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Xing WY, Xie LR, Zeng X, Yang Y, Zhang CC. Functional Dissection of Genes Encoding DNA Polymerases Based on Conditional Mutants in the Heterocyst-Forming Cyanobacterium Anabaena PCC 7120. Front Microbiol 2020; 11:1108. [PMID: 32582078 PMCID: PMC7283527 DOI: 10.3389/fmicb.2020.01108] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Accepted: 05/04/2020] [Indexed: 01/08/2023] Open
Abstract
The filamentous cyanobacterium Anabaena sp. PCC 7120 develops N2-fixing heterocyst cells under condition of combined-nitrogen deprivation and constitutes an excellent model for studying cell differentiation. The mechanism of heterocyst development has been extensively investigated and a network of regulating factors has been identified. A few studies have showed that the process of heterocyst differentiation relates with cell cycle events, but further investigation is still required to understand this relationship. In a previous study, we created a conditional mutant of PolI encoding gene, polA, by using a CRISPR/Cpf1 gene-editing technique. Here, we were able to create another conditional mutant of a PolIII encoding gene dnaENI using a similar strategy and subsequently confirmed the essential roles of both polA and dnaENI in DNA replication. Further investigation on the phenotype of the mutants showed that lack of PolI caused defects in chromosome segregation and cell division, while lack of DnaENI (PolIII) prevented bulk DNA synthesis, causing significant loss of DNA content. Our findings also suggested the possible existence of a SOS-response like mechanism operating in Anabaena PCC 7120. Moreover, we found that heterocyst development was differently affected in the two conditional mutants, with double heterocysts/proheterocysts found in PolI conditional mutant. We further showed that formation of such double heterocysts/proheterocysts are likely caused by the difficulty in nucleoids segregation, resulting delayed, or non-complete closure of the septum between the two daughter cells. This study uncovers a link between DNA replication process and heterocyst differentiation, paving the way for further studies on the relationship between cell cycle and cell development.
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Affiliation(s)
- Wei-Yue Xing
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China.,Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Li-Rui Xie
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China.,Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
| | - Xiaoli Zeng
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China.,Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
| | - Yiling Yang
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China.,Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
| | - Cheng-Cai Zhang
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China.,Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China.,Institut WUT-AMU, Aix-Marseille Université and Wuhan University of Technology, Wuhan, China
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Abstract
The Anabaena organismic unit is a filament of communicating cells. Under conditions of nitrogen scarcity, some cells along the filament differentiate into heterocysts, which are specialized in the fixation of atmospheric N2 and provide the vegetative cells with N2 fixation products. At a certain stage, the differentiation process becomes irreversible, so that even when nitrogen is replenished, no return to the vegetative cell state takes place, possibly as a consequence of loss of cell division capacity. Upon N-stepdown, midcell FtsZ-rings were detected in vegetative cells, but not in differentiating cells, and this was also the case for ZipN, an essential protein that participates in FtsZ tethering to the cytoplasmic membrane and divisome organization. Later, expression of ftsZ was arrested in mature heterocysts. PatA is a protein required for the differentiation of intercalary heterocysts in Anabaena The expression level of the patA gene was increased in differentiating cells, and a mutant strain lacking PatA exhibited enhanced FtsZ-rings. PatA was capable of direct interactions with ZipN and SepF, another essential component of the Anabaena Z-ring. Thus, PatA appears to promote inhibition of cell division in the differentiating cells, allowing progress of the differentiation process. PatA, which in mature heterocysts was detected at the cell poles, could interact also with SepJ, a protein involved in production of the septal junctions that provide cell-cell adhesion and intercellular communication in the filament, hinting at a further role of PatA in the formation or stability of the intercellular structures that are at the basis of the multicellular character of Anabaena IMPORTANCE Anabaena is a cyanobacterial model that represents an ancient and simple form of biological multicellularity. The Anabaena organism is a filament of cohesive and communicating cells that can include cells specialized in different tasks. Thus, under conditions of nitrogen scarcity, certain cells of the filament differentiate into heterocysts, which fix atmospheric nitrogen and provide organic nitrogen to the rest of cells, which, in turn, provide heterocysts with organic carbon. Heterocyst differentiation involves extensive morphological, biochemical, and genetic changes, becoming irreversible at a certain stage. We studied the regulation during heterocyst differentiation of several essential components of the Anabaena cell division machinery and found that protein PatA, which is required for differentiation and is induced in differentiating cells, interacts with essential cell division factors and destabilizes the cell division complex. This suggests a mechanism for establishment of commitment to differentiation by inhibition of cell division.
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Zhou C, Zhang J, Hu X, Li C, Wang L, Huang Q, Chen W. RNase II binds to RNase E and modulates its endoribonucleolytic activity in the cyanobacterium Anabaena PCC 7120. Nucleic Acids Res 2020; 48:3922-3934. [PMID: 32055835 PMCID: PMC7144899 DOI: 10.1093/nar/gkaa092] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Revised: 02/03/2020] [Accepted: 02/10/2020] [Indexed: 11/16/2022] Open
Abstract
In Escherichia coli, the endoribonuclease E (RNase E) can recruit several other ribonucleases and regulatory proteins via its noncatalytic domain to form an RNA degradosome that controls cellular RNA turnover. Similar RNA degradation complexes have been found in other bacteria; however, their compositions are varied among different bacterial species. In cyanobacteria, only the exoribonuclease PNPase was shown to bind to the noncatalytic domain of RNase E. Here, we showed that Alr1240, a member of the RNB family of exoribonucleases, could be co-isolated with RNase E from the lysate of the cyanobacterium Anabaena PCC 7120. Enzymatic analysis revealed that Alr1240 is an exoribonuclease II (RNase II), as it only degrades non-structured single-stranded RNA substrates. In contrast to known RNase E-interacting ribonucleases, which bind to the noncatalytic domain of RNase E, the Anabaena RNase II was shown to associate with the catalytic domain of RNase E. Using a strain in which RNase E and RNase II were tagged in situ with GFP and BFP, respectively, we showed that RNase E and RNase II form a compact complex in vivo by a fluorescence resonance energy transfer (FRET) assay. RNase E activity on several synthetic substrates was boosted in the presence of RNase II, suggesting that the activity of RNase E could be regulated by RNase II-RNase E interaction. To our knowledge, Anabaena RNase II is an unusual ribonuclease that interacts with the catalytic domain of RNase E, and it may represent a new type of RNA degradosome and a novel mechanism for regulating the activity of the RNA degradosome. As Anabaena RNase E interacts with RNase II and PNPase via different regions, it is very likely that the three ribonucleases form a large complex and cooperatively regulate RNA metabolism in the cell.
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Affiliation(s)
- Cong Zhou
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China
| | - Juyuan Zhang
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430070, China
| | - Xinyu Hu
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China
| | - Changchang Li
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China
| | - Li Wang
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China
| | - Qiaoyun Huang
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China
| | - Wenli Chen
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China
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Dienst D, Wichmann J, Mantovani O, Rodrigues JS, Lindberg P. High density cultivation for efficient sesquiterpenoid biosynthesis in Synechocystis sp. PCC 6803. Sci Rep 2020; 10:5932. [PMID: 32246065 PMCID: PMC7125158 DOI: 10.1038/s41598-020-62681-w] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Accepted: 03/05/2020] [Indexed: 12/23/2022] Open
Abstract
Cyanobacteria and microalgae are attractive photoautotrophic host systems for climate-friendly production of fuels and other value-added biochemicals. However, for economic applications further development and implementation of efficient and sustainable cultivation strategies are essential. Here, we present a comparative study on cyanobacterial sesquiterpenoid biosynthesis in Synechocystis sp. PCC 6803 using a commercial lab-scale High Density Cultivation (HDC) platform in the presence of dodecane as in-situ extractant. Operating in a two-step semi-batch mode over a period of eight days, volumetric yields of (E)-α-bisabolene were more than two orders of magnitude higher than previously reported for cyanobacteria, with final titers of 179.4 ± 20.7 mg * L−1. Likewise, yields of the sesquiterpene alcohols (−)-patchoulol and (−)-α-bisabolol were many times higher than under reference conditions, with final titers of 17.3 ± 1.85 mg * L−1 and 96.3 ± 2.2 mg * L−1, respectively. While specific productivity was compromised particularly for (E)-α-bisabolene in the HDC system during phases of high biomass accumulation rates, volumetric productivity enhancements during linear growth at high densities were more pronounced for (E)-α-bisabolene than for the hydroxylated terpenoids. Together, this study provides additional insights into cell density-related process characteristics, introducing HDC as highly efficient strategy for phototrophic terpenoid production in cyanobacteria.
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Affiliation(s)
- Dennis Dienst
- Department of Chemistry - Ångström, Uppsala University, Box 523, Uppsala, 75120, Sweden
| | - Julian Wichmann
- Faculty of Biology - Center for Biotechnology, Bielefeld University, Bielefeld, Germany
| | - Oliver Mantovani
- Department of Chemistry - Ångström, Uppsala University, Box 523, Uppsala, 75120, Sweden
| | - João S Rodrigues
- Department of Chemistry - Ångström, Uppsala University, Box 523, Uppsala, 75120, Sweden
| | - Pia Lindberg
- Department of Chemistry - Ångström, Uppsala University, Box 523, Uppsala, 75120, Sweden.
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Srivastava A, Ballal A, Forchhammer K, Tripathi AK. Construction of Antisense RNA-mediated Gene Knock-downStrains in the Cyanobacterium Anabaena sp. PCC 7120. Bio Protoc 2020; 10:e3528. [PMID: 33654752 DOI: 10.21769/bioprotoc.3528] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Revised: 01/26/2020] [Accepted: 01/28/2020] [Indexed: 11/02/2022] Open
Abstract
Anabaena sp. PCC 7120 (hereafter Anabaena) is a model cyanobacterium to study nitrogen fixation, cellular differentiation and several other key biological functions that are analogous in plants. As with any other organism, many genes in Anabaena encode an essential life function and hence cannot be deleted, causing a bottleneck in the elucidation of its genomic function. Antisense RNA (asRNA) mediated approach renders the study of essential genes possible by suppressing (but not completely eliminating) expression of the target gene, thus allowing them to function to some extent. Recently, we have successfully implemented this approach using the strong endogenous promoter of the psbA1 gene (D1 subunit of Photosystem II) introduced into a high-copy replicative plasmid (pAM1956) to suppress the transcript level of the target gene alr0277 (encoding a sigma factor, SigJ/Alr0277) in Anabaena. This protocol represents an efficient and easy procedure to further explore the functional genomics, expanding the scope of basic and applied research in these ecologically important cyanobacteria.
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Affiliation(s)
- Amit Srivastava
- School of Biotechnology, Institute of Science, Banaras Hindu University, Varanasi-221005, India
| | - Anand Ballal
- Molecular Biology Division, Bhabha Atomic Research Centre, Trombay, Mumbai-400085, India; Homi Bhabha National Institute, Anushaktinagar, Mumbai-400094, India
| | - Karl Forchhammer
- Interfaculty Institute of Microbiology and Infection Medicine Tübingen, Department of Organismic Interactions, University of Tübingen, Tübingen-72076, Germany
| | - Anil Kumar Tripathi
- School of Biotechnology, Institute of Science, Banaras Hindu University, Varanasi-221005, India
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56
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Kuznetsova V, Dominguez-Martin MA, Bao H, Gupta S, Sutter M, Kloz M, Rebarz M, Přeček M, Chen Y, Petzold CJ, Ralston CY, Kerfeld CA, Polívka T. Comparative ultrafast spectroscopy and structural analysis of OCP1 and OCP2 from Tolypothrix. BIOCHIMICA ET BIOPHYSICA ACTA. BIOENERGETICS 2020; 1861:148120. [PMID: 31734194 PMCID: PMC6943196 DOI: 10.1016/j.bbabio.2019.148120] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2019] [Revised: 10/09/2019] [Accepted: 11/04/2019] [Indexed: 01/12/2023]
Abstract
The orange carotenoid protein (OCP) is a structurally and functionally modular photoactive protein involved in cyanobacterial photoprotection. Recently, based on bioinformatic analysis and phylogenetic relationships, new families of OCP have been described, OCP2 and OCPx. The first characterization of the OCP2 showed both faster photoconversion and back-conversion, and lower fluorescence quenching of phycobilisomes relative to the well-characterized OCP1. Moreover, OCP2 is not regulated by the fluorescence recovery protein (FRP). In this work, we present a comprehensive study combining ultrafast spectroscopy and structural analysis to compare the photoactivation mechanisms of OCP1 and OCP2 from Tolypothrix PCC 7601. We show that despite significant differences in their functional characteristics, the spectroscopic properties of OCP1 and OCP2 are comparable. This indicates that the OCP functionality is not directly related to the spectroscopic properties of the bound carotenoid. In addition, the structural analysis by X-ray footprinting reveals that, overall, OCP1 and OCP2 have grossly the same photoactivation mechanism. However, the OCP2 is less reactive to radiolytic labeling, suggesting that the protein is less flexible than OCP1. This observation could explain fast photoconversion of OCP2.
