1
|
Turunen O, Saleem T, Kurkela J, Kallio P, Tyystjärvi T. Engineering RNA polymerase to construct biotechnological host strains of cyanobacteria. PHYSIOLOGIA PLANTARUM 2024; 176:e14263. [PMID: 38528669 DOI: 10.1111/ppl.14263] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Revised: 03/06/2024] [Accepted: 03/08/2024] [Indexed: 03/27/2024]
Abstract
Application of cyanobacteria for bioproduction, bioremediation and biotransformation is being increasingly explored. Photoautotrophs are carbon-negative by default, offering a direct pathway to reducing emissions in production systems. More robust and versatile host strains are needed for constructing production strains that would function as efficient and carbon-neutral cyanofactories. We have tested if the engineering of sigma factors, regulatory units of the bacterial RNA polymerase, could be used to generate better host strains of the model cyanobacterium Synechocystis sp. PCC 6803. Overexpressing the stress-responsive sigB gene under the strong psbA2 promoter (SigB-oe) led to improved tolerance against heat, oxidative stress and toxic end-products. By targeting transcription initiation in the SigB-oe strain, we could simultaneously activate a wide spectrum of cellular protective mechanisms, including carotenoids, the HspA heat shock protein, and highly activated non-photochemical quenching. Yellow fluorescent protein was used to test the capacity of the SigB-oe strain to produce heterologous proteins. In standard conditions, the SigB-oe strain reached a similar production as the control strain, but when cultures were challenged with oxidative stress, the production capacity of SigB-oe surpassed the control strain. We also tested the production of growth-rate-controlled host strains via manipulation of RNA polymerase, but post-transcriptional regulation prevented excessive overexpression of the primary sigma factor SigA, and overproduction of the growth-restricting SigC factor was lethal. Thus, more research is needed before cyanobacteria growth can be manipulated by engineering RNA polymerase.
Collapse
Affiliation(s)
- Otso Turunen
- Department of Life Technologies/Molecular Plant Biology, University of Turku, Turku, Finland
| | - Tayyab Saleem
- Department of Life Technologies/Molecular Plant Biology, University of Turku, Turku, Finland
| | - Juha Kurkela
- Department of Life Technologies/Molecular Plant Biology, University of Turku, Turku, Finland
| | - Pauli Kallio
- Department of Life Technologies/Molecular Plant Biology, University of Turku, Turku, Finland
| | - Taina Tyystjärvi
- Department of Life Technologies/Molecular Plant Biology, University of Turku, Turku, Finland
| |
Collapse
|
2
|
Cano-Ramirez DL, Panter PE, Takemura T, de Fraine TS, de Barros Dantas LL, Dekeya R, Barros-Galvão T, Paajanen P, Bellandi A, Batstone T, Manley BF, Tanaka K, Imamura S, Franklin KA, Knight H, Dodd AN. Low-temperature and circadian signals are integrated by the sigma factor SIG5. NATURE PLANTS 2023; 9:661-672. [PMID: 36997687 PMCID: PMC10119024 DOI: 10.1038/s41477-023-01377-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Accepted: 02/20/2023] [Indexed: 06/19/2023]
Abstract
Chloroplasts are a common feature of plant cells and aspects of their metabolism, including photosynthesis, are influenced by low-temperature conditions. Chloroplasts contain a small circular genome that encodes essential components of the photosynthetic apparatus and chloroplast transcription/translation machinery. Here, we show that in Arabidopsis, a nuclear-encoded sigma factor that controls chloroplast transcription (SIGMA FACTOR5) contributes to adaptation to low-temperature conditions. This process involves the regulation of SIGMA FACTOR5 expression in response to cold by the bZIP transcription factors ELONGATED HYPOCOTYL5 and ELONGATED HYPOCOTYL5 HOMOLOG. The response of this pathway to cold is gated by the circadian clock, and it enhances photosynthetic efficiency during long-term cold and freezing exposure. We identify a process that integrates low-temperature and circadian signals, and modulates the response of chloroplasts to low-temperature conditions.
Collapse
Affiliation(s)
- Dora L Cano-Ramirez
- The Sainsbury Laboratory, University of Cambridge, Cambridge, UK
- School of Biological Sciences, University of Bristol, Bristol, UK
| | | | - Tokiaki Takemura
- Laboratory for Chemistry and Life Science, Institute for Innovative Research, Tokyo Institute of Technology, Yokohama, Japan
| | | | | | | | | | | | - Annalisa Bellandi
- John Innes Centre, Norwich, UK
- Laboratoire de Reproduction et Développement des Plantes, ENS de Lyon, Université de Lyon, UCBL, INRAE, CNRS, Lyon, France
| | - Tom Batstone
- School of Biological Sciences, University of Bristol, Bristol, UK
| | - Bethan F Manley
- School of Biological Sciences, University of Bristol, Bristol, UK
- Wellcome Trust Sanger Institute, Hinxton, UK
| | - Kan Tanaka
- Laboratory for Chemistry and Life Science, Institute for Innovative Research, Tokyo Institute of Technology, Yokohama, Japan
| | - Sousuke Imamura
- Laboratory for Chemistry and Life Science, Institute for Innovative Research, Tokyo Institute of Technology, Yokohama, Japan
- Space Environment and Energy Laboratories, Nippon Telegraph and Telephone Corporation, Musashino-shi, Japan
| | - Keara A Franklin
- School of Biological Sciences, University of Bristol, Bristol, UK
| | - Heather Knight
- Department of Biosciences, Durham University, Durham, UK
| | | |
Collapse
|
3
|
Koskinen S, Kurkela J, Linhartová M, Tyystjärvi T. The genome sequence of Synechocystis sp. PCC 6803 substrain GT-T and its implications for the evolution of PCC 6803 substrains. FEBS Open Bio 2023; 13:701-712. [PMID: 36792971 PMCID: PMC10068330 DOI: 10.1002/2211-5463.13576] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Revised: 02/02/2023] [Accepted: 02/07/2023] [Indexed: 02/17/2023] Open
Abstract
Synechocystis sp. PCC 6803 is a model cyanobacterium, glucose-tolerant substrains of which are commonly used as laboratory strains. In recent years, it has become evident that 'wild-type' strains used in different laboratories show some differences in their phenotypes. We report here the chromosome sequence of our Synechocystis sp. PCC 6803 substrain, named substrain GT-T. The chromosome sequence of GT-T was compared to those of two other commonly used laboratory substrains, GT-S and PCC-M. We identified 11 specific mutations in the GT-T substrain, whose physiological consequences are discussed. We also provide an update on evolutionary relationships between different Synechocystis sp. PCC 6803 substrains.
