1
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Mallén-Ponce MJ, Florencio FJ, Huertas MJ. Thioredoxin A regulates protein synthesis to maintain carbon and nitrogen partitioning in cyanobacteria. PLANT PHYSIOLOGY 2024; 195:2921-2936. [PMID: 38386687 PMCID: PMC11288746 DOI: 10.1093/plphys/kiae101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Revised: 01/18/2024] [Accepted: 01/19/2024] [Indexed: 02/24/2024]
Abstract
Thioredoxins play an essential role in regulating enzyme activity in response to environmental changes, especially in photosynthetic organisms. They are crucial for metabolic regulation in cyanobacteria, but the key redox-regulated central processes remain to be determined. Physiological, metabolic, and transcriptomic characterization of a conditional mutant of the essential Synechocystis sp. PCC 6803 thioredoxin trxA gene (STXA2) revealed that decreased TrxA levels alter cell morphology and induce a dormant-like state. Furthermore, TrxA depletion in the STXA2 strain inhibited protein synthesis and led to changes in amino acid pools and nitrogen/carbon reserve polymers, accompanied by oxidation of the elongation factor-Tu. Transcriptomic analysis of TrxA depletion in STXA2 revealed a robust transcriptional response. Downregulated genes formed a large cluster directly related to photosynthesis, ATP synthesis, and CO2 fixation. In contrast, upregulated genes were grouped into different clusters related to respiratory electron transport, carotenoid biosynthesis, amino acid metabolism, and protein degradation, among others. These findings highlight the complex regulatory mechanisms that govern cyanobacterial metabolism, where TrxA acts as a critical regulator that orchestrates the transition from anabolic to maintenance metabolism and regulates carbon and nitrogen balance.
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Affiliation(s)
- Manuel J Mallén-Ponce
- Departamento de Bioquímica Vegetal y Biología Molecular, Universidad de Sevilla, 41012 Sevilla, Spain
- Instituto de Bioquímica Vegetal y Fotosíntesis (Universidad de Sevilla, Consejo Superior de Investigaciones Científicas), 41092 Sevilla, Spain
| | - Francisco Javier Florencio
- Departamento de Bioquímica Vegetal y Biología Molecular, Universidad de Sevilla, 41012 Sevilla, Spain
- Instituto de Bioquímica Vegetal y Fotosíntesis (Universidad de Sevilla, Consejo Superior de Investigaciones Científicas), 41092 Sevilla, Spain
| | - María José Huertas
- Departamento de Bioquímica Vegetal y Biología Molecular, Universidad de Sevilla, 41012 Sevilla, Spain
- Instituto de Bioquímica Vegetal y Fotosíntesis (Universidad de Sevilla, Consejo Superior de Investigaciones Científicas), 41092 Sevilla, Spain
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2
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Dou B, Li Y, Wang F, Chen L, Zhang W. Chassis engineering for high light tolerance in microalgae and cyanobacteria. Crit Rev Biotechnol 2024:1-19. [PMID: 38987975 DOI: 10.1080/07388551.2024.2357368] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2024] [Accepted: 05/05/2024] [Indexed: 07/12/2024]
Abstract
Oxygenic photosynthesis in microalgae and cyanobacteria is considered an important chassis to accelerate energy transition and mitigate global warming. Currently, cultivation systems for photosynthetic microbes for large-scale applications encountered excessive light exposure stress. High light stress can: affect photosynthetic efficiency, reduce productivity, limit cell growth, and even cause cell death. Deciphering photoprotection mechanisms and constructing high-light tolerant chassis have been recent research focuses. In this review, we first briefly introduce the self-protection mechanisms of common microalgae and cyanobacteria in response to high light stress. These mechanisms mainly include: avoiding excess light absorption, dissipating excess excitation energy, quenching excessive high-energy electrons, ROS detoxification, and PSII repair. We focus on the species-specific differences in these mechanisms as well as recent advancements. Then, we review engineering strategies for creating high-light tolerant chassis, such as: reducing the size of the light-harvesting antenna, optimizing non-photochemical quenching, optimizing photosynthetic electron transport, and enhancing PSII repair. Finally, we propose a comprehensive exploration of mechanisms: underlying identified high light tolerant chassis, identification of new genes pertinent to high light tolerance using innovative methodologies, harnessing CRISPR systems and artificial intelligence for chassis engineering modification, and introducing plant photoprotection mechanisms as future research directions.