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Affiliation(s)
- Valentyna Kuznetsova
- Institute of Physics, Faculty of Science, University of South Bohemia, Branišovská 1760, 370 05 České Budějovice, Czech Republic
| | | | - Han Bao
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI 48824, USA
| | - Sayan Gupta
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Markus Sutter
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI 48824, USA; Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA; Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Miroslav Kloz
- ELI Beamlines, Institute of Physics, Czech Academy of Sciences, Za Radnicí 835, 252 41 Dolní Břežany, Czech Republic
| | - Mateusz Rebarz
- ELI Beamlines, Institute of Physics, Czech Academy of Sciences, Za Radnicí 835, 252 41 Dolní Břežany, Czech Republic
| | - Martin Přeček
- ELI Beamlines, Institute of Physics, Czech Academy of Sciences, Za Radnicí 835, 252 41 Dolní Břežany, Czech Republic
| | - Yan Chen
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Christopher J Petzold
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Corie Y Ralston
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Cheryl A Kerfeld
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI 48824, USA; Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA; Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA; Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, USA
| | - Tomáš Polívka
- Institute of Physics, Faculty of Science, University of South Bohemia, Branišovská 1760, 370 05 České Budějovice, Czech Republic.
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Videau P, Wells KN, Singh AJ, Eiting J, Proteau PJ, Philmus B. Expanding the Natural Products Heterologous Expression Repertoire in the Model Cyanobacterium Anabaena sp. Strain PCC 7120: Production of Pendolmycin and Teleocidin B-4. ACS Synth Biol 2020; 9:63-75. [PMID: 31846576 DOI: 10.1021/acssynbio.9b00334] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Cyanobacteria are prolific producers of natural products, and genome mining has shown that many orphan biosynthetic gene clusters can be found in sequenced cyanobacterial genomes. New tools and methodologies are required to investigate these biosynthetic gene clusters, and here we present the use of Anabaena sp. strain PCC 7120 as a host for combinatorial biosynthesis of natural products using the indolactam natural products (lyngbyatoxin A, pendolmycin, and teleocidin B-4) as a test case. We were able to successfully produce all three compounds using codon optimized genes from Actinobacteria. We also introduce a new plasmid backbone based on the native Anabaena 7120 plasmid pCC7120ζ and show that production of teleocidin B-4 can be accomplished using a two-plasmid system, which can be introduced by coconjugation.
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Affiliation(s)
- Patrick Videau
- Department of Pharmaceutical Sciences, College of Pharmacy, Oregon State University, Corvallis, Oregon 97331, United States
| | - Kaitlyn N. Wells
- Department of Pharmaceutical Sciences, College of Pharmacy, Oregon State University, Corvallis, Oregon 97331, United States
- Undergraduate Honors College, Oregon State University, Corvallis, Oregon 97331, United States
| | - Arun J. Singh
- Department of Pharmaceutical Sciences, College of Pharmacy, Oregon State University, Corvallis, Oregon 97331, United States
| | - Jessie Eiting
- Department of Pharmaceutical Sciences, College of Pharmacy, Oregon State University, Corvallis, Oregon 97331, United States
| | - Philip J. Proteau
- Department of Pharmaceutical Sciences, College of Pharmacy, Oregon State University, Corvallis, Oregon 97331, United States
| | - Benjamin Philmus
- Department of Pharmaceutical Sciences, College of Pharmacy, Oregon State University, Corvallis, Oregon 97331, United States
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58
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Lin PC, Zhang F, Pakrasi HB. Enhanced production of sucrose in the fast-growing cyanobacterium Synechococcus elongatus UTEX 2973. Sci Rep 2020; 10:390. [PMID: 31942010 PMCID: PMC6962321 DOI: 10.1038/s41598-019-57319-5] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Accepted: 12/28/2019] [Indexed: 11/13/2022] Open
Abstract
Cyanobacteria are attractive microbial hosts for production of chemicals using light and CO2. However, their low productivity of chemicals is a major challenge for commercial applications. This is mostly due to their relatively slow growth rate and carbon partitioning toward biomass rather than products. Many cyanobacterial strains synthesize sucrose as an osmoprotectant to cope with salt stress environments. In this study, we harnessed the photosynthetic machinery of the fast-growing cyanobacterium Synechococcus elongatus UTEX 2973 to produce sucrose under salt stress conditions and investigated if the high efficiency of photosynthesis can enhance the productivity of sucrose. By expressing the sucrose transporter CscB, Synechococcus 2973 produced 8 g L-1 of sucrose with a highest productivity of 1.9 g L-1 day-1 under salt stress conditions. The salt stress activated the sucrose biosynthetic pathway mostly via upregulating the sps gene, which encodes the rate-limiting sucrose-phosphate synthase enzyme. To alleviate the demand on high concentrations of salt for sucrose production, we further overexpressed the sucrose synthesis genes in Synechococcus 2973. The engineered strain produced sucrose with a productivity of 1.1 g L-1 day-1 without the need of salt induction. The engineered Synechococcus 2973 in this study demonstrated the highest productivity of sucrose in cyanobacteria.
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Affiliation(s)
- Po-Cheng Lin
- Department of Energy, Environmental & Chemical Engineering, Washington University, St. Louis, MO, 63130, USA
| | - Fuzhong Zhang
- Department of Energy, Environmental & Chemical Engineering, Washington University, St. Louis, MO, 63130, USA
| | - Himadri B Pakrasi
- Department of Biology, Washington University, St. Louis, MO, 63130, USA.
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59
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Arévalo S, Flores E. Pentapeptide-repeat, cytoplasmic-membrane protein HglK influences the septal junctions in the heterocystous cyanobacterium Anabaena. Mol Microbiol 2020; 113:794-806. [PMID: 31880364 DOI: 10.1111/mmi.14444] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Revised: 11/28/2019] [Indexed: 12/01/2022]
Abstract
N2 -fixing heterocystous cyanobacteria grow as chains of cells that are connected by proteinaceous septal junctions, which traverse the septal peptidoglycan through nanopores and mediate intercellular molecular transfer. In the model organism Anabaena sp. strain PCC 7120, proteins SepJ, FraC and FraD, which are localized at the cell poles in the intercellular septa, are needed to produce septal junctions. The pentapeptide-repeat, membrane-spanning protein HglK has been described to be involved in the deposition of the heterocyst-specific glycolipid layer, but the hglK mutant also showed intercellular septa broader than in the wild type. Here we found that hglK mutant of Anabaena is impaired in the expression of heterocyst-related genes coxB2A2C2 (cytochrome c oxidase) and nifHDK (nitrogenase), indicating a defect in heterocyst differentiation. HglK was predominantly localized at the intercellular septa and was required to make long filaments, produce a normal number of nanopores and express full intercellular molecular transfer activity. However, the effects of hglK inactivation were not additive to those of the inactivation of sepJ and/or fraC-fraD. We suggest that HglK contributes to the architecture of the intercellular septa with an impact on the function of septal junctions.
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Affiliation(s)
- Sergio Arévalo
- Instituto de Bioquímica Vegetal y Fotosíntesis, Consejo Superior de Investigaciones Científicas and Universidad de Sevilla, Seville, Spain
| | - Enrique Flores
- Instituto de Bioquímica Vegetal y Fotosíntesis, Consejo Superior de Investigaciones Científicas and Universidad de Sevilla, Seville, Spain
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60
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Lechno-Yossef S, Rohnke BA, Belza ACO, Melnicki MR, Montgomery BL, Kerfeld CA. Cyanobacterial carboxysomes contain an unique rubisco-activase-like protein. THE NEW PHYTOLOGIST 2020; 225:793-806. [PMID: 31518434 DOI: 10.1111/nph.16195] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Accepted: 09/05/2019] [Indexed: 06/10/2023]
Abstract
In plants, rubisco activase (Rca) regulates rubisco by removing inhibitory molecules such as ribulose-1,5-bisphosphate (RuBP). In cyanobacteria, a homologous protein (activase-like cyanobacterial protein, ALC), contains a distinctive C-terminal fusion resembling the small-subunit of rubisco. Although cyanobacterial rubisco is believed to be less sensitive to RuBP inhibition, the ALC is widely distributed among diverse cyanobacteria. Using microscopy, biochemistry and molecular biology, the cellular localization of the ALC, its effect on carboxysome/cell ultrastructure in Fremyella diplosiphon, and its function in vitro were studied. Bioinformatic analysis uncovered evolutionary relationships between the ALC and rubisco. ALC localizes to carboxysomes and exhibits ATPase activity. Furthermore, the ALC induces rubisco aggregation in a manner similar to that of another carboxysomal protein, M35, and this activity is affected by ATP. An alc deletion mutant showed modified cell morphology when grown under enriched CO2 and impaired regulation of carboxysome biogenesis, without affecting growth rate. Carbamylation of Fremyella recombinant rubisco was inhibited by RuBP, but this inhibition was not relieved by the ALC. The ALC does not appear to function like a canonical Rca; instead, it exerts an effect on the response to CO2 availability at the level of a metabolic module, the carboxysome, through rubisco network formation, and carboxysome organization.
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Affiliation(s)
- Sigal Lechno-Yossef
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, 48824, USA
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, 48824, USA
| | - Brandon A Rohnke
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, 48824, USA
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, 48824, USA
| | - Ana C O Belza
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, 48824, USA
| | - Matthew R Melnicki
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, 48824, USA
| | - Beronda L Montgomery
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, 48824, USA
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, 48824, USA
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI, 48824, USA
| | - Cheryl A Kerfeld
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, 48824, USA
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, 48824, USA
- Environmental Genomics and Systems Biology and Molecular Biophysics and Integrated Bioimaging Divisions, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
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61
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Yunus IS, Palma A, Trudeau DL, Tawfik DS, Jones PR. Methanol-free biosynthesis of fatty acid methyl ester (FAME) in Synechocystis sp. PCC 6803. Metab Eng 2020; 57:217-227. [DOI: 10.1016/j.ymben.2019.12.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 12/01/2019] [Accepted: 12/04/2019] [Indexed: 12/11/2022]
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62
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Hurtado-Gallego J, Redondo-López A, Leganés F, Rosal R, Fernández-Piñas F. Peroxiredoxin (2-cys-prx) and catalase (katA) cyanobacterial-based bioluminescent bioreporters to detect oxidative stress in the aquatic environment. CHEMOSPHERE 2019; 236:124395. [PMID: 31545198 DOI: 10.1016/j.chemosphere.2019.124395] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Revised: 07/16/2019] [Accepted: 07/17/2019] [Indexed: 06/10/2023]
Abstract
The detection of oxidative stress caused by emerging pollutants in aquatic systems is essential to carry out toxicological analysis since they can bring us information about the mechanisms of toxic action of the pollutants, which might be useful to address this contamination. To achieve this goal, two self-bioluminescent strains that respond to oxidative stress based on the filamentous cyanobacterium Nostoc sp. PCC7120, which has a high ecological relevance in aquatic continental systems, have been constructed. Nostoc sp. PCC7120 pBG2172 harbours the promoter region of the 2-cys-prx gene (P2-cys-prx), encoding a cytoplasmic peroxiredoxin, fused to luxCDABE genes of the bacterium Photorhabdus luminescens. Nostoc sp. PCC7120 pBG2173 harbours the promoter region of the KatA gene (PkatA), a cytoplasmic catalase, also fused to luxCDABE genes. Both strains have been characterized by exposing them to H2O2: Nostoc sp. PCC7120 pBG2172 responded while Nostoc sp. PCC7120 pBG2173 did not respond to this pollutant. In order to know their specificity, they were exposed to methyl viologen (MV), an herbicide that produces superoxide anion (O2-) and a bioluminescence response was observed in both strains. Besides, the utility of these strains for the detection of H2O2 and MV in natural water samples, both pristine and wastewater samples has been tested by spiking experiments. Finally, the possible application of these strains for the detection of the emerging pollutant triclosan has also been tested showing to be suitable bioreporters to study oxidative stress in aquatic environments.
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Affiliation(s)
- Jara Hurtado-Gallego
- Departamento de Biología, Facultad de Ciencias, Universidad Autónoma de Madrid, 28029, Madrid, Spain
| | - Arturo Redondo-López
- Departamento de Biología, Facultad de Ciencias, Universidad Autónoma de Madrid, 28029, Madrid, Spain
| | - Francisco Leganés
- Departamento de Biología, Facultad de Ciencias, Universidad Autónoma de Madrid, 28029, Madrid, Spain
| | - Roberto Rosal
- Departamento de Ingeniería Química, Universidad de Alcalá, 28871, Alcalá de Henares, Madrid, Spain
| | - Francisca Fernández-Piñas
- Departamento de Biología, Facultad de Ciencias, Universidad Autónoma de Madrid, 28029, Madrid, Spain.
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63
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Chakravarty D, Banerjee M, Ballal A. Facile generation of a biotechnologically-relevant catalase showcases the efficacy of a blue-green algal biomass as a suitable bioresource for protein overproduction. BIORESOURCE TECHNOLOGY 2019; 293:122013. [PMID: 31494434 DOI: 10.1016/j.biortech.2019.122013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Revised: 08/11/2019] [Accepted: 08/12/2019] [Indexed: 06/10/2023]
Abstract
Here, we show the utility of a cyanobacterial biomass for overproduction and easy downstream processing of the thermostable protein KatB (a Mn-catalase). The nitrogen-fixing blue-green alga, Anabaena, was bioengineered to overexpress the KatB protein (An-KatB). Interestingly, pure An-KatB could be isolated from Anabaena by a simple physical process, obviating the need of expensive resins or chromatographic steps. An-KatB was an efficient H2O2-detoxifying protein that retained all the properties of Mn-catalases. Surprisingly, the purified An-KatB showed improved characteristics than the corresponding KatB (Ec-KatB) protein purified after over-expression in E. coli. An-KatB was unaffected by exposure to high temperature (85 °C), whereas a commercially procured heme-catalase showed an appreciable drop in activity beyond 50 °C. These data convincingly demonstrate the utility of Anabaena as a competent microbial bioresource for overproduction of proteins and further highlight the advantage of An-KatB over heme-catalases in bioprocesses where H2O2 is to be decomposed at elevated temperatures.
