1
|
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.
Collapse
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
| |
Collapse
|
2
|
Turunen O, Saleem T, Kurkela J, Kallio P, Tyystjärvi T. Engineering RNA polymerase to construct biotechnological host strains of cyanobacteria. PHYSIOLOGIA PLANTARUM 2024; 176:e14263. [PMID: 38528669 DOI: 10.1111/ppl.14263] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Revised: 03/06/2024] [Accepted: 03/08/2024] [Indexed: 03/27/2024]
Abstract
Application of cyanobacteria for bioproduction, bioremediation and biotransformation is being increasingly explored. Photoautotrophs are carbon-negative by default, offering a direct pathway to reducing emissions in production systems. More robust and versatile host strains are needed for constructing production strains that would function as efficient and carbon-neutral cyanofactories. We have tested if the engineering of sigma factors, regulatory units of the bacterial RNA polymerase, could be used to generate better host strains of the model cyanobacterium Synechocystis sp. PCC 6803. Overexpressing the stress-responsive sigB gene under the strong psbA2 promoter (SigB-oe) led to improved tolerance against heat, oxidative stress and toxic end-products. By targeting transcription initiation in the SigB-oe strain, we could simultaneously activate a wide spectrum of cellular protective mechanisms, including carotenoids, the HspA heat shock protein, and highly activated non-photochemical quenching. Yellow fluorescent protein was used to test the capacity of the SigB-oe strain to produce heterologous proteins. In standard conditions, the SigB-oe strain reached a similar production as the control strain, but when cultures were challenged with oxidative stress, the production capacity of SigB-oe surpassed the control strain. We also tested the production of growth-rate-controlled host strains via manipulation of RNA polymerase, but post-transcriptional regulation prevented excessive overexpression of the primary sigma factor SigA, and overproduction of the growth-restricting SigC factor was lethal. Thus, more research is needed before cyanobacteria growth can be manipulated by engineering RNA polymerase.
Collapse
Affiliation(s)
- Otso Turunen
- Department of Life Technologies/Molecular Plant Biology, University of Turku, Turku, Finland
| | - Tayyab Saleem
- Department of Life Technologies/Molecular Plant Biology, University of Turku, Turku, Finland
| | - Juha Kurkela
- Department of Life Technologies/Molecular Plant Biology, University of Turku, Turku, Finland
| | - Pauli Kallio
- Department of Life Technologies/Molecular Plant Biology, University of Turku, Turku, Finland
| | - Taina Tyystjärvi
- Department of Life Technologies/Molecular Plant Biology, University of Turku, Turku, Finland
| |
Collapse
|
3
|
Lin S, Li S, Ouyang T, Chen G. Site-2 Protease Slr1821 Regulates Carbon/Nitrogen Homeostasis during Ammonium Stress Acclimation in Cyanobacterium Synechocystis sp. PCC 6803. Int J Mol Sci 2023; 24:ijms24076606. [PMID: 37047577 PMCID: PMC10094980 DOI: 10.3390/ijms24076606] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Revised: 03/25/2023] [Accepted: 03/27/2023] [Indexed: 04/05/2023] Open
Abstract
Excess ammonium imposes toxicity and stress response in cyanobacteria. How cyanobacteria acclimate to NH4+ stress is so far poorly understood. Here, Synechocystis sp. PCC6803 S2P homolog Slr1821 was identified as the essential regulator through physiological characterization and transcriptomic analysis of its knockout mutant. The proper expression of 60% and 67% of the NH4+ activated and repressed genes, respectively, were actually Slr1821-dependent since they were abolished or reversed in ∆slr1821. Synechocystis 6803 suppressed nitrogen uptake and assimilation, ammonium integration and mobilization of other nitrogen sources upon NH4+ stress. Opposite regulation on genes for assimilation of nitrogen and carbon, such as repression of nitrogen regulatory protein PII, PII interactive protein PirC and activation of carbon acquisition regulator RcbR, demonstrated that Synechocystis 6803 coordinated regulation to maintain carbon/nitrogen homeostasis under increasing nitrogen, while functional Slr1821 was indispensable for most of this coordinated regulation. Additionally, slr1821 knockout disrupted the proper response of regulators and transporters in the ammonium-specific stimulon, and resulted in defective photosynthesis as well as compromised translational and transcriptional machinery. These results provide new insight into the coordinated regulation of nutritional fluctuation and the functional characterization of S2Ps. They also provide new targets for bioengineering cyanobacteria in bioremediation and improving ammonium tolerance in crop plants.
Collapse
Affiliation(s)
- Shiqi Lin
- School of Food Sciences and Engineering, South China University of Technology, 381 Wushan Road, Guangzhou 510641, China
| | - Shiliang Li
- School of Food Sciences and Engineering, South China University of Technology, 381 Wushan Road, Guangzhou 510641, China
| | - Tong Ouyang
- School of Food Sciences and Engineering, South China University of Technology, 381 Wushan Road, Guangzhou 510641, China
| | - Gu Chen
- School of Food Sciences and Engineering, South China University of Technology, 381 Wushan Road, Guangzhou 510641, China
| |
Collapse
|
4
|
Koskinen S, Kurkela J, Linhartová M, Tyystjärvi T. The genome sequence of Synechocystis sp. PCC 6803 substrain GT-T and its implications for the evolution of PCC 6803 substrains. FEBS Open Bio 2023; 13:701-712. [PMID: 36792971 PMCID: PMC10068330 DOI: 10.1002/2211-5463.13576] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Revised: 02/02/2023] [Accepted: 02/07/2023] [Indexed: 02/17/2023] Open
Abstract
Synechocystis sp. PCC 6803 is a model cyanobacterium, glucose-tolerant substrains of which are commonly used as laboratory strains. In recent years, it has become evident that 'wild-type' strains used in different laboratories show some differences in their phenotypes. We report here the chromosome sequence of our Synechocystis sp. PCC 6803 substrain, named substrain GT-T. The chromosome sequence of GT-T was compared to those of two other commonly used laboratory substrains, GT-S and PCC-M. We identified 11 specific mutations in the GT-T substrain, whose physiological consequences are discussed. We also provide an update on evolutionary relationships between different Synechocystis sp. PCC 6803 substrains.
