute a major superfamily of light-sensing proteins that are reversibly photoconverted between a red-absorbing (Pr) and a far-red-absorbing (Pfr) state. Bacteriophytochromes (BphPs) are found among photosynthetic and non-photosynthetic bacteria, including pathogens. To date, several BphPs have been biophysically characterized. However, it is still not fully understood how structural changes are propagated from the photosensory module to the output module during the signal transduction event. Most phytochromes share a common architecture consisting of an N-terminal photosensor that includes the PAS2-GAF-PHY domain triad and a C-terminal variable output module. Here we present the crystal structure of the full-length BphP from the plant pathogen Xanthomonas campestris pv. campestris (XccBphP) bearing its photosensor and its complete output module, a PAS9 domain. In the crystals, the protein was found to be in the Pr state, whereas diffraction data together with resonance Raman spectroscopic and theoretical results indicate a ZZZssa and a ZZEssa chromophore configuration corresponding to a mixture of Pr and Meta-R state, the precursor of Pfr. The XccBphP quaternary assembly reveals a head-to-head dimer in which the output module contributes to the helical dimer interface. The photosensor, which is shown to be a bathy-like BphP, is influenced in its dark reactions by the output module. Our structural analyses suggest that the photoconversion between the Pr and Pfr states in the full-length XccBphP may involve changes in the relative positioning of the output module. This work contributes to understand the light-induced structural changes propagated from the photosensor to the output modules in phytochrome signaling.
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Affiliation(s)
- Lisandro Horacio Otero
- Fundación Instituto Leloir-IIBBA-CONICET, Av. Patricias Argentinas 435 (C1405BWE), Buenos Aires, Argentina; Plataforma Argentina de Biología Estructural y Metabolómica PLABEM, Av. Patricias Argentinas 435 (C1405BWE), Buenos Aires, Argentina
| | - Sebastián Klinke
- Fundación Instituto Leloir-IIBBA-CONICET, Av. Patricias Argentinas 435 (C1405BWE), Buenos Aires, Argentina; Plataforma Argentina de Biología Estructural y Metabolómica PLABEM, Av. Patricias Argentinas 435 (C1405BWE), Buenos Aires, Argentina
| | - Jimena Rinaldi
- Fundación Instituto Leloir-IIBBA-CONICET, Av. Patricias Argentinas 435 (C1405BWE), Buenos Aires, Argentina
| | - Francisco Velázquez-Escobar
- Institut für Chemie, Technische Universität Berlin, Sekr. PC 14, Straße des 17. Juni 135 (10623), Berlin, Germany
| | - María Andrea Mroginski
- Institut für Chemie, Technische Universität Berlin, Sekr. PC 14, Straße des 17. Juni 135 (10623), Berlin, Germany
| | - María Fernández López
- Institut für Chemie, Technische Universität Berlin, Sekr. PC 14, Straße des 17. Juni 135 (10623), Berlin, Germany
| | - Florencia Malamud
- UNSAM Campus Miguelete IIB-Instituto de Investigaciones Biotecnológicas, Av. 25 de Mayo y Francia (B1650KNA), Buenos Aires, Argentina
| | - Adrián Alberto Vojnov
- Instituto de Ciencia y Tecnología Dr. Cesar Milstein, Fundación Pablo Cassará, CONICET, Saladillo 2468 (C1440FFX), Buenos Aires, Argentina
| | - Peter Hildebrandt
- Institut für Chemie, Technische Universität Berlin, Sekr. PC 14, Straße des 17. Juni 135 (10623), Berlin, Germany
| | - Fernando Alberto Goldbaum
- Fundación Instituto Leloir-IIBBA-CONICET, Av. Patricias Argentinas 435 (C1405BWE), Buenos Aires, Argentina; Plataforma Argentina de Biología Estructural y Metabolómica PLABEM, Av. Patricias Argentinas 435 (C1405BWE), Buenos Aires, Argentina
| | - Hernán Ruy Bonomi
- Fundación Instituto Leloir-IIBBA-CONICET, Av. Patricias Argentinas 435 (C1405BWE), Buenos Aires, Argentina.