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Affiliation(s)
- Dhiman Chakravarty
- Molecular Biology Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India; Homi Bhabha National Institute, Anushaktinagar, Mumbai 400094, India
| | - Manisha Banerjee
- Molecular Biology Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India; Homi Bhabha National Institute, Anushaktinagar, Mumbai 400094, India
| | - Anand Ballal
- Molecular Biology Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India; Homi Bhabha National Institute, Anushaktinagar, Mumbai 400094, India.
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64
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Lin WR, Tan SI, Hsiang CC, Sung PK, Ng IS. Challenges and opportunity of recent genome editing and multi-omics in cyanobacteria and microalgae for biorefinery. BIORESOURCE TECHNOLOGY 2019; 291:121932. [PMID: 31387837 DOI: 10.1016/j.biortech.2019.121932] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Revised: 07/26/2019] [Accepted: 07/27/2019] [Indexed: 06/10/2023]
Abstract
Microalgae and cyanobacteria are easy to culture, with higher growth rates and photosynthetic efficiencies compared to terrestrial plants, and thus generating higher productivity. The concept of microalgal biorefinery is to assimilate carbon dioxide and convert it to chemical energy/value-added products, such as vitamins, carotenoids, fatty acids, proteins and nucleic acids, to be applied in bioenergy, health foods, aquaculture feed, pharmaceutical and medical fields. Therefore, microalgae are annotated as the third generation feedstock in bioenergy and biorefinery. In past decades, many studies thrived to improve the carbon sequestration efficiency as well as enhance value-added compounds from different algae, especially via genetic engineering, synthetic biology, metabolic design and regulation. From the traditional Agrobacterium-mediated transformation DNA to novel CRISPR (clustered regularly interspaced short palindromic repeats) technology applied in microalgae and cyanobacteria, this review has highlighted the genome editing technology for biorefinery that is a highly environmental friendly trend to sustainable and renewable development.
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Affiliation(s)
- Way-Rong Lin
- Department of Chemical Engineering, National Cheng Kung University, Tainan 701, Taiwan, ROC
| | - Shih-I Tan
- Department of Chemical Engineering, National Cheng Kung University, Tainan 701, Taiwan, ROC
| | - Chuan-Chieh Hsiang
- Department of Chemical Engineering, National Cheng Kung University, Tainan 701, Taiwan, ROC
| | - Po-Kuei Sung
- Department of Chemical Engineering, National Cheng Kung University, Tainan 701, Taiwan, ROC
| | - I-Son Ng
- Department of Chemical Engineering, National Cheng Kung University, Tainan 701, Taiwan, ROC.
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Bishé B, Taton A, Golden JW. Modification of RSF1010-Based Broad-Host-Range Plasmids for Improved Conjugation and Cyanobacterial Bioprospecting. iScience 2019; 20:216-228. [PMID: 31585408 PMCID: PMC6817606 DOI: 10.1016/j.isci.2019.09.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 08/23/2019] [Accepted: 09/01/2019] [Indexed: 01/22/2023] Open
Abstract
To facilitate the genetic engineering of diverse cyanobacterial strains, we have modified broad-host-range RSF1010-based plasmids to improve transmissibility, increase copy number, and facilitate cloning. RSF1010-based plasmids replicate in diverse bacterial strains but produce low amounts of useable DNA for cloning. We previously engineered a mobAY25F mutation in RSF1010-based plasmids that improved cloning but decreased conjugation efficiency. Here, we engineered RSF1010-based plasmids to restore conjugation efficiency, which was demonstrated in three diverse laboratory strains of cyanobacteria. We then used an improved RSF1010-based plasmid in mating experiments with cultured samples of wild cyanobacteria. This plasmid, which confers antibiotic resistance and carries a yfp reporter gene, allowed selection of exconjugant cyanobacteria and facilitated the isolation of genetically tractable strains from mixed wild cultures. Improved RSF1010 vectors can be used for bioprospecting genetically tractable strains and are compatible with the CYANO-VECTOR cloning system, a versatile toolbox for constructing plasmids for cyanobacterial genetic engineering. An RSF1010 mobAY25F mutation facilitates plasmid cloning but reduces conjugation Addition of an RK2-bom site improves conjugation efficiency of mobAY25F vectors A helper plasmid carrying the mobA gene improves conjugation efficiency of mobAY25F Improved RSF1010-based vectors can be used for bioprospecting of cyanobacteria
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Affiliation(s)
- Bryan Bishé
- Division of Biological Sciences, University of California San Diego, 9500 Gilman Dr., La Jolla, CA 92093, USA
| | - Arnaud Taton
- Division of Biological Sciences, University of California San Diego, 9500 Gilman Dr., La Jolla, CA 92093, USA
| | - James W Golden
- Division of Biological Sciences, University of California San Diego, 9500 Gilman Dr., La Jolla, CA 92093, USA.
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Sevilla E, Sarasa-Buisan C, González A, Cases R, Kufryk G, Peleato ML, Fillat MF. Regulation by FurC in Anabaena Links the Oxidative Stress Response to Photosynthetic Metabolism. PLANT & CELL PHYSIOLOGY 2019; 60:1778-1789. [PMID: 31111929 DOI: 10.1093/pcp/pcz094] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Accepted: 05/10/2019] [Indexed: 06/09/2023]
Abstract
The FUR (Ferric Uptake Regulator) family in Anabaena sp. PCC 7120 consists of three paralogs named FurA (Fur), FurB (Zur) and FurC (PerR). furC seems to be an essential gene in the filamentous nitrogen-fixing strain Anabaena sp. PCC 7120, suggesting that it plays a fundamental role in this organism. In order to better understand the functions of FurC in Anabaena, the phenotype of a derivative strain that overexpresses this regulator (EB2770FurC) has been characterized. The furC-overexpressing variant presented alterations in growth rate, morphology and ultrastructure, as well as higher sensitivity to peroxide than Anabaena sp. PCC 7120. Interestingly, the overexpression of furC led to reduced photosynthetic O2 evolution, increased respiratory activity, and had a significant influence in the composition and efficiency of both photosystems. Comparative transcriptional analyses, together with electrophoretic mobility shift assays allowed the identification of different genes directly controlled by FurC, and involved in processes not previously related to PerR proteins, such as the cell division gene ftsZ and the major thylakoid membrane protease ftsH. The rise in the transcription of ftsH in EB2770FurC cells correlated with reduced levels of the D1 protein, which is involved in the PSII repair cycle. Deregulation of the oxidative stress response in EB2770FurC cells led to the identification of novel FurC targets involved in the response to H2O2 through different mechanisms. These results, together with the effect of furC overexpression on the composition, stability and efficiency of the photosynthetic machinery of Anabaena, disclose novel links between PerR proteins, cell division and photosynthesis in filamentous cyanobacteria.
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Affiliation(s)
- Emma Sevilla
- Departamento de Bioquímica y Biología Molecular y Celular, Universidad de Zaragoza, Pedro Cerbuna 12, Zaragoza, Spain
- Institute for Biocomputation and Physics of Complex Systems, Universidad de Zaragoza, Pedro Cerbuna 12, Zaragoza, Spain
| | - Cristina Sarasa-Buisan
- Departamento de Bioquímica y Biología Molecular y Celular, Universidad de Zaragoza, Pedro Cerbuna 12, Zaragoza, Spain
- Institute for Biocomputation and Physics of Complex Systems, Universidad de Zaragoza, Pedro Cerbuna 12, Zaragoza, Spain
| | - Andrés González
- Departamento de Bioquímica y Biología Molecular y Celular, Universidad de Zaragoza, Pedro Cerbuna 12, Zaragoza, Spain
- Institute for Biocomputation and Physics of Complex Systems, Universidad de Zaragoza, Pedro Cerbuna 12, Zaragoza, Spain
- Aragon Institute for Health Research (IIS Aragón), Zaragoza, Spain
| | - Rafael Cases
- Instituto de Ciencia de Materiales de Aragón, Universidad de Zaragoza-CSIC, Zaragoza, Spain
- Departamento de Física de la Materia Condensada, Facultad de Ciencias, Universidad de Zaragoza-CSIC, Zaragoza, Spain
| | - Galyna Kufryk
- College of Science, Engineering and Technology, Grand Canyon University, 3300 W. Camelback Rd, Phoenix, AZ, USA
| | - M Luisa Peleato
- Departamento de Bioquímica y Biología Molecular y Celular, Universidad de Zaragoza, Pedro Cerbuna 12, Zaragoza, Spain
- Institute for Biocomputation and Physics of Complex Systems, Universidad de Zaragoza, Pedro Cerbuna 12, Zaragoza, Spain
| | - María F Fillat
- Departamento de Bioquímica y Biología Molecular y Celular, Universidad de Zaragoza, Pedro Cerbuna 12, Zaragoza, Spain
- Institute for Biocomputation and Physics of Complex Systems, Universidad de Zaragoza, Pedro Cerbuna 12, Zaragoza, Spain
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Chakravarty D, Bihani SC, Banerjee M, Ballal A. Novel molecular insights into the anti-oxidative stress response and structure-function of a salt-inducible cyanobacterial Mn-catalase. PLANT, CELL & ENVIRONMENT 2019; 42:2508-2521. [PMID: 30993731 DOI: 10.1111/pce.13563] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Accepted: 04/07/2019] [Indexed: 06/09/2023]
Abstract
KatB, a salt-inducible Mn-catalase, protects the cyanobacterium Anabaena from salinity/oxidative stress. In this report, we provide distinctive insights into the biological-biochemical function of KatB at the molecular level. Anabaena overexpressing the wild-type KatB protein (KatBWT) detoxified H2 O2 efficiently, showing reduced burden of reactive oxygen species compared with the strain overproducing KatBF2V (wherein F-2 is replaced by V). Correspondingly, the KatBWT protein also displayed several folds more activity than KatBF2V. Interestingly, the KatB variants with large hydrophobic amino acids (F/W/Y) were more compact, showed enhanced activity, and were resistant to thermal/chemical denaturation than variants with smaller residues (G/A/V) at the second position. X-ray crystallography-based analysis showed that F-2 was required for appropriate interactions between two subunits. These contacts provided stability to the hexamer, making it more compact. F-2, through its interaction with F-66 and W-43, formed the proper hydrophobic pocket that held the active site together. Consequently, only residues that supported activity (i.e., F/Y/W) were selected at the second position in Mn-catalases during evolution. This study (a) demonstrates that modification of nonactive site residues can alter the response of catalases to environmental stress and (b) has expanded the scope of amino acids that can be targeted for rational protein engineering in plants.
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Affiliation(s)
- Dhiman Chakravarty
- Molecular Biology Division, Bhabha Atomic Research Centre, Trombay, Mumbai, 400085, India
- Homi Bhabha National Institute, Anushakti Nagar, Mumbai, 400094, India
| | - Subhash C Bihani
- Radiation Biology & Health Sciences Division, Bhabha Atomic Research Centre, Trombay, Mumbai, 400085, India
| | - Manisha Banerjee
- Molecular Biology Division, Bhabha Atomic Research Centre, Trombay, Mumbai, 400085, India
- Homi Bhabha National Institute, Anushakti Nagar, Mumbai, 400094, India
| | - Anand Ballal
- Molecular Biology Division, Bhabha Atomic Research Centre, Trombay, Mumbai, 400085, India
- Homi Bhabha National Institute, Anushakti Nagar, Mumbai, 400094, India
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Development of a shuttle plasmid without host restriction sites for efficient transformation and heterologous gene expression in Clostridium cellulovorans. Appl Microbiol Biotechnol 2019; 103:5391-5400. [DOI: 10.1007/s00253-019-09882-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Revised: 04/16/2019] [Accepted: 04/29/2019] [Indexed: 10/26/2022]
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69
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Russo DA, Zedler JAZ, Wittmann DN, Möllers B, Singh RK, Batth TS, van Oort B, Olsen JV, Bjerrum MJ, Jensen PE. Expression and secretion of a lytic polysaccharide monooxygenase by a fast-growing cyanobacterium. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:74. [PMID: 30976324 PMCID: PMC6442416 DOI: 10.1186/s13068-019-1416-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Accepted: 03/21/2019] [Indexed: 05/03/2023]
Abstract
BACKGROUND Cyanobacteria have the potential to become next-generation cell factories due to their ability to use CO2, light and inorganic nutrients to produce a range of biomolecules of commercial interest. Synechococcus elongatus UTEX 2973, in particular, is a fast-growing, genetically tractable, cyanobacterium that has garnered attention as a potential biotechnological chassis. To establish this unique strain as a host for heterologous protein production, we aimed to demonstrate expression and secretion of the industrially relevant TfAA10A, a lytic polysaccharide monooxygenase from the Gram-positive bacterium Thermobifida fusca. RESULTS Two variations of TfAA10A were successfully expressed in S. elongatus UTEX 2973: One containing the native N-terminal, Sec-targeted, signal peptide and a second with a Tat-targeted signal peptide from the Escherichia coli trimethylamine-N-oxide reductase (TorA). Although the TorA signal peptide correctly targeted the protein to the plasma membrane, the majority of the TorA-TfAA10A was found unprocessed in the plasma membrane with a small fraction of the mature protein ultimately translocated to the periplasm. The native Sec signal peptide allowed for efficient secretion of TfAA10A into the medium with virtually no protein being found in the cytosol, plasma membrane or periplasm. TfAA10A was demonstrated to be correctly cleaved and active on the model substrate phosphoric acid swollen cellulose. Additionally, expression and secretion only had a minor impact on cell growth. The secretion yield was estimated at 779 ± 40 µg L-1 based on densitometric analysis. To our knowledge, this is the highest secretion yield ever registered in cyanobacteria. CONCLUSIONS We have shown for the first time high-titer expression and secretion of an industrially relevant and catalytically active enzyme in S. elongatus UTEX 2973. This proof-of-concept study will be valuable for the development of novel and sustainable applications in the fields of bioremediation and biocatalysis.
