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Bolay P, Dodge N, Janssen K, Jensen PE, Lindberg P. Tailoring regulatory components for metabolic engineering in cyanobacteria. PHYSIOLOGIA PLANTARUM 2024; 176:e14316. [PMID: 38686633 DOI: 10.1111/ppl.14316] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Revised: 03/26/2024] [Accepted: 04/03/2024] [Indexed: 05/02/2024]
Abstract
The looming climate crisis has prompted an ever-growing interest in cyanobacteria due to their potential as sustainable production platforms for the synthesis of energy carriers and value-added chemicals from CO2 and sunlight. Nonetheless, cyanobacteria are yet to compete with heterotrophic systems in terms of space-time yields and consequently production costs. One major drawback leading to the low production performance observed in cyanobacteria is the limited ability to utilize the full capacity of the photosynthetic apparatus and its associated systems, i.e. CO2 fixation and the directly connected metabolism. In this review, novel insights into various levels of metabolic regulation of cyanobacteria are discussed, including the potential of targeting these regulatory mechanisms to create a chassis with a phenotype favorable for photoautotrophic production. Compared to conventional metabolic engineering approaches, minor perturbations of regulatory mechanisms can have wide-ranging effects.
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Affiliation(s)
- Paul Bolay
- Microbial Chemistry, Department of Chemistry - Ångström, Uppsala University, Uppsala, SE, Sweden
| | - Nadia Dodge
- Plant Based Foods and Biochemistry, Food Analytics and Biotechnology, Department of Food Science, University of Copenhagen, Denmark
| | - Kim Janssen
- Microbial Chemistry, Department of Chemistry - Ångström, Uppsala University, Uppsala, SE, Sweden
| | - Poul Erik Jensen
- Plant Based Foods and Biochemistry, Food Analytics and Biotechnology, Department of Food Science, University of Copenhagen, Denmark
| | - Pia Lindberg
- Microbial Chemistry, Department of Chemistry - Ångström, Uppsala University, Uppsala, SE, Sweden
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2
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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.
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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
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3
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Srivastava A, Thapa S, Chakdar H, Babele PK, Shukla P. Cyanobacterial myxoxanthophylls: biotechnological interventions and biological implications. Crit Rev Biotechnol 2024; 44:63-77. [PMID: 36137567 DOI: 10.1080/07388551.2022.2117682] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2022] [Revised: 07/09/2022] [Accepted: 08/06/2022] [Indexed: 11/03/2022]
Abstract
Cyanobacteria safeguard their photosynthetic machinery from oxidative damage caused by adverse environmental factors such as high-intensity light. Together with many photoprotective compounds, they contain myxoxanthophylls, a rare group of glycosidic carotenoids containing a high number of conjugated double bonds. These carotenoids have been shown to: have strong photoprotective effects, contribute to the integrity of the thylakoid membrane, and upregulate in cyanobacteria under a variety of stress conditions. However, their metabolic potential has not been fully utilized in the stress biology of cyanobacteria and the pharmaceutical industry due to a lack of mechanistic understanding and their insufficient biosynthesis. This review summarizes current knowledge on: biological function, genetic regulation, biotechnological production, and pharmaceutical potential of myxoxanthophyll, with a focus on strain engineering and parameter optimization strategies for increasing their cellular content. The summarized knowledge can be utilized in cyanobacterial metabolic engineering to improve the stress tolerance of useful strains and enhance the commercial-scale synthesis of myxoxanthophyll for pharmaceutical uses.
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Affiliation(s)
- Amit Srivastava
- Department of Chemistry, Purdue University, West Lafayette, United States of America
| | - Shobit Thapa
- ICAR-National Bureau of Agriculturally Important Microorganisms (NBAIM), Mau, India
| | - Hillol Chakdar
- ICAR-National Bureau of Agriculturally Important Microorganisms (NBAIM), Mau, India
| | | | - Pratyoosh Shukla
- Enzyme Technology and Protein Bioinformatics Laboratory, School of Biotechnology, Institute of Science, Banaras Hindu University, Varanasi, India
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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.
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Bouaïcha N, Metcalf JS, Porzani SJ, Konur O. Plant-cyanobacteria interactions: Beneficial and harmful effects of cyanobacterial bioactive compounds on soil-plant systems and subsequent risk to animal and human health. PHYTOCHEMISTRY 2021; 192:112959. [PMID: 34649057 DOI: 10.1016/j.phytochem.2021.112959] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2021] [Revised: 09/10/2021] [Accepted: 09/15/2021] [Indexed: 05/17/2023]
Abstract
Plant-cyanobacteria interactions occur in different ways and at many different levels, both beneficial and harmful. Plant-cyanobacteria interactions, as a beneficial symbiosis, have long been demonstrated in rice-growing areas (Poaceae) where the most efficient nitrogen-fixing cyanobacteria are present in paddies. Moreover, cyanobacteria may in turn produce and/or secrete numerous bioactive compounds that have plant growth-promoting abilities or that may make the plant more resistant to abiotic or biotic stress. In recent years, there has been a growing worldwide interest in the use of cyanobacterial biomass as biofertilizers to replace chemical fertilizers, in part to overcome increasing organic-farming demands. However, the potential presence of harmful cyanotoxins has delayed the use of such cyanobacterial biomass, which can be found in large quantities in freshwater ecosystems around the world. In this review, we describe the existing evidence for the positive benefit of plant-cyanobacteria interactions and discuss the use of cyanobacterial biomass as biofertilizers and its growing worldwide interest. Although mass cyanobacterial blooms and scums are a current and emerging threat to the degradation of ecosystems and to animal and human health, they may serve as a source of numerous bioactive compounds with multiple positive effects that could be of use as an alternative to chemical fertilizers in the context of sustainable development.
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Affiliation(s)
- Noureddine Bouaïcha
- Laboratory Ecology, Systematic and Evolution, UMR 8079 Univ. Paris-Sud, CNRS, AgroParisTech, University Paris-Saclay, 91405, Orsay, France
| | | | - Samaneh Jafari Porzani
- Department of Biology, Science and Research Branch, Islamic Azad University, Tehran, Iran
| | - Ozcan Konur
- Formerly, Ankara Yildirim Beyazit University, Ankara, Turkey
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Takashima K, Nagao S, Kizawa A, Suzuki T, Dohmae N, Hihara Y. The role of transcriptional repressor activity of LexA in salt-stress responses of the cyanobacterium Synechocystis sp. PCC 6803. Sci Rep 2020; 10:17393. [PMID: 33060671 PMCID: PMC7567884 DOI: 10.1038/s41598-020-74534-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2020] [Accepted: 10/05/2020] [Indexed: 12/24/2022] Open
Abstract
Different from typical LexA repressors in heterotrophic bacteria exerting SOS response by auto-cleavage, cyanobacterial LexAs, especially that of Synechocystis sp. PCC 6803 (S.6803), have been suggested be involved in regulation of a number of genes related to various cellular processes, rather than the typical SOS regulon. When and how cyanobacterial LexAs are triggered to regulate its target genes have remained unknown. In this study, we found the profound repressing effect of LexA on salt-stress inducible genes in S.6803. The repressing activity of LexA was likely to persist during salt stress and the salt response of these genes was mainly achieved by other regulators than LexA, suggesting that the physiological role of LexA is fine-tuning of gene expression in response to environmental changes. Although the amount and oligomeric state of LexA were unchanged upon salt stress, two-dimensional electrophoresis and liquid chromatography-tandem mass spectrometry analyses detected a change in posttranslational modification in a small fraction of LexA molecules, possibly dephosphorylation of Ser173, after 30 min upon the upshift in salt concentration. Activity of LexA in S.6803 may be under gradual control by posttranslational modification to fine-tune gene expression, which is contrasted with the digital switching-off regulation by auto-cleavage in heterotrophic bacteria.