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18
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Carreira-Blanco C, Singer P, Diller R, Luis Pérez Lustres J. Ultrafast deactivation of bilirubin: dark intermediates and two-photon isomerization. Phys Chem Chem Phys 2016; 18:7148-55. [DOI: 10.1039/c5cp06971h] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The Franck-Condon state A couples to the dark intermediate B, which shows tight molecular skeleton and distorted hydrogen bonding. B deactivates with nearly 100% efficiency. 2-Photon excitation at 400 nm triggers Z,E isomerization efficiently.
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Affiliation(s)
- Carlos Carreira-Blanco
- Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CIQUS) and Department of Physical Chemistry
- Universidade de Santiago de Compostela
- E-15782 Santiago de Compostela
- Spain
| | - Patrick Singer
- Fachbereich Physik
- Technische Universität Kaiserslautern
- D-67663 Kaiserslautern
- Germany
| | - Rolf Diller
- Fachbereich Physik
- Technische Universität Kaiserslautern
- D-67663 Kaiserslautern
- Germany
| | - J. Luis Pérez Lustres
- Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CIQUS) and Department of Physical Chemistry
- Universidade de Santiago de Compostela
- E-15782 Santiago de Compostela
- Spain
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19
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Ihalainen JA, Takala H, Lehtivuori H. Fast Photochemistry of Prototypical Phytochromes-A Species vs. Subunit Specific Comparison. Front Mol Biosci 2015; 2:75. [PMID: 26779488 PMCID: PMC4689126 DOI: 10.3389/fmolb.2015.00075] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2015] [Accepted: 12/07/2015] [Indexed: 11/13/2022] Open
Abstract
Phytochromes are multi-domain red light photosensor proteins, which convert red light photons to biological activity utilizing the multitude of structural and chemical reactions. The steady increase in structural information obtained from various bacteriophytochromes has increased understanding about the functional mechanism of the photochemical processes of the phytochromes. Furthermore, a number of spectroscopic studies have revealed kinetic information about the light-induced reactions. The spectroscopic changes are, however, challenging to connect with the structural changes of the chromophore and the protein environment, as the excited state properties of the chromophores are very sensitive to the small structural and chemical changes of their environment. In this article, we concentrate on the results of ultra-fast spectroscopic experiments which reveal information about the important initial steps of the photoreactions of the phytochromes. We survey the excited state properties obtained during the last few decades. The differences in kinetics between different research laboratories are traditionally related to the differences of the studied species. However, we notice that the variation in the excited state properties depends on the subunit composition of the protein as well. This observation illustrates a feedback mechanism from the other domains to the chromophore. We propose that two feedback routes exist in phytochromes between the chromophore and the remotely located effector domain. The well-known connection between the subunits is the so-called tongue region, which changes its secondary structure while changing the light-activated state of the system. The other feedback route which we suggest is less obvious, it is made up of several water molecules ranging from the dimer interface to the vicinity of the chromophore, allowing even proton transfer reactions nearby the chromophore.
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Affiliation(s)
- Janne A Ihalainen
- Department of Biological and Environmental Sciences, Nanoscience Center, University of Jyväskylä Jyväskylä, Finland
| | - Heikki Takala
- Department of Biological and Environmental Sciences, Nanoscience Center, University of JyväskyläJyväskylä, Finland; Department of Anatomy, Institute of Biomedicine, University of HelsinkiHelsinki, Finland
| | - Heli Lehtivuori
- Department of Biological and Environmental Sciences, Nanoscience Center, University of JyväskyläJyväskylä, Finland; Department of Physics, Nanoscience Center, University of JyväskyläJyväskylä, Finland
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20
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Lindner R, Heintz U, Winkler A. Applications of hydrogen deuterium exchange (HDX) for the characterization of conformational dynamics in light-activated photoreceptors. Front Mol Biosci 2015; 2:33. [PMID: 26157802 PMCID: PMC4477167 DOI: 10.3389/fmolb.2015.00033] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Accepted: 05/26/2015] [Indexed: 11/13/2022] Open
Abstract
Rational design of optogenetic tools is inherently linked to the understanding of photoreceptor function. Structural analysis of elements involved in signal integration in individual sensor domains provides an initial idea of their mode of operation, but understanding how local structural rearrangements eventually affect signal transmission to output domains requires inclusion of the effector regions in the characterization. However, the dynamic nature of these assemblies renders their structural analysis challenging and therefore a combination of high- and low-resolution techniques is required to appreciate functional aspects of photoreceptors. This review focuses on the potential of hydrogen-deuterium exchange coupled to mass spectrometry (HDX-MS) for complementing the structural characterization of photoreceptors. In this respect, the ability of HDX-MS to provide information on conformational dynamics and the possibility to address multiple functionally relevant states in solution render this methodology ideally suitable. We highlight recent examples demonstrating the potential of HDX-MS and discuss how these results can help to improve existing optogenetic systems or guide the design of novel optogenetic tools.