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Affiliation(s)
- Biyun Dou
- Laboratory of Synthetic Microbiology, School of Chemical Engineering and Technology, Tianjin University, Tianjin, P.R. China
- Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin, P.R. China
| | - Yang Li
- Laboratory of Synthetic Microbiology, School of Chemical Engineering and Technology, Tianjin University, Tianjin, P.R. China
- Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin, P.R. China
| | - Fangzhong Wang
- Laboratory of Synthetic Microbiology, School of Chemical Engineering and Technology, Tianjin University, Tianjin, P.R. China
- Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin, P.R. China
- Center for Biosafety Research and Strategy, Tianjin University, Tianjin, P.R. China
| | - Lei Chen
- Laboratory of Synthetic Microbiology, School of Chemical Engineering and Technology, Tianjin University, Tianjin, P.R. China
- Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin, P.R. China
| | - Weiwen Zhang
- Laboratory of Synthetic Microbiology, School of Chemical Engineering and Technology, Tianjin University, Tianjin, P.R. China
- Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin, P.R. China
- Center for Biosafety Research and Strategy, Tianjin University, Tianjin, P.R. China
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3
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Espinoza-Corral R, Iwai M, Zavřel T, Lechno-Yossef S, Sutter M, Červený J, Niyogi KK, Kerfeld CA. Phycobilisome protein ApcG interacts with PSII and regulates energy transfer in Synechocystis. PLANT PHYSIOLOGY 2024; 194:1383-1396. [PMID: 37972281 PMCID: PMC10904348 DOI: 10.1093/plphys/kiad615] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Revised: 10/25/2023] [Accepted: 10/25/2023] [Indexed: 11/19/2023]
Abstract
Photosynthetic organisms harvest light using pigment-protein complexes. In cyanobacteria, these are water-soluble antennae known as phycobilisomes (PBSs). The light absorbed by PBS is transferred to the photosystems in the thylakoid membrane to drive photosynthesis. The energy transfer between these complexes implies that protein-protein interactions allow the association of PBS with the photosystems. However, the specific proteins involved in the interaction of PBS with the photosystems are not fully characterized. Here, we show in Synechocystis sp. PCC 6803 that the recently discovered PBS linker protein ApcG (sll1873) interacts specifically with PSII through its N-terminal region. Growth of cyanobacteria is impaired in apcG deletion strains under light-limiting conditions. Furthermore, complementation of these strains using a phospho-mimicking version of ApcG causes reduced growth under normal growth conditions. Interestingly, the interaction of ApcG with PSII is affected when a phospho-mimicking version of ApcG is used, targeting the positively charged residues interacting with the thylakoid membrane, suggesting a regulatory role mediated by phosphorylation of ApcG. Low-temperature fluorescence measurements showed decreased PSI fluorescence in apcG deletion and complementation strains. The PSI fluorescence was the lowest in the phospho-mimicking complementation strain, while the pull-down experiment showed no interaction of ApcG with PSI under any tested condition. Our results highlight the importance of ApcG for selectively directing energy harvested by the PBS and imply that the phosphorylation status of ApcG plays a role in regulating energy transfer from PSII to PSI.