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Affiliation(s)
- D. A. Russo
- Copenhagen Plant Science Centre, Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg C, Denmark
| | - J. A. Z. Zedler
- Copenhagen Plant Science Centre, Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg C, Denmark
| | - D. N. Wittmann
- Copenhagen Plant Science Centre, Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg C, Denmark
| | - B. Möllers
- Department of Geosciences and Natural Resource Management, University of Copenhagen, Frederiksberg C, Denmark
| | - R. K. Singh
- Department of Chemistry, University of Copenhagen, Copenhagen, Denmark
| | - T. S. Batth
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - B. van Oort
- Biophysics of Photosynthesis, Department of Physics and Astronomy, Faculty of Sciences, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - J. V. Olsen
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - M. J. Bjerrum
- Department of Chemistry, University of Copenhagen, Copenhagen, Denmark
| | - P. E. Jensen
- Copenhagen Plant Science Centre, Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg C, Denmark
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Enhanced Nitrogen Fixation in a glgX-Deficient Strain of Cyanothece sp. Strain ATCC 51142, a Unicellular Nitrogen-Fixing Cyanobacterium. Appl Environ Microbiol 2019; 85:AEM.02887-18. [PMID: 30709817 DOI: 10.1128/aem.02887-18] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Accepted: 01/25/2019] [Indexed: 01/15/2023] Open
Abstract
Cyanobacteria are oxygenic photosynthetic prokaryotes with important roles in the global carbon and nitrogen cycles. Unicellular nitrogen-fixing cyanobacteria are known to be ubiquitous, contributing to the nitrogen budget in diverse ecosystems. In the unicellular cyanobacterium Cyanothece sp. strain ATCC 51142, carbon assimilation and carbohydrate storage are crucial processes that occur as part of a robust diurnal cycle of photosynthesis and nitrogen fixation. During the light period, cells accumulate fixed carbon in glycogen granules to use as stored energy to power nitrogen fixation in the dark. These processes have not been thoroughly investigated, due to the lack of a genetic modification system in this organism. In bacterial glycogen metabolism, the glgX gene encodes a debranching enzyme that functions in storage polysaccharide catabolism. To probe the consequences of modifying the cycle of glycogen accumulation and subsequent mobilization, we engineered a strain of Cyanothece 51142 in which the glgX gene was genetically disrupted. We found that the ΔglgX strain exhibited a higher growth rate than the wild-type strain and displayed a higher rate of nitrogen fixation. Glycogen accumulated to higher levels at the end of the light period in the ΔglgX strain, compared to the wild-type strain. These data suggest that the larger glycogen pool maintained by the ΔglgX mutant is able to fuel greater growth and nitrogen fixation ability.IMPORTANCE Cyanobacteria are oxygenic photosynthetic bacteria that are found in a wide variety of ecological environments, where they are important contributors to global carbon and nitrogen cycles. Genetic manipulation systems have been developed in a number of cyanobacterial strains, allowing both the interruption of endogenous genes and the introduction of new genes and entire pathways. However, unicellular diazotrophic cyanobacteria have been generally recalcitrant to genetic transformation. These cyanobacteria are becoming important model systems to study diurnally regulated processes. Strains of the Cyanothece genus have been characterized as displaying robust growth and high rates of nitrogen fixation. The significance of our study is in the establishment of a genetic modification system in a unicellular diazotrophic cyanobacterium, the demonstration of the interruption of the glgX gene in Cyanothece sp. strain ATCC 51142, and the characterization of the increased nitrogen-fixing ability of this strain.
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Dominguez-Martin MA, Polívka T, Sutter M, Ferlez B, Lechno-Yossef S, Montgomery BL, Kerfeld CA. Structural and spectroscopic characterization of HCP2. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2019; 1860:414-424. [PMID: 30880081 DOI: 10.1016/j.bbabio.2019.03.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Revised: 02/09/2019] [Accepted: 03/11/2019] [Indexed: 10/27/2022]
Abstract
The Helical Carotenoid Proteins (HCPs) are a large group of newly identified carotenoid-binding proteins found in ecophysiologically diverse cyanobacteria. They likely evolved before becoming the effector (quenching) domain of the modular Orange Carotenoid Protein (OCP). The number of discrete HCP families-at least nine-suggests they are involved in multiple distinct functions. Here we report the 1.7 Å crystal structure of HCP2, one of the most widespread HCPs found in nature, from the chromatically acclimating cyanobacterium Tolypothrix sp. PCC 7601. By purifying HCP2 from the native source we are able to identify its natively-bound carotenoid, which is exclusively canthaxanthin. In solution, HCP2 is a monomer with an absorbance maximum of 530 nm. However, the HCP2 crystals have a maximum absorbance at 548 nm, which is accounted by the stacking of the β1 rings of the carotenoid in the two molecules in the asymmetric unit. Our results demonstrate how HCPs provide a valuable system to study carotenoid-protein interactions and their spectroscopic implications, and contribute to efforts to understand the functional roles of this large, newly discovered family of pigment proteins, which to-date remain enigmatic.
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Affiliation(s)
| | - Tomáš Polívka
- Institute of Physics, Faculty of Science, University of South Bohemia, Branišovská 31, 370 05 České Budějovice, Czech Republic
| | - Markus Sutter
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI 48824, USA; Environmental Genomics and Systems Biology and Molecular Biophysics and Integrated Bioimaging Divisions, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Bryan Ferlez
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI 48824, USA
| | - Sigal Lechno-Yossef
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI 48824, USA
| | - Beronda L Montgomery
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI 48824, USA; Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, USA; Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI 48824, USA
| | - Cheryl A Kerfeld
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI 48824, USA; Environmental Genomics and Systems Biology and Molecular Biophysics and Integrated Bioimaging Divisions, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA; Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, USA.
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Camargo S, Picossi S, Corrales-Guerrero L, Valladares A, Arévalo S, Herrero A. ZipN is an essential FtsZ membrane tether and contributes to the septal localization of SepJ in the filamentous cyanobacterium Anabaena. Sci Rep 2019; 9:2744. [PMID: 30808920 PMCID: PMC6391411 DOI: 10.1038/s41598-019-39336-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Accepted: 01/23/2019] [Indexed: 11/23/2022] Open
Abstract
The organismic unit of heterocyst-forming cyanobacteria is a filament of communicating cells connected by septal junctions, proteinaceous structures bridging the cytoplasms of contiguous cells. This distinct bacterial organization is preserved during cell division. In Anabaena, deletion of the zipN gene could not be segregated. We generated strain CSL109 that expresses zipN from a synthetic regulatable promoter. Under conditions of ZipN depletion, cells progressively enlarged, reflecting restricted cell division, and showed drastic morphological alterations including cell detachment from the filaments, to finish lysing. In contrast to the wild-type localization in midcell Z-rings, FtsZ was found in delocalized aggregates in strain CSL109. Consistently, the proportion of membrane-associated to soluble FtsZ in fractionated cell extracts was lower in CSL109. Bacterial two-hybrid analysis showed that ZipN interacts with FtsZ and other cell-division proteins including cytoplasmic Ftn6 and SepF, and polytopic FtsW, FtsX, FtsQ and FtsI. Additionally, ZipN interacted with the septal protein SepJ, and in CSL109 depletion of ZipN was concomitant with a progressive loss of septal specificity of SepJ. Thus, in Anabaena ZipN represents an essential FtsZ membrane tether and an organizer of the divisome, and it contributes to the conformation of septal structures for filament integrity and intercellular communication.
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Affiliation(s)
- Sergio Camargo
- Instituto de Bioquímica Vegetal y Fotosíntesis, Consejo Superior de Investigaciones Científicas and Universidad de Sevilla, Américo Vespucio 49, E-41092, Seville, Spain
| | - Silvia Picossi
- Instituto de Bioquímica Vegetal y Fotosíntesis, Consejo Superior de Investigaciones Científicas and Universidad de Sevilla, Américo Vespucio 49, E-41092, Seville, Spain
| | | | - Ana Valladares
- Instituto de Bioquímica Vegetal y Fotosíntesis, Consejo Superior de Investigaciones Científicas and Universidad de Sevilla, Américo Vespucio 49, E-41092, Seville, Spain
| | - Sergio Arévalo
- Instituto de Bioquímica Vegetal y Fotosíntesis, Consejo Superior de Investigaciones Científicas and Universidad de Sevilla, Américo Vespucio 49, E-41092, Seville, Spain
| | - Antonia Herrero
- Instituto de Bioquímica Vegetal y Fotosíntesis, Consejo Superior de Investigaciones Científicas and Universidad de Sevilla, Américo Vespucio 49, E-41092, Seville, Spain.
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Burnat M, Picossi S, Valladares A, Herrero A, Flores E. Catabolic pathway of arginine in Anabaena involves a novel bifunctional enzyme that produces proline from arginine. Mol Microbiol 2019; 111:883-897. [PMID: 30636068 DOI: 10.1111/mmi.14203] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/07/2019] [Indexed: 12/16/2022]
Abstract
Arginine participates widely in metabolic processes. The heterocyst-forming cyanobacterium Anabaena catabolizes arginine to produce proline and glutamate, with concomitant release of ammonium, as major products. Analysis of mutant Anabaena strains showed that this catabolic pathway is the product of two genes, agrE (alr4995) and putA (alr0540). The predicted PutA protein is a conventional, bifunctional proline oxidase that produces glutamate from proline. In contrast, AgrE is a hitherto unrecognized enzyme that contains both an N-terminal α/β propeller domain and a unique C-terminal domain of previously unidentified function. In vitro analysis of the proteins expressed in Escherichia coli or Anabaena showed arginine dihydrolase activity of the N-terminal domain and ornithine cyclodeaminase activity of the C-terminal domain, overall producing proline from arginine. In the diazotrophic filaments of Anabaena, β-aspartyl-arginine dipeptide is transferred from the heterocysts to the vegetative cells, where it is cleaved producing aspartate and arginine. Both agrE and putA were found to be expressed at higher levels in vegetative cells than in heterocysts, implying that arginine is catabolized by the AgrE-PutA pathway mainly in the vegetative cells. Expression in Anabaena of a homolog of the C-terminal domain of AgrE obtained from Methanococcus maripaludis enabled us to identify an archaeal ornithine cyclodeaminase.
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Affiliation(s)
- Mireia Burnat
- Instituto de Bioquímica Vegetal y Fotosíntesis, CSIC and Universidad de Sevilla, Américo Vespucio 49, E-41092, Sevilla, Spain
| | - Silvia Picossi
- Instituto de Bioquímica Vegetal y Fotosíntesis, CSIC and Universidad de Sevilla, Américo Vespucio 49, E-41092, Sevilla, Spain
| | - Ana Valladares
- Instituto de Bioquímica Vegetal y Fotosíntesis, CSIC and Universidad de Sevilla, Américo Vespucio 49, E-41092, Sevilla, Spain
| | - Antonia Herrero
- Instituto de Bioquímica Vegetal y Fotosíntesis, CSIC and Universidad de Sevilla, Américo Vespucio 49, E-41092, Sevilla, Spain
| | - Enrique Flores
- Instituto de Bioquímica Vegetal y Fotosíntesis, CSIC and Universidad de Sevilla, Américo Vespucio 49, E-41092, Sevilla, Spain
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Niu TC, Lin GM, Xie LR, Wang ZQ, Xing WY, Zhang JY, Zhang CC. Expanding the Potential of CRISPR-Cpf1-Based Genome Editing Technology in the Cyanobacterium Anabaena PCC 7120. ACS Synth Biol 2019; 8:170-180. [PMID: 30525474 DOI: 10.1021/acssynbio.8b00437] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
CRISPR systems, such as CRISPR-Cas9 and CRISPR-Cpf1, have been successfully used for genome editing in a variety of organisms. Although the technique of CRISPR-Cpf1 has been applied in cyanobacteria recently, its use was limited without exploiting the full potential of such a powerful genetic system. Using the cyanobacterium Anabaena PCC 7120 as a model strain, we improved the tools and designed genetic strategies based on CRISPR-Cpf1, which enabled us to realize genetic experiments that have been so far difficult to do in cyanobacteria. The development includes: (1) a "two-spacers" strategy for single genomic modification, with a success rate close to 100%; (2) rapid multiple genome editing using editing plasmids with different resistance markers; (3) using sacB, a counter-selection marker conferring sucrose sensitivity, to enable the active loss of the editing plasmids and facilitate multiple rounds of genetic modification or phenotypic analysis; (4) manipulation of essential genes by the creation of conditional mutants, using as example, polA encoding the DNA polymerase I essential for DNA replication and repair; (5) large DNA fragment deletion, up to 118 kb, from the Anabaena chromosome, corresponding to the largest bacterial chromosomal region removed with CRISPR systems so far. The genome editing vectors and the strategies developed here will expand our ability to study and engineer cyanobacteria, which are extensively used for fundamental studies, biotechnological applications including biofuel production, and synthetic biology research. The vectors developed here have a broad host range, and could be readily used for genetic modification in other microorganisms.