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Affiliation(s)
- Kosuke Takashima
- Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Saitama, 338-8570, Japan
| | - Syota Nagao
- Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Saitama, 338-8570, Japan
| | - Ayumi Kizawa
- Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Saitama, 338-8570, Japan.,Department of Biological Sciences, Faculty of Science and Engineering, Chuo University, 1-13-27 Kasuga, Bunkyo-ku, Tokyo, 112-8551, Japan
| | - Takehiro Suzuki
- Biomolecular Characterization Unit, RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan
| | - Naoshi Dohmae
- Biomolecular Characterization Unit, RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan
| | - Yukako Hihara
- Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Saitama, 338-8570, Japan.
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Engineering salt tolerance of photosynthetic cyanobacteria for seawater utilization. Biotechnol Adv 2020; 43:107578. [PMID: 32553809 DOI: 10.1016/j.biotechadv.2020.107578] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2020] [Revised: 05/17/2020] [Accepted: 06/05/2020] [Indexed: 02/04/2023]
Abstract
Photosynthetic cyanobacteria are capable of utilizing sunlight and CO2 as sole energy and carbon sources, respectively. With genetically modified cyanobacteria being used as a promising chassis to produce various biofuels and chemicals in recent years, future large-scale cultivation of cyanobacteria would have to be performed in seawater, since freshwater supplies of the earth are very limiting. However, high concentration of salt is known to inhibit the growth of cyanobacteria. This review aims at comparing the mechanisms that different cyanobacteria respond to salt stress, and then summarizing various strategies of developing salt-tolerant cyanobacteria for seawater cultivation, including the utilization of halotolerant cyanobacteria and the engineering of salt-tolerant freshwater cyanobacteria. In addition, the challenges and potential strategies related to further improving salt tolerance in cyanobacteria are also discussed.
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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]
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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.
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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.
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Genomic Survey of Salt Acclimation-Related Genes in the Halophilic Cyanobacterium Euhalothece sp. Z-M001. Sci Rep 2020; 10:676. [PMID: 31959801 PMCID: PMC6971039 DOI: 10.1038/s41598-020-57546-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Accepted: 01/02/2020] [Indexed: 12/30/2022] Open
Abstract
Like other halophilic cyanobacterial genomes, the de novo-assembled genome of Euhalothece sp. Z-M001 lacks genes encoding keto-carotenoid biosynthesis enzymes, despite the presence of genes encoding carotenoid-binding proteins (CBPs). Consistent with this, HPLC analysis of carotenoids identified β-carotene and zeaxanthin as the dominant carotenoids. CBPs coexpressed with the zeaxanthin biosynthesis gene increased the survival rates of Escherichia coli strains by preventing antibiotic-induced accumulation of reactive oxygen species (ROS). RNA-seq analysis of Euhalothece revealed that among various salt resistance-related genes, those encoding the Na+ transporting multiple resistance and pH adaptation (Mrp) systems, glycine betaine biosynthesis enzymes, exopolysaccharide metabolic enzymes, and CBPs were highly upregulated, suggesting their importance in hypersaline habitats. During the early phase of salt deprivation, the amounts of β-carotene and zeaxanthin showed a negative correlation with ROS content. Overall, we propose that in some halophilic cyanobacteria, β-carotene and zeaxanthin, rather than keto-carotenoids, serve as the major chromophores for CBPs, which in turn act as effective antioxidants.
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Wu W, Du W, Gallego RP, Hellingwerf KJ, van der Woude AD, Branco dos Santos F. Using osmotic stress to stabilize mannitol production in Synechocystis sp. PCC6803. BIOTECHNOLOGY FOR BIOFUELS 2020; 13:117. [PMID: 32636923 PMCID: PMC7331161 DOI: 10.1186/s13068-020-01755-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Accepted: 06/23/2020] [Indexed: 05/03/2023]
Abstract
BACKGROUND Mannitol is a C(6) polyol that is used in the food and medical sector as a sweetener and antioxidant, respectively. The sustainable production of mannitol, especially via the direct conversion of CO2 by photosynthetic cyanobacteria, has become increasingly appealing. However, previous work aiming to achieve mannitol production in the marine Synechococcus sp. PCC7002 via heterologous expression of mannitol-1-phosphate-5-dehydrogenase (mtlD) and mannitol-1-phosphatase (m1p, in short: a 'mannitol cassette'), proved to be genetically unstable. In this study, we aim to overcome this genetic instability by conceiving a strategy to stabilize mannitol production using Synechocystis sp. PCC6803 as a model cyanobacterium. RESULTS Here, we explore the stabilizing effect that mannitol production may have on cells faced with osmotic stress, in the freshwater cyanobacterium Synechocystis sp. PCC6803. We first validated that mannitol can function as a compatible solute in Synechocystis sp. PCC6803, and in derivative strains in which the ability to produce one or both of the native compatible solutes was impaired. Wild-type Synechocystis, complemented with a mannitol cassette, indeed showed increased salt tolerance, which was even more evident in Synechocystis strains in which the ability to synthesize the endogenous compatible solutes was impaired. Next we tested the genetic stability of all these strains with respect to their mannitol productivity, with and without salt stress, during prolonged turbidostat cultivations. The obtained results show that mannitol production under salt stress conditions in the Synechocystis strain that cannot synthesize its endogenous compatible solutes is remarkably stable, while the control strain completely loses this ability in only 6 days. DNA sequencing results of the control groups that lost the ability to synthesize mannitol revealed that multiple types of mutation occurred in the mtlD gene that can explain the disruption of mannitol production. CONCLUSIONS Mannitol production in freshwater Synechocsytis sp. PCC6803 confers it with increased salt tolerance. Under this strategy, genetically instability which was the major challenge for mannitol production in cyanobacteria is tackled. This paper marks the first report of utilization of the response to salt stress as a factor that can increase the stability of mannitol production in a cyanobacterial cell factory.