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Affiliation(s)
- Robert Lindner
- Department of Biomolecular Mechanisms, Max Planck Institute for Medical Research Heidelberg, Germany
| | - Udo Heintz
- Department of Biomolecular Mechanisms, Max Planck Institute for Medical Research Heidelberg, Germany
| | - Andreas Winkler
- Institute of Biochemistry, Graz University of Technology Graz, Austria
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21
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Klinke S, Otero LH, Rinaldi J, Sosa S, Guimarães BG, Shepard WE, Goldbaum FA, Bonomi HR. Crystallization and preliminary X-ray characterization of the full-length bacteriophytochrome from the plant pathogen Xanthomonas campestris pv. campestris. Acta Crystallogr F Struct Biol Commun 2014; 70:1636-9. [PMID: 25484215 PMCID: PMC4259229 DOI: 10.1107/s2053230x14023243] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Accepted: 10/21/2014] [Indexed: 11/11/2022] Open
Abstract
Phytochromes give rise to the largest photosensor family known to date. However, they are underrepresented in the Protein Data Bank. Plant, cyanobacterial, fungal and bacterial phytochromes share a canonical architecture consisting of an N-terminal photosensory module (PAS2-GAF-PHY domains) and a C-terminal variable output module. The bacterium Xanthomonas campestris pv. campestris, a worldwide agricultural pathogen, codes for a single bacteriophytochrome (XccBphP) that has this canonical architecture, bearing a C-terminal PAS9 domain as the output module. Full-length XccBphP was cloned, expressed and purified to homogeneity by nickel-NTA affinity and size-exclusion chromatography and was then crystallized at room temperature bound to its cofactor biliverdin. A complete native X-ray diffraction data set was collected to a maximum resolution of 3.25 Å. The crystals belonged to space group P43212, with unit-cell parameters a = b = 103.94, c = 344.57 Å and a dimer in the asymmetric unit. Refinement is underway after solving the structure by molecular replacement.
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Affiliation(s)
- Sebastián Klinke
- Fundación Instituto Leloir, IIBBA–CONICET, Avenida Patricias Argentinas 435, Buenos Aires, C1405BWE Buenos Aires, Argentina
| | - Lisandro H. Otero
- Fundación Instituto Leloir, IIBBA–CONICET, Avenida Patricias Argentinas 435, Buenos Aires, C1405BWE Buenos Aires, Argentina
| | - Jimena Rinaldi
- Fundación Instituto Leloir, IIBBA–CONICET, Avenida Patricias Argentinas 435, Buenos Aires, C1405BWE Buenos Aires, Argentina
| | - Santiago Sosa
- Fundación Instituto Leloir, IIBBA–CONICET, Avenida Patricias Argentinas 435, Buenos Aires, C1405BWE Buenos Aires, Argentina
| | - Beatriz G. Guimarães
- Synchrotron SOLEIL, L’Orme des Merisiers, Saint-Aubin BP 48, 91192 Gif-sur-Yvette CEDEX, France
| | - William E. Shepard
- Synchrotron SOLEIL, L’Orme des Merisiers, Saint-Aubin BP 48, 91192 Gif-sur-Yvette CEDEX, France
| | - Fernando A. Goldbaum
- Fundación Instituto Leloir, IIBBA–CONICET, Avenida Patricias Argentinas 435, Buenos Aires, C1405BWE Buenos Aires, Argentina
| | - Hernán R. Bonomi
- Fundación Instituto Leloir, IIBBA–CONICET, Avenida Patricias Argentinas 435, Buenos Aires, C1405BWE Buenos Aires, Argentina
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22
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Singer P, Fey S, Göller AH, Hermann G, Diller R. Femtosecond Dynamics in the Lactim Tautomer of Phycocyanobilin: A Long-Wavelength Absorbing Model Compound for the Phytochrome Chromophore. Chemphyschem 2014; 15:3824-31. [DOI: 10.1002/cphc.201402383] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2014] [Indexed: 11/11/2022]
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23
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Burgie ES, Wang T, Bussell AN, Walker JM, Li H, Vierstra RD. Crystallographic and electron microscopic analyses of a bacterial phytochrome reveal local and global rearrangements during photoconversion. J Biol Chem 2014; 289:24573-87. [PMID: 25006244 DOI: 10.1074/jbc.m114.571661] [Citation(s) in RCA: 81] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Phytochromes are multidomain photoswitches that drive light perception in plants and microorganisms by coupling photoreversible isomerization of their bilin chromophore to various signaling cascades. How changes in bilin conformation affect output by these photoreceptors remains poorly resolved and might include several species-specific