Collapse
Affiliation(s)
- Satu Koskinen
- Department of Life Sciences/Molecular Plant Biology, University of Turku, Finland
| | - Juha Kurkela
- Department of Life Sciences/Molecular Plant Biology, University of Turku, Finland
| | - Markéta Linhartová
- Institute of Microbiology of the Czech Academy of Sciences, Třeboň, Czech Republic
| | - Taina Tyystjärvi
- Department of Life Sciences/Molecular Plant Biology, University of Turku, Finland
| |
Collapse
|
5
|
Sukkasam N, Incharoensakdi A, Monshupanee T. Chemicals Affecting Cyanobacterial Poly(3-hydroxybutyrate) Accumulation: 2-Phenylethanol Treatment Combined with Nitrogen Deprivation Synergistically Enhanced Poly(3-hydroxybutyrate) Storage in Synechocystis sp. PCC6803 and Anabaena sp. TISTR8076. PLANT & CELL PHYSIOLOGY 2022; 63:1253-1272. [PMID: 35818829 DOI: 10.1093/pcp/pcac100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2022] [Revised: 07/04/2022] [Accepted: 07/11/2022] [Indexed: 06/15/2023]
Abstract
Various photoautotrophic cyanobacteria increase the accumulation of bioplastic poly(3-hydroxybutyrate) (PHB) under nitrogen deprivation (-N) for energy storage. Several metabolic engineering enhanced cyanobacterial PHB accumulation, but these strategies are not applicable in non-gene-transformable strains. Alternatively, stimulating PHB levels by chemical exposure is desirable because it might be applied to various cyanobacterial strains. However, the study of such chemicals is still limited. Here, 19 compounds previously reported to affect bacterial cellular processes were evaluated for their effect on PHB accumulation in Synechocystis sp. PCC6803, where 3-(3,4-dichlorophenyl)-1,1-dimethylurea, methyl viologen, arsenite, phenoxyethanol and 2-phenylethanol were found to increase PHB accumulation. When cultivated with optimal nitrate supply, Synechocystis contained less than 0.5% [w/w dry weight (DW)] PHB, while cultivation under -N conditions increased the PHB content to 7% (w/w DW). Interestingly, the -N cultivation combined with 2-phenylethanol exposure reduced the Synechocystis protein content by 27% (w/w DW) but significantly increased PHB levels up to 33% (w/w DW), the highest ever reported photoautotrophic cyanobacterial PHB accumulation in a wild-type strain. Results from transcriptomic and metabolomic analysis suggested that under 2-phenylethanol treatment, Synechocystis proteins were degraded to amino acids, which might be subsequently utilized as the source of carbon and energy for PHB biosynthesis. 2-Phenylethanol treatment also increased the levels of metabolites required for Synechocystis PHB synthesis (acetyl-CoA, acetoacetyl-CoA, 3-hydroxybutyryl-CoA and NADPH). Additionally, under -N, the exposure to phenoxyethanol and 2-phenylethanol increased the PHB levels of Anabaena sp. from 0.4% to 4.1% and 6.6% (w/w DW), respectively. The chemicals identified in this study might be applicable for enhancing PHB accumulation in other cyanobacteria.
Collapse
Affiliation(s)
- Nannaphat Sukkasam
- Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
- Program in Biotechnology, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
| | - Aran Incharoensakdi
- Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
- Academy of Science, Royal Society of Thailand, Bangkok 10300, Thailand
| | - Tanakarn Monshupanee
- Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
- Program in Biotechnology, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
| |
Collapse
|
6
|
Simkovsky R, Parnasa R, Wang J, Nagar E, Zecharia E, Suban S, Yegorov Y, Veltman B, Sendersky E, Schwarz R, Golden SS. Transcriptomic and Phenomic Investigations Reveal Elements in Biofilm Repression and Formation in the Cyanobacterium Synechococcus elongatus PCC 7942. Front Microbiol 2022; 13:899150. [PMID: 35814646 PMCID: PMC9260433 DOI: 10.3389/fmicb.2022.899150] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Accepted: 05/23/2022] [Indexed: 11/13/2022] Open
Abstract
Biofilm formation by photosynthetic organisms is a complex behavior that serves multiple functions in the environment. Biofilm formation in the unicellular cyanobacterium Synechococcus elongatus PCC 7942 is regulated in part by a set of small secreted proteins that promotes biofilm formation and a self-suppression mechanism that prevents their expression. Little is known about the regulatory and structural components of the biofilms in PCC 7942, or response to the suppressor signal(s). We performed transcriptomics (RNA-Seq) and phenomics (RB-TnSeq) screens that identified four genes involved in biofilm formation and regulation, more than 25 additional candidates that may impact biofilm formation, and revealed the transcriptomic adaptation to the biofilm state. In so doing, we compared the effectiveness of these two approaches for gene discovery.