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Affiliation(s)
- Tian-Cai Niu
- Key Laboratory of Algal Biology, Institute of Hydrobiology, the Chinese Academy of Sciences, Wuhan, Hubei Province, China
| | - Gui-Ming Lin
- Key Laboratory of Algal Biology, Institute of Hydrobiology, the Chinese Academy of Sciences, Wuhan, Hubei Province, China
| | - Li-Rui Xie
- Key Laboratory of Algal Biology, Institute of Hydrobiology, the Chinese Academy of Sciences, Wuhan, Hubei Province, China
| | - Zi-Qian Wang
- Key Laboratory of Algal Biology, Institute of Hydrobiology, the Chinese Academy of Sciences, Wuhan, Hubei Province, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Wei-Yue Xing
- Key Laboratory of Algal Biology, Institute of Hydrobiology, the Chinese Academy of Sciences, Wuhan, Hubei Province, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Ju-Yuan Zhang
- Key Laboratory of Algal Biology, Institute of Hydrobiology, the Chinese Academy of Sciences, Wuhan, Hubei Province, China
| | - Cheng-Cai Zhang
- Key Laboratory of Algal Biology, Institute of Hydrobiology, the Chinese Academy of Sciences, Wuhan, Hubei Province, China
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Bellefleur MPA, Wanda SY, Curtiss R. Characterizing active transportation mechanisms for free fatty acids and antibiotics in Synechocystis sp. PCC 6803. BMC Biotechnol 2019; 19:5. [PMID: 30630457 PMCID: PMC6329066 DOI: 10.1186/s12896-019-0500-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Accepted: 01/02/2019] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND Synechocystis sp. PCC 6803 is a photosynthetic bacterium that has been genetically modified to produce industrially relevant chemicals, yet efflux mechanisms have not been well elucidated. These photosynthetic organisms live in environments that are often nutrient limited; therefore, the genome of these organisms encodes far fewer proteins used for efflux of chemicals when compared to members of the Enterobacteriaceae family. Understanding efflux mechanisms can lead to a greater efficiency of chemical production within the cyanobacterial cell. RESULTS Both sll0180 and slr2131 genes that encode the Sll0180 and Slr2131 proteins, respectively, were removed from Synechocystis sp. PCC 6803 and SD277, a high fatty acid-producing Synechocystis-based strain, to test the hypothesis that Sll0180 and Slr2131 contribute to the efflux of chemicals out of Synechocystis sp. PCC 6803 and SD277. The mutant Synechocystis sp. PCC 6803 and SD277 strains with either sll0180 or slr2131 removed from the chromosome had significantly decreased half maximal inhibitory concentrations to various antibiotics. The free fatty acid (FFA) concentration of the SD277 mutant strains increased intracellularly yet decreased extracellularly indicating that Sll0180 and Slr2131 have a role in FFA efflux. E. coli wild-type gene acrA (a homolog to sll0180) was added on a plasmid to the respective mutant strains lacking the sll0180 gene. Similarly, the E. coli wild-type gene acrB (a homolog to slr2131) was added to the respective mutant strains lacking the slr2131 gene. The tolerance to chloramphenicol of each mutant strain containing the wild-type E. coli gene was restored when compared to the parent stains. The extracellular FFA concentration of SD277 Δslr2131 with E. coli acrB increased significantly compared to both SD277 and SD277 Δslr2131. CONCLUSIONS Two proteins involved in the transportation of antibiotics and FFAs out of the Synechocystis sp. PCC 6803 cell were identified. In an effort to alleviate costs associated with mechanically or chemically separating the cells from the FFAs, the combination of genome editing of SD277 and the addition of exogenous transport gene increased extracellular concentrations of FFAs. This understanding of active transportation is critical to improving the production efficiency for all industrially relevant chemicals produced in Synechocystis sp. PCC 6803.
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Affiliation(s)
- Matthew P. A. Bellefleur
- School of Life Sciences, Arizona State University, 427 E. Tyler Mall, Tempe, AZ 85287 USA
- College of Veterinary Medicine, University of Florida, 2015 SW 16th Ave, Gainesville, FL 32608 USA
| | - Soo-Young Wanda
- School of Life Sciences, Arizona State University, 427 E. Tyler Mall, Tempe, AZ 85287 USA
- College of Veterinary Medicine, University of Florida, 2015 SW 16th Ave, Gainesville, FL 32608 USA
| | - Roy Curtiss
- School of Life Sciences, Arizona State University, 427 E. Tyler Mall, Tempe, AZ 85287 USA
- College of Veterinary Medicine, University of Florida, 2015 SW 16th Ave, Gainesville, FL 32608 USA
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Sommer M, Sutter M, Gupta S, Kirst H, Turmo A, Lechno-Yossef S, Burton RL, Saechao C, Sloan NB, Cheng X, Chan LJG, Petzold CJ, Fuentes-Cabrera M, Ralston CY, Kerfeld CA. Heterohexamers Formed by CcmK3 and CcmK4 Increase the Complexity of Beta Carboxysome Shells. PLANT PHYSIOLOGY 2019; 179:156-167. [PMID: 30389783 PMCID: PMC6324227 DOI: 10.1104/pp.18.01190] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Accepted: 10/26/2018] [Indexed: 05/10/2023]
Abstract
Bacterial microcompartments (BMCs) encapsulate enzymes within a selectively permeable, proteinaceous shell. Carboxysomes are BMCs containing ribulose-1,5-bisphosphate carboxylase oxygenase and carbonic anhydrase that enhance carbon dioxide fixation. The carboxysome shell consists of three structurally characterized protein types, each named after the oligomer they form: BMC-H (hexamer), BMC-P (pentamer), and BMC-T (trimer). These three protein types form cyclic homooligomers with pores at the center of symmetry that enable metabolite transport across the shell. Carboxysome shells contain multiple BMC-H paralogs, each with distinctly conserved residues surrounding the pore, which are assumed to be associated with specific metabolites. We studied the regulation of β-carboxysome shell composition by investigating the BMC-H genes ccmK3 and ccmK4 situated in a locus remote from other carboxysome genes. We made single and double deletion mutants of ccmK3 and ccmK4 in Synechococcus elongatus PCC7942 and show that, unlike CcmK3, CcmK4 is necessary for optimal growth. In contrast to other CcmK proteins, CcmK3 does not form homohexamers; instead CcmK3 forms heterohexamers with CcmK4 with a 1:2 stoichiometry. The CcmK3-CcmK4 heterohexamers form stacked dodecamers in a pH-dependent manner. Our results indicate that CcmK3-CcmK4 heterohexamers potentially expand the range of permeability properties of metabolite channels in carboxysome shells. Moreover, the observed facultative formation of dodecamers in solution suggests that carboxysome shell permeability may be dynamically attenuated by "capping" facet-embedded hexamers with a second hexamer. Because β-carboxysomes are obligately expressed, heterohexamer formation and capping could provide a rapid and reversible means to alter metabolite flux across the shell in response to environmental/growth conditions.
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Affiliation(s)
- Manuel Sommer
- Department of Plant and Microbial Biology, University of California, Berkeley, California 94720
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720
| | - Markus Sutter
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720
- Michigan State University-U.S. Department of Energy Plant Research Laboratory and Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824
| | - Sayan Gupta
- Michigan State University-U.S. Department of Energy Plant Research Laboratory and Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824
| | - Henning Kirst
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720
- Michigan State University-U.S. Department of Energy Plant Research Laboratory and Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824
| | - Aiko Turmo
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720
| | - Sigal Lechno-Yossef
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720
| | - Rodney L Burton
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720
| | - Christine Saechao
- Department of Plant and Microbial Biology, University of California, Berkeley, California 94720
- Michigan State University-U.S. Department of Energy Plant Research Laboratory and Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824
| | - Nancy B Sloan
- Michigan State University-U.S. Department of Energy Plant Research Laboratory and Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824
| | - Xiaolin Cheng
- Division of Medicinal Chemistry and Pharmacognosy and Biophysics Graduate Program, Ohio State University, Columbus, Ohio 43210
| | - Leanne-Jade G Chan
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720
| | - Christopher J Petzold
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720
| | - Miguel Fuentes-Cabrera
- Center for Nanophase Materials Sciences and Computational Sciences and Engineering Division, Oak Ridge National Laboratory, Oak Ridge, Tennesse 37831
| | - Corie Y Ralston
- Michigan State University-U.S. Department of Energy Plant Research Laboratory and Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824
| | - Cheryl A Kerfeld
- Department of Plant and Microbial Biology, University of California, Berkeley, California 94720
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720
- Michigan State University-U.S. Department of Energy Plant Research Laboratory and Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824
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77
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Zhang H, Xu X. Manipulation of Pattern of Cell Differentiation in a hetR Mutant of Anabaena sp. PCC 7120 by Overexpressing hetZ Alone or with hetP. Life (Basel) 2018; 8:life8040060. [PMID: 30513635 PMCID: PMC6316738 DOI: 10.3390/life8040060] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2018] [Revised: 11/23/2018] [Accepted: 11/27/2018] [Indexed: 12/29/2022] Open
Abstract
In the filamentous cyanobacterium, Anabaena sp. PCC 7120, single heterocysts differentiate at semi-regular intervals in response to nitrogen stepdown. HetR is a principal regulator of heterocyst differentiation, and hetP and hetZ are two genes that are regulated directly by HetR. In a hetR mutant generated from the IHB (Institute of Hydrobiology) substrain of PCC 7120, heterocyst formation can be restored by moderate expression of hetZ and hetP. The resulting heterocysts are located at terminal positions. We used a tandem promoter, PrbcLPpetE, to express hetZ and hetP strongly in the hetR mutant. Co-expression of hetZ and hetP enabled the hetR mutant to form multiple contiguous heterocysts at both terminal and intercalary positions. Expression of hetZ, alone resulted in terminally located heterocysts, whereas expression of hetP, alone produced enlarged cells in strings. In the absence of HetR, formation of heterocysts was insensitive to the peptide inhibitor, RGSGR.
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Affiliation(s)
- He Zhang
- The State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China.
| | - Xudong Xu
- The State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China.
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78
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Elhai J, Khudyakov I. Ancient association of cyanobacterial multicellularity with the regulator HetR and an RGSGR pentapeptide-containing protein (PatX). Mol Microbiol 2018; 110:931-954. [PMID: 29885033 DOI: 10.1111/mmi.14003] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/04/2018] [Indexed: 12/14/2022]
Abstract
One simple model to explain biological pattern postulates the existence of a stationary regulator of differentiation that positively affects its own expression, coupled with a diffusible suppressor of differentiation that inhibits the regulator's expression. The first has been identified in the filamentous, heterocyst-forming cyanobacterium, Anabaena PCC 7120 as the transcriptional regulator, HetR and the second as the small protein, PatS, which contains a critical RGSGR motif that binds to HetR. HetR is present in almost all filamentous cyanobacteria, but only a subset of heterocyst-forming strains carry proteins similar to PatS. We identified a third protein, PatX that also carries the RGSGR motif and is coextensive with HetR. Amino acid sequences of PatX contain two conserved regions: the RGSGR motif and a hydrophobic N-terminus. Within 69 nt upstream from all instances of the gene is a DIF1 motif correlated in Anabaena with promoter induction in developing heterocysts, preceded in heterocyst-forming strains by an apparent NtcA-binding site, associated with regulation by nitrogen-status. Consistent with a role in the simple model, PatX is expressed dependent on HetR and acts to inhibit differentiation. The acquisition of the PatX/HetR pair preceded the appearance of both PatS and heterocysts, dating back to the beginnings of multicellularity.