Collapse
Affiliation(s)
- Satu Koskinen
- Department of Life Sciences/Molecular Plant Biology, University of Turku, Finland
| | - Juha Kurkela
- Department of Life Sciences/Molecular Plant Biology, University of Turku, Finland
| | - Markéta Linhartová
- Institute of Microbiology of the Czech Academy of Sciences, Třeboň, Czech Republic
| | - Taina Tyystjärvi
- Department of Life Sciences/Molecular Plant Biology, University of Turku, Finland
| |
Collapse
|
4
|
Roles of Close Homologues SigB and SigD in Heat and High Light Acclimation of the Cyanobacterium Synechocystis sp. PCC 6803. Life (Basel) 2022; 12:life12020162. [PMID: 35207450 PMCID: PMC8875361 DOI: 10.3390/life12020162] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 01/15/2022] [Accepted: 01/19/2022] [Indexed: 11/18/2022] Open
Abstract
Acclimation of cyanobacterium Synechocystis sp. PCC6803 to suboptimal conditions is largely dependent on adjustments of gene expression, which is highly controlled by the σ factor subunits of RNA polymerase (RNAP). The SigB and SigD σ factors are close homologues. Here we show that the sigB and sigD genes are both induced in high light and heat stresses. Comparison of transcriptomes of the control strain (CS), ΔsigB, ΔsigD, ΔsigBCE (containing SigD as the only functional group 2 σ factor), and ΔsigCDE (SigB as the only functional group 2 σ factor) strains in standard, high light, and high temperature conditions revealed that the SigB and SigD factors regulate different sets of genes and SigB and SigD regulons are highly dependent on stress conditions. The SigB regulon is bigger than the SigD regulon at high temperature, whereas, in high light, the SigD regulon is bigger than the SigB regulon. Furthermore, our results show that favoring the SigB or SigD factor by deleting other group 2 σ factors does not lead to superior acclimation to high light or high temperature, indicating that all group 2 σ factors play roles in the acclimation processes.
Collapse
|
5
|
Cyanobacterial sigma factors: Current and future applications for biotechnological advances. Biotechnol Adv 2020; 40:107517. [DOI: 10.1016/j.biotechadv.2020.107517] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Revised: 01/07/2020] [Accepted: 01/09/2020] [Indexed: 11/15/2022]
|
6
|
Valev D, Kurkela J, Tyystjärvi E, Tyystjärvi T. Testing the Potential of Regulatory Sigma Factor Mutants for Wastewater Purification or Bioreactor Run in High Light. Curr Microbiol 2020; 77:1590-1599. [PMID: 32266454 PMCID: PMC7334282 DOI: 10.1007/s00284-020-01973-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2019] [Accepted: 03/27/2020] [Indexed: 11/25/2022]
Abstract
It is shown that a freshly inoculated culture of the model cyanobacterium Synechocystis sp. PCC 6803 consumed almost all phosphate and 50% of nitrate within 6 days from the nutrient-rich BG-11 growth medium, indicating potential of cyanobacteria to purify wastewaters. Synechocystis sp. PCC 6803 control strain also collected nutrients efficiently from a landfill leachate wastewater KA2 (5.9-6.9 mM ammonium and 0.073-0.077 mM phosphate). Wastewaters might induce oxidative stress to microalgae, which prompted us to test growth of sigma factor inactivation strains, as ΔsigBCE and ΔsigCDE strains show superior growth in chemically induced oxidative stress. All cyanobacterial strains, including a stress-sensitive strain ΔsigBCDE, grew well in KA2 for four days, indicating that KA2 did not cause immediate oxidative stress. Completely arrested growth and bleaching of ΔsigBCDE cells after one week in KA2 wastewater point to the importance of group 2 sigma factor-mediated changes in gene expression during wastewater treatment. The growth of ΔsigBCD was arrested early in un-buffered and Hepes buffered (pH 7.5) KA2. In ΔsigBCD, all phosphate transporter genes are upregulated in standard conditions, and ΔsigBCD cells showed growth defects in low-phosphate BG-11 medium. ΔsigBCD cells removed phosphate slower from KA2 than the control strain, but phosphate supplementation of KA2 did not improve growth of ΔsigBCD. The ΔsigBCE strain showed superior growth in a laboratory-scale bioreactor in bright light and removed phosphate even slightly more efficiently than the control strain if KA2 was Hepes buffered although ΔsigBCE grew slowly in un-buffered KA2 and in low-phosphate BG-11 medium. The results indicate that engineering expression of regulatory group 2 sigma factor(s) might be useful for practical applications.
Collapse
Affiliation(s)
- Dimitar Valev
- Department of Biochemistry/Molecular Plant Biology, University of Turku, 20014, Turku, Finland
| | - Juha Kurkela
- Department of Biochemistry/Molecular Plant Biology, University of Turku, 20014, Turku, Finland
| | - Esa Tyystjärvi
- Department of Biochemistry/Molecular Plant Biology, University of Turku, 20014, Turku, Finland
| | - Taina Tyystjärvi
- Department of Biochemistry/Molecular Plant Biology, University of Turku, 20014, Turku, Finland.
| |
Collapse
|
7
|
Hakkila K, Valev D, Antal T, Tyystjï Rvi E, Tyystjï Rvi T. Group 2 Sigma Factors are Central Regulators of Oxidative Stress Acclimation in Cyanobacteria. PLANT & CELL PHYSIOLOGY 2019; 60:436-447. [PMID: 30407607 DOI: 10.1093/pcp/pcy221] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Accepted: 11/04/2018] [Indexed: 06/08/2023]
Abstract
Regulatory σ factors of the RNA polymerase (RNAP) adjust gene expression according to environmental cues when the cyanobacterium Synechocystis sp. PCC 6803 acclimates to suboptimal conditions. Here we show central roles of the non-essential group 2 σ factors in oxidative stress responses. Cells missing all group 2 σ factors fail to acclimate to chemically induced singlet oxygen, superoxide or H2O2 stresses, and lose pigments in high light. SigB and SigD are the major σ factors in oxidative stress, whereas SigC and SigE play only minor roles. The SigD factor is up-regulated in high light, singlet oxygen and H2O2 stresses, and overproduction of the SigD factor in the ΔsigBCE strain leads to superior growth of ΔsigBCE cells in those stress conditions. Superoxide does not induce the production of the SigD factor but instead SigB and SigC factors are moderately induced. The SigB factor alone in ΔsigCDE can support almost as fast growth in superoxide stress as the full complement of σ factors in the control strain, but an overdose of the stationary phase-related SigC factor causes growth arrest of ΔsigBDE in superoxide stress. A drastic decrease of the functional RNAP limits the transcription capacity of the cells in H2O2 stress, which explains why cyanobacteria are sensitive to H2O2. Formation of RNAP-SigB and RNAP-SigD holoenzymes is highly enhanced in H2O2 stress, and cells containing only SigB (ΔsigCDE) or SigD (ΔsigBCE) show superior growth in H2O2 stress.