Collapse
Affiliation(s)
- Ryan Simkovsky
- Division of Biological Sciences, University of California, San Diego, San Diego, CA, United States
| | - Rami Parnasa
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan, Israel
| | - Jingtong Wang
- Division of Biological Sciences, University of California, San Diego, San Diego, CA, United States
| | - Elad Nagar
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan, Israel
| | - Eli Zecharia
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan, Israel
| | - Shiran Suban
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan, Israel
| | - Yevgeni Yegorov
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan, Israel
| | - Boris Veltman
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan, Israel
| | - Eleonora Sendersky
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan, Israel
| | - Rakefet Schwarz
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan, Israel
| | - Susan S Golden
- Division of Biological Sciences, University of California, San Diego, San Diego, CA, United States
- Center for Circadian Biology, University of California, San Diego, San Diego, CA, United States
| |
Collapse
|
7
|
Kariyazono R, Osanai T. Identification of the genome-wide distribution of cyanobacterial group-2 sigma factor SigE, accountable for its regulon. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2022; 110:548-561. [PMID: 35092706 DOI: 10.1111/tpj.15687] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2021] [Revised: 01/18/2022] [Accepted: 01/24/2022] [Indexed: 06/14/2023]
Affiliation(s)
- Ryo Kariyazono
- School of Agriculture, Meiji University, 1-1-1 Higashimita, Tama-ku, Kawasaki, Kanagawa, 214-8571, Japan
| | - Takashi Osanai
- School of Agriculture, Meiji University, 1-1-1 Higashimita, Tama-ku, Kawasaki, Kanagawa, 214-8571, Japan
| |
Collapse
|
8
|
Sukkasam N, Incharoensakdi A, Monshupanee T. Disruption of Hydrogen Gas Synthesis Enhances the Cellular Levels of NAD(P)H, Glycogen, Poly(3-hydroxybutyrate) and Photosynthetic Pigments Under Specific Nutrient Condition(s) in Cyanobacterium Synechocystis sp. PCC 6803. PLANT & CELL PHYSIOLOGY 2022; 63:135-147. [PMID: 34698867 DOI: 10.1093/pcp/pcab156] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Revised: 10/15/2021] [Accepted: 10/25/2021] [Indexed: 06/13/2023]
Abstract
In photoautotrophic Synechocystis sp. PCC 6803, NADPH is generated from photosynthesis and utilized in various metabolism, including the biosynthesis of glyceraldehyde 3-phosphate (the upstream substrate for carbon metabolism), poly(3-hydroxybutyrate) (PHB), photosynthetic pigments, and hydrogen gas (H2). Redirecting NADPH flow from one biosynthesis pathway to another has yet to be studied. Synechocystis's H2 synthesis, one of the pathways consuming NAD(P)H, was disrupted by the inactivation of hoxY and hoxH genes encoding the two catalytic subunits of hydrogenase. Such inactivation with a complete disruption of H2 synthesis led to 1.4-, 1.9-, and 2.1-fold increased cellular NAD(P)H levels when cells were cultured in normal medium (BG11), the medium without nitrate (-N), and the medium without phosphate (-P), respectively. After 49-52 d of cultivation in BG11 (when the nitrogen source in the media was depleted), the cells with disrupted H2 synthesis had 1.3-fold increased glycogen level compared to wild type of 83-85% (w/w dry weight), the highest level reported for cyanobacterial glycogen. The increased glycogen content observed by transmission electron microscopy was correlated with the increased levels of glucose 6-phosphate and glucose 1-phosphate, the two substrates in glycogen synthesis. Disrupted H2 synthesis also enhanced PHB accumulation up to 1.4-fold under -P and 1.6-fold under -N and increased levels of photosynthetic pigments (chlorophyll a, phycocyanin, and allophycocyanin) by 1.3- to 1.5-fold under BG11. Thus, disrupted H2 synthesis increased levels of NAD(P)H, which may be utilized for the biosynthesis of glycogen, PHB, and pigments. This strategy might be applicable for enhancing other biosynthetic pathways that utilize NAD(P)H.
Collapse
Affiliation(s)
- Nannaphat Sukkasam
- Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
- Program in Biotechnology, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
| | - Aran Incharoensakdi
- Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
- Academy of Science, Royal Society of Thailand, Bangkok 10300, Thailand
| | - Tanakarn Monshupanee
- Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
- Program in Biotechnology, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
| |
Collapse
|
9
|
Roles of Close Homologues SigB and SigD in Heat and High Light Acclimation of the Cyanobacterium Synechocystis sp. PCC 6803. Life (Basel) 2022; 12:life12020162. [PMID: 35207450 PMCID: PMC8875361 DOI: 10.3390/life12020162] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 01/15/2022] [Accepted: 01/19/2022] [Indexed: 11/18/2022] Open
Abstract
Acclimation of cyanobacterium Synechocystis sp. PCC6803 to suboptimal conditions is largely dependent on adjustments of gene expression, which is highly controlled by the σ factor subunits of RNA polymerase (RNAP). The SigB and SigD σ factors are close homologues. Here we show that the sigB and sigD genes are both induced in high light and heat stresses. Comparison of transcriptomes of the control strain (CS), ΔsigB, ΔsigD, ΔsigBCE (containing SigD as the only functional group 2 σ factor), and ΔsigCDE (SigB as the only functional group 2 σ factor) strains in standard, high light, and high temperature conditions revealed that the SigB and SigD factors regulate different sets of genes and SigB and SigD regulons are highly dependent on stress conditions. The SigB regulon is bigger than the SigD regulon at high temperature, whereas, in high light, the SigD regulon is bigger than the SigB regulon. Furthermore, our results show that favoring the SigB or SigD factor by deleting other group 2 σ factors does not lead to superior acclimation to high light or high temperature, indicating that all group 2 σ factors play roles in the acclimation processes.
Collapse
|
10
|
Simkovsky R, Parnasa R, Wang J, Nagar E, Zecharia E, Suban S, Yegorov Y, Veltman B, Sendersky E, Schwarz R, Golden SS. Transcriptomic and Phenomic Investigations Reveal Elements in Biofilm Repression and Formation in the Cyanobacterium Synechococcus elongatus PCC 7942. Front Microbiol 2022; 13:899150. [PMID: 35814646 DOI: 10.1101/2022.01.27.477154] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Accepted: 05/23/2022] [Indexed: 05/20/2023] Open
Abstract
Biofilm formation by photosynthetic organisms is a complex behavior that serves multiple functions in the environment. Biofilm formation in the unicellular cyanobacterium Synechococcus elongatus PCC 7942 is regulated in part by a set of small secreted proteins that promotes biofilm formation and a self-suppression mechanism that prevents their expression. Little is known about the regulatory and structural components of the biofilms in PCC 7942, or response to the suppressor signal(s). We performed transcriptomics (RNA-Seq) and phenomics (RB-TnSeq) screens that identified four genes involved in biofilm formation and regulation, more than 25 additional candidates that may impact biofilm formation, and revealed the transcriptomic adaptation to the biofilm state. In so doing, we compared the effectiveness of these two approaches for gene discovery.