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Affiliation(s)
- Wenyang Wu
- Molecular Microbial Physiology Group, Swammerdam Institute for Life Sciences, Faculty of Science, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Wei Du
- Molecular Microbial Physiology Group, Swammerdam Institute for Life Sciences, Faculty of Science, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Ruth Perez Gallego
- Photanol B.V, Matrix V, Science Park 406, 1098 XH Amsterdam, The Netherlands
- Present Address: NIOZ Royal Netherlands Institute for Sea Research, Department of Marine Microbiology and Biogeochemistry, Utrecht University, P.O. Box 59, Den Burg, Texel, 1790 AB Utrecht, The Netherlands
| | - Klaas J. Hellingwerf
- Molecular Microbial Physiology Group, Swammerdam Institute for Life Sciences, Faculty of Science, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
- Photanol B.V, Matrix V, Science Park 406, 1098 XH Amsterdam, The Netherlands
| | | | - Filipe Branco dos Santos
- Molecular Microbial Physiology Group, Swammerdam Institute for Life Sciences, Faculty of Science, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
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Transcription in cyanobacteria: a distinctive machinery and putative mechanisms. Biochem Soc Trans 2019; 47:679-689. [DOI: 10.1042/bst20180508] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Revised: 01/11/2019] [Accepted: 02/04/2019] [Indexed: 02/03/2023]
Abstract
Abstract
Transcription in cyanobacteria involves several fascinating features. Cyanobacteria comprise one of the very few groups in which no proofreading factors (Gre homologues) have been identified. Gre factors increase the efficiency of RNA cleavage, therefore helping to maintain the fidelity of the RNA transcript and assist in the resolution of stalled RNAPs to prevent genome damage. The vast majority of bacterial species encode at least one of these highly conserved factors and so their absence in cyanobacteria is intriguing. Additionally, the largest subunit of bacterial RNAP has undergone a split in cyanobacteria to form two subunits and the SI3 insertion within the integral trigger loop element is roughly 3.5 times larger than in Escherichia coli. The Rho termination factor also appears to be absent, leaving cyanobacteria to rely solely on an intrinsic termination mechanism. Furthermore, cyanobacteria must be able to respond to environment signals such as light intensity and tightly synchronise gene expression and other cell activities to a circadian rhythm.
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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.
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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
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Cui L, Liu Y, Yang Y, Ye S, Luo H, Qiu B, Gao X. The drnf1 Gene from the Drought-Adapted Cyanobacterium Nostoc flagelliforme Improved Salt Tolerance in Transgenic Synechocystis and Arabidopsis Plant. Genes (Basel) 2018; 9:genes9090441. [PMID: 30181517 PMCID: PMC6162714 DOI: 10.3390/genes9090441] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2018] [Revised: 08/26/2018] [Accepted: 08/28/2018] [Indexed: 01/06/2023] Open
Abstract
Environmental abiotic stresses are limiting factors for less tolerant organisms, including soil plants. Abiotic stress tolerance-associated genes from prokaryotic organisms are supposed to have a bright prospect for transgenic application. The drought-adapted cyanobacterium Nostoc flagelliforme is arising as a valuable prokaryotic biotic resource for gene excavation. In this study, we evaluated the salt-tolerant function and application potential of a candidate gene drnf1 from N. flagelliforme, which contains a P-loop NTPase (nucleoside-triphosphatase) domain, through heterologous expression in two model organisms Synechocystis sp. PCC 6803 and Arabidopsis thaliana. It was found that DRNF1 could confer significant salt tolerance in both transgenic organisms. In salt-stressed transgenic Synechocystis, DRNF1 could enhance the respiration rate; slow-down the accumulation of exopolysaccharides; up-regulate the expression of salt tolerance-related genes at a higher level, such as those related to glucosylglycerol synthesis, Na+/H+ antiport, and sugar metabolism; and maintain a better K+/Na+ homeostasis, as compared to the wild-type strain. These results imply that DRNF1 could facilitate salt tolerance by affecting the respiration metabolism and indirectly regulating the expression of important salt-tolerant genes. Arabidopsis was employed to evaluate the salt tolerance-conferring potential of DRNF1 in plants. The results show that it could enhance the seed germination and shoot growth of transgenic plants under saline conditions. In general, a novel prokaryotic salt-tolerant gene from N. flagelliforme was identified and characterized in this study, enriching the candidate gene pool for genetic engineering in plants.
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Affiliation(s)
- Lijuan Cui
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan 430079, China.
| | - Yinghui Liu
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan 430079, China.
| | - Yiwen Yang
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan 430079, China.
| | - Shuifeng Ye
- Shanghai Agrobiological Gene Center, Shanghai 201106, China.
| | - Hongyi Luo
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan 430079, China.
| | - Baosheng Qiu
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan 430079, China.
| | - Xiang Gao
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan 430079, China.
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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.
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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.
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16
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Ge H, Fang L, Huang X, Wang J, Chen W, Liu Y, Zhang Y, Wang X, Xu W, He Q, Wang Y. Translating Divergent Environmental Stresses into a Common Proteome Response through the Histidine Kinase 33 (Hik33) in a Model Cyanobacterium. Mol Cell Proteomics 2018; 16:1258-1274. [PMID: 28668777 DOI: 10.1074/mcp.m116.068080] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2017] [Revised: 05/07/2017] [Indexed: 01/18/2023] Open
Abstract
The histidine kinase Hik33 plays important roles in mediating cyanobacterial response to divergent types of abiotic stresses including cold, salt, high light (HL), and osmotic stresses. However, how these functions are regulated by Hik33 remains to be addressed. Using a hik33-deficient strain (Δhik33) of Synechocystis sp. PCC 6803 (Synechocystis) and quantitative proteomics, we found that Hik33 depletion induces differential protein expression highly like that induced by divergent types of stresses. This typically includes downregulation of proteins in photosynthesis and carbon assimilation that are necessary for cell propagation, and upregulation of heat shock proteins, chaperons, and proteases that are important for cell survival. This observation indicates that depletion of Hik33 alone mimics divergent types of abiotic stresses, and that Hik33 could be important for preventing abnormal stress response in the normal condition. Moreover, we found most proteins of plasmid origin were significantly upregulated in Δhik33, though their biological significance remains to be addressed. Together, the systematically characterized Hik33-regulated cyanobacterial proteome, which is largely involved in stress responses, builds the molecular basis for Hik33 as a general regulator of stress responses.