routes. Here, we present detailed three-dimensional models of the photosensing module and a picture of an entire dimeric photoreceptor through structural analysis of the Deinococcus radiodurans phytochrome BphP assembled with biliverdin (BV). A 1.16-Å resolution crystal structure of the bilin-binding pocket in the dark-adapted red light-absorbing state illuminated the intricate network of bilin/protein/water interactions and confirmed the protonation and ZZZssa conformation of BV. Structural and spectroscopic comparisons with the photochemically compromised D207A mutant revealed that substitutions of Asp-207 allow inclusion of cyclic porphyrins in addition to BV. A crystal structure of the entire photosensing module showed a head-to-head, twisted dimeric arrangement with bowed helical spines and a hairpin protrusion connecting the cGMP phosphodiesterase/adenylyl cyclase/FhlA (GAF) and phytochrome-specific (PHY) domains. A key conserved hairpin feature is its anti-parallel, two β-strand stem, which we show by mutagenesis to be critical for BphP photochemistry. Comparisons of single particle electron microscopic images of the full-length BphP dimer in the red light-absorbing state and the photoactivated far-red light-absorbing state revealed a large scale reorientation of the PHY domain relative to the GAF domain, which alters the position of the downstream histidine kinase output module. Together, our data support a toggle model whereby bilin photoisomerization alters GAF/PHY domain interactions through conformational modification of the hairpin, which regulates signaling by impacting the relationship between sister output modules.
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Affiliation(s)
- E Sethe Burgie
- From the Department of Genetics, University of Wisconsin, Madison, Wisconsin 53706
| | - Tong Wang
- the Biology Department, Brookhaven National Laboratory, Upton, New York 11973, and
| | - Adam N Bussell
- From the Department of Genetics, University of Wisconsin, Madison, Wisconsin 53706
| | - Joseph M Walker
- From the Department of Genetics, University of Wisconsin, Madison, Wisconsin 53706
| | - Huilin Li
- the Biology Department, Brookhaven National Laboratory, Upton, New York 11973, and the Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, New York 11794
| | - Richard D Vierstra
- From the Department of Genetics, University of Wisconsin, Madison, Wisconsin 53706,
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24
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Crystal structure of the photosensing module from a red/far-red light-absorbing plant phytochrome. Proc Natl Acad Sci U S A 2014; 111:10179-84. [PMID: 24982198 DOI: 10.1073/pnas.1403096111] [Citation(s) in RCA: 166] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Many aspects of plant photomorphogenesis are controlled by the phytochrome (Phy) family of bilin-containing photoreceptors that detect red and far-red light by photointerconversion between a dark-adapted Pr state and a photoactivated Pfr state. Whereas 3D models of prokaryotic Phys are available, models of their plant counterparts have remained elusive. Here, we present the crystal structure of the photosensing module (PSM) from a seed plant Phy in the Pr state using the PhyB isoform from Arabidopsis thaliana. The PhyB PSM crystallized as a head-to-head dimer with strong structural homology to its bacterial relatives, including a 5(Z)syn, 10(Z)syn, 15(Z)anti configuration of the phytochromobilin chromophore buried within the cGMP phosphodiesterase/adenylyl cyclase/FhlA (GAF) domain, and a well-ordered hairpin protruding from the Phy-specific domain toward the bilin pocket. However, its Per/Arnt/Sim (PAS) domain, knot region, and helical spine show distinct structural differences potentially important to signaling. Included is an elongated helical spine, an extended β-sheet connecting the GAF domain and hairpin stem, and unique interactions between the region upstream of the PAS domain knot and the bilin A and B pyrrole rings. Comparisons of this structure with those from bacterial Phys combined with mutagenic studies support a toggle model for photoconversion that engages multiple features within the PSM to stabilize the Pr and Pfr end states after rotation of the D pyrrole ring. Taken together, this Arabidopsis PhyB structure should enable molecular insights into plant Phy signaling and provide an essential scaffold to redesign their activities for agricultural benefit and as optogenetic reagents.