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Affiliation(s)
- Roberto Espinoza-Corral
- 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
| | - Masakazu Iwai
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
- Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720, USA
| | - Tomáš Zavřel
- Department of Adaptive Biotechnologies, Global Change Research Institute of the Czech Academy of Sciences, Drásov 470, CZ-66424 Drásov, Czech Republic
| | - 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
| | - 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
| | - Jan Červený
- Department of Adaptive Biotechnologies, Global Change Research Institute of the Czech Academy of Sciences, Drásov 470, CZ-66424 Drásov, Czech Republic
| | - Krishna K Niyogi
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
- Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720, USA
- Howard Hughes Medical Institute, University of California, Berkeley, CA 94720, 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
- 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
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4
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Liu SJ, Lin GM, Yuan YQ, Chen W, Zhang JY, Zhang CC. A conserved protein inhibitor brings under check the activity of RNase E in cyanobacteria. Nucleic Acids Res 2024; 52:404-419. [PMID: 38000383 PMCID: PMC10783494 DOI: 10.1093/nar/gkad1094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 09/21/2023] [Accepted: 10/31/2023] [Indexed: 11/26/2023] Open
Abstract
The bacterial ribonuclease RNase E plays a key role in RNA metabolism. Yet, with a large substrate spectrum and poor substrate specificity, its activity must be well controlled under different conditions. Only a few regulators of RNase E are known, limiting our understanding on posttranscriptional regulatory mechanisms in bacteria. Here we show that, RebA, a protein universally present in cyanobacteria, interacts with RNase E in the cyanobacterium Anabaena PCC 7120. Distinct from those known regulators of RNase E, RebA interacts with the catalytic region of RNase E, and suppresses the cleavage activities of RNase E for all tested substrates. Consistent with the inhibitory function of RebA on RNase E, depletion of RNase E and overproduction of RebA caused formation of elongated cells, whereas the absence of RebA and overproduction of RNase E resulted in a shorter-cell phenotype. We further showed that the morphological changes caused by altered levels of RNase E or RebA are dependent on their physical interaction. The action of RebA represents a new mechanism, potentially conserved in cyanobacteria, for RNase E regulation. Our findings provide insights into the regulation and the function of RNase E, and demonstrate the importance of balanced RNA metabolism in bacteria.
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Affiliation(s)
- Su-Juan Liu
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430070, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Gui-Ming Lin
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430070, China
| | - Yu-Qi Yuan
- 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
| | - Ju-Yuan Zhang
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430070, China
| | - Cheng-Cai Zhang
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430070, China
- Key Laboratory of Lake and Watershed Science for Water Security, Chinese Academy of Sciences, Nanjing 210008, China
- Hubei Hongshan Laboratory, Wuhan 430070, China
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5
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Hoffmann UA, Lichtenberg E, Rogh SN, Bilger R, Reimann V, Heyl F, Backofen R, Steglich C, Hess WR, Wilde A. The role of the 5' sensing function of ribonuclease E in cyanobacteria. RNA Biol 2024; 21:1-18. [PMID: 38469716 PMCID: PMC10939160 DOI: 10.1080/15476286.2024.2328438] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/05/2024] [Indexed: 03/13/2024] Open
Abstract
RNA degradation is critical for synchronising gene expression with changing conditions in prokaryotic and eukaryotic organisms. In bacteria, the preference of the central ribonucleases RNase E, RNase J and RNase Y for 5'-monophosphorylated RNAs is considered important for RNA degradation. For RNase E, the underlying mechanism is termed 5' sensing, contrasting to the alternative 'direct entry' mode, which is independent of monophosphorylated 5' ends. Cyanobacteria, such as Synechocystis sp. PCC 6803 (Synechocystis), encode RNase E and RNase J homologues. Here, we constructed a Synechocystis strain lacking the 5' sensing function of RNase E and mapped on a transcriptome-wide level 283 5'-sensing-dependent cleavage sites. These included so far unknown targets such as mRNAs encoding proteins related to energy metabolism and carbon fixation. The 5' sensing function of cyanobacterial RNase E is important for the maturation of rRNA and several tRNAs, including tRNAGluUUC. This tRNA activates glutamate for tetrapyrrole biosynthesis in plant chloroplasts and in most prokaryotes. Furthermore, we found that increased RNase activities lead to a higher copy number of the major Synechocystis plasmids pSYSA and pSYSM. These results provide a first step towards understanding the importance of the different target mechanisms of RNase E outside Escherichia coli.