Collapse
Affiliation(s)
- Kaisa Hakkila
- Department of Biochemistry/Molecular Plant Biology, University of Turku, Turku, Finland
| | - Dimitar Valev
- Department of Biochemistry/Molecular Plant Biology, University of Turku, Turku, Finland
| | - Taras Antal
- Biological Faculty, Moscow State University, Vorobyevi Gory, Moscow, Russia
| | - Esa Tyystjï Rvi
- Department of Biochemistry/Molecular Plant Biology, University of Turku, Turku, Finland
| | - Taina Tyystjï Rvi
- Department of Biochemistry/Molecular Plant Biology, University of Turku, Turku, Finland
| |
Collapse
|
8
|
Koskinen S, Hakkila K, Kurkela J, Tyystjärvi E, Tyystjärvi T. Inactivation of group 2 σ factors upregulates production of transcription and translation machineries in the cyanobacterium Synechocystis sp. PCC 6803. Sci Rep 2018; 8:10305. [PMID: 29985458 PMCID: PMC6037674 DOI: 10.1038/s41598-018-28736-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Accepted: 06/26/2018] [Indexed: 11/17/2022] Open
Abstract
We show that the formation of the RNAP holoenzyme with the primary σ factor SigA increases in the ΔsigBCDE strain of the cyanobacterium Synechocystis sp. PCC 6803 lacking all group 2 σ factors. The high RNAP-SigA holoenzyme content directly induces transcription of a particular set of housekeeping genes, including ones encoding transcription and translation machineries. In accordance with upregulated transcripts, ΔsigBCDE contain more RNAPs and ribosomal subunits than the control strain. Extra RNAPs are fully active, and the RNA content of ΔsigBCDE cells is almost tripled compared to that in the control strain. Although ΔsigBCDE cells produce extra rRNAs and ribosomal proteins, functional extra ribosomes are not formed, and translation activity and protein content remained similar in ΔsigBCDE as in the control strain. The arrangement of the RNA polymerase core genes together with the ribosomal protein genes might play a role in the co-regulation of transcription and translation machineries. Sequence logos were constructed to compare promoters of those housekeeping genes that directly react to the RNAP-SigA holoenzyme content and those ones that do not. Cyanobacterial strains with engineered transcription and translation machineries might provide solutions for construction of highly efficient production platforms for biotechnical applications in the future.
Collapse
Affiliation(s)
- Satu Koskinen
- Department of Biochemistry, University of Turku, FI-20014, Turku, Finland
| | - Kaisa Hakkila
- Department of Biochemistry, University of Turku, FI-20014, Turku, Finland
| | - Juha Kurkela
- Department of Biochemistry, University of Turku, FI-20014, Turku, Finland
| | - Esa Tyystjärvi
- Department of Biochemistry, University of Turku, FI-20014, Turku, Finland
| | - Taina Tyystjärvi
- Department of Biochemistry, University of Turku, FI-20014, Turku, Finland.
| |
Collapse
|
9
|
Systematic identification of light-regulated cold-responsive proteome in a model cyanobacterium. J Proteomics 2018; 179:100-109. [DOI: 10.1016/j.jprot.2018.03.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Revised: 03/02/2018] [Accepted: 03/06/2018] [Indexed: 11/19/2022]
|
10
|
Tailoring cyanobacterial cell factory for improved industrial properties. Biotechnol Adv 2018; 36:430-442. [DOI: 10.1016/j.biotechadv.2018.01.005] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Revised: 01/07/2018] [Accepted: 01/08/2018] [Indexed: 11/20/2022]
|
11
|
Stensjö K, Vavitsas K, Tyystjärvi T. Harnessing transcription for bioproduction in cyanobacteria. PHYSIOLOGIA PLANTARUM 2018; 162:148-155. [PMID: 28762505 DOI: 10.1111/ppl.12606] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Revised: 07/04/2017] [Accepted: 07/10/2017] [Indexed: 06/07/2023]
Abstract
Sustainable production of biofuels and other valuable compounds is one of our future challenges. One tempting possibility is to use photosynthetic cyanobacteria as production factories. Currently, tools for genetic engineering of cyanobacteria are not good enough to exploit the full potential of cyanobacteria. A wide variety of expression systems will be required to adjust both the expression of heterologous enzyme(s) and metabolic routes to the best possible balance, allowing the optimal production of a particular substance. In bacteria, transcription, especially the initiation of transcription, has a central role in adjusting gene expression and thus also metabolic fluxes of cells according to environmental cues. Here we summarize the recent progress in developing tools for efficient cyanofactories, focusing especially on transcriptional regulation.
Collapse
Affiliation(s)
- Karin Stensjö
- Department of Chemistry-Ångström Laboratory, Uppsala University, Box 523, 75120 Uppsala, Sweden
| | - Konstantinos Vavitsas
- Copenhagen Plant Science Centre, Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg C, Denmark
| | - Taina Tyystjärvi
- Molecular Plant Biology, Department of Biochemistry, University of Turku, FI-20014 Turku, Finland
| |
Collapse
|
12
|
Evaluation of light energy to H 2 energy conversion efficiency in thin films of cyanobacteria and green alga under photoautotrophic conditions. ALGAL RES 2017. [DOI: 10.1016/j.algal.2017.09.027] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
|
13
|
Singh AK, Mallick N. Advances in cyanobacterial polyhydroxyalkanoates production. FEMS Microbiol Lett 2017; 364:4107776. [DOI: 10.1093/femsle/fnx189] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2017] [Accepted: 09/06/2017] [Indexed: 12/25/2022] Open
|
14
|
Soitamo A, Havurinne V, Tyystjärvi E. Photoinhibition in marine picocyanobacteria. PHYSIOLOGIA PLANTARUM 2017; 161:97-108. [PMID: 28370227 DOI: 10.1111/ppl.12571] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Revised: 01/19/2017] [Accepted: 02/22/2017] [Indexed: 05/28/2023]
Abstract
Marine Synechococcus and Prochlorococcus cyanobacteria have different antenna compositions although they are genetically near to each other, and different strains thrive in very different illumination conditions. We measured growth and photoinhibition of PSII in two low-light and one high-light Prochlorococcus strains and in one Synechococcus strain. All strains were found to be able to shortly utilize moderate or even high light, but the low-light strains bleached rapidly in moderate light. Measurements of photoinhibition in the presence of the antibiotic lincomycin showed that a low-light Prochlorococcus strain was more sensitive than a high-light strain and both were more sensitive than the marine Synechococcus. The action spectrum of photoinhibition showed an increase from blue to ultraviolet wavelengths in all strains, suggesting contribution of manganese absorption to photoinhibition, but blue light caused less photoinhibition in marine cyanobacteria than expected on the basis of earlier results from plants and cyanobacteria. The visible-light part of the action spectrum resembled the absorption spectrum of the organism, suggesting that photosynthetic antenna pigments, especially divinyl chlorophylls, have a more important role as photoreceptors of visible-light photoinhibition in marine cyanobacteria than in other photoautotrophs.