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25
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Casal JJ, Candia AN, Sellaro R. Light perception and signalling by phytochrome A. JOURNAL OF EXPERIMENTAL BOTANY 2014; 65:2835-45. [PMID: 24220656 DOI: 10.1093/jxb/ert379] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
In etiolated seedlings, phytochrome A (phyA) mediates very-low-fluence responses (VLFRs), which initiate de-etiolation at the interphase between the soil and above-ground environments, and high-irradiance responses (HIR), which complete de-etiolation under dense canopies and require more sustained activation with far-red light. Light-activated phyA is transported to the nucleus by FAR-RED ELONGATED HYPOCOTYL1 (FHY1). The nuclear pool of active phyA increases under prolonged far-red light of relatively high fluence rates. This condition maximizes the rate of FHY1-phyA complex assembly and disassembly, allowing FHY1 to return to the cytoplasm to translocate further phyA to the nucleus, to replace phyA degraded in the proteasome. The core signalling pathways downstream of nuclear phyA involve the negative regulation of CONSTITUTIVE PHOTOMORPHOGENIC 1, which targets for degradation transcription factors required for photomorphogenesis, and PHYTOCHROME-INTERACTING FACTORs, which are transcription factors that repress photomorphogenesis. Under sustained far-red light activation, released FHY1 can also be recruited with active phyA to target gene promoters as a transcriptional activator, and nuclear phyA signalling activates a positive regulatory loop involving BELL-LIKE HOMEODOMAIN 1 that reinforces the HIR.
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Affiliation(s)
- J J Casal
- IFEVA, Facultad de Agronomía, Universidad de Buenos Aires and CONICET, 1417 Buenos Aires, Argentina Fundación Instituto Leloir, Instituto de Investigaciones Bioquímicas de Buenos Aires-CONICET, C1405BWE Buenos Aires, Argentina
| | - A N Candia
- IFEVA, Facultad de Agronomía, Universidad de Buenos Aires and CONICET, 1417 Buenos Aires, Argentina
| | - R Sellaro
- IFEVA, Facultad de Agronomía, Universidad de Buenos Aires and CONICET, 1417 Buenos Aires, Argentina
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26
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Cornilescu CC, Cornilescu G, Burgie ES, Markley JL, Ulijasz AT, Vierstra RD. Dynamic structural changes underpin photoconversion of a blue/green cyanobacteriochrome between its dark and photoactivated states. J Biol Chem 2013; 289:3055-65. [PMID: 24337572 DOI: 10.1074/jbc.m113.531053] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The phytochrome superfamily of photoreceptors exploits reversible light-driven changes in the bilin chromophore to initiate a variety of signaling cascades. The nature of these alterations and how they impact the protein moiety remain poorly resolved and might include several species-specific routes. Here, we provide a detailed picture of photoconversion for the photosensing cGMP phosphodiesterase/adenylyl cyclase/FhlA (GAF) domain from Thermosynechococcus elongatus (Te) PixJ, a member of the cyanobacteriochrome clade. Solution NMR structures of the blue light-absorbing dark state Pb and green light-absorbing photoactivated state Pg, combined with paired crystallographic models, revealed that the bilin and GAF domain dynamically transition via breakage of the C10/Cys-494 thioether bond, opposite rotations of the A and D pyrrole rings, sliding of the bilin in the GAF pocket, and the appearance of an extended region of disorder that includes Cys-494. Changes in GAF domain backbone dynamics were also observed that are likely important for inter-domain signal propagation. Taken together, photoconversion of T. elongatus PixJ from Pb to Pg involves complex structural changes within the GAF domain pocket that transduce light into a mechanical signal, many aspects of which should be relevant to others within the extended phytochrome superfamily.