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Affiliation(s)
- Jeff Elhai
- Center for the Study of Biological Complexity, Virginia Commonwealth University, Richmond, VA, 23284, USA
| | - Ivan Khudyakov
- All-Russia Research Institute for Agricultural Microbiology, Saint-Petersburg, 196608, Russia
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Charubin K, Bennett RK, Fast AG, Papoutsakis ET. Engineering Clostridium organisms as microbial cell-factories: challenges & opportunities. Metab Eng 2018; 50:173-191. [DOI: 10.1016/j.ymben.2018.07.012] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Revised: 07/18/2018] [Accepted: 07/19/2018] [Indexed: 11/25/2022]
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Biosensors-Based In Vivo Quantification of 2-Oxoglutarate in Cyanobacteria and Proteobacteria. Life (Basel) 2018; 8:life8040051. [PMID: 30373229 PMCID: PMC6315671 DOI: 10.3390/life8040051] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2018] [Revised: 10/24/2018] [Accepted: 10/25/2018] [Indexed: 01/12/2023] Open
Abstract
2-oxoglutarate (α-ketoglutarate; 2-OG) is an intermediate of the Krebs cycle, and constitutes the carbon skeleton for nitrogen assimilation and the synthesis of a variety of compounds. In addition to being an important metabolite, 2-OG is a signaling molecule with a broad regulatory repertoire in a variety of organisms, including plants, animals, and bacteria. Although challenging, measuring the levels and variations of metabolic signals in vivo is critical to better understand how cells control specific processes. To measure cellular 2-OG concentrations and dynamics, we designed a set of biosensors based on the fluorescence resonance energy transfer (FRET) technology that can be used in vivo in different organisms. For this purpose, we took advantage of the conformational changes of two cyanobacterial proteins induced by 2-OG binding. We show that these biosensors responded immediately and specifically to different 2-OG levels, and hence allowed to measure 2-OG variations in function of environmental modifications in the proteobacterium Escherichia coli and in the cyanobacterium Anabaena sp. PCC 7120. Our results pave the way to study 2-OG dynamics at the cellular level in uni- and multi-cellular organisms.
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81
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Liu H, Ni J, Xu P, Tao F. Enhancing Light-Driven 1,3-Propanediol Production by Using Natural Compartmentalization of Differentiated Cells. ACS Synth Biol 2018; 7:2436-2446. [PMID: 30234972 DOI: 10.1021/acssynbio.8b00239] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Synthetic biology emerges as a powerful approach for unlocking the potential of cyanobacteria to produce various chemicals. However, the highly oxidative intracellular environment of cyanobacteria is incompatible to numerous introduced enzymes from anaerobes. In this study, we explore a strategy based on natural compartmentalization of cyanobacterial heterocysts to overcome the incompatibility. Hence, the oxygen-sensitive 1,3-propanediol (1,3-PDO) biosynthetic pathway was selected as a model and insulated in heterocysts to evaluate the proposed strategy. Thus, the genes from different sources for 1,3-PDO production were tandemly arrayed with promoter, resulting the assembled 1,3-PDO synthetic cassettes. Then the synthetic cassettes were integrated into the chromosome of Anabaena sp. strain PCC7120 by homologous recombination, respectively. The engineered strain P11 containing the genes from facultative anaerobe Klebsiella pneumoniae (cassette KP) accumulated 46.0 mg L-1 of 1,3-PDO when heterocysts were present, which is approximately 1.7-fold higher than that of no heterocysts. As for the strains (P12, P13, and P14) containing the genes from strictly anaerobic bacterium Clostridium butyricum (cassette CB), the product 1,3-PDO could only be detected when heterocysts were present. These results indicate that insulation of the oxygen-sensitive 1,3-PDO pathway with heterocysts is an effective way to protect these enzymes in cyanobacteria. The strategy may have the potential of serving as a universal strategy to overcome the incompatibility of oxygen-sensitivity in synthetic biology.
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Affiliation(s)
- Hongyu Liu
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, and School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, People’s Republic of China
| | - Jun Ni
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, and School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, People’s Republic of China
| | - Ping Xu
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, and School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, People’s Republic of China
| | - Fei Tao
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, and School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, People’s Republic of China
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Ramos-León F, Arévalo S, Mariscal V, Flores E. Specific mutations in the permease domain of septal protein SepJ differentially affect functions related to multicellularity in the filamentous cyanobacterium Anabaena. MICROBIAL CELL 2018; 5:555-565. [PMID: 30533420 PMCID: PMC6282017 DOI: 10.15698/mic2018.12.661] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Filamentous, heterocyst-forming cyanobacteria are multicellular organisms in which growth requires the activity of two interdependent cell types that exchange nutrients and regulators. Vegetative cells provide heterocysts with reduced carbon, and heterocysts provide vegetative cells with fixed nitrogen. Additionally, heterocyst differentiation from vegetative cells is regulated by inhibitors of differentiation produced by prospective heterocysts and heterocysts. Proteinaceous structures known as septal junctions join the cells in the filament. The SepJ protein is involved in formation of septal junctions in the model heterocyst-forming cyanobacterium Anabaena sp. strain PCC 7120. SepJ bears extra-membrane and membrane (permease) domains and is located at the cell poles in the intercellular septa of the filament. Here we created Anabaena mutants that produce SepJ proteins altered in the permease domain. Some of these mutant SepJ proteins did not provide functions needed for Anabaena to form long filaments and (in some cases) differentiate heterocysts, identifying amino acids and amino acid stretches that are important for the structure or function of the protein. Some other mutant SepJ proteins fulfilled filamentation and heterocyst differentiation functions but failed to provide normal communication function assessed via the intercellular transfer of the fluorescent marker calcein. These mutant SepJ proteins bore mutations in amino acids located at the cytoplasmic face of the permease, which could affect access of the fluorescent marker to the septal junctions. Overall, the data are consistent with the idea that SepJ carries out multiple roles in the multicellular function of the Anabaena filament.
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Affiliation(s)
- Félix Ramos-León
- Instituto de Bioquímica Vegetal y Fotosíntesis, CSIC and Universidad de Sevilla, Américo Vespucio 49, E-41092 Seville, Spain
| | - Sergio Arévalo
- Instituto de Bioquímica Vegetal y Fotosíntesis, CSIC and Universidad de Sevilla, Américo Vespucio 49, E-41092 Seville, Spain
| | - Vicente Mariscal
- Instituto de Bioquímica Vegetal y Fotosíntesis, CSIC and Universidad de Sevilla, Américo Vespucio 49, E-41092 Seville, Spain
| | - Enrique Flores
- Instituto de Bioquímica Vegetal y Fotosíntesis, CSIC and Universidad de Sevilla, Américo Vespucio 49, E-41092 Seville, Spain
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83
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Gibbons J, Gu L, Zhu H, Gibbons W, Zhou R. Identification of two genes required for heptadecane production in a N 2-fixing cyanobacterium Anabaena sp. strain PCC 7120. AMB Express 2018; 8:167. [PMID: 30317393 PMCID: PMC6186262 DOI: 10.1186/s13568-018-0700-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Accepted: 10/09/2018] [Indexed: 12/27/2022] Open
Abstract
Cyanobacteria photosynthetically produce long-chain hydrocarbons, which are considered as infrastructure-compatible biofuels. However, native cyanobacteria do not produce these hydrocarbons at sufficient rates or yields to warrant commercial deployment. This research sought to identify specific genes required for photosynthetic production of alkanes to enable future metabolic engineering for commercially viable production of alkanes. The two putative genes (alr5283 and alr5284) required for long-chain hydrocarbon production in Anabaena sp. PCC 7120 were knocked out through a double crossover approach. The knockout mutant abolished the production of heptadecane (C17H36). The mutant is able to be complemented by a plasmid bearing the two genes along with their native promoters only. The complemented mutant restored photosynthetic production of heptadecane. This combined genetic and metabolite (alkanes) profiling approach may be broadly applicable to characterization of knockout mutants, using N2-fixing cyanobacteria as a cellular factory driven by solar energy to produce a wide range of commodity chemicals and drop-in-fuels from atmospheric gases (CO2 and N2 gas) and mineralized water.
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84
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Burnat M, Li B, Kim SH, Michael AJ, Flores E. Homospermidine biosynthesis in the cyanobacteriumAnabaenarequires a deoxyhypusine synthase homologue and is essential for normal diazotrophic growth. Mol Microbiol 2018; 109:763-780. [DOI: 10.1111/mmi.14006] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/11/2018] [Indexed: 12/11/2022]
Affiliation(s)
- Mireia Burnat
- Instituto de Bioquímica Vegetal y Fotosíntesis, CSIC and Universidad de Sevilla Avda. Américo Vespucio 49E‐41092Sevilla Spain
| | - Bin Li
- Department of Biochemistry University of Texas Southwestern Medical Center 5323 Harry Hines BlvdDallas TX 75390‐9041USA
| | - Sok Ho Kim
- Department of Biochemistry University of Texas Southwestern Medical Center 5323 Harry Hines BlvdDallas TX 75390‐9041USA
| | - Anthony J. Michael
- Department of Biochemistry University of Texas Southwestern Medical Center 5323 Harry Hines BlvdDallas TX 75390‐9041USA
| | - Enrique Flores
- Instituto de Bioquímica Vegetal y Fotosíntesis, CSIC and Universidad de Sevilla Avda. Américo Vespucio 49E‐41092Sevilla Spain
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Corrales-Guerrero L, Camargo S, Valladares A, Picossi S, Luque I, Ochoa de Alda JAG, Herrero A. FtsZ of Filamentous, Heterocyst-Forming Cyanobacteria Has a Conserved N-Terminal Peptide Required for Normal FtsZ Polymerization and Cell Division. Front Microbiol 2018; 9:2260. [PMID: 30333801 PMCID: PMC6175996 DOI: 10.3389/fmicb.2018.02260] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Accepted: 09/05/2018] [Indexed: 12/03/2022] Open
Abstract
Filamentous cyanobacteria grow by intercalary cell division, which should involve distinct steps compared to those producing separate daughter cells. The N-terminal region of FtsZ is highly conserved in the clade of filamentous cyanobacteria capable of cell differentiation. A derivative of the model strain Anabaena sp. PCC 7120 expressing only an FtsZ lacking the amino acids 2–51 of the N-terminal peptide (ΔN-FtsZ) could not be segregated. Strain CSL110 expresses both ΔN-FtsZ, from the endogenous ftsZ gene promoter, and the native FtsZ from a synthetic regulated promoter. Under conditions of ΔN-FtsZ predominance, cells of strain CSL110 progressively enlarge, reflecting reduced cell division, and show instances of asymmetric cell division and aberrant Z-structures notably differing from the Z-ring formed by FtsZ in the wild type. In bacterial 2-hybrid assays FtsZ interacted with ΔN-FtsZ. However, ΔN-FtsZ-GFP appeared impaired for incorporation into Z-rings when expressed together with FtsZ. FtsZ, but not ΔN-FtsZ, interacted with the essential protein SepF. Both FtsZ and ΔN-FtsZ polymerize in vitro exhibiting comparable GTPase activities. However, filaments of FtsZ show a distinct curling forming toroids, whereas ΔN-FtsZ form thick bundles of straight filaments. Thus, the N-terminal FtsZ sequence appears to contribute to a distinct FtsZ polymerization mode that is essential for cell division and division plane location in Anabaena.
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Affiliation(s)
- Laura Corrales-Guerrero
- Instituto de Bioquímica Vegetal y Fotosíntesis, Consejo Superior de Investigaciones Científicas and Universidad de Sevilla, Seville, Spain
| | - Sergio Camargo
- Instituto de Bioquímica Vegetal y Fotosíntesis, Consejo Superior de Investigaciones Científicas and Universidad de Sevilla, Seville, Spain
| | - Ana Valladares
- Instituto de Bioquímica Vegetal y Fotosíntesis, Consejo Superior de Investigaciones Científicas and Universidad de Sevilla, Seville, Spain
| | - Silvia Picossi
- Instituto de Bioquímica Vegetal y Fotosíntesis, Consejo Superior de Investigaciones Científicas and Universidad de Sevilla, Seville, Spain
| | - Ignacio Luque
- Instituto de Bioquímica Vegetal y Fotosíntesis, Consejo Superior de Investigaciones Científicas and Universidad de Sevilla, Seville, Spain
| | | | - Antonia Herrero
- Instituto de Bioquímica Vegetal y Fotosíntesis, Consejo Superior de Investigaciones Científicas and Universidad de Sevilla, Seville, Spain
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86
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Fukushima SI, Ehira S. The Ser/Thr Kinase PknH Is Essential for Maintaining Heterocyst Pattern in the Cyanobacterium Anabaena sp. Strain PCC 7120. Life (Basel) 2018; 8:life8030034. [PMID: 30149508 PMCID: PMC6160991 DOI: 10.3390/life8030034] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Revised: 08/21/2018] [Accepted: 08/22/2018] [Indexed: 02/01/2023] Open
Abstract
In the filamentous cyanobacterium Anabaena sp. strain, PCC 7120, heterocysts (which are nitrogen-fixing cells) are formed in the absence of combined nitrogen in the medium. Heterocysts are separated from one another by 10 to 15 vegetative cells along the filaments, which consist of a few hundred of cells. hetR is necessary for heterocyst differentiation; and patS and hetN, expressed in heterocysts, play important roles in heterocyst pattern formation by laterally inhibiting the expression of hetR in adjacent cells. The results of this study indicated that pknH, which encodes a Ser/Thr kinase, was also involved in heterocyst pattern formation. In the pknH mutant, the heterocyst pattern was normal within 24 h after nitrogen deprivation, but multiple contiguous heterocysts were formed from 24 to 48 h. A time-lapse analysis of reporter strains harboring a fusion between gfp and the hetR promoter indicated that pknH was required to suppress hetR expression in cells adjacent to the preexisting heterocysts. These results indicated that pknH was necessary for the lateral inhibition of heterocyst differentiation to maintain the heterocyst pattern.