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Affiliation(s)
- Ute A. Hoffmann
- Molecular Genetics of Prokaryotes, Institute of Biology III, University of Freiburg, Freiburg, Germany
- School of Engineering Sciences in Chemistry, Biotechnology and Health, Science for Life Laboratory, KTH - Royal Institute of Technology, Stockholm, Sweden
| | - Elisabeth Lichtenberg
- Molecular Genetics of Prokaryotes, Institute of Biology III, University of Freiburg, Freiburg, Germany
| | - Said N. Rogh
- Molecular Genetics of Prokaryotes, Institute of Biology III, University of Freiburg, Freiburg, Germany
| | - Raphael Bilger
- Genetics and Experimental Bioinformatics, Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Viktoria Reimann
- Genetics and Experimental Bioinformatics, Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Florian Heyl
- Bioinformatics Group, Department of Computer Science, University of Freiburg, Freiburg, Germany
| | - Rolf Backofen
- Bioinformatics Group, Department of Computer Science, University of Freiburg, Freiburg, Germany
- Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Freiburg, Germany
| | - Claudia Steglich
- Genetics and Experimental Bioinformatics, Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Wolfgang R. Hess
- Genetics and Experimental Bioinformatics, Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Annegret Wilde
- Molecular Genetics of Prokaryotes, Institute of Biology III, University of Freiburg, Freiburg, Germany
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6
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Kwok ACM, Leung SK, Wong JTY. DNA:RNA Hybrids Are Major Dinoflagellate Minicircle Molecular Types. Int J Mol Sci 2023; 24:ijms24119651. [PMID: 37298602 DOI: 10.3390/ijms24119651] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Revised: 05/30/2023] [Accepted: 05/31/2023] [Indexed: 06/12/2023] Open
Abstract
Peridinin-containing dinoflagellate plastomes are predominantly encoded in nuclear genomes, with less than 20 essential chloroplast proteins carried on "minicircles". Each minicircle generally carries one gene and a short non-coding region (NCR) with a median length of approximately 400-1000 bp. We report here differential nuclease sensitivity and two-dimensional southern blot patterns, suggesting that dsDNA minicircles are in fact the minor forms, with substantial DNA:RNA hybrids (DRHs). Additionally, we observed large molecular weight intermediates, cell-lysate-dependent NCR secondary structures, multiple bidirectional predicted ssDNA structures, and different southern blot patterns when probed with different NCR fragments. In silico analysis suggested the existence of substantial secondary structures with inverted repeats (IR) and palindrome structures within the initial ~650 bp of the NCR sequences, in accordance with conversion event(s) outcomes with PCR. Based on these findings, we propose a new transcription-templating-translation model, which is associated with cross-hopping shift intermediates. Since dinoflagellate chloroplasts are cytosolic and lack nuclear envelope breakdown, the dynamic DRH minicircle transport could have contributed to the spatial-temporal dynamics required for photosystem repair. This represents a paradigm shift from the previous understanding of "minicircle DNAs" to a "working plastome", which will have significant implications for its molecular functionality and evolution.