Collapse
Affiliation(s)
- Arto Soitamo
- Department of Biochemistry/Molecular Plant Biology, University of Turku, Turku, Finland
| | - Vesa Havurinne
- Department of Biochemistry/Molecular Plant Biology, University of Turku, Turku, Finland
| | - Esa Tyystjärvi
- Department of Biochemistry/Molecular Plant Biology, University of Turku, Turku, Finland
| |
Collapse
|
15
|
Sarnaik A, Pandit R, Lali A. Growth engineering ofSynechococcus elongatusPCC 7942 for mixotrophy under natural light conditions for improved feedstock production. Biotechnol Prog 2017; 33:1182-1192. [DOI: 10.1002/btpr.2490] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Revised: 03/22/2017] [Indexed: 01/04/2023]
Affiliation(s)
- Aditya Sarnaik
- DBT-ICT Centre for Energy Biosciences, Inst. of Chemical Technology; Mumbai Maharashtra 400019 India
| | - Reena Pandit
- DBT-ICT Centre for Energy Biosciences, Inst. of Chemical Technology; Mumbai Maharashtra 400019 India
| | - Arvind Lali
- DBT-ICT Centre for Energy Biosciences, Inst. of Chemical Technology; Mumbai Maharashtra 400019 India
- Department of Chemical Engineering; Inst. of Chemical Technology; Mumbai Maharashtra 400019 India
| |
Collapse
|
16
|
Kurkela J, Hakkila K, Antal T, Tyystjärvi T. Acclimation to High CO 2 Requires the ω Subunit of the RNA Polymerase in Synechocystis. PLANT PHYSIOLOGY 2017; 174:172-184. [PMID: 28351910 PMCID: PMC5411146 DOI: 10.1104/pp.16.01953] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Accepted: 03/23/2017] [Indexed: 06/06/2023]
Abstract
Inactivation of the nonessential ω-subunit of the RNA polymerase core in the ΔrpoZ strain of the model cyanobacterium Synechocystis sp. PCC 6803 leads to a unique high-CO2-sensitive phenotype. Supplementing air in the growth chamber with 30 mL L-1 (3%) CO2 accelerated the growth rate of the control strain (CS) 4-fold, whereas ΔrpoZ did not grow faster than under ambient air. The slow growth of ΔrpoZ during the first days in high CO2 was due to the inability of the mutant cells to adjust photosynthesis to high CO2 The light-saturated photosynthetic activity of ΔrpoZ in high CO2 was only half of that measured in CS, Rubisco content was one-third lower, and cells of ΔrpoZ were not able to increase light-harvesting phycobilisome antenna like CS upon high-CO2 treatment. In addition, altered structural and functional organization of photosystem I and photosystem II were detected in the ΔrpoZ strain compared with CS when cells were grown in high CO2 but not in ambient air. Moreover, respiration of ΔrpoZ did not acclimate to high CO2 Unlike the photosynthetic complexes, the RNA polymerase complex and ribosomes were produced in high CO2 similarly as in CS Our results indicate that the deletion of the ω-subunit specifically affects photosynthesis and respiration, but transcription and translation remain active. Thus, the specific effect of the ω-subunit on photosynthesis but not on all household processes suggests that the ω-subunit might have a regulatory function in cyanobacteria.
Collapse
Affiliation(s)
- Juha Kurkela
- Department of Biochemistry/Molecular Plant Biology, University of Turku, FI-20014 Turku, Finland (J.K., K.H., T.T.); and
- Biological Faculty, Moscow State University, Vorobyevi Gory 119992, Moscow, Russia (T.A.)
| | - Kaisa Hakkila
- Department of Biochemistry/Molecular Plant Biology, University of Turku, FI-20014 Turku, Finland (J.K., K.H., T.T.); and
- Biological Faculty, Moscow State University, Vorobyevi Gory 119992, Moscow, Russia (T.A.)
| | - Taras Antal
- Department of Biochemistry/Molecular Plant Biology, University of Turku, FI-20014 Turku, Finland (J.K., K.H., T.T.); and
- Biological Faculty, Moscow State University, Vorobyevi Gory 119992, Moscow, Russia (T.A.)
| | - Taina Tyystjärvi
- Department of Biochemistry/Molecular Plant Biology, University of Turku, FI-20014 Turku, Finland (J.K., K.H., T.T.); and
- Biological Faculty, Moscow State University, Vorobyevi Gory 119992, Moscow, Russia (T.A.)
| |
Collapse
|
17
|
Srivastava A, Brilisauer K, Rai AK, Ballal A, Forchhammer K, Tripathi AK. Down-Regulation of the Alternative Sigma Factor SigJ Confers a Photoprotective Phenotype to Anabaena PCC 7120. PLANT & CELL PHYSIOLOGY 2017; 58:287-297. [PMID: 27837096 DOI: 10.1093/pcp/pcw188] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2016] [Accepted: 10/28/2016] [Indexed: 06/06/2023]
Abstract
Alternative sigma factors belonging to Group 3 are thought to play an important role in the adaptation of cyanobacteria to environmental challenges by altering expression of genes needed for coping with such stresses. In this study, the role of an alternative sigma factor, SigJ, was analyzed in the filamentous nitrogen-fixing cyanobacterium, Anabaena sp. PCC 7120 by knocking down the expression of the sigJ gene (alr0277) employing an antisense RNA-mediated approach. In the absence of any stress, the knock-down (KD0277) or the wild-type strain both grew similarly. Upon exposure to high-intensity light, KD0277 showed substantially reduced bleaching of its pigments, higher photosynthetic activity and consequently better survival than the wild type. KD0277 also showed an enhanced accumulation of two carotenoids, which were identified as myxoxanthophyll and keto-myxoxanthophyll. Further, KD0277 was more tolerant to ammonium-triggered photodamage than the wild type. Moreover, PSII was better protected against photodamage in KD0277 than in the wild type. Down-regulation of sigJ in Anabaena PCC 7120, however, reduced its ability to cope with desiccation. This study demonstrates that down-regulation of the sigJ gene in Anabaena PCC 7120 differentially affects its ability to tolerate two environmentally relevant stresses, i.e. high-intensity light and desiccation.
Collapse
Affiliation(s)
- Amit Srivastava
- School of Biotechnology, Institute of Science, Banaras Hindu University, Varanasi, India
| | - Klaus Brilisauer
- Interfaculty Institute of Microbiology and Infection Medicine, Eberhard-Karls-Universität Tübingen, Auf der Morgenstelle, Tübingen, Germany
| | - Ashutosh K Rai
- School of Biotechnology, Institute of Science, Banaras Hindu University, Varanasi, India
| | - Anand Ballal
- Molecular Biology Division, Bhabha Atomic Research Centre, Mumbai, India
- Homi Bhabha National Institute, Anushakti Nagar, Mumbai, India
| | - Karl Forchhammer
- Interfaculty Institute of Microbiology and Infection Medicine, Eberhard-Karls-Universität Tübingen, Auf der Morgenstelle, Tübingen, Germany
| | - Anil K Tripathi
- School of Biotechnology, Institute of Science, Banaras Hindu University, Varanasi, India
| |
Collapse
|
18
|
Antal T, Kurkela J, Parikainen M, Kårlund A, Hakkila K, Tyystjärvi E, Tyystjärvi T. Roles of Group 2 Sigma Factors in Acclimation of the Cyanobacterium Synechocystis sp. PCC 6803 to Nitrogen Deficiency. PLANT & CELL PHYSIOLOGY 2016; 57:1309-1318. [PMID: 27095737 DOI: 10.1093/pcp/pcw079] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Accepted: 04/10/2016] [Indexed: 06/05/2023]
Abstract
Acclimation of cyanobacteria to environmental conditions is mainly controlled at the transcriptional level, and σ factors of the RNA polymerase have a central role in this process. The model cyanobacterium Synechocystis sp. PCC 6803 has four non-essential group 2 σ factors (SigB, SigC, SigD and SigE) that regulate global metabolic responses to various adverse environmental conditions. Here we show that although none of the group 2 σ factors is essential for the major metabolic realignments induced by a short period of nitrogen starvation, the quadruple mutant without any group 2 σ factors and triple mutants missing both SigB and SigD grow slowly in BG-11 medium containing only 5% of the nitrate present in standard BG-11. These ΔsigBCDE, ΔsigBCD and ΔsigBDE strains lost PSII activity rapidly in low nitrogen and accumulated less glycogen than the control strain. An abnormally high glycogen content was detected in ΔsigBCE (SigD is active), while the carotenoid content became high in ΔsigCDE (SigB is active), indicating that SigB and SigD regulate the partitioning of carbon skeletons in low nitrogen. Long-term survival and recovery of the cells after nitrogen deficiency was strongly dependent on group 2 σ factors. The quadruple mutant and the ΔsigBDE strain (only SigC is active) recovered more slowly from nitrogen deficiency than the control strain, and ΔsigBCDE in particular lost viability during nitrogen starvation. Nitrogen deficiency-induced changes in the pigment content of the control strain recovered essentially in 1 d in nitrogen-replete medium, but little recovery occurred in ΔsigBCDE and ΔsigBDE.