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Affiliation(s)
- Claudia C Cornilescu
- From the National Magnetic Resonance Facility at Madison, Department of Biochemistry and
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27
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Anders K, Daminelli-Widany G, Mroginski MA, von Stetten D, Essen LO. Structure of the cyanobacterial phytochrome 2 photosensor implies a tryptophan switch for phytochrome signaling. J Biol Chem 2013; 288:35714-25. [PMID: 24174528 DOI: 10.1074/jbc.m113.510461] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Phytochromes are highly versatile photoreceptors, which occur ubiquitously in plants as well as in many light-responsive microorganisms. Here, photosynthetic cyanobacteria utilize up to three different phytochrome architectures, where only the plant-like and the single-domain cyanobacteriochromes are structurally characterized so far. Cph2 represents a third group in Synechocystis species and affects their capability of phototaxis by controlling c-di-GMP synthesis and degradation. The 2.6-Å crystal structure of its red/far-red responsive photosensory module in the Pr state reveals a tandem-GAF bidomain that lacks the figure-of-eight knot of the plant/cph1 subfamily. Its covalently attached phycocyanobilin chromophore adopts a highly tilted ZZZssa conformation with a novel set of interactions between its propionates and the GAF1 domain. The tongue-like protrusion from the GAF2 domain interacts with the GAF1-bound chromophore via its conserved PRXSF, WXE, and W(G/A)G motifs. Mutagenesis showed that the integrity of the tongue is indispensable for Pr → Pfr photoconversion and involves a swap of the motifs' tryptophans within the tongue-GAF1 interface. This "Trp switch" is supposed to be a crucial element for the photochromicity of all multidomain phytochromes.
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Affiliation(s)
- Katrin Anders
- From the Department of Chemistry, Biomedical Research Centre, Philipps-Universität, D-35032 Marburg, Germany
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28
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Control of a four-color sensing photoreceptor by a two-color sensing photoreceptor reveals complex light regulation in cyanobacteria. Proc Natl Acad Sci U S A 2013; 110:12834-9. [PMID: 23858449 DOI: 10.1073/pnas.1303371110] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Photoreceptors are biologically important for sensing changes in the color and intensity of ambient light and, for photosynthetic organisms, processing this light information to optimize food production through photosynthesis. Cyanobacteria are an evolutionarily and ecologically important prokaryotic group of oxygenic photosynthesizers that contain cyanobacteriochrome (CBCR) photoreceptors, whose family members sense nearly the entire visible spectrum of light colors. Some cyanobacteria contain 12 to 15 different CBCRs, and many family members contain multiple light-sensing domains. However, the complex interactions that must be occurring within and between these photoreceptors remain unexplored. Here we describe the regulation and photobiology of a unique CBCR called IflA (influenced by far-red light), demonstrating that a second CBCR called RcaE strongly regulates IflA abundance and that IflA uses two distinct photosensory domains to respond to four different light colors: blue, green, red, and far-red. The absorption of red or far-red light by one domain affects the conformation of the other domain, and the rate of relaxation of one of these domains is influenced by the conformation of the other. Deletion of iflA results in delayed growth at low cell density, suggesting that IflA accelerates growth under this condition, apparently by sensing the ratio of red to far-red light in the environment. The types of complex photobiological interactions described here, both between unrelated CBCR family members and within photosensory domains of a single CBCR, may be advantageous for species using these photoreceptors in aquatic environments, where light color ratios are influenced by many biotic and abiotic factors.
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Piatkevich KD, Subach FV, Verkhusha VV. Engineering of bacterial phytochromes for near-infrared imaging, sensing, and light-control in mammals. Chem Soc Rev 2013; 42:3441-52. [PMID: 23361376 PMCID: PMC3618476 DOI: 10.1039/c3cs35458j] [Citation(s) in RCA: 117] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Near-infrared light is favourable for imaging in mammalian tissues due to low absorbance of hemoglobin, melanin, and water. Therefore, fluorescent proteins, biosensors and optogenetic constructs for optimal imaging, optical readout and light manipulation in mammals should have fluorescence and action spectra within the near-infrared window. Interestingly, natural Bacterial Phytochrome Photoreceptors (BphPs) utilize the low molecular weight biliverdin, found in most mammalian tissues, as a photoreactive chromophore. Due to their near-infrared absorbance BphPs are preferred templates for designing optical molecular tools for applications in mammals. Moreover, BphPs spectrally complement existing genetically-encoded probes. Several BphPs were already developed into the near-infrared fluorescent variants. Based on the analysis of the photochemistry and structure of BphPs we suggest a variety of possible BphP-based fluorescent proteins, biosensors, and optogenetic tools. Putative design strategies and experimental considerations for such probes are discussed.