Collapse
Affiliation(s)
- Ryan Simkovsky
- Division of Biological Sciences, University of California, San Diego, San Diego, CA, United States
| | - Rami Parnasa
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan, Israel
| | - Jingtong Wang
- Division of Biological Sciences, University of California, San Diego, San Diego, CA, United States
| | - Elad Nagar
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan, Israel
| | - Eli Zecharia
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan, Israel
| | - Shiran Suban
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan, Israel
| | - Yevgeni Yegorov
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan, Israel
| | - Boris Veltman
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan, Israel
| | - Eleonora Sendersky
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan, Israel
| | - Rakefet Schwarz
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan, Israel
| | - Susan S Golden
- Division of Biological Sciences, University of California, San Diego, San Diego, CA, United States
- Center for Circadian Biology, University of California, San Diego, San Diego, CA, United States
| |
Collapse
|
11
|
Protasova EA, Antal TK, Zlenko DV, Elanskaya IV, Lukashev EP, Friedrich T, Mironov KS, Sluchanko NN, Ge B, Qin S, Maksimov EG. State of the phycobilisome determines effective absorption cross-section of Photosystem II in Synechocystis sp. PCC 6803. BIOCHIMICA ET BIOPHYSICA ACTA. BIOENERGETICS 2021; 1862:148494. [PMID: 34534546 DOI: 10.1016/j.bbabio.2021.148494] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Revised: 08/23/2021] [Accepted: 09/07/2021] [Indexed: 11/23/2022]
Abstract
Quenching of excess excitation energy is necessary for the photoprotection of light-harvesting complexes. In cyanobacteria, quenching of phycobilisome (PBS) excitation energy is induced by the Orange Carotenoid Protein (OCP), which becomes photoactivated under high light conditions. A decrease in energy transfer efficiency from the PBSs to the reaction centers decreases photosystem II (PS II) activity. However, quantitative analysis of OCP-induced photoprotection in vivo is complicated by similar effects of both photochemical and non-photochemical quenching on the quantum yield of the PBS fluorescence overlapping with the emission of chlorophyll. In the present study, we have analyzed chlorophyll a fluorescence induction to estimate the effective cross-section of PS II and compared the effects of reversible OCP-dependent quenching of PBS fluorescence with reduction of PBS content upon nitrogen starvation or mutations of key PBS components. This approach allowed us to estimate the dependency of the rate constant of PS II primary electron acceptor reduction on the amount of PBSs in the cell. We found that OCP-dependent quenching triggered by blue light affects approximately half of PBSs coupled to PS II, indicating that under normal conditions, the concentration of OCP is not sufficient for quenching of all PBSs coupled to PS II.
Collapse
Affiliation(s)
- Elena A Protasova
- Department of Biophysics, Faculty of Biology, Lomonosov Moscow State University, Moscow 119991, Russia.
| | - Taras K Antal
- Department of Biophysics, Faculty of Biology, Lomonosov Moscow State University, Moscow 119991, Russia
| | - Dmitry V Zlenko
- Department of Biophysics, Faculty of Biology, Lomonosov Moscow State University, Moscow 119991, Russia
| | - Irina V Elanskaya
- Department of Genetics, Faculty of Biology, Lomonosov Moscow State University, Moscow 119991, Russia
| | - Evgeny P Lukashev
- Department of Biophysics, Faculty of Biology, Lomonosov Moscow State University, Moscow 119991, Russia
| | - Thomas Friedrich
- Technical University of Berlin, Institute of Chemistry, D-10623 Berlin, Germany
| | - Kirill S Mironov
- Timiryazev Institute of Plant Physiology, Russian Academy of Sciences, Moscow 127276, Russia
| | - Nikolai N Sluchanko
- A.N. Bach Institute of Biochemistry, Federal Research Center of Biotechnology, Russian Academy of Sciences, Moscow 119071, Russia
| | - Baosheng Ge
- China University of Petroleum (Huadong), College of Chemical Engineering, Qingdao 266580, PR China
| | - Song Qin
- China University of Petroleum (Huadong), College of Chemical Engineering, Qingdao 266580, PR China; Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264003, PR China.
| | - Eugene G Maksimov
- Department of Biophysics, Faculty of Biology, Lomonosov Moscow State University, Moscow 119991, Russia
| |
Collapse
|
12
|
Cross-Activation of Two Nitrogenase Gene Clusters by CnfR1 or CnfR2 in the Cyanobacterium Anabaena variabilis. Microbiol Spectr 2021; 9:e0106021. [PMID: 34612667 PMCID: PMC8510180 DOI: 10.1128/spectrum.01060-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In Anabaena variabilis, the nif1 genes, which are activated by CnfR1, produce a Mo-nitrogenase that is expressed only in heterocysts. Similarly, the nif2 genes, which are activated by CnfR2, make a Mo-nitrogenase that is expressed only in anaerobic vegetative cells. However, CnfR1, when it was expressed in anaerobic vegetative cells under the control of the cnfR2 promoter or from the Co2+-inducible coaT promoter, activated the expression of both nifB1 and nifB2. Activation of nifB2, but not nifB1, by CnfR1 required NtcA. Thus, expression of the nif1 system requires no heterocyst-specific factor other than CnfR1. In contrast, CnfR2, when it was expressed in heterocysts under the control of the cnfR1 promoter or from the coaT promoter, did not activate the expression of nifB1 or nifB2. Thus, activation of the nif2 system in anaerobic vegetative cells by CnfR2 requires additional factors absent in heterocysts. CnfR2 made from the coaT promoter activated nifB2 expression in anaerobic vegetative cells grown with fixed nitrogen; however, oxygen inhibited CnfR2 activation of nifB2 expression. In contrast, activation of nifB1 and nifB2 by CnfR1 was unaffected by oxygen. CnfR1, which does not activate the nifB2 promoter in heterocysts, activated the expression of the entire nif2 gene cluster from a nifB2::nifB1::nifB2 hybrid promoter in heterocysts, producing functional Nif2 nitrogenase in heterocysts. However, activity was poor compared to the normal Nif1 nitrogenase. Expression of the nif2 cluster in anaerobic vegetative cells of Nostoc sp. PCC 7120, a strain lacking the nif2 nitrogenase, resulted in expression of the nif2 genes but weak nitrogenase activity. IMPORTANCE Cyanobacterial nitrogen fixation is important in the global nitrogen cycle, in oceanic productivity, and in many plant and fungal symbioses. While the proteins that mediate nitrogen fixation have been well characterized, the regulation of this complex and expensive process is poorly understood in cyanobacteria. Using a genetic approach, we have characterized unique and overlapping functions for two homologous transcriptional activators CnfR1 and CnfR2 that activate two distinct nitrogenases in a single organism. We found that CnfR1 is promiscuous in its ability to activate both nitrogenase systems, whereas CnfR2 depends on additional cellular factors; thus, it activates only one nitrogenase system.