Collapse
Affiliation(s)
- Taras Antal
- Department of Biochemistry, University of Turku, FI-20014 Turku, Finland Biological Faculty, Moscow State University, Vorobyevi Gory 119992, Moscow, Russia
| | - Juha Kurkela
- Department of Biochemistry, University of Turku, FI-20014 Turku, Finland
| | | | - Anna Kårlund
- Department of Biochemistry, University of Turku, FI-20014 Turku, Finland
| | - Kaisa Hakkila
- Department of Biochemistry, University of Turku, FI-20014 Turku, Finland
| | - Esa Tyystjärvi
- Department of Biochemistry, University of Turku, FI-20014 Turku, Finland
| | - Taina Tyystjärvi
- Department of Biochemistry, University of Turku, FI-20014 Turku, Finland
| |
Collapse
|
19
|
Kuwahara A, Arisaka S, Takeya M, Iijima H, Hirai MY, Osanai T. Modification of photosynthetic electron transport and amino acid levels by overexpression of a circadian-related histidine kinase hik8 in Synechocystis sp. PCC 6803. Front Microbiol 2015; 6:1150. [PMID: 26539179 PMCID: PMC4611142 DOI: 10.3389/fmicb.2015.01150] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Accepted: 10/05/2015] [Indexed: 11/13/2022] Open
Abstract
Cyanobacteria perform oxygenic photosynthesis, and the maintenance of photosynthetic electron transport chains is indispensable to their survival in various environmental conditions. Photosynthetic electron transport in cyanobacteria can be studied through genetic analysis because of the natural competence of cyanobacteria. We here show that a strain overexpressing hik8, a histidine kinase gene related to the circadian clock, exhibits an altered photosynthetic electron transport chain in the unicellular cyanobacterium Synechocystis sp. PCC 6803. Respiratory activity was down-regulated under nitrogen-replete conditions. Photosynthetic activity was slightly lower in the hik8-overexpressing strain than in the wild-type after nitrogen depletion, and the values of photosynthetic parameters were altered by hik8 overexpression under nitrogen-replete and nitrogen-depleted conditions. Transcripts of genes encoding Photosystem I and II were increased by hik8 overexpression under nitrogen-replete conditions. Nitrogen starvation triggers increase in amino acids but the magnitude of the increase in several amino acids was diminished by hik8 overexpression. These genetic data indicate that Hik8 regulates the photosynthetic electron transport, which in turn alters primary metabolism during nitrogen starvation in this cyanobacterium.
Collapse
Affiliation(s)
- Ayuko Kuwahara
- RIKEN Center for Sustainable Resource ScienceYokohama, Japan
| | - Satomi Arisaka
- Department of Agricultural Chemistry, School of Agriculture, Meiji UniversityKawasaki, Japan
| | - Masahiro Takeya
- Department of Agricultural Chemistry, School of Agriculture, Meiji UniversityKawasaki, Japan
| | - Hiroko Iijima
- Department of Agricultural Chemistry, School of Agriculture, Meiji UniversityKawasaki, Japan
| | | | - Takashi Osanai
- RIKEN Center for Sustainable Resource ScienceYokohama, Japan
- Department of Agricultural Chemistry, School of Agriculture, Meiji UniversityKawasaki, Japan
| |
Collapse
|
20
|
Koskinen S, Hakkila K, Gunnelius L, Kurkela J, Wada H, Tyystjärvi T. In vivorecruitment analysis and a mutant strain without any group 2 σ factor reveal roles of different σ factors in cyanobacteria. Mol Microbiol 2015; 99:43-54. [DOI: 10.1111/mmi.13214] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/07/2015] [Indexed: 10/23/2022]
Affiliation(s)
- Satu Koskinen
- Department of Biochemistry; University of Turku; FIN-20014 Turku Finland
| | - Kaisa Hakkila
- Department of Biochemistry; University of Turku; FIN-20014 Turku Finland
| | - Liisa Gunnelius
- Department of Biochemistry; University of Turku; FIN-20014 Turku Finland
| | - Juha Kurkela
- Department of Biochemistry; University of Turku; FIN-20014 Turku Finland
| | - Hajime Wada
- Department of Life Sciences; University of Tokyo; Komaba 3-8-1, Meguro-ku Tokyo 153-8902 Japan
| | - Taina Tyystjärvi
- Department of Biochemistry; University of Turku; FIN-20014 Turku Finland
| |
Collapse
|
21
|
Gunnelius L, Kurkela J, Hakkila K, Koskinen S, Parikainen M, Tyystjärvi T. The ω subunit of RNA polymerase is essential for thermal acclimation of the cyanobacterium Synechocystis sp. PCC 6803. PLoS One 2014; 9:e112599. [PMID: 25386944 PMCID: PMC4227741 DOI: 10.1371/journal.pone.0112599] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2014] [Accepted: 10/09/2014] [Indexed: 01/26/2023] Open
Abstract
The rpoZ gene encodes the small ω subunit of RNA polymerase. A ΔrpoZ strain of the cyanobacterium Synechocystis sp. PCC 6803 grew well in standard conditions (constant illumination at 40 µmol photons m−2 s−1; 32°C; ambient CO2) but was heat sensitive and died at 40°C. In the control strain, 71 genes were at least two-fold up-regulated and 91 genes down-regulated after a 24-h treatment at 40°C, while in ΔrpoZ 394 genes responded to heat. Only 62 of these heat-responsive genes were similarly regulated in both strains, and 80% of heat-responsive genes were unique for ΔrpoZ. The RNA polymerase core and the primary σ factor SigA were down-regulated in the control strain at 40°C but not in ΔrpoZ. In accordance with reduced RNA polymerase content, the total RNA content of mild-heat-stress-treated cells was lower in the control strain than in ΔrpoZ. Light-saturated photosynthetic activity decreased more in ΔrpoZ than in the control strain upon mild heat stress. The amounts of photosystem II and rubisco decreased at 40°C in both strains while PSI and the phycobilisome antenna protein allophycocyanin remained at the same level as in standard conditions. The phycobilisome rod proteins, phycocyanins, diminished during the heat treatment in ΔrpoZ but not in the control strain, and the nblA1 and nblA2 genes (encode NblA proteins required for phycobilisome degradation) were up-regulated only in ΔrpoZ. Our results show that the ω subunit of RNAP is essential in heat stress because it is required for heat acclimation of diverse cellular processes.