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Affiliation(s)
- Kiryl D. Piatkevich
- Gruss-Lipper Biophotonics Center and Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA. Fax: +1 (718) 430-8996; Tel: +1 (718) 430-8591
| | - Fedor V. Subach
- Gruss-Lipper Biophotonics Center and Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA. Fax: +1 (718) 430-8996; Tel: +1 (718) 430-8591
| | - Vladislav V. Verkhusha
- Gruss-Lipper Biophotonics Center and Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA. Fax: +1 (718) 430-8996; Tel: +1 (718) 430-8591
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Zhang J, Stankey RJ, Vierstra RD. Structure-guided engineering of plant phytochrome B with altered photochemistry and light signaling. PLANT PHYSIOLOGY 2013; 161:1445-57. [PMID: 23321421 PMCID: PMC3585608 DOI: 10.1104/pp.112.208892] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2012] [Accepted: 01/10/2013] [Indexed: 05/22/2023]
Abstract
Phytochromes (phys) encompass a diverse collection of biliproteins that enable cellular light perception by photoconverting between a red-light-absorbing ground state (Pr) and a far-red light-absorbing active state (Pfr). Based on the central role of plant phys in controlling numerous agriculturally important processes, their rational redesign offers great promise toward accelerating crop improvement. Employing as templates the available three-dimensional models of the photosensory module within bacterial phys, we report here our initial attempt to apply structure-guided mutagenesis to phy engineering using Arabidopsis (Arabidopsis thaliana) phyB, the dominant isoform in light-grown plants, as the example. A collection of phyB mutants was generated affecting the bilin-binding pocket that altered photochemistry, thermal stability, and/or nuclear localization patterns, some of which also impacted phenotypic outputs. Of particular interest are the Y361F substitution, which created Arabidopsis plants with greatly enhanced light sensitivity, mutants variably altered in Pfr-to-Pr thermal reversion and nuclear aggregation, and the D307A substitution, which failed to photoconvert from Pr to Pfr and display light-induced nuclear aggregation but retained some biological activity and accelerated turnover in red light. Taken together, this collection provides variants potentially useful to agriculture as well as new tools to better understand the molecular mechanisms underpinning phy signaling.
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Burgie E, Walker J, Phillips G, Vierstra R. A Photo-Labile Thioether Linkage to Phycoviolobilin Provides the Foundation for the Blue/Green Photocycles in DXCF-Cyanobacteriochromes. Structure 2013; 21:88-97. [DOI: 10.1016/j.str.2012.11.001] [Citation(s) in RCA: 70] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2012] [Revised: 10/31/2012] [Accepted: 11/03/2012] [Indexed: 10/27/2022]
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Abstract
The dynamic light environment of vegetation canopies is perceived by phytochromes, cryptochromes, phototropins, and UV RESISTANCE LOCUS 8 (UVR8). These receptors control avoidance responses to preclude exposure to limiting or excessive light and acclimation responses to cope with conditions that cannot be avoided. The low red/far-red ratios of shade light reduce phytochrome B activity, which allows PHYTOCHROME INTERACTING FACTORS (PIFs) to directly activate the transcription of auxin-synthesis genes, leading to shade-avoidance responses. Direct PIF interaction with DELLA proteins links gibberellin and brassinosteroid signaling to shade avoidance. Shade avoidance also requires CONSTITUTIVE PHOTOMORPHOGENESIS 1 (COP1), a target of cryptochromes, phytochromes, and UVR8. Multiple regulatory loops and the input of the circadian clock create a complex network able to respond even to subtle threats of competition with neighbors while still compensating for major environmental fluctuations such as the day-night cycles.
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Affiliation(s)
- Jorge J Casal
- IFEVA, Facultad de Agronomía, Universidad de Buenos Aires and CONICET, 1417 Buenos Aires, Argentina.