Collapse
|
13
|
Srivastava A, Varshney RK, Shukla P. Sigma Factor Modulation for Cyanobacterial Metabolic Engineering. Trends Microbiol 2020; 29:266-277. [PMID: 33229204 DOI: 10.1016/j.tim.2020.10.012] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2020] [Revised: 10/25/2020] [Accepted: 10/26/2020] [Indexed: 11/18/2022]
Abstract
Sigma (σ) factors are key regulatory proteins that control the transcription initiation in prokaryotes. In response to environmental or developmental cues, σ factors initiate the transcription of necessary genes responsible for maintaining a life-sustaining metabolic balance. Due to the significant role of σ factors in bacterial metabolism, their rational engineering for commercial metabolite production in photoautotrophic, cyanobacterial cells is a desirable venture. As cyanobacterial genomes typically encode multiple σ factors, effective execution of metabolic engineering efforts largely relies on uncovering the complicated gene regulatory network and further characterization of the members of σ factor regulatory circuits. This review outlines the prospects of σ factor in metabolic engineering of cyanobacteria, summarizes the challenges in the path towards an efficient strain construction and highlights the genomic context of putative regulators of cyanobacterial σ factors.
Collapse
Affiliation(s)
- Amit Srivastava
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, USA
| | - Rajeev K Varshney
- Center of Excellence in Genomics and Systems Biology, International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Patancheru, India
| | - Pratyoosh Shukla
- Enzyme Technology and Protein Bioinformatics Laboratory, Department of Microbiology, Maharshi Dayanand University, Rohtak-124001, Haryana, India.
| |
Collapse
|
14
|
Lott SC, Voigt K, Lambrecht SJ, Hess WR, Steglich C. A framework for the computational prediction and analysis of non-coding RNAs in microbial environmental populations and their experimental validation. THE ISME JOURNAL 2020; 14:1955-1965. [PMID: 32346084 PMCID: PMC7368042 DOI: 10.1038/s41396-020-0658-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Revised: 03/22/2020] [Accepted: 04/07/2020] [Indexed: 11/09/2022]
Abstract
Small regulatory RNAs and antisense RNAs play important roles in the regulation of gene expression in bacteria but are underexplored, especially in natural populations. While environmentally relevant microbes often are not amenable to genetic manipulation or cannot be cultivated in the laboratory, extensive metagenomic and metatranscriptomic datasets for these organisms might be available. Hence, dedicated workflows for specific analyses are needed to fully benefit from this information. Here, we identified abundant sRNAs from oceanic environmental populations of the ecologically important primary producer Prochlorococcus starting from a metatranscriptomic differential RNA-Seq (mdRNA-Seq) dataset. We tracked their homologs in laboratory isolates, and we provide a framework for their further detailed characterization. Several of the experimentally validated sRNAs responded to ecologically relevant changes in cultivation conditions. The expression of the here newly discovered sRNA Yfr28 was highly stimulated in low-nitrogen conditions. Its predicted top targets include mRNAs encoding cell division proteins, a sigma factor, and several enzymes and transporters, suggesting a pivotal role of Yfr28 in the coordination of primary metabolism and cell division. A cis-encoded antisense RNA was identified as a possible positive regulator of atpF encoding subunit b' of the ATP synthase complex. The presented workflow will also be useful for other environmentally relevant microorganisms for which experimental validation abilities are frequently limiting although there is wealth of sequence information available.
Collapse
Affiliation(s)
- Steffen C Lott
- University of Freiburg, Faculty of Biology, D-79104, Freiburg, Germany
| | - Karsten Voigt
- University of Freiburg, Faculty of Biology, D-79104, Freiburg, Germany
| | - S Joke Lambrecht
- University of Freiburg, Faculty of Biology, D-79104, Freiburg, Germany
| | - Wolfgang R Hess
- University of Freiburg, Faculty of Biology, D-79104, Freiburg, Germany
| | - Claudia Steglich
- University of Freiburg, Faculty of Biology, D-79104, Freiburg, Germany.
| |
Collapse
|
15
|
Thiel T. Organization and regulation of cyanobacterial nif gene clusters: implications for nitrogenase expression in plant cells. FEMS Microbiol Lett 2020; 366:5470946. [PMID: 31062027 DOI: 10.1093/femsle/fnz077] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Accepted: 04/11/2019] [Indexed: 12/16/2022] Open
Abstract
For over 50 years scientists have considered the possibility of engineering a plant with nitrogen fixation capability, freeing farmers from their dependence on nitrogen fertilizers. With the development of the tools of synthetic biology, more progress has been made toward this goal in the last 5 years than in the previous five decades. Most of the effort has focused on nitrogenase genes from Klebsiella oxytoca, which has complex gene regulation. There may be advantages in using nitrogenase genes from cyanobacteria, which comprise large polycistronic gene clusters that may be easier to manipulate and eventually express in a plant. The fact that some diatoms have a cyanobacterial nitrogen fixing organelle further supports the idea that a cyanobacterial nitrogenase gene cluster may function in a newly-engineered, cyanobacterial-based plant organelle, a nitroplast. This review describes recent attempts to express the nif genes from Anabaena variabilis ATCC 29413, Leptolyngbya boryana dg5 and Cyanothece sp. ATCC 51142 in heterologous cyanobacteria in the context of the organization of the nitrogenase genes and their regulation by the transcription factor CnfR via its highly conserved binding sites.
Collapse
Affiliation(s)
- Teresa Thiel
- Department of Biology, University of Missouri-St. Louis, One University Blvd., St. Louis, MO 63121, USA
| |
Collapse
|
16
|
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]
|
17
|
Valev D, Kurkela J, Tyystjärvi E, Tyystjärvi T. Testing the Potential of Regulatory Sigma Factor Mutants for Wastewater Purification or Bioreactor Run in High Light. Curr Microbiol 2020; 77:1590-1599. [PMID: 32266454 PMCID: PMC7334282 DOI: 10.1007/s00284-020-01973-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2019] [Accepted: 03/27/2020] [Indexed: 11/25/2022]
Abstract
It is shown that a freshly inoculated culture of the model cyanobacterium Synechocystis sp. PCC 6803 consumed almost all phosphate and 50% of nitrate within 6 days from the nutrient-rich BG-11 growth medium, indicating potential of cyanobacteria to purify wastewaters. Synechocystis sp. PCC 6803 control strain also collected nutrients efficiently from a landfill leachate wastewater KA2 (5.9-6.9 mM ammonium and 0.073-0.077 mM phosphate). Wastewaters might induce oxidative stress to microalgae, which prompted us to test growth of sigma factor inactivation strains, as ΔsigBCE and ΔsigCDE strains show superior growth in chemically induced oxidative stress. All cyanobacterial strains, including a stress-sensitive strain ΔsigBCDE, grew well in KA2 for four days, indicating that KA2 did not cause immediate oxidative stress. Completely arrested growth and bleaching of ΔsigBCDE cells after one week in KA2 wastewater point to the importance of group 2 sigma factor-mediated changes in gene expression during wastewater treatment. The growth of ΔsigBCD was arrested early in un-buffered and Hepes buffered (pH 7.5) KA2. In ΔsigBCD, all phosphate transporter genes are upregulated in standard conditions, and ΔsigBCD cells showed growth defects in low-phosphate BG-11 medium. ΔsigBCD cells removed phosphate slower from KA2 than the control strain, but phosphate supplementation of KA2 did not improve growth of ΔsigBCD. The ΔsigBCE strain showed superior growth in a laboratory-scale bioreactor in bright light and removed phosphate even slightly more efficiently than the control strain if KA2 was Hepes buffered although ΔsigBCE grew slowly in un-buffered KA2 and in low-phosphate BG-11 medium. The results indicate that engineering expression of regulatory group 2 sigma factor(s) might be useful for practical applications.