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Affiliation(s)
- Shun-Ichi Fukushima
- Department of Biological Sciences, Graduate School of Science, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji, Tokyo 192-0397, Japan.
| | - Shigeki Ehira
- Department of Biological Sciences, Graduate School of Science, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji, Tokyo 192-0397, Japan.
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87
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Jin H, Wang Y, Idoine A, Bhaya D. Construction of a Shuttle Vector Using an Endogenous Plasmid From the Cyanobacterium Synechocystis sp. PCC6803. Front Microbiol 2018; 9:1662. [PMID: 30087668 PMCID: PMC6066503 DOI: 10.3389/fmicb.2018.01662] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2017] [Accepted: 07/04/2018] [Indexed: 12/21/2022] Open
Abstract
To advance synthetic biology in the photosynthetic cyanobacterium Synechocystis sp. PCC6803 (Syn6803), we constructed a shuttle vector with some versatile features. This shuttle vector, pSCB-YFP, consists of a putative replicon identified on the plasmid pCC5.2, the origin of replication of pMB1 from E. coli, as well as the YFP reporter gene and a spectinomycin/streptomycin resistance cassette. pSCB-YFP is stably maintained in Syn6803M (a motile strain that lacks the endogenous pCC5.2) and expresses YFP. In addition, we engineered a fragment into pSCB-YFP that has multiple cloning sites and other features such that this plasmid can also be used as an expression vector (pSCBe). The shuttle vector pSCB-YFP can be stably maintained for at least 50 generations without antibiotic selection. It is a high copy number plasmid and can stably co-exist with the RSF1010-based pPMQAK1-GFP.
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Affiliation(s)
- Haojie Jin
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA, United States
| | - Yan Wang
- Department of Neurosurgery and Stanford Stroke Center, Stanford University, Stanford, CA, United States
| | - Adam Idoine
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA, United States
| | - Devaki Bhaya
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA, United States
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88
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Hurtado-Gallego J, Martín-Betancor K, Rodea-Palomares I, Leganés F, Rosal R, Fernández-Piñas F. Two novel cyanobacterial bioluminescent whole-cell bioreporters based on superoxide dismutases MnSod and FeSod to detect superoxide anion. CHEMOSPHERE 2018; 201:772-779. [PMID: 29550571 DOI: 10.1016/j.chemosphere.2018.03.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Revised: 02/13/2018] [Accepted: 03/03/2018] [Indexed: 06/08/2023]
Abstract
This work describes the construction of two novel self-luminescent bioreporter strains of the cyanobacterium Nostoc sp. PCC 7120 by fusing the promoter region of the sodA and sodB genes (encoding the superoxide dismutases MnSod and FeSod, respectively) to luxCDABE from Photorhabdus luminescens aimed at detecting pollutants that generate reactive oxygen species (ROS), particularly O2-. Bioreporters were tested against methyl viologen (MV) as the inducer of superoxide anion (O2-). Both bioreporters were specific for O2- and Limits of detection (LODs) and Maximum Permissive Concentrations (MPCs) were calculated: Nostoc sp. PCC 7120 pBG2154 (sodA) had a range of detection from 400 to 1000 pM of MV and for Nostoc sp. PCC 7120 pBG2165 (sodB) the range of detection was from 500 to 1800 pM of MV after 5 h-exposure. To further validate the bioreporters, they were tested with the emerging pollutant Triclosan which induced bioluminescence in both strains. Furthermore, the bioreporters performance was tested in two real environmental samples with different water matrix complexity, spiked with MV. Both bioreporters were induced by O2- in these environmental samples. In the case of the river water sample, the amount of bioavailable MV as calculated from the bioreporters output was similar to that nominally added. For the waste water sample, the bioavailable MV concentration detected by the bioreporters was one order of magnitude lower than nominal. These differences could be due to MV complexation with organic matter and/or co-occurring organic contaminants. These results confirm their high sensitivity to O2- and their suitability to detect oxidative stress-generating pollutants in fresh-waters.
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Affiliation(s)
- J Hurtado-Gallego
- Departamento de Biología, Facultad de Ciencias, Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - K Martín-Betancor
- Departamento de Biología, Facultad de Ciencias, Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - I Rodea-Palomares
- Departamento de Biología, Facultad de Ciencias, Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - F Leganés
- Departamento de Biología, Facultad de Ciencias, Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - R Rosal
- Departamento de Ingeniería Química, Universidad de Alcalá, E-28871 Alcalá de Henares, Madrid, Spain
| | - F Fernández-Piñas
- Departamento de Biología, Facultad de Ciencias, Universidad Autónoma de Madrid, 28049 Madrid, Spain.
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89
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T V D, Chandwadkar P, Acharya C. NmtA, a novel metallothionein of Anabaena sp. strain PCC 7120 imparts protection against cadmium stress but not oxidative stress. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2018; 199:152-161. [PMID: 29626757 DOI: 10.1016/j.aquatox.2018.03.035] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Revised: 03/12/2018] [Accepted: 03/29/2018] [Indexed: 06/08/2023]
Abstract
Metallothioneins (MTs) are low molecular weight, sulfhydryl-containing, cysteine-rich, metal-binding proteins. Eukaryotes have multiple metallothionein genes; however, there is dearth of reports on prokaryotic metallothioneins. Bacterial MTs with SmtA from Synechococcus PCC 7942 as prototype have been studied in the context of cadmium detoxification. In this study, a smtA related ORF, namely nmtA, was identified in the heterocystous, nitrogen-fixing cyanobacterium, Anabaena PCC 7120. A recombinant N-terminal histidine-tagged Anabaena NmtA protein was overexpressed in Escherichia coli and purified. The protein was identified by peptide mass fingerprinting using MALDI-TOF Mass Spectrometry as putative metallothionein of Anabaena PCC 7120 with a calculated mass of ∼6.1 kDa. While the native metallated NmtA exhibited resistance against proteolysis, metal free apo-NmtA resulting from acid and dithiothreitol (DTT) treatment could be digested by proteinase K revealing a metal dependent proteolytic protection of NmtA. Expression of nmtA in Anabaena PCC 7120 was induced evidently by cadmium, zinc and copper but not by uranium or hydrogen peroxide. Recombinant Anabaena PCC 7120 overexpressing NmtA protein revealed superior cadmium tolerance but showed limited influence against oxidative stress tolerance as compared with the strain carrying vector alone. In contrast, a mutant of Synechococcus PCC 7942 deficient in MT locus was found to be highly susceptible to H2O2 indicating a likely involvement of cyanobacterial MT in protection against oxidative damage. Overall, the study improved our understanding of metal tolerance mechanisms in Anabaena PCC 7120 by demonstrating a key role of NmtA in cadmium tolerance.
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Affiliation(s)
- Divya T V
- Molecular Biology Division, Bhabha Atomic Research Centre, Trombay, Mumbai, 400085, India
| | - Pallavi Chandwadkar
- Molecular Biology Division, Bhabha Atomic Research Centre, Trombay, Mumbai, 400085, India
| | - Celin Acharya
- Molecular Biology Division, Bhabha Atomic Research Centre, Trombay, Mumbai, 400085, India; Homi Bhabha National Institute, Anushakti Nagar, Mumbai, 400094, India.
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90
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Tomatsu C, Uesaka K, Yamakawa H, Tsuchiya T, Ihara K, Fujita Y. In vivo transposon tagging in the nonheterocystous nitrogen-fixing cyanobacterium Leptolyngbya boryana. FEBS Lett 2018; 592:1634-1642. [PMID: 29723391 DOI: 10.1002/1873-3468.13079] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Revised: 04/23/2018] [Accepted: 04/23/2018] [Indexed: 01/16/2023]
Abstract
Nitrogenase is an oxygen-vulnerable metalloenzyme that catalyzes nitrogen fixation. It largely remains unknown how nitrogenase coexists with oxygenic photosynthesis in nonheterocystous cyanobacteria, since there have been no appropriate model cyanobacteria so far. Here, we demonstrate in vivo transposon tagging in the nonheterocystous cyanobacterium Leptolyngbya boryana as a forward genetics approach. By conjugative transfer, a mini-Tn5-derived vector, pKUT-Tn5-Sm/Sp, was transferred from Escherichia coli to L. boryana cells. Of 1839 streptomycin-resistant colonies, we isolated three mutants showing aberrant diazotrophic growth. Genome resequencing identified the insertion sites of the transposon in the mutants. This in vivo transposon tagging mutagenesis of L. boryana provides a promising system to investigate molecular mechanisms to resolve the Oxygen Paradox between nitrogen fixation and oxygenic photosynthesis in cyanobacteria.
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Affiliation(s)
- Chie Tomatsu
- Graduate School of Bioagricultural Sciences, Nagoya University, Japan
| | | | - Hisanori Yamakawa
- Graduate School of Bioagricultural Sciences, Nagoya University, Japan
| | - Tohru Tsuchiya
- Graduate School of Global Environmental Studies, Kyoto University, Japan.,Graduate School of Human and Environmental Studies, Kyoto University, Japan
| | - Kunio Ihara
- Center for Gene Research, Nagoya University, Japan
| | - Yuichi Fujita
- Graduate School of Bioagricultural Sciences, Nagoya University, Japan
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91
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Zhang JY, Lin GM, Xing WY, Zhang CC. Diversity of Growth Patterns Probed in Live Cyanobacterial Cells Using a Fluorescent Analog of a Peptidoglycan Precursor. Front Microbiol 2018; 9:791. [PMID: 29740419 PMCID: PMC5928242 DOI: 10.3389/fmicb.2018.00791] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Accepted: 04/09/2018] [Indexed: 01/07/2023] Open
Abstract
Cyanobacteria were the first oxygenic photosynthetic organisms during evolution and were ancestors of plastids. Cyanobacterial cells exhibit an extraordinary diversity in their size and shape, and bacterial cell morphology largely depends on the synthesis and the dynamics of the peptidoglycan (PG) layer. Here, we used a fluorescence analog of the PG synthesis precursor D-Ala, 7-Hydroxycoumarin-amino-D-alanine (HADA), to probe the PG synthesis pattern in live cells of cyanobacteria with different morphology. They displayed diverse synthesis patterns, with some strains showing an intensive HADA incorporation at the septal region, whereas others gave an HADA signal distributed around the cells. Growth zones covering several cells at the tips of the filament were present in some filamentous strains such as in Arthrospira. In Anabaena PCC 7120, which is capable of differentiating heterocysts for N2 fixation, PG synthesis followed the cell division cycle. In addition, an HADA incorporation was strongly activated from 12 to 15 h following the initiation of heterocyst development, indicating a thickening of the PG layer in heterocysts. The PG synthesis pattern is diverse in cyanobacteria and responds to developmental regulation. The use of fluorescent analogs may serve as a useful tool for understanding the mechanisms of cell growth and morphogenesis operating in these organisms.
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Affiliation(s)
- Ju-Yuan Zhang
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
| | - Gui-Ming Lin
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
| | - Wei-Yue Xing
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Cheng-Cai Zhang
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
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92
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Abstract
ABSTRACT
Conjugative plasmids are the main carriers of transmissible antibiotic resistance (AbR) genes. For that reason, strategies to control plasmid transmission have been proposed as potential solutions to prevent AbR dissemination. Natural mechanisms that bacteria employ as defense barriers against invading genomes, such as restriction-modification or CRISPR-Cas systems, could be exploited to control conjugation. Besides, conjugative plasmids themselves display mechanisms to minimize their associated burden or to compete with related or unrelated plasmids. Thus, FinOP systems, composed of FinO repressor protein and FinP antisense RNA, aid plasmids to regulate their own transfer; exclusion systems avoid conjugative transfer of related plasmids to the same recipient bacteria; and fertility inhibition systems block transmission of unrelated plasmids from the same donor cell. Artificial strategies have also been designed to control bacterial conjugation. For instance, intrabodies against R388 relaxase expressed in recipient cells inhibit plasmid R388 conjugative transfer; pIII protein of bacteriophage M13 inhibits plasmid F transmission by obstructing conjugative pili; and unsaturated fatty acids prevent transfer of clinically relevant plasmids in different hosts, promoting plasmid extinction in bacterial populations. Overall, a number of exogenous and endogenous factors have an effect on the sophisticated process of bacterial conjugation. This review puts them together in an effort to offer a wide picture and inform research to control plasmid transmission, focusing on Gram-negative bacteria.
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93
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Taton A, Ma AT, Ota M, Golden SS, Golden JW. NOT Gate Genetic Circuits to Control Gene Expression in Cyanobacteria. ACS Synth Biol 2017; 6:2175-2182. [PMID: 28803467 DOI: 10.1021/acssynbio.7b00203] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
To downregulate gene expression in cyanobacteria, we constructed NOT gate genetic circuits using orthogonal promoters and their cognate repressors regulated translationally by synthetic riboswitches. Four NOT gates were tested and characterized in five cyanobacterial strains using fluorescent reporter-gene assays. In comparison to alternative systems used to downregulate gene expression in cyanobacteria, these NOT gates performed well, reducing YFP reporter expression by 4 to 50-fold. We further evaluated these NOT gates by controlling the expression of the ftsZ gene, which encodes a prokaryotic tubulin homologue that is required for cell division and is essential for Synechococcus elongatus PCC 7942. These NOT gates would facilitate cyanobacterial genetic engineering or the study of essential cellular processes.