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Affiliation(s)
- Haitao Ge
- From the ‡State Key Laboratory of Microbial Technology, College of Life Science, Shandong University, Jinan 250100, China
| | - Longfa Fang
- §State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, No.1 West Beichen Rd., Beijing 100101, China.,¶University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Xiahe Huang
- §State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, No.1 West Beichen Rd., Beijing 100101, China
| | - Jinlong Wang
- §State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, No.1 West Beichen Rd., Beijing 100101, China.,¶University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Weiyang Chen
- §State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, No.1 West Beichen Rd., Beijing 100101, China.,¶University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Ye Liu
- §State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, No.1 West Beichen Rd., Beijing 100101, China.,¶University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yuanya Zhang
- §State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, No.1 West Beichen Rd., Beijing 100101, China
| | - Xiaorong Wang
- §State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, No.1 West Beichen Rd., Beijing 100101, China.,¶University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Wu Xu
- ‖Department of Chemistry, University of Louisiana at Lafayette, Lafayette, Louisiana 70504
| | - Qingfang He
- From the ‡State Key Laboratory of Microbial Technology, College of Life Science, Shandong University, Jinan 250100, China; .,**Department of Applied Science, University of Arkansas at Little Rock, Little Rock, Arkansas
| | - Yingchun Wang
- §State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, No.1 West Beichen Rd., Beijing 100101, China; .,¶University of Chinese Academy of Sciences, Beijing, 100049, China
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17
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Teikari JE, Hou S, Wahlsten M, Hess WR, Sivonen K. Comparative Genomics of the Baltic Sea Toxic Cyanobacteria Nodularia spumigena UHCC 0039 and Its Response to Varying Salinity. Front Microbiol 2018; 9:356. [PMID: 29568283 PMCID: PMC5853447 DOI: 10.3389/fmicb.2018.00356] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Accepted: 02/14/2018] [Indexed: 11/13/2022] Open
Abstract
Salinity is an important abiotic factor controlling the distribution and abundance of Nodularia spumigena, the dominating diazotrophic and toxic phototroph, in the brackish water cyanobacterial blooms of the Baltic Sea. To expand the available genomic information for brackish water cyanobacteria, we sequenced the isolate Nodularia spumigena UHCC 0039 using an Illumina-SMRT hybrid sequencing approach, revealing a chromosome of 5,294,286 base pairs (bp) and a single plasmid of 92,326 bp. Comparative genomics in Nostocales showed pronounced genetic similarity among Nodularia spumigena strains evidencing their short evolutionary history. The studied Baltic Sea strains share similar sets of CRISPR-Cas cassettes and a higher number of insertion sequence (IS) elements compared to Nodularia spumigena CENA596 isolated from a shrimp production pond in Brazil. Nodularia spumigena UHCC 0039 proliferated similarly at three tested salinities, whereas the lack of salt inhibited its growth and triggered transcriptome remodeling, including the up-regulation of five sigma factors and the down-regulation of two other sigma factors, one of which is specific for strain UHCC 0039. Down-regulated genes additionally included a large genetic region for the synthesis of two yet unidentified natural products. Our results indicate a remarkable plasticity of the Nodularia salinity acclimation, and thus salinity strongly impacts the intensity and distribution of cyanobacterial blooms in the Baltic Sea.
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Affiliation(s)
- Jonna E Teikari
- Department of Microbiology, University of Helsinki, Helsinki, Finland
| | - Shengwei Hou
- Genetics and Experimental Bioinformatics, Institute of Biology III, University of Freiburg, Freiburg, Germany
| | - Matti Wahlsten
- Department of Microbiology, University of Helsinki, Helsinki, Finland
| | - Wolfgang R Hess
- Genetics and Experimental Bioinformatics, Institute of Biology III, University of Freiburg, Freiburg, Germany.,Freiburg Institute for Advanced Studies, University of Freiburg, Freiburg, Germany
| | - Kaarina Sivonen
- Department of Microbiology, University of Helsinki, Helsinki, Finland
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18
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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]
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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.
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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
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20
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6S RNA plays a role in recovery from nitrogen depletion in Synechocystis sp. PCC 6803. BMC Microbiol 2017; 17:229. [PMID: 29216826 PMCID: PMC5721685 DOI: 10.1186/s12866-017-1137-9] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Accepted: 11/27/2017] [Indexed: 12/30/2022] Open
Abstract
Background The 6S RNA is a global transcriptional riboregulator, which is exceptionally widespread among most bacterial phyla. While its role is well-characterized in some heterotrophic bacteria, we subjected a cyanobacterial homolog to functional analysis, thereby extending the scope of 6S RNA action to the special challenges of photoautotrophic lifestyles. Results Physiological characterization of a 6S RNA deletion strain (ΔssaA) demonstrates a delay in the recovery from nitrogen starvation. Significantly decelerated phycobilisome reassembly and glycogen degradation are accompanied with reduced photosynthetic activity compared to the wild type. Transcriptome profiling further revealed that predominantly genes encoding photosystem components, ATP synthase, phycobilisomes and ribosomal proteins were negatively affected in ΔssaA. In vivo pull-down studies of the RNA polymerase complex indicated that the presence of 6S RNA promotes the recruitment of the cyanobacterial housekeeping σ factor SigA, concurrently supporting dissociation of group 2 σ factors during recovery from nitrogen starvation. Conclusions The combination of genetic, physiological and biochemical studies reveals the homologue of 6S RNA as an integral part of the cellular response of Synechocystis sp. PCC 6803 to changing nitrogen availability. According to these results, 6S RNA supports a rapid acclimation to changing nitrogen supply by accelerating the switch from group 2 σ factors SigB, SigC and SigE to SigA-dependent transcription. We therefore introduce the cyanobacterial 6S RNA as a novel candidate regulator of RNA polymerase sigma factor recruitment in Synechocystis sp. PCC 6803. Further studies on mechanistic features of the postulated interaction should shed additional light on the complexity of transcriptional regulation in cyanobacteria. Electronic supplementary material The online version of this article (10.1186/s12866-017-1137-9) contains supplementary material, which is available to authorized users.
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21
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Gao X, Sun T, Wu L, Chen L, Zhang W. Co-overexpression of response regulator genes slr1037 and sll0039 improves tolerance of Synechocystis sp. PCC 6803 to 1-butanol. BIORESOURCE TECHNOLOGY 2017; 245:1476-1483. [PMID: 28533065 DOI: 10.1016/j.biortech.2017.04.112] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2017] [Revised: 04/26/2017] [Accepted: 04/28/2017] [Indexed: 05/22/2023]
Abstract
In this study, two response regulator (RR) encoding genes slr1037 as well as sll0039 were co-overexpressed in Synechocystis sp. PCC 6803 by metabolic engineering and the 1-butanol tolerance was successfully improved by 133%. Aiming to explore the possible mechanisms for the enhancing 1-butanol tolerance, a quantitative iTRAQ-LC-MS/MS proteomics approach was then employed, identifying 216 up-regulated and 99 down-regulated proteins compared to wild type after 1-butanol treatment. This study mapped the potential target genes regulated by Slr1037 and Sll0039 and demonstrated the feasibility of engineering response regulators for modifying the biofuel tolerance in cyanobacteria.
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Affiliation(s)
- Xinyan Gao
- Laboratory of Synthetic Microbiology, School of Chemical Engineering & Technology, Tianjin University, Tianjin, PR China; Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin, PR China; SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, PR China
| | - Tao Sun
- Laboratory of Synthetic Microbiology, School of Chemical Engineering & Technology, Tianjin University, Tianjin, PR China; Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin, PR China; SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, PR China
| | - Lina Wu
- Laboratory of Synthetic Microbiology, School of Chemical Engineering & Technology, Tianjin University, Tianjin, PR China; Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin, PR China; SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, PR China
| | - Lei Chen
- Laboratory of Synthetic Microbiology, School of Chemical Engineering & Technology, Tianjin University, Tianjin, PR China; Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin, PR China; SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, PR China.
| | - Weiwen Zhang
- Laboratory of Synthetic Microbiology, School of Chemical Engineering & Technology, Tianjin University, Tianjin, PR China; Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin, PR China; SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, PR China; Center for Biosafety Research and Strategy, Tianjin University, Tianjin, PR China
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22
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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.