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Affiliation(s)
- Alvin Chun Man Kwok
- Division of Life Science, The Hong Kong University of Science and Technology, Clearwater Bay, Kowloon, Hong Kong, China
| | - Siu Kai Leung
- Division of Life Science, The Hong Kong University of Science and Technology, Clearwater Bay, Kowloon, Hong Kong, China
| | - Joseph Tin Yum Wong
- Division of Life Science, The Hong Kong University of Science and Technology, Clearwater Bay, Kowloon, Hong Kong, China
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7
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Brenes-Álvarez M, Vioque A, Muro-Pastor AM. Nitrogen-regulated antisense transcription in the adaptation to nitrogen deficiency in Nostoc sp. PCC 7120. PNAS NEXUS 2023; 2:pgad187. [PMID: 37361547 PMCID: PMC10287535 DOI: 10.1093/pnasnexus/pgad187] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Revised: 05/24/2023] [Accepted: 05/30/2023] [Indexed: 06/28/2023]
Abstract
Transcriptomic analyses using high-throughput methods have revealed abundant antisense transcription in bacteria. Antisense transcription is often due to the overlap of mRNAs with long 5' or 3' regions that extend beyond the coding sequence. In addition, antisense RNAs that do not contain any coding sequence are also observed. Nostoc sp. PCC 7120 is a filamentous cyanobacterium that, under nitrogen limitation, behaves as a multicellular organism with division of labor among two different cell types that depend on each other, the vegetative CO2-fixing cells and the nitrogen-fixing heterocysts. The differentiation of heterocysts depends on the global nitrogen regulator NtcA and requires the specific regulator HetR. To identify antisense RNAs potentially involved in heterocyst differentiation, we assembled the Nostoc transcriptome using RNA-seq analysis of cells subjected to nitrogen limitation (9 or 24 h after nitrogen removal) in combination with a genome-wide set of transcriptional start sites and a prediction of transcriptional terminators. Our analysis resulted in the definition of a transcriptional map that includes >4,000 transcripts, 65% of which contain regions in antisense orientation to other transcripts. In addition to overlapping mRNAs, we identified nitrogen-regulated noncoding antisense RNAs transcribed from NtcA- or HetR-dependent promoters. As an example of this last category, we further analyzed an antisense (as_gltA) of the gene-encoding citrate synthase and showed that transcription of as_gltA takes place specifically in heterocysts. Since the overexpression of as_gltA reduces citrate synthase activity, this antisense RNA could eventually contribute to the metabolic remodeling that occurs during the differentiation of vegetative cells into heterocysts.
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Affiliation(s)
| | - Agustín Vioque
- Instituto de Bioquímica Vegetal y Fotosíntesis, Consejo Superior de Investigaciones Científicas and Universidad de Sevilla, Américo Vespucio 49, 41092 Sevilla, Spain
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8
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Watanabe S, Stazic D, Georg J, Ohtake S, Sakamaki Y, Numakura M, Asayama M, Chibazakura T, Wilde A, Steglich C, Hess WR. Regulation of RNase E during the UV stress response in the cyanobacterium Synechocystis sp. PCC 6803. MLIFE 2023; 2:43-57. [PMID: 38818332 PMCID: PMC10989929 DOI: 10.1002/mlf2.12056] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/01/2022] [Revised: 12/07/2022] [Accepted: 12/15/2022] [Indexed: 06/01/2024]
Abstract
Endoribonucleases govern the maturation and degradation of RNA and are indispensable in the posttranscriptional regulation of gene expression. A key endoribonuclease in Gram-negative bacteria is RNase E. To ensure an appropriate supply of RNase E, some bacteria, such as Escherichia coli, feedback-regulate RNase E expression via the rne 5'-untranslated region (5' UTR) in cis. However, the mechanisms involved in the control of RNase E in other bacteria largely remain unknown. Cyanobacteria rely on solar light as an energy source for photosynthesis, despite the inherent ultraviolet (UV) irradiation. In this study, we first investigated globally the changes in gene expression in the cyanobacterium Synechocystis sp. PCC 6803 after a brief exposure to UV. Among the 407 responding genes 2 h after UV exposure was a prominent upregulation of rne mRNA level. Moreover, the enzymatic activity of RNase E rapidly increased as well, although the protein stability decreased. This unique response was underpinned by the increased accumulation of full-length rne mRNA caused by the stabilization of its 5' UTR and suppression of premature transcriptional termination, but not by an increased transcription rate. Mapping of RNA 3' ends and in vitro cleavage assays revealed that RNase E cleaves within a stretch of six consecutive uridine residues within the rne 5' UTR, indicating autoregulation. These observations suggest that RNase E in cyanobacteria contributes to reshaping the transcriptome during the UV stress response and that its required activity level is secured at the RNA level despite the enhanced turnover of the protein.
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Affiliation(s)
- Satoru Watanabe
- Faculty of Biology, Genetics and Experimental BioinformaticsUniversity of FreiburgFreiburgGermany
| | - Damir Stazic
- Department of BioscienceTokyo University of AgricultureSetagaya‐kuTokyoJapan
- Present address