Collapse
Affiliation(s)
- Dimitar Valev
- Department of Biochemistry/Molecular Plant Biology, University of Turku, 20014, Turku, Finland
| | - Juha Kurkela
- Department of Biochemistry/Molecular Plant Biology, University of Turku, 20014, Turku, Finland
| | - Esa Tyystjärvi
- Department of Biochemistry/Molecular Plant Biology, University of Turku, 20014, Turku, Finland
| | - Taina Tyystjärvi
- Department of Biochemistry/Molecular Plant Biology, University of Turku, 20014, Turku, Finland.
| |
Collapse
|
18
|
Gonzalez A, Riley KW, Harwood TV, Zuniga EG, Risser DD. A Tripartite, Hierarchical Sigma Factor Cascade Promotes Hormogonium Development in the Filamentous Cyanobacterium Nostoc punctiforme. mSphere 2019; 4:e00231-19. [PMID: 31043519 PMCID: PMC6495340 DOI: 10.1128/msphere.00231-19] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Accepted: 04/12/2019] [Indexed: 11/24/2022] Open
Abstract
Cyanobacteria are prokaryotes capable of oxygenic photosynthesis, and frequently, nitrogen fixation as well. As a result, they contribute substantially to global primary production and nitrogen cycles. Furthermore, the multicellular filamentous cyanobacteria in taxonomic subsections IV and V are developmentally complex, exhibiting an array of differentiated cell types and filaments, including motile hormogonia, making them valuable model organisms for studying development. To investigate the role of sigma factors in the gene regulatory network (GRN) controlling hormogonium development, a combination of genetic, immunological, and time-resolved transcriptomic analyses were conducted in the model filamentous cyanobacterium Nostoc punctiforme, which, unlike other common model cyanobacteria, retains the developmental complexity of field isolates. The results support a model where the hormogonium GRN is driven by a hierarchal sigma factor cascade, with sigJ activating the expression of both sigC and sigF, as well as a substantial portion of additional hormogonium-specific genes, including those driving changes to cellular architecture. In turn, sigC regulates smaller subsets of genes for several processes, plays a dominant role in promoting reductive cell division, and may also both positively and negatively regulate sigJ to reinforce the developmental program and coordinate the timing of gene expression, respectively. In contrast, the sigF regulon is extremely limited. Among genes with characterized roles in hormogonium development, only pilA shows stringent sigF dependence. For sigJ-dependent genes, a putative consensus promoter was also identified, consisting primarily of a highly conserved extended -10 region, here designated a J-Box, which is widely distributed among diverse members of the cyanobacterial lineage.IMPORTANCE Cyanobacteria are integral to global carbon and nitrogen cycles, and their metabolic capacity coupled with their ease of genetic manipulation make them attractive platforms for applications such as biomaterial and biofertilizer production. Achieving these goals will likely require a detailed understanding and precise rewiring of these organisms' GRNs. The complex phenotypic plasticity of filamentous cyanobacteria has also made them valuable models of prokaryotic development. However, current research has been limited by focusing primarily on a handful of model strains which fail to reflect the phenotypes of field counterparts, potentially limiting biotechnological advances and a more comprehensive understanding of developmental complexity. Here, using Nostoc punctiforme, a model filamentous cyanobacterium that retains the developmental range of wild isolates, we define previously unknown definitive roles for a trio of sigma factors during hormogonium development. These findings substantially advance our understanding of cyanobacterial development and gene regulation and could be leveraged for future applications.
Collapse
Affiliation(s)
- Alfonso Gonzalez
- Department of Biology, University of the Pacific, Stockton, California, USA
| | - Kelsey W Riley
- Department of Biology, University of the Pacific, Stockton, California, USA
| | - Thomas V Harwood
- Department of Biology, University of the Pacific, Stockton, California, USA
| | - Esthefani G Zuniga
- Department of Biology, University of the Pacific, Stockton, California, USA
| | - Douglas D Risser
- Department of Biology, University of the Pacific, Stockton, California, USA
| |
Collapse
|
19
|
Hakkila K, Valev D, Antal T, Tyystjï Rvi E, Tyystjï Rvi T. Group 2 Sigma Factors are Central Regulators of Oxidative Stress Acclimation in Cyanobacteria. PLANT & CELL PHYSIOLOGY 2019; 60:436-447. [PMID: 30407607 DOI: 10.1093/pcp/pcy221] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Accepted: 11/04/2018] [Indexed: 06/08/2023]
Abstract
Regulatory σ factors of the RNA polymerase (RNAP) adjust gene expression according to environmental cues when the cyanobacterium Synechocystis sp. PCC 6803 acclimates to suboptimal conditions. Here we show central roles of the non-essential group 2 σ factors in oxidative stress responses. Cells missing all group 2 σ factors fail to acclimate to chemically induced singlet oxygen, superoxide or H2O2 stresses, and lose pigments in high light. SigB and SigD are the major σ factors in oxidative stress, whereas SigC and SigE play only minor roles. The SigD factor is up-regulated in high light, singlet oxygen and H2O2 stresses, and overproduction of the SigD factor in the ΔsigBCE strain leads to superior growth of ΔsigBCE cells in those stress conditions. Superoxide does not induce the production of the SigD factor but instead SigB and SigC factors are moderately induced. The SigB factor alone in ΔsigCDE can support almost as fast growth in superoxide stress as the full complement of σ factors in the control strain, but an overdose of the stationary phase-related SigC factor causes growth arrest of ΔsigBDE in superoxide stress. A drastic decrease of the functional RNAP limits the transcription capacity of the cells in H2O2 stress, which explains why cyanobacteria are sensitive to H2O2. Formation of RNAP-SigB and RNAP-SigD holoenzymes is highly enhanced in H2O2 stress, and cells containing only SigB (ΔsigCDE) or SigD (ΔsigBCE) show superior growth in H2O2 stress.