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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
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Rantamäki S, Meriluoto J, Spoof L, Puputti EM, Tyystjärvi T, Tyystjärvi E. Oxygen produced by cyanobacteria in simulated Archaean conditions partly oxidizes ferrous iron but mostly escapes-conclusions about early evolution. PHOTOSYNTHESIS RESEARCH 2016; 130:103-111. [PMID: 26895438 DOI: 10.1007/s11120-016-0231-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2015] [Accepted: 02/10/2016] [Indexed: 06/05/2023]
Abstract
The Earth has had a permanently oxic atmosphere only since the great oxygenation event (GOE) 2.3-2.4 billion years ago but recent geochemical research has revealed short periods of oxygen in the atmosphere up to a billion years earlier before the permanent oxygenation. If these "whiffs" of oxygen truly occurred, then oxygen-evolving (proto)cyanobacteria must have existed throughout the Archaean aeon. Trapping of oxygen by ferrous iron and other reduced substances present in Archaean oceans has often been suggested to explain why the oxygen content of the atmosphere remained negligible before the GOE although cyanobacteria produced oxygen. We tested this hypothesis by growing cyanobacteria in anaerobic high-CO2 atmosphere in a medium with a high concentration of ferrous iron. Microcystins are known to chelate iron, which prompted us also to test the effects of microcystins and nodularins on iron tolerance. The results show that all tested cyanobacteria, especially nitrogen-fixing species grown in the absence of nitrate, and irrespective of the ability to produce cyanotoxins, were iron sensitive in aerobic conditions but tolerated high concentrations of iron in anaerobicity. This result suggests that current cyanobacteria would have tolerated the high-iron content of Archaean oceans. However, only 1 % of the oxygen produced by the cyanobacterial culture was trapped by iron, suggesting that large-scale cyanobacterial photosynthesis would have oxygenated the atmosphere even if cyanobacteria grew in a reducing ocean. Recent genomic analysis suggesting that ability to colonize seawater is a secondary trait in cyanobacteria may offer a partial explanation for the sustained inefficiency of cyanobacterial photosynthesis during the Archaean aeon, as fresh water has always covered a very small fraction of the Earth's surface. If oxygenic photosynthesis originated in fresh water, then the GOE marks the adaptation of cyanobacteria to seawater, and the late-Proterozoic increase in oxygen concentration of the atmosphere is caused by full oxidation of the oceans.
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Affiliation(s)
- Susanne Rantamäki
- Department of Biochemistry/Molecular Plant Biology, University of Turku, 20014, Turku, Finland
| | - Jussi Meriluoto
- Biochemistry, Faculty of Biosciences, Åbo Akademi University, Tykistökatu 6 A, 20520, Turku, Finland
| | - Lisa Spoof
- Biochemistry, Faculty of Biosciences, Åbo Akademi University, Tykistökatu 6 A, 20520, Turku, Finland
| | - Eeva-Maija Puputti
- 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
| | - Esa Tyystjärvi
- Department of Biochemistry/Molecular Plant Biology, University of Turku, 20014, Turku, Finland.
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Spermidine Synthase is Required for Growth of Synechococcus sp. PCC 7942 Under Osmotic Stress. Curr Microbiol 2016; 73:639-645. [PMID: 27460582 DOI: 10.1007/s00284-016-1107-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Accepted: 07/18/2016] [Indexed: 10/21/2022]
Abstract
The Synechococcus sp. PCC 7942 spermidine synthase encoded by spds gene (Synpcc7942_0628) is responsible for spermidine biosynthesis. Two Synechococcus strains, the overexpressing spds (OX-spds) and the spds knockout (Δspds), were constructed and characterized for their growth and photosynthetic efficiency under osmotic stress imposed by sorbitol. The growth of Δspds was completely inhibited when cells were grown in the presence of 400 mM sorbitol. Under the same condition, the OX-spds showed a slightly higher growth than the wild type. The OX-spds under osmotic stress also had a significant increase of spermidine level in conjunction with the up-regulation of the genes involved in spermidine biosynthesis. A higher ratio of spermidine to putrescine, an index for stress tolerance, under osmotic stress was found in the OX-spds strain than in the wild type. Overall results indicated that the spermidine synthase enzyme plays an essential role in the survival of Synechococcus sp. PCC 7942 under osmotic stress.
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Galmozzi CV, Florencio FJ, Muro-Pastor MI. The Cyanobacterial Ribosomal-Associated Protein LrtA Is Involved in Post-Stress Survival in Synechocystis sp. PCC 6803. PLoS One 2016; 11:e0159346. [PMID: 27442126 PMCID: PMC4956104 DOI: 10.1371/journal.pone.0159346] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2016] [Accepted: 06/30/2016] [Indexed: 02/06/2023] Open
Abstract
A light-repressed transcript encodes the LrtA protein in cyanobacteria. We show that half-life of lrtA transcript from Synechocystis sp. PCC 6803 is higher in dark-treated cells as compared to light-grown cells, suggesting post-transcriptional control of lrtA expression. The lrtA 5´ untranslated leader region is involved in that darkness-dependent regulation. We also found that Synechocystis sp. PCC 6803 LrtA is a ribosome-associated protein present in both 30S and 70S ribosomal particles. In order to investigate the function of this protein we have constructed a deletion mutant of the lrtA gene. Cells lacking LrtA (∆lrtA) had significantly lower amount of 70S particles and a greater amount of 30S and 50S particles, suggesting a role of LrtA in stabilizing 70S particles. Synechocystis strains with different amounts of LrtA protein: wild-type, ∆lrtA, and LrtAS (overexpressing lrtA) showed no differences in their growth rate under standard laboratory conditions. However, a clear LrtA dose-dependent effect was observed in the presence of the antibiotic tylosin, being the LrtAS strains the most sensitive. Similar results were obtained under hyperosmotic stress caused by sorbitol. Conversely, after prolonged periods of starvation, ∆lrtA strains were delayed in their growth with respect to the wild-type and the LrtAS strains. A positive role of LrtA protein in post-stress survival is proposed.
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Affiliation(s)
- Carla V. Galmozzi
- Instituto de Bioquímica Vegetal y Fotosíntesis, CSIC-Universidad de Sevilla, Sevilla, Spain
| | - Francisco J. Florencio
- Instituto de Bioquímica Vegetal y Fotosíntesis, CSIC-Universidad de Sevilla, Sevilla, Spain
| | - M. Isabel Muro-Pastor
- Instituto de Bioquímica Vegetal y Fotosíntesis, CSIC-Universidad de Sevilla, Sevilla, Spain
- * E-mail:
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26
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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.