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Affiliation(s)
- Arnaud Taton
- Division of Biological Sciences, University of California San Diego, 9500 Gilman Drive, La Jolla, California 92093, United States
| | - Amy T. Ma
- Division of Biological Sciences, University of California San Diego, 9500 Gilman Drive, La Jolla, California 92093, United States
| | - Mizuho Ota
- Division of Biological Sciences, University of California San Diego, 9500 Gilman Drive, La Jolla, California 92093, United States
| | - Susan S. Golden
- Division of Biological Sciences, University of California San Diego, 9500 Gilman Drive, La Jolla, California 92093, United States
| | - James W. Golden
- Division of Biological Sciences, University of California San Diego, 9500 Gilman Drive, La Jolla, California 92093, United States
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94
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Getino M, Palencia-Gándara C, Garcillán-Barcia MP, de la Cruz F. PifC and Osa, Plasmid Weapons against Rival Conjugative Coupling Proteins. Front Microbiol 2017; 8:2260. [PMID: 29201021 PMCID: PMC5696584 DOI: 10.3389/fmicb.2017.02260] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Accepted: 11/02/2017] [Indexed: 12/26/2022] Open
Abstract
Bacteria display a variety of mechanisms to control plasmid conjugation. Among them, fertility inhibition (FI) systems prevent conjugation of co-resident plasmids within donor cells. Analysis of the mechanisms of inhibition between conjugative plasmids could provide new alternatives to fight antibiotic resistance dissemination. In this work, inhibition of conjugation of broad host range IncW plasmids was analyzed in the presence of a set of co-resident plasmids. Strong FI systems against plasmid R388 conjugation were found in IncF/MOBF12 as well as in IncI/MOBP12 plasmids, represented by plasmids F and R64, respectively. In both cases, the responsible gene was pifC, known also to be involved in FI of IncP plasmids and Agrobacterium T-DNA transfer to plant cells. It was also discovered that the R388 gene osa, which affects T-DNA transfer, also prevented conjugation of IncP-1/MOBP11 plasmids represented by plasmids RP4 and R751. Conjugation experiments of different mobilizable plasmids, helped by either FI-susceptible or FI-resistant transfer systems, demonstrated that the conjugative component affected by both PifC and Osa was the type IV conjugative coupling protein. In addition, in silico analysis of FI proteins suggests that they represent recent acquisitions of conjugative plasmids, i.e., are not shared by members of the same plasmid species. This implies that FI are rapidly-moving accessory genes, possibly acting on evolutionary fights between plasmids for the colonization of specific hosts.
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Affiliation(s)
- María Getino
- Instituto de Biomedicina y Biotecnología de Cantabria, Universidad de Cantabria-Consejo Superior de Investigaciones Científicas, Santander, Spain
| | - Carolina Palencia-Gándara
- Instituto de Biomedicina y Biotecnología de Cantabria, Universidad de Cantabria-Consejo Superior de Investigaciones Científicas, Santander, Spain
| | - M Pilar Garcillán-Barcia
- Instituto de Biomedicina y Biotecnología de Cantabria, Universidad de Cantabria-Consejo Superior de Investigaciones Científicas, Santander, Spain
| | - Fernando de la Cruz
- Instituto de Biomedicina y Biotecnología de Cantabria, Universidad de Cantabria-Consejo Superior de Investigaciones Científicas, Santander, Spain
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95
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Spatial separation of photosynthesis and ethanol production by cell type-specific metabolic engineering of filamentous cyanobacteria. Appl Microbiol Biotechnol 2017; 102:1523-1531. [DOI: 10.1007/s00253-017-8620-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Revised: 10/24/2017] [Accepted: 10/30/2017] [Indexed: 12/22/2022]
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96
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Ehira S, Shimmori Y, Watanabe S, Kato H, Yoshikawa H, Ohmori M. The nitrogen-regulated response regulator NrrA is a conserved regulator of glycogen catabolism in β-cyanobacteria. Microbiology (Reading) 2017; 163:1711-1719. [DOI: 10.1099/mic.0.000549] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- Shigeki Ehira
- Department of Biological Science, Faculty of Science and Engineering, Chuo University, 1-13-27 Kasuga, Bunkyo-ku, Tokyo 112-8551, Japan
- Department of Biological Sciences, Graduate School of Science and Engineering, Tokyo Metropolitan University, 1-1 Minami-Ohsawa, Hachioji, Tokyo 192-0397, Japan
| | - Yuka Shimmori
- Department of Biological Sciences, Graduate School of Science and Engineering, Tokyo Metropolitan University, 1-1 Minami-Ohsawa, Hachioji, Tokyo 192-0397, Japan
| | - Satoru Watanabe
- Department of Bioscience, Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Setagaya-ku, Tokyo 156-8502, Japan
| | - Hiroaki Kato
- Department of Bioscience, Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Setagaya-ku, Tokyo 156-8502, Japan
| | - Hirofumi Yoshikawa
- Department of Bioscience, Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Setagaya-ku, Tokyo 156-8502, Japan
| | - Masayuki Ohmori
- Department of Biological Science, Faculty of Science and Engineering, Chuo University, 1-13-27 Kasuga, Bunkyo-ku, Tokyo 112-8551, Japan
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97
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Antonaru LA, Nürnberg DJ. Role of PatS and cell type on the heterocyst spacing pattern in a filamentous branching cyanobacterium. FEMS Microbiol Lett 2017; 364:3983256. [PMID: 28859320 PMCID: PMC5812504 DOI: 10.1093/femsle/fnx154] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Accepted: 07/19/2017] [Indexed: 12/16/2022] Open
Abstract
Cell differentiation is one of the marks of multicellular organisms. Terminally specialised nitrogen-fixing cells, termed heterocysts, evolved in filamentous cyanobacteria more than 2 Gya. The development of their spacing pattern has been thoroughly investigated in model organisms such as Anabaena sp. PCC 7120. This paper focuses on the more complex, branching cyanobacterium Mastigocladus laminosus (Stigonematales). Contrary to what has been previously published, a heterocyst spacing pattern is present in M. laminosus but it varies with the age of the culture and the morphology of the cells. Heterocysts in young, narrow trichomes were more widely spaced (∼14.8 cells) than those in old, wide trichomes (∼9.4 cells). Biochemical and transgenic experiments reveal that the heterocyst spacing pattern is affected by the heterocyst inhibitor PatS. Addition of the pentapeptide RGSGR (PatS-5) to the growth medium and overexpression of patS from Anabaena sp. PCC 7120 in M. laminosus resulted in the loss of heterocyst differentiation under nitrogen deprivation. Bioinformatics investigations indicated that putative PatS sequences within cyanobacteria are highly diverse, and fall into two main clades. Both are present in most branching cyanobacteria. Despite its more complex, branching phenotype, M. laminosus appears to use a PatS-based pathway for heterocyst differentiation, a property shared by Anabaena/Nostoc.
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98
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Molecular basis of function and the unusual antioxidant activity of a cyanobacterial cysteine desulfurase. Biochem J 2017; 474:2435-2447. [PMID: 28592683 DOI: 10.1042/bcj20170290] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Revised: 06/06/2017] [Accepted: 06/07/2017] [Indexed: 11/17/2022]
Abstract
Cysteine desulfurases, which supply sulfur for iron-sulfur cluster biogenesis, are broadly distributed in all phyla including cyanobacteria, the progenitors of plant chloroplasts. The SUF (sulfur utilization factor) system is responsible for Fe-S cluster biosynthesis under stress. The suf operon from cyanobacterium Anabaena PCC 7120 showed the presence of a cysteine desulfurase, sufS (alr2495), but not the accessory sulfur-accepting protein (SufE). However, an open reading frame (alr3513) encoding a SufE-like protein (termed AsaE, Anabaena sulfur acceptor E) was found at a location distinct from the suf operon. The purified SufS protein existed as a pyridoxal 5' phosphate (PLP)-containing dimer with a relatively low desulfurase activity. Interestingly, in the presence of the AsaE protein, the catalytic efficiency of this reaction increased 10-fold. In particular, for sulfur mobilization, the AsaE protein partnered only SufS and not other cysteine desulfurases from Anabaena. The SufS protein was found to physically interact with the AsaE protein, demonstrating that AsaE was indeed the missing partner of Anabaena SufS. The conserved cysteine of the SufS or the AsaE protein was essential for activity but not for their physical association. Curiously, overexpression of the SufS protein in Anabaena caused reduced formation of reactive oxygen species on exposure to hydrogen peroxide (H2O2), resulting in superior oxidative stress tolerance to the oxidizing agent when compared with the wild-type strain. Overall, the results highlight the functional interaction between the two proteins that mediate sulfur mobilization, in the cyanobacterial SUF pathway, and further reveal that overexpression of SufS can protect cyanobacteria from oxidative stress.
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Tailor V, Ballal A. Novel molecular insights into the function and the antioxidative stress response of a Peroxiredoxin Q protein from cyanobacteria. Free Radic Biol Med 2017; 106:278-287. [PMID: 28159708 DOI: 10.1016/j.freeradbiomed.2017.01.031] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Revised: 01/18/2017] [Accepted: 01/20/2017] [Indexed: 12/11/2022]
Abstract
The Peroxiredoxin Q (PrxQ) proteins are thiol-based peroxidases that are important for maintaining redox homeostasis in several organisms. Activity of PrxQs is mediated by two cysteines, peroxidatic (Cp) and resolving (Cr), in association with a reducing partner. A PrxQ, Alr3183, from the cyanobacterium, Anabaena PCC 7120, was characterized in this study. Alr3183, which required thioredoxin A (TrxA) for peroxidase activity, was an intramolecular disulfide bond-containing monomeric protein. However, Alr3183 lacking Cp (Alr3183C46S) or Cr (Alr3183C51S) formed intermolecular disulfide linkages and was dimeric. Alr3183C46S was completely inactive, while Alr3183C51S required higher concentration of TrxA for peroxidase activity. Surface plasmon resonance analysis showed that unlike Alr3183 or Alr3183C46S, Alr3183C51S bound rather poorly to TrxA. Also, compared to the oxidized protein, the DTT-treated (reduced) Alr3183 displayed decreased interaction with TrxA. In vivo, Alr3183 was found to be induced in response to γ-radiation. On exposure to H2O2, Anabaena strain over-expressing Alr3183 showed reduced formation of ROS, intact photosynthetic pigments and consequently better survival than the wild-type, whereas overproduction of Alr3183C46S did not provide any protection. Significantly, this study (1) reveals the importance of Cr for interaction with thioredoxins and (2) demonstrates that over-expression of PrxQs can protect cyanobacteria from oxidative stresses.
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Affiliation(s)
- Vijay Tailor
- Molecular Biology Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India; Homi Bhabha National Institute, Anushakti Nagar, Mumbai 400094, India.
| | - Anand Ballal
- Molecular Biology Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India; Homi Bhabha National Institute, Anushakti Nagar, Mumbai 400094, India.
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Jeamton W, Dulsawat S, Tanticharoen M, Vonshak A, Cheevadhanarak S. Overcoming Intrinsic Restriction Enzyme Barriers Enhances Transformation Efficiency in Arthrospira platensis C1. PLANT & CELL PHYSIOLOGY 2017; 58:822-830. [PMID: 28158667 DOI: 10.1093/pcp/pcx016] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2016] [Accepted: 01/23/2017] [Indexed: 06/06/2023]
Abstract
The development of a reliable genetic transformation system for Arthrospira platensis has been a long-term goal, mainly for those trying either to improve its performance in large-scale cultivation systems or to enhance its value as food and feed additives. However, so far, most of the attempts to develop such a transformation system have had limited success. In this study, an efficient and stable transformation system for A. platensis C1 was successfully developed. Based on electroporation and transposon techniques, exogenous DNA could be transferred to and stably maintained in the A. platensis C1 genome. Most strains of Arthrospira possess strong restriction barriers, hampering the development of a gene transfer system for this group of cyanobacteria. By using a type I restriction inhibitor and liposomes to protect the DNA from nuclease digestion, the transformation efficiency was significantly improved. The transformants were able to grow on a selective medium for more than eight passages, and the transformed DNA could be detected from the stable transformants. We propose that the intrinsic endonuclease enzymes, particularly the type I restriction enzyme, in A. platensis C1 play an important role in the transformation efficiency of this industrial important cyanobacterium.
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Affiliation(s)
- Wattana Jeamton
- Pilot Plant Development and Training Institute, King Mongkut's University of Technology Thonburi (Bang Khun Thian), Bangkok, Thailand
| | - Sudarat Dulsawat
- Pilot Plant Development and Training Institute, King Mongkut's University of Technology Thonburi (Bang Khun Thian), Bangkok, Thailand
| | - Morakot Tanticharoen
- Pilot Plant Development and Training Institute, King Mongkut's University of Technology Thonburi (Bang Khun Thian), Bangkok, Thailand
| | - Avigad Vonshak
- The Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede Boqer campus, Israel
| | - Supapon Cheevadhanarak
- Pilot Plant Development and Training Institute, King Mongkut's University of Technology Thonburi (Bang Khun Thian), Bangkok, Thailand
- School of Bioresources and Technology, King Mongkut's University of Technology Thonburi (Bang Khun Thian), Bangkok, Thailand
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