Collapse
Affiliation(s)
- Kaisa Hakkila
- Department of Biochemistry/Molecular Plant Biology, University of Turku, Turku, Finland
| | - Dimitar Valev
- Department of Biochemistry/Molecular Plant Biology, University of Turku, Turku, Finland
| | - Taras Antal
- Biological Faculty, Moscow State University, Vorobyevi Gory, Moscow, Russia
| | - Esa Tyystjï Rvi
- Department of Biochemistry/Molecular Plant Biology, University of Turku, Turku, Finland
| | - Taina Tyystjï Rvi
- Department of Biochemistry/Molecular Plant Biology, University of Turku, Turku, Finland
| |
Collapse
|
20
|
Flores C, Santos M, Pereira SB, Mota R, Rossi F, De Philippis R, Couto N, Karunakaran E, Wright PC, Oliveira P, Tamagnini P. The alternative sigma factor SigF is a key player in the control of secretion mechanisms inSynechocystissp. PCC 6803. Environ Microbiol 2018; 21:343-359. [DOI: 10.1111/1462-2920.14465] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Revised: 09/14/2018] [Accepted: 10/31/2018] [Indexed: 11/30/2022]
Affiliation(s)
- Carlos Flores
- Bioengineering and Synthetic Microbiology Group; i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto; Porto Portugal
- Bioengineering and Synthetic Microbiology Group; IBMC - Instituto de Biologia Celular e Molecular, Universidade do Porto; Porto Portugal
- Departamento de Biologia Molecular; ICBAS - Instituto de Ciências Biomédicas Abel Salazar; Porto Portugal
| | - Marina Santos
- Bioengineering and Synthetic Microbiology Group; i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto; Porto Portugal
- Bioengineering and Synthetic Microbiology Group; IBMC - Instituto de Biologia Celular e Molecular, Universidade do Porto; Porto Portugal
- Departamento de Biologia Molecular; ICBAS - Instituto de Ciências Biomédicas Abel Salazar; Porto Portugal
| | - Sara B. Pereira
- Bioengineering and Synthetic Microbiology Group; i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto; Porto Portugal
- Bioengineering and Synthetic Microbiology Group; IBMC - Instituto de Biologia Celular e Molecular, Universidade do Porto; Porto Portugal
| | - Rita Mota
- Bioengineering and Synthetic Microbiology Group; i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto; Porto Portugal
- Bioengineering and Synthetic Microbiology Group; IBMC - Instituto de Biologia Celular e Molecular, Universidade do Porto; Porto Portugal
| | - Federico Rossi
- Department of Agrifood Production and Environmental Sciences; University of Florence; Florence Italy
| | - Roberto De Philippis
- Department of Agrifood Production and Environmental Sciences; University of Florence; Florence Italy
| | - Narciso Couto
- Department of Chemical and Biological Engineering; ChELSI Institute, University of Sheffield; Sheffield UK
| | - Esther Karunakaran
- Department of Chemical and Biological Engineering; ChELSI Institute, University of Sheffield; Sheffield UK
| | - Phillip C. Wright
- Department of Chemical and Biological Engineering; ChELSI Institute, University of Sheffield; Sheffield UK
| | - Paulo Oliveira
- Bioengineering and Synthetic Microbiology Group; i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto; Porto Portugal
- Bioengineering and Synthetic Microbiology Group; IBMC - Instituto de Biologia Celular e Molecular, Universidade do Porto; Porto Portugal
| | - Paula Tamagnini
- Bioengineering and Synthetic Microbiology Group; i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto; Porto Portugal
- Bioengineering and Synthetic Microbiology Group; IBMC - Instituto de Biologia Celular e Molecular, Universidade do Porto; Porto Portugal
- Faculdade de Ciências, Departamento de Biologia; Universidade do Porto; Porto Portugal
| |
Collapse
|
21
|
Koskinen S, Hakkila K, Kurkela J, Tyystjärvi E, Tyystjärvi T. Inactivation of group 2 σ factors upregulates production of transcription and translation machineries in the cyanobacterium Synechocystis sp. PCC 6803. Sci Rep 2018; 8:10305. [PMID: 29985458 PMCID: PMC6037674 DOI: 10.1038/s41598-018-28736-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Accepted: 06/26/2018] [Indexed: 11/17/2022] Open
Abstract
We show that the formation of the RNAP holoenzyme with the primary σ factor SigA increases in the ΔsigBCDE strain of the cyanobacterium Synechocystis sp. PCC 6803 lacking all group 2 σ factors. The high RNAP-SigA holoenzyme content directly induces transcription of a particular set of housekeeping genes, including ones encoding transcription and translation machineries. In accordance with upregulated transcripts, ΔsigBCDE contain more RNAPs and ribosomal subunits than the control strain. Extra RNAPs are fully active, and the RNA content of ΔsigBCDE cells is almost tripled compared to that in the control strain. Although ΔsigBCDE cells produce extra rRNAs and ribosomal proteins, functional extra ribosomes are not formed, and translation activity and protein content remained similar in ΔsigBCDE as in the control strain. The arrangement of the RNA polymerase core genes together with the ribosomal protein genes might play a role in the co-regulation of transcription and translation machineries. Sequence logos were constructed to compare promoters of those housekeeping genes that directly react to the RNAP-SigA holoenzyme content and those ones that do not. Cyanobacterial strains with engineered transcription and translation machineries might provide solutions for construction of highly efficient production platforms for biotechnical applications in the future.