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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
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Kizawa A, Kawahara A, Takimura Y, Nishiyama Y, Hihara Y. RNA-seq Profiling Reveals Novel Target Genes of LexA in the Cyanobacterium Synechocystis sp. PCC 6803. Front Microbiol 2016; 7:193. [PMID: 26925056 PMCID: PMC4759255 DOI: 10.3389/fmicb.2016.00193] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Accepted: 02/04/2016] [Indexed: 11/13/2022] Open
Abstract
LexA is a well-established transcriptional repressor of SOS genes induced by DNA damage in Escherichia coli and other bacterial species. However, LexA in the cyanobacterium Synechocystis sp. PCC 6803 has been suggested not to be involved in SOS response. In this study, we performed RNA-seq analysis of the wild-type strain and the lexA-disrupted mutant to obtain the comprehensive view of LexA-regulated genes in Synechocystis. Disruption of lexA positively or negatively affected expression of genes related to various cellular functions such as phototactic motility, accumulation of the major compatible solute glucosylglycerol and subunits of bidirectional hydrogenase, photosystem I, and phycobilisome complexes. We also observed increase in the expression level of genes related to iron and manganese uptake in the mutant at the later stage of cultivation. However, none of the genes related to DNA metabolism were affected by disruption of lexA. DNA gel mobility shift assay using the recombinant LexA protein suggested that LexA binds to the upstream region of pilA7, pilA9, ggpS, and slr1670 to directly regulate their expression, but changes in the expression level of photosystem I genes by disruption of lexA is likely a secondary effect.
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Affiliation(s)
- Ayumi Kizawa
- Department of Biochemistry and Molecular Biology, Graduate School of Science and Engineering, Saitama University Saitama, Japan
| | - Akihito Kawahara
- Biological Science Laboratories, KAO Corporation Wakayama, Japan
| | - Yasushi Takimura
- Biological Science Laboratories, KAO Corporation Wakayama, Japan
| | - Yoshitaka Nishiyama
- Department of Biochemistry and Molecular Biology, Graduate School of Science and Engineering, Saitama University Saitama, Japan
| | - Yukako Hihara
- Department of Biochemistry and Molecular Biology, Graduate School of Science and Engineering, Saitama UniversitySaitama, Japan; Core Research of Evolutional Science and Technology, Japan Science and Technology AgencySaitama, Japan
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Cyanobacterial chassis engineering for enhancing production of biofuels and chemicals. Appl Microbiol Biotechnol 2016; 100:3401-13. [DOI: 10.1007/s00253-016-7374-2] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Revised: 01/29/2016] [Accepted: 02/01/2016] [Indexed: 10/22/2022]
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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
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Salt acclimation of cyanobacteria and their application in biotechnology. Life (Basel) 2014; 5:25-49. [PMID: 25551682 PMCID: PMC4390839 DOI: 10.3390/life5010025] [Citation(s) in RCA: 87] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Accepted: 12/19/2014] [Indexed: 12/25/2022] Open
Abstract
The long evolutionary history and photo-autotrophic lifestyle of cyanobacteria has allowed them to colonize almost all photic habitats on Earth, including environments with high or fluctuating salinity. Their basal salt acclimation strategy includes two principal reactions, the active export of ions and the accumulation of compatible solutes. Cyanobacterial salt acclimation has been characterized in much detail using selected model cyanobacteria, but their salt sensing and regulatory mechanisms are less well understood. Here, we briefly review recent advances in the identification of salt acclimation processes and the essential genes/proteins involved in acclimation to high salt. This knowledge is of increasing importance because the necessary mass cultivation of cyanobacteria for future use in biotechnology will be performed in sea water. In addition, cyanobacterial salt resistance genes also can be applied to improve the salt tolerance of salt sensitive organisms, such as crop plants.
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Lei H, Chen G, Wang Y, Ding Q, Wei D. Sll0528, a Site-2-Protease, Is Critically Involved in Cold, Salt and Hyperosmotic Stress Acclimation of Cyanobacterium Synechocystis sp. PCC 6803. Int J Mol Sci 2014; 15:22678-22693. [PMID: 25493476 PMCID: PMC4284730 DOI: 10.3390/ijms151222678] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2014] [Revised: 11/21/2014] [Accepted: 11/25/2014] [Indexed: 12/17/2022] Open
Abstract
Site-2-proteases (S2Ps) mediated proteolysis of transmembrane transcriptional regulators is a conserved mechanism to regulate transmembrane signaling. The universal presence of S2P homologs in different cyanobacterial genomes suggest conserved and fundamental functions, though limited data has been available. Here we provide the first evidence that Sll0528, a site-2-protease in Synechocystis sp. PCC 6803 is crucial for salt, cold and hyperosmotic stress acclimation. Remarkable induction of sll0528 gene expression was observed under salt, cold and hyperosmotic stress, much higher than induction of the other three S2Ps. Knock-out of sll0528 gene in wild type Synechocystis sp. PCC 6803 increased their sensitivity to salt, cold and hyperosmotic stress, as revealed by retarded growth, reduced pigments and disrupted photosystems. The sll0528 gene was induced to a much smaller extent by high light and mixotrophic growth with glucose. Similar growth responses of the sll0528 knockout mutant and wild type under high light and mixotrophic growth indicated that sll0528 was dispensable for these conditions. Recombinant Sll0528 protein could cleave beta-casein into smaller fragments. These results together suggest that the Sll0528 metalloprotease plays a role in the stress response and lays the foundation for further investigation of its mechanism, as well as providing hints for the functional analysis of other S2Ps in cyanobacteria.
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Affiliation(s)
- Haijin Lei
- College of Light Industry and Food Sciences, South China University of Technology, 381 Wushan Road, Guangzhou 510641, China.
| | - Gu Chen
- College of Light Industry and Food Sciences, South China University of Technology, 381 Wushan Road, Guangzhou 510641, China.
| | - Yuling Wang
- College of Light Industry and Food Sciences, South China University of Technology, 381 Wushan Road, Guangzhou 510641, China.
| | - Qinglong Ding
- College of Light Industry and Food Sciences, South China University of Technology, 381 Wushan Road, Guangzhou 510641, China.
| | - Dong Wei
- College of Light Industry and Food Sciences, South China University of Technology, 381 Wushan Road, Guangzhou 510641, China.