Collapse
Affiliation(s)
- Liisa Gunnelius
- Department of Biochemistry, University of Turku, Turku, Finland
| | - Juha Kurkela
- Department of Biochemistry, University of Turku, Turku, Finland
| | - Kaisa Hakkila
- Department of Biochemistry, University of Turku, Turku, Finland
| | - Satu Koskinen
- Department of Biochemistry, University of Turku, Turku, Finland
| | | | - Taina Tyystjärvi
- Department of Biochemistry, University of Turku, Turku, Finland
- * E-mail:
| |
Collapse
|
22
|
Atkins KA, Dodd AN. Circadian regulation of chloroplasts. CURRENT OPINION IN PLANT BIOLOGY 2014; 21:43-50. [PMID: 25026538 DOI: 10.1016/j.pbi.2014.06.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2014] [Revised: 06/20/2014] [Accepted: 06/23/2014] [Indexed: 05/08/2023]
Abstract
Circadian rhythms produce a biological measure of time that increases plant performance. The mechanisms that underlie this increase in productivity require investigation to provide information that will underpin future crop improvement. There is a growing body of evidence that a sophisticated signalling network interconnects the circadian oscillator and chloroplasts. We consider this in the context of circadian signalling to chloroplasts and the relationship between retrograde signalling and circadian regulation. We place circadian signalling to chloroplasts by sigma factors within an evolutionary context. We describe selected recent developments in the integration of light and circadian signals that control chloroplast gene expression.
Collapse
Affiliation(s)
- Kelly A Atkins
- School of Biological Sciences, Bristol Life Sciences Building, University of Bristol, Bristol BS8 1TQ, UK
| | - Antony N Dodd
- School of Biological Sciences, Bristol Life Sciences Building, University of Bristol, Bristol BS8 1TQ, UK; Cabot Institute, University of Bristol, Bristol BS8 1UJ, UK.
| |
Collapse
|
23
|
Montgomery BL. The Regulation of Light Sensing and Light-Harvesting Impacts the Use of Cyanobacteria as Biotechnology Platforms. Front Bioeng Biotechnol 2014; 2:22. [PMID: 25023122 PMCID: PMC4090899 DOI: 10.3389/fbioe.2014.00022] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2014] [Accepted: 06/13/2014] [Indexed: 12/22/2022] Open
Abstract
Light is harvested in cyanobacteria by chlorophyll-containing photosystems embedded in the thylakoid membranes and phycobilisomes (PBSs), photosystem-associated light-harvesting antennae. Light absorbed by the PBSs and photosystems can be converted to chemical energy through photosynthesis. Photosynthetically fixed carbon pools, which are constrained by photosynthetic light capture versus the dissipation of excess light absorbed, determine the available organismal energy budget. The molecular bases of the environmental regulation of photosynthesis, photoprotection, and photomorphogenesis are still being elucidated in cyanobacteria. Thus, the potential impacts of these phenomena on the efficacy of developing cyanobacteria as robust biotechnological platforms require additional attention. Current advances and persisting needs for developing cyanobacterial production platforms that are related to light sensing and harvesting include the development of tools to balance the utilization of absorbed photons for conversion to chemical energy and biomass versus light dissipation in photoprotective mechanisms. Such tools can be used to direct energy to more effectively support the production of desired bioproducts from sunlight.
Collapse
Affiliation(s)
- Beronda L. Montgomery
- Plant Research Laboratory, Department of Energy, Michigan State University, East Lansing, MI, USA
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, USA
| |
Collapse
|
24
|
Osanai T, Oikawa A, Numata K, Kuwahara A, Iijima H, Doi Y, Saito K, Hirai MY. Pathway-level acceleration of glycogen catabolism by a response regulator in the cyanobacterium Synechocystis species PCC 6803. PLANT PHYSIOLOGY 2014; 164:1831-41. [PMID: 24521880 PMCID: PMC3982746 DOI: 10.1104/pp.113.232025] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2013] [Accepted: 02/10/2014] [Indexed: 05/04/2023]
Abstract
Response regulators of two-component systems play pivotal roles in the transcriptional regulation of responses to environmental signals in bacteria. Rre37, an OmpR-type response regulator, is induced by nitrogen depletion in the unicellular cyanobacterium Synechocystis species PCC 6803. Microarray and quantitative real-time polymerase chain reaction analyses revealed that genes related to sugar catabolism and nitrogen metabolism were up-regulated by rre37 overexpression. Protein levels of GlgP(slr1367), one of the two glycogen phosphorylases, in the rre37-overexpressing strain were higher than those of the parental wild-type strain under both nitrogen-replete and nitrogen-depleted conditions. Glycogen amounts decreased to less than one-tenth by rre37 overexpression under nitrogen-replete conditions. Metabolome analysis revealed that metabolites of the sugar catabolic pathway and amino acids were altered in the rre37-overexpressing strain after nitrogen depletion. These results demonstrate that Rre37 is a pathway-level regulator that activates the metabolic flow from glycogen to polyhydroxybutyrate and the hybrid tricarboxylic acid and ornithine cycle, unraveling the mechanism of the transcriptional regulation of primary metabolism in this unicellular cyanobacterium.
Collapse
Affiliation(s)
- Takashi Osanai
- RIKEN Center for Sustainable Resource Science, Tsurumi-ku, Yokohama, Kanagawa 230–0045, Japan (T.O., A.O., K.N., A.K., H.I., Y.D., K.S., M.Y.H.)
- PRESTO, Japan Science and Technology Agency, Kawaguchi, Saitama 332–0012, Japan (T.O.)
- Yamagata University, Faculty of Agriculture, Wakaba-machi, Tsuruoka-shi, Yamagata 997–8555, Japan (A.O.); and
- Graduate School of Pharmaceutical Sciences, Chiba University, Chuo-ku, Chiba 260–8522, Japan (K.S.)
| | - Akira Oikawa
- RIKEN Center for Sustainable Resource Science, Tsurumi-ku, Yokohama, Kanagawa 230–0045, Japan (T.O., A.O., K.N., A.K., H.I., Y.D., K.S., M.Y.H.)
- PRESTO, Japan Science and Technology Agency, Kawaguchi, Saitama 332–0012, Japan (T.O.)
- Yamagata University, Faculty of Agriculture, Wakaba-machi, Tsuruoka-shi, Yamagata 997–8555, Japan (A.O.); and
- Graduate School of Pharmaceutical Sciences, Chiba University, Chuo-ku, Chiba 260–8522, Japan (K.S.)
| | - Keiji Numata
- RIKEN Center for Sustainable Resource Science, Tsurumi-ku, Yokohama, Kanagawa 230–0045, Japan (T.O., A.O., K.N., A.K., H.I., Y.D., K.S., M.Y.H.)
- PRESTO, Japan Science and Technology Agency, Kawaguchi, Saitama 332–0012, Japan (T.O.)