Collapse
Affiliation(s)
- Satu Koskinen
- Department of Biochemistry, University of Turku, FI-20014, Turku, Finland
| | - Kaisa Hakkila
- Department of Biochemistry, University of Turku, FI-20014, Turku, Finland
| | - Juha Kurkela
- Department of Biochemistry, University of Turku, FI-20014, Turku, Finland
| | - Esa Tyystjärvi
- Department of Biochemistry, University of Turku, FI-20014, Turku, Finland
| | - Taina Tyystjärvi
- Department of Biochemistry, University of Turku, FI-20014, Turku, Finland.
| |
Collapse
|
22
|
Comparative Targeted Proteomics of the Central Metabolism and Photosystems in SigE Mutant Strains of Synechocystis sp. PCC 6803. Molecules 2018; 23:molecules23051051. [PMID: 29723969 PMCID: PMC6102573 DOI: 10.3390/molecules23051051] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Revised: 04/27/2018] [Accepted: 04/27/2018] [Indexed: 12/17/2022] Open
Abstract
A targeted proteome analysis was conducted to investigate the SigE dependent-regulation of central metabolism in Synechocystis sp. PCC 6803 by directly comparing the protein abundance profiles among the wild type, a sigE deletion mutant (ΔsigE), and a sigE over-expression (sigEox) strains. Expression levels of 112 target proteins, including the central metabolism related-enzymes and the subunits of the photosystems, were determined by quantifying the tryptic peptides in the multiple reaction monitoring (MRM) mode of liquid-chromatography–triple quadrupole mass spectrometry (LC–MS/MS). Comparison with gene-expression data showed that although the abundance of Gnd protein was closely correlated with that of gnd mRNA, there were poor correlations for GdhA/gdhA and glycogen degradation-related genes such as GlgX/glgX and GlgP/glgP pairs. These results suggested that the regulation of protein translation and degradation played a role in regulating protein abundance. The protein abundance profile suggested that SigE overexpression reduced the proteins involved in photosynthesis and increased GdhA abundance, which is involved in the nitrogen assimilation pathway using NADPH. The results obtained in this study successfully demonstrated that targeted proteome analysis enables direct comparison of the abundance of central metabolism- and photosystem-related proteins.
Collapse
|
23
|
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.
Collapse
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
| |
Collapse
|
24
|
Stensjö K, Vavitsas K, Tyystjärvi T. Harnessing transcription for bioproduction in cyanobacteria. PHYSIOLOGIA PLANTARUM 2018; 162:148-155. [PMID: 28762505 DOI: 10.1111/ppl.12606] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Revised: 07/04/2017] [Accepted: 07/10/2017] [Indexed: 06/07/2023]
Abstract
Sustainable production of biofuels and other valuable compounds is one of our future challenges. One tempting possibility is to use photosynthetic cyanobacteria as production factories. Currently, tools for genetic engineering of cyanobacteria are not good enough to exploit the full potential of cyanobacteria. A wide variety of expression systems will be required to adjust both the expression of heterologous enzyme(s) and metabolic routes to the best possible balance, allowing the optimal production of a particular substance. In bacteria, transcription, especially the initiation of transcription, has a central role in adjusting gene expression and thus also metabolic fluxes of cells according to environmental cues. Here we summarize the recent progress in developing tools for efficient cyanofactories, focusing especially on transcriptional regulation.
Collapse
Affiliation(s)
- Karin Stensjö
- Department of Chemistry-Ångström Laboratory, Uppsala University, Box 523, 75120 Uppsala, Sweden
| | - Konstantinos Vavitsas
- Copenhagen Plant Science Centre, Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg C, Denmark
| | - Taina Tyystjärvi
- Molecular Plant Biology, Department of Biochemistry, University of Turku, FI-20014 Turku, Finland
| |
Collapse
|
25
|
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.
Collapse
|
26
|
Srivastava A, Brilisauer K, Rai AK, Ballal A, Forchhammer K, Tripathi AK. Down-Regulation of the Alternative Sigma Factor SigJ Confers a Photoprotective Phenotype to Anabaena PCC 7120. PLANT & CELL PHYSIOLOGY 2017; 58:287-297. [PMID: 27837096 DOI: 10.1093/pcp/pcw188] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2016] [Accepted: 10/28/2016] [Indexed: 06/06/2023]
Abstract
Alternative sigma factors belonging to Group 3 are thought to play an important role in the adaptation of cyanobacteria to environmental challenges by altering expression of genes needed for coping with such stresses. In this study, the role of an alternative sigma factor, SigJ, was analyzed in the filamentous nitrogen-fixing cyanobacterium, Anabaena sp. PCC 7120 by knocking down the expression of the sigJ gene (alr0277) employing an antisense RNA-mediated approach. In the absence of any stress, the knock-down (KD0277) or the wild-type strain both grew similarly. Upon exposure to high-intensity light, KD0277 showed substantially reduced bleaching of its pigments, higher photosynthetic activity and consequently better survival than the wild type. KD0277 also showed an enhanced accumulation of two carotenoids, which were identified as myxoxanthophyll and keto-myxoxanthophyll. Further, KD0277 was more tolerant to ammonium-triggered photodamage than the wild type. Moreover, PSII was better protected against photodamage in KD0277 than in the wild type. Down-regulation of sigJ in Anabaena PCC 7120, however, reduced its ability to cope with desiccation. This study demonstrates that down-regulation of the sigJ gene in Anabaena PCC 7120 differentially affects its ability to tolerate two environmentally relevant stresses, i.e. high-intensity light and desiccation.
Collapse
Affiliation(s)
- Amit Srivastava
- School of Biotechnology, Institute of Science, Banaras Hindu University, Varanasi, India
| | - Klaus Brilisauer
- Interfaculty Institute of Microbiology and Infection Medicine, Eberhard-Karls-Universität Tübingen, Auf der Morgenstelle, Tübingen, Germany
| | - Ashutosh K Rai
- School of Biotechnology, Institute of Science, Banaras Hindu University, Varanasi, India
| | - Anand Ballal
- Molecular Biology Division, Bhabha Atomic Research Centre, Mumbai, India
- Homi Bhabha National Institute, Anushakti Nagar, Mumbai, India
| | - Karl Forchhammer
- Interfaculty Institute of Microbiology and Infection Medicine, Eberhard-Karls-Universität Tübingen, Auf der Morgenstelle, Tübingen, Germany
| | - Anil K Tripathi
- School of Biotechnology, Institute of Science, Banaras Hindu University, Varanasi, India
| |
Collapse
|