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Song Z, Chen L, Wang J, Lu Y, Jiang W, Zhang W. A transcriptional regulator Sll0794 regulates tolerance to biofuel ethanol in photosynthetic Synechocystis sp. PCC 6803. Mol Cell Proteomics 2014; 13:3519-32. [PMID: 25239498 DOI: 10.1074/mcp.m113.035675] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
To improve ethanol production directly from CO2 in photosynthetic cyanobacterial systems, one key issue that needs to be addressed is the low ethanol tolerance of cyanobacterial cells. Our previous proteomic and transcriptomic analyses found that several regulatory proteins were up-regulated by exogenous ethanol in Synechocystis sp. PCC6803. In this study, through tolerance analysis of the gene disruption mutants of the up-regulated regulatory genes, we uncovered that one transcriptional regulator, Sll0794, was related directly to ethanol tolerance in Synechocystis. Using a quantitative iTRAQ-LC-MS/MS proteomics approach coupled with quantitative real-time reverse transcription-PCR (RT-qPCR), we further determined the possible regulatory network of Sll0794. The proteomic analysis showed that in the Δsll0794 mutant grown under ethanol stress a total of 54 and 87 unique proteins were down- and up-regulated, respectively. In addition, electrophoretic mobility shift assays demonstrated that the Sll0794 transcriptional regulator was able to bind directly to the upstream regions of sll1514, slr1512, and slr1838, which encode a 16.6 kDa small heat shock protein, a putative sodium-dependent bicarbonate transporter and a carbon dioxide concentrating mechanism protein CcmK, respectively. The study provided a proteomic description of the putative ethanol-tolerance network regulated by the sll0794 gene, and revealed new insights on the ethanol-tolerance regulatory mechanism in Synechocystis. As the first regulatory protein discovered related to ethanol tolerance, the gene may serve as a valuable target for transcription machinery engineering to further improve ethanol tolerance in Synechocystis. All MS data have been deposited in the ProteomeXchange with identifier PXD001266 (http://proteomecentral.proteomexchange.org/dataset/PXD001266).
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Affiliation(s)
- Zhongdi Song
- From the ‡Laboratory of Synthetic Microbiology, School of Chemical Engineering & Technology, Tianjin University, Tianjin 300072, P.R. China; §Key Laboratory of Systems Bioengineering, Ministry of Education of China, Tianjin 300072, P.R. China; ¶Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, P.R. China
| | - Lei Chen
- From the ‡Laboratory of Synthetic Microbiology, School of Chemical Engineering & Technology, Tianjin University, Tianjin 300072, P.R. China; §Key Laboratory of Systems Bioengineering, Ministry of Education of China, Tianjin 300072, P.R. China; ¶Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, P.R. China;
| | - Jiangxin Wang
- From the ‡Laboratory of Synthetic Microbiology, School of Chemical Engineering & Technology, Tianjin University, Tianjin 300072, P.R. China; §Key Laboratory of Systems Bioengineering, Ministry of Education of China, Tianjin 300072, P.R. China; ¶Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, P.R. China
| | - Yinhua Lu
- ‖Key Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, P.R. China
| | - Weihong Jiang
- ‖Key Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, P.R. China
| | - Weiwen Zhang
- From the ‡Laboratory of Synthetic Microbiology, School of Chemical Engineering & Technology, Tianjin University, Tianjin 300072, P.R. China; §Key Laboratory of Systems Bioengineering, Ministry of Education of China, Tianjin 300072, P.R. China; ¶Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, P.R. China;
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Singh S. A review on possible elicitor molecules of cyanobacteria: their role in improving plant growth and providing tolerance against biotic or abiotic stress. J Appl Microbiol 2014; 117:1221-44. [DOI: 10.1111/jam.12612] [Citation(s) in RCA: 76] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2014] [Revised: 07/25/2014] [Accepted: 07/25/2014] [Indexed: 11/28/2022]
Affiliation(s)
- S. Singh
- Center for Biotechnology; Department of Biological Sciences; Birla Institute of Technology and Science; Pilani India
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Sucrose synthesis in the nitrogen-fixing Cyanobacterium Anabaena sp. strain PCC 7120 is controlled by the two-component response regulator OrrA. Appl Environ Microbiol 2014; 80:5672-9. [PMID: 25002430 DOI: 10.1128/aem.01501-14] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The filamentous, nitrogen-fixing cyanobacterium Anabaena sp. strain PCC 7120 accumulates sucrose as a compatible solute against salt stress. Sucrose-phosphate synthase activity, which is responsible for the sucrose synthesis, is increased by salt stress, but the mechanism underlying the regulation of sucrose synthesis remains unknown. In the present study, a response regulator, OrrA, was shown to control sucrose synthesis. Expression of spsA, which encodes a sucrose-phosphate synthase, and susA and susB, which encode sucrose synthases, was induced by salt stress. In the orrA disruptant, salt induction of these genes was completely abolished. The cellular sucrose level of the orrA disruptant was reduced to 40% of that in the wild type under salt stress conditions. Moreover, overexpression of orrA resulted in enhanced expression of spsA, susA, and susB, followed by accumulation of sucrose, without the addition of NaCl. We also found that SigB2, a group 2 sigma factor of RNA polymerase, regulated the early response to salt stress under the control of OrrA. It is concluded that OrrA controls sucrose synthesis in collaboration with SigB2.
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Overexpression of sigma factor SigB improves temperature and butanol tolerance of Synechocystis sp. PCC6803. J Biotechnol 2014; 182-183:54-60. [DOI: 10.1016/j.jbiotec.2014.04.017] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2014] [Revised: 04/17/2014] [Accepted: 04/25/2014] [Indexed: 11/21/2022]
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Rajaram H, Chaurasia AK, Apte SK. Cyanobacterial heat-shock response: role and regulation of molecular chaperones. Microbiology (Reading) 2014; 160:647-658. [DOI: 10.1099/mic.0.073478-0] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Cyanobacteria constitute a morphologically diverse group of oxygenic photoautotrophic microbes which range from unicellular to multicellular, and non-nitrogen-fixing to nitrogen-fixing types. Sustained long-term exposure to changing environmental conditions, during their three billion years of evolution, has presumably led to their adaptation to diverse ecological niches. The ability to maintain protein conformational homeostasis (folding–misfolding–refolding or aggregation–degradation) by molecular chaperones holds the key to the stress adaptability of cyanobacteria. Although cyanobacteria possess several genes encoding DnaK and DnaJ family proteins, these are not the most abundant heat-shock proteins (Hsps), as is the case in other bacteria. Instead, the Hsp60 family of proteins, comprising two phylogenetically conserved proteins, and small Hsps are more abundant during heat stress. The contribution of the Hsp100 (ClpB) family of proteins and of small Hsps in the unicellular cyanobacteria (Synechocystis and Synechococcus) as well as that of Hsp60 proteins in the filamentous cyanobacteria (Anabaena) to thermotolerance has been elucidated. The regulation of chaperone genes by several cis-elements and trans-acting factors has also been well documented. Recent studies have demonstrated novel transcriptional and translational (mRNA secondary structure) regulatory mechanisms in unicellular cyanobacteria. This article provides an insight into the heat-shock response: its organization, and ecophysiological regulation and role of molecular chaperones, in unicellular and filamentous nitrogen-fixing cyanobacterial strains.
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Affiliation(s)
- Hema Rajaram
- Molecular Biology Division, Bhabha Atomic Research Centre, Mumbai, 400085 India
| | - Akhilesh Kumar Chaurasia
- Samsung Biomedical Research Institute, School of Medicine, SKKU, Suwon, 440-746 Republic of Korea
- Molecular Biology Division, Bhabha Atomic Research Centre, Mumbai, 400085 India
| | - Shree Kumar Apte
- Molecular Biology Division, Bhabha Atomic Research Centre, Mumbai, 400085 India
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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]
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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.