- Yamagata University, Faculty of Agriculture, Wakaba-machi, Tsuruoka-shi, Yamagata 997–8555, Japan (A.O.); and
- Graduate School of Pharmaceutical Sciences, Chiba University, Chuo-ku, Chiba 260–8522, Japan (K.S.)
| | - Ayuko Kuwahara
- RIKEN Center for Sustainable Resource Science, Tsurumi-ku, Yokohama, Kanagawa 230–0045, Japan (T.O., A.O., K.N., A.K., H.I., Y.D., K.S., M.Y.H.)
- PRESTO, Japan Science and Technology Agency, Kawaguchi, Saitama 332–0012, Japan (T.O.)
- Yamagata University, Faculty of Agriculture, Wakaba-machi, Tsuruoka-shi, Yamagata 997–8555, Japan (A.O.); and
- Graduate School of Pharmaceutical Sciences, Chiba University, Chuo-ku, Chiba 260–8522, Japan (K.S.)
| | - Hiroko Iijima
- RIKEN Center for Sustainable Resource Science, Tsurumi-ku, Yokohama, Kanagawa 230–0045, Japan (T.O., A.O., K.N., A.K., H.I., Y.D., K.S., M.Y.H.)
- PRESTO, Japan Science and Technology Agency, Kawaguchi, Saitama 332–0012, Japan (T.O.)
- Yamagata University, Faculty of Agriculture, Wakaba-machi, Tsuruoka-shi, Yamagata 997–8555, Japan (A.O.); and
- Graduate School of Pharmaceutical Sciences, Chiba University, Chuo-ku, Chiba 260–8522, Japan (K.S.)
| | - Yoshiharu Doi
- RIKEN Center for Sustainable Resource Science, Tsurumi-ku, Yokohama, Kanagawa 230–0045, Japan (T.O., A.O., K.N., A.K., H.I., Y.D., K.S., M.Y.H.)
- PRESTO, Japan Science and Technology Agency, Kawaguchi, Saitama 332–0012, Japan (T.O.)
- Yamagata University, Faculty of Agriculture, Wakaba-machi, Tsuruoka-shi, Yamagata 997–8555, Japan (A.O.); and
- Graduate School of Pharmaceutical Sciences, Chiba University, Chuo-ku, Chiba 260–8522, Japan (K.S.)
| | - Kazuki Saito
- RIKEN Center for Sustainable Resource Science, Tsurumi-ku, Yokohama, Kanagawa 230–0045, Japan (T.O., A.O., K.N., A.K., H.I., Y.D., K.S., M.Y.H.)
- PRESTO, Japan Science and Technology Agency, Kawaguchi, Saitama 332–0012, Japan (T.O.)
- Yamagata University, Faculty of Agriculture, Wakaba-machi, Tsuruoka-shi, Yamagata 997–8555, Japan (A.O.); and
- Graduate School of Pharmaceutical Sciences, Chiba University, Chuo-ku, Chiba 260–8522, Japan (K.S.)
| | | |
Collapse
|
25
|
Hakkila K, Antal T, Rehman AU, Kurkela J, Wada H, Vass I, Tyystjärvi E, Tyystjärvi T. Oxidative stress and photoinhibition can be separated in the cyanobacterium Synechocystis sp. PCC 6803. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2014; 1837:217-25. [DOI: 10.1016/j.bbabio.2013.11.011] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2013] [Revised: 11/09/2013] [Accepted: 11/15/2013] [Indexed: 01/15/2023]
|
26
|
Gunnelius L, Hakkila K, Kurkela J, Wada H, Tyystjärvi E, Tyystjärvi T. The omega subunit of the RNA polymerase core directs transcription efficiency in cyanobacteria. Nucleic Acids Res 2014; 42:4606-14. [PMID: 24476911 PMCID: PMC3985657 DOI: 10.1093/nar/gku084] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The eubacterial RNA polymerase core, a transcription machinery performing DNA-dependent RNA polymerization, consists of two α subunits and β, β' and ω subunits. An additional σ subunit is recruited for promoter recognition and transcription initiation. Cyanobacteria, a group of eubacteria characterized by oxygenic photosynthesis, have a unique composition of the RNA polymerase (RNAP) core due to splitting of the β' subunit to N-terminal γ and C-terminal β' subunits. The physiological roles of the small ω subunit of RNAP, encoded by the rpoZ gene, are not yet completely understood in any bacteria. We found that although ω is non-essential in cyanobacteria, it has a major impact on the overall gene expression pattern. In ΔrpoZ strain, recruitment of the primary σ factor into the RNAP holoenzyme is inefficient, which causes downregulation of highly expressed genes and upregulation of many low-expression genes. Especially, genes encoding proteins of photosynthetic carbon concentrating and carbon fixing complexes were down, and the ΔrpoZ mutant showed low light-saturated photosynthetic activity and accumulated photoprotective carotenoids and α-tocopherol. The results indicate that the ω subunit facilitates the association of the primary σ factor with the RNAP core, thereby allowing efficient transcription of highly expressed genes.
Collapse
Affiliation(s)
- Liisa Gunnelius
- Department of Biochemistry, University of Turku, FIN-20014 Turku, Finland and Department of Life Sciences, University of Tokyo, Komaba 3-8-1, Meguro-ku, Tokyo 153-8902, Japan
| | | | | | | | | | | |
Collapse
|
27
|
Osanai T, Kuwahara A, Iijima H, Toyooka K, Sato M, Tanaka K, Ikeuchi M, Saito K, Hirai MY. Pleiotropic effect of sigE over-expression on cell morphology, photosynthesis and hydrogen production in Synechocystis sp. PCC 6803. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2013; 76:456-65. [PMID: 23941239 DOI: 10.1111/tpj.12310] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2013] [Revised: 08/07/2013] [Accepted: 08/09/2013] [Indexed: 05/04/2023]
Abstract
Over-expression of sigE, a gene encoding an RNA polymerase sigma factor in the unicellular cyanobacterium Synechocystis sp. PCC 6803, is known to activate sugar catabolism and bioplastic production. In this study, we investigated the effects of sigE over-expression on cell morphology, photosynthesis and hydrogen production in this cyanobacterium. Transmission electron and scanning probe microscopic analyses revealed that sigE over-expression increased the cell size, possibly as a result of aberrant cell division. Over-expression of sigE reduced respiration and photosynthesis activities via changes in gene expression and chlorophyll fluorescence. Hydrogen production under micro-oxic conditions is enhanced in sigE over-expressing cells. Despite these pleiotropic phenotypes, the sigE over-expressing strain showed normal cell viability under both nitrogen-replete and nitrogen-depleted conditions. These results provide insights into the inter-relationship among metabolism, cell morphology, photosynthesis and hydrogen production in this unicellular cyanobacterium.