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Mandalari C, Losi A, Gärtner W. Distance-tree analysis, distribution and co-presence of bilin- and flavin-binding prokaryotic photoreceptors for visible light. Photochem Photobiol Sci 2013; 12:1144-57. [DOI: 10.1039/c3pp25404f] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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Depauw FA, Rogato A, Ribera d'Alcalá M, Falciatore A. Exploring the molecular basis of responses to light in marine diatoms. JOURNAL OF EXPERIMENTAL BOTANY 2012; 63:1575-91. [PMID: 22328904 DOI: 10.1093/jxb/ers005] [Citation(s) in RCA: 118] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Light is an essential source of energy for life on Earth and is one of the most important signals that organisms use to obtain information from the surrounding environment, on land and in the oceans. Prominent marine microalgae, such as diatoms, display a suite of sophisticated responses (physiological, biochemical, and behavioural) to optimize their photosynthesis and growth under changing light conditions. However, the molecular mechanisms controlling diatom responses to light are still largely unknown. Recent progress in marine diatom genomics and genetics, combined with well-established (eco) physiological and biophysical approaches, now offers novel opportunities to address these issues. This review provides a description of the molecular components identified in diatom genomes that are involved in light perception and acclimation mechanisms. How the initial functional characterizations of specific light regulators provide the basis to investigate the conservation or diversification of light-mediated processes in diatoms is also discussed. Hypotheses on the role of the identified factors in determining the growth, distribution, and adaptation of diatoms in different marine environments are reported.
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Affiliation(s)
- Frauke Angelique Depauw
- Université Pierre et Marie Curie, Paris 06, Centre National de la Recherche Scientifique, UMR7238, Laboratoire de Génomique des Microorganismes, 75006 Paris, France
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Allen JF, de Paula WBM, Puthiyaveetil S, Nield J. A structural phylogenetic map for chloroplast photosynthesis. TRENDS IN PLANT SCIENCE 2011; 16:645-55. [PMID: 22093371 DOI: 10.1016/j.tplants.2011.10.004] [Citation(s) in RCA: 152] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2011] [Revised: 10/08/2011] [Accepted: 10/10/2011] [Indexed: 05/08/2023]
Abstract
Chloroplasts are cytoplasmic organelles and the sites of photosynthesis in eukaryotic cells. Advances in structural biology and comparative genomics allow us to identify individual components of the photosynthetic apparatus precisely with respect to the subcellular location of their genes. Here we present outline maps of four energy-transducing thylakoid membranes. The maps for land plants and red and green algae distinguish protein subunits encoded in the nucleus from those encoded in the chloroplast. We find no defining structural feature that is common to all chloroplast gene products. Instead, conserved patterns of gene location are consistent with photosynthetic redox chemistry exerting gene regulatory control over its own rate-limiting steps. Chloroplast DNA carries genes whose expression is placed under this control.
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Affiliation(s)
- John F Allen
- School of Biological and Chemical Sciences, Queen Mary, University of London, Mile End Road, London E1 4NS, UK.
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Oka Y, Kong SG, Matsushita T. A non-covalently attached chromophore can mediate phytochrome B signaling in Arabidopsis. PLANT & CELL PHYSIOLOGY 2011; 52:2088-102. [PMID: 22006939 DOI: 10.1093/pcp/pcr139] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Phytochrome B (phyB) is the major informational photoreceptor in light-grown plants. The phyB polypeptide is folded into two domains, the N-terminal domain and the C-terminal domain. The N-terminal domain covalently binds to the chromophore via a particular cysteine residue, which allows the holoprotein to absorb light and undergo a photoreversible conformational change. The N-terminal domain of phyB interacts with transcription factors, such as PIF3 (PHYTOCHROME-INTERACTING FACTOR 3), to transduce the light signal to downstream components. Since substitution of the chromophore attachment site, Cys357, with alanine (C357A) abolishes the biological activity of Arabidopsis phyB, the covalent attachment with the chromophore is widely assumed to be necessary for phyB signal transduction. In this study, we show that Arabidopsis phyB is capable of transducing signals with a non-covalently retained chromophore. Substituting the Tyr276 residue of phyB with histidine (Y276H) is known to confer constitutive phyB signaling. PhyB containing both Y276H and C357A substitutions exhibited light-independent biological activity in transgenic Arabidopsis plants in a chromophore-dependent manner. Spectrophotometric analysis showed that the N-terminal domain of phyB containing just the C357A substitution could retain the chromophore non-covalently. The N-terminal domain containing both the Y276H and C357A substitutions interacted with PIF3 in a light-independent but chromophore-dependent fashion in yeast two-hybrid assays. From these results, we conclude that the constitutive phyB signaling conferred by Y276H requires the chromophore, but that the chromophore does not need to be covalently bonded to phyB.
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Affiliation(s)
- Yoshito Oka
- RIKEN Plant Science Center, Yokohama, 230-0045 Japan
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