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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
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Mikkat S, Fulda S, Hagemann M. A 2D gel electrophoresis-based snapshot of the phosphoproteome in the cyanobacterium Synechocystis sp. strain PCC 6803. MICROBIOLOGY-SGM 2013; 160:296-306. [PMID: 24275102 DOI: 10.1099/mic.0.074443-0] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Cyanobacteria are photoautotrophic prokaryotes that occur in highly variable environments. Protein phosphorylation is one of the most widespread means to adjust cell metabolism and gene expression to the demands of changing growth conditions. Using a 2D gel electrophoresis-based approach and a phosphoprotein-specific dye, we investigated the protein phosphorylation pattern in cells of the model cyanobacterium Synechocystis sp. strain PCC 6803. The comparison of gels stained for total and phosphorylated proteins revealed that approximately 5 % of the protein spots seemed to be phosphoproteins, from which 32 were identified using MALDI-TOF MS. For eight of them the phosphorylated amino acid residues were mapped by subsequent mass spectrometric investigations of isolated phosphopeptides. Among the phosphoproteins, we found regulatory proteins, mostly putative anti-sigma factor antagonists, and proteins involved in translation. Moreover, a number of enzymes catalysing steps in glycolysis or the Calvin-Benson cycle were found to be phosphorylated, implying that protein phosphorylation might represent an important mechanism for the regulation of the primary carbon metabolism in cyanobacterial cells.
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Affiliation(s)
- Stefan Mikkat
- Core Facility Proteomanalytik, Universitätsmedizin, Universität Rostock, Schillingallee 69, 18057 Rostock, Germany
| | - Sabine Fulda
- Zellphysiologie, Institut Biowissenschaften, Universität Rostock, Albert-Einstein-Str. 3, 18051 Rostock, Germany
| | - Martin Hagemann
- Pflanzenphysiologie, Institut Biowissenschaften, Universität Rostock, Albert-Einstein-Str. 3, 18051 Rostock, Germany
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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.
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Affiliation(s)
- Kaisa Hakkila
- Department of Biochemistry, University of Turku, FI-20014 Turku, Finland
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41
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Plastids of marine phytoplankton produce bioactive pigments and lipids. Mar Drugs 2013; 11:3425-71. [PMID: 24022731 PMCID: PMC3806458 DOI: 10.3390/md11093425] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2013] [Revised: 07/02/2013] [Accepted: 07/24/2013] [Indexed: 12/20/2022] Open
Abstract
Phytoplankton is acknowledged to be a very diverse source of bioactive molecules. These compounds play physiological roles that allow cells to deal with changes of the environmental constrains. For example, the diversity of light harvesting pigments allows efficient photosynthesis at different depths in the seawater column. Identically, lipid composition of cell membranes can vary according to environmental factors. This, together with the heterogenous evolutionary origin of taxa, makes the chemical diversity of phytoplankton compounds much larger than in terrestrial plants. This contribution is dedicated to pigments and lipids synthesized within or from plastids/photosynthetic membranes. It starts with a short review of cyanobacteria and microalgae phylogeny. Then the bioactivity of pigments and lipids (anti-oxidant, anti-inflammatory, anti-mutagenic, anti-cancer, anti-obesity, anti-allergic activities, and cardio- neuro-, hepato- and photoprotective effects), alone or in combination, is detailed. To increase the cellular production of bioactive compounds, specific culture conditions may be applied (e.g., high light intensity, nitrogen starvation). Regardless of the progress made in blue biotechnologies, the production of bioactive compounds is still limited. However, some examples of large scale production are given, and perspectives are suggested in the final section.
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Qiao J, Huang S, Te R, Wang J, Chen L, Zhang W. Integrated proteomic and transcriptomic analysis reveals novel genes and regulatory mechanisms involved in salt stress responses in Synechocystis sp. PCC 6803. Appl Microbiol Biotechnol 2013; 97:8253-64. [PMID: 23925534 DOI: 10.1007/s00253-013-5139-8] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2013] [Revised: 07/15/2013] [Accepted: 07/15/2013] [Indexed: 11/30/2022]
Abstract
Salt stress is a common stress that limits growth and productivity of photosynthetic microbes in natural environments. Although cellular responses of a model cyanobacterium Synechocystis sp. PCC6803 to high and changing salt concentration have been studied, it remains undefined of the gene components and their regulation in the long-term salt acclimation networks. In this study, we performed an integrated study coupling a quantitative iTRAQ-LC-MS/MS proteomics and a next-generation sequencing-based RNA-seq transcriptomics on Synechocystis under salt stress for an extended period of time. Comparative quantification of protein abundances led to the identification of 68 and 108 proteins differentially regulated by salt treatment at 24 and 48 h, respectively. RNA-seq transcriptomic analysis showed that genes involved in energy metabolism and protein synthesis, and genes encoding hypothetical proteins responded to salt stress in a phase-dependent pattern. Notably, a gene encoding CO2-uptake-related protein (CupA) and three genes encoding hypothetical proteins were induced significantly at either transcript or protein level after long-term salt stress. Gene knockout and comparative growth analysis demonstrated that these four genes were involved in salt tolerance in Synechocystis. In addition, a complementary proteome and transcriptome analysis showed that concordance between protein abundances and their corresponding mRNAs varied significantly between various gene-protein pairs, indicating divergent regulation of transcriptional and post-transcriptional processes during salt stress adaptation in Synechocystis. The study provided new insights on genes and regulatory mechanism involved in salt stress response in Synechocystis.
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Affiliation(s)
- Jianjun Qiao
- School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, People's Republic of China
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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.
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Affiliation(s)
- Taina Tyystjärvi
- Molecular Plant Biology, Department of Biochemistry and Food Chemistry, University of Turku, Turku, Finland.
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Kim HW, Vannela R, Rittmann BE. Responses of Synechocystis sp. PCC 6803 to total dissolved solids in long-term continuous operation of a photobioreactor. BIORESOURCE TECHNOLOGY 2013. [PMID: 23201518 DOI: 10.1016/j.biortech.2012.10.046] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
This study evaluated how Synechocystis sp. PCC 6803 responds to high total dissolved solids (TDS) associated with eliminating nutrient limitation during long-term operation of a photobioreactor. The unique feature is that the TDS were not dominated by Na(+) and Cl(-), as in seawater, but by HCO(3)(-) and NO(3)(-) from nutrient delivery. The TDS-stress threshold was about 10 g/L. Whereas inorganic N and P limitations slowed the rate of inorganic C (C(i)) uptake in the light, TDS stress was manifested most strongly as a substantial increase of endogenous respiration rate at night. Relief from TDS stress was incomplete when lowered pH led to a HCO(3)(-) increase (560 mgC/L as a threshold). Impaired photosynthesis led to a cascade of reduced C(i)-uptake, pH decrease, HCO(3)(-) accumulation, and HCO(3)(-)-associated stress. Thus, long-term photobioreactor operation requires balancing the delivery rates of CO(2), N, P, and other TDS components to avoid general and C(i)-associated TDS stresses.
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Affiliation(s)
- Hyun Woo Kim
- Swette Center for Environmental Biotechnology, The Biodesign Institute at Arizona State University, PO Box 875701, Tempe, AZ 85287-5701, USA
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