Collapse
Affiliation(s)
- Takashi Osanai
- RIKEN Plant Science Center, 1-7-22, Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa, 230-0045, Japan; Japan Science and Technology Agency, PRESTO, 4-1-8, Honcho, Kawaguchi, Saitama, 332-0012, Japan
| | | | | | | | | | | | | | | | | |
Collapse
|
28
|
Hakkila K, Antal T, Gunnelius L, Kurkela J, Matthijs HCP, Tyystjärvi E, Tyystjärvi T. Group 2 sigma factor mutant ΔsigCDE of the cyanobacterium Synechocystis sp. PCC 6803 reveals functionality of both carotenoids and flavodiiron proteins in photoprotection of photosystem II. PLANT & CELL PHYSIOLOGY 2013; 54:1780-1790. [PMID: 24009334 DOI: 10.1093/pcp/pct123] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Adjustment of gene expression during acclimation to stress conditions, such as bright light, in the cyanobacterium Synechocystis sp. PCC 6803 depends on four group 2 σ factors (SigB, SigC, SigD, SigE). A ΔsigCDE strain containing the stress-responsive SigB as the only functional group 2 σ factor appears twice as resistant to photoinhibition of photosystem II (PSII) as the control strain. Microarray analyses of the ΔsigCDE strain indicated that 77 genes in standard conditions and 79 genes in high light were differently expressed compared with the control strain. Analysis of possible photoprotective mechanisms revealed that high carotenoid content and up-regulation of the photoprotective flavodiiron operon flv4-sll0218-flv2 protected PSII in ΔsigCDE, while up-regulation of pgr5-like, hlipB or isiA genes in the mutant strain did not offer particular protection against photoinhibition. Photoinhibition resistance was lost if ΔsigCDE was grown in high CO2, where carotenoid and Flv4, Sll0218, and Flv2 contents were low. Additionally, photoinhibition resistance of the ΔrpoZ strain (lacking the omega subunit of RNA polymerase), with high carotenoid but low Flv4-Sll0218-Flv2 content, supported the importance of carotenoids in PSII protection. Carotenoids likely protect mainly by quenching of singlet oxygen, but efficient nonphotochemical quenching in ΔsigCDE might offer some additional protection. Comparison of photoinhibition kinetics in control, ΔsigCDE, and ΔrpoZ strains showed that protection by the flavodiiron operon was most efficient during the first minutes of high-light illumination.
Collapse
Affiliation(s)
- Kaisa Hakkila
- Department of Biochemistry, University of Turku, FI-20014 Turku, Finland
| | | | | | | | | | | | | |
Collapse
|
29
|
Tyystjärvi T, Huokko T, Rantamäki S, Tyystjärvi E. Impact of different group 2 sigma factors on light use efficiency and high salt stress in the cyanobacterium Synechocystis sp. PCC 6803. PLoS One 2013; 8:e63020. [PMID: 23638176 PMCID: PMC3637157 DOI: 10.1371/journal.pone.0063020] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2013] [Accepted: 03/27/2013] [Indexed: 11/24/2022] Open
Abstract
Sigma factors of RNA polymerase recognize promoters and have a central role in controlling transcription initiation and acclimation to changing environmental conditions. The cyanobacterium Synechocystis sp. PCC 6803 encodes four non-essential group 2 sigma factors, SigB, SigC, SigD and SigE that closely resemble the essential SigA factor. Three out of four group 2 sigma factors were simultaneously inactivated and acclimation responses of the triple inactivation strains were studied. All triple inactivation strains grew slowly in low light, and our analysis suggests that the reason is a reduced capacity to adjust the perception of light. Simultaneous inactivation of SigB and SigD hampered growth also in high light. SigB is the most important group 2 sigma factor for salt acclimation, and elimination of all the other group 2 sigma factors slightly improved the salt tolerance of Synechocystis. Presence of only SigE allowed full salt acclimation including up-regulation of hspA and ggpS genes, but more slowly than SigB. Cells with only SigD acclimated to high salt but the acclimation processes differed from those of the control strain. Presence of only SigC prevented salt acclimation.
Collapse
Affiliation(s)
- Taina Tyystjärvi
- Molecular Plant Biology, Department of Biochemistry and Food Chemistry, University of Turku, Turku, Finland.
| | | | | | | |
Collapse
|
30
|
Muramatsu M, Hihara Y. Acclimation to high-light conditions in cyanobacteria: from gene expression to physiological responses. JOURNAL OF PLANT RESEARCH 2012; 125:11-39. [PMID: 22006212 DOI: 10.1007/s10265-011-0454-6] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2011] [Accepted: 08/23/2011] [Indexed: 05/04/2023]
Abstract
Photosynthetic organisms have evolved various acclimatory responses to high-light (HL) conditions to maintain a balance between energy supply (light harvesting and electron transport) and consumption (cellular metabolism) and to protect the photosynthetic apparatus from photodamage. The molecular mechanism of HL acclimation has been extensively studied in the unicellular cyanobacterium Synechocystis sp. PCC 6803. Whole genome DNA microarray analyses have revealed that the change in gene expression profile under HL is closely correlated with subsequent acclimatory responses such as (1) acceleration in the rate of photosystem II turnover, (2) downregulation of light harvesting capacity, (3) development of a protection mechanism for the photosystems against excess light energy, (4) upregulation of general protection mechanism components, and (5) regulation of carbon and nitrogen assimilation. In this review article, we survey recent progress in the understanding of the molecular mechanisms of these acclimatory responses in Synechocystis sp. PCC 6803. We also briefly describe attempts to understand HL acclimation in various cyanobacterial species in their natural environments.
Collapse
Affiliation(s)
- Masayuki Muramatsu
- Division of Plant Sciences, National Institute of Agrobiological Sciences, Ibaraki, 305-8602, Japan
| | | |
Collapse
|
31
|
Nikkinen HL, Hakkila K, Gunnelius L, Huokko T, Pollari M, Tyystjärvi T. The SigB σ factor regulates multiple salt acclimation responses of the cyanobacterium Synechocystis sp. PCC 6803. PLANT PHYSIOLOGY 2012; 158:514-23. [PMID: 22095043 PMCID: PMC3252095 DOI: 10.1104/pp.111.190058] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Changing of principal σ factor in RNA polymerase holoenzyme to a group 2 σ factor redirects transcription when cyanobacteria acclimate to suboptimal environmental conditions. The group 2 sigma factor SigB was found to be important for the growth of the cyanobacterium Synechocystis sp. PCC 6803 in high-salt (0.7 m NaCl) stress but not in mild heat stress at 43°C although the expression of the sigB gene was similarly highly, but only transiently up-regulated at both conditions. The SigB factor was found to regulate many salt acclimation processes. The amount of glucosylglycerol-phosphate synthase, a key enzyme in the production of the compatible solute glucosylglycerol, was lower in the inactivation strain ΔsigB than in the control strain. Addition of the compatible solute trehalose almost completely restored the growth of the ΔsigB strain at 0.7 m NaCl. High-salt conditions lowered the chlorophyll and phycobilin contents of the cells while protective carotenoid pigments, especially zeaxanthin and myxoxanthophyll, were up-regulated in the control strain. These carotenoids were up-regulated in the ΔsigCDE strain (SigB is the only functional group 2 σ factor) and down-regulated in the ΔsigB strain under standard conditions. In addition, the HspA heat shock protein was less abundant and more abundant in the ΔsigB and ΔsigCDE strains, respectively, than in the control strain in high-salt conditions. Some cellular responses are common to heat and salt stresses, but pretreatment with mild heat did not protect cells against salt shock although protection against heat shock was evident.
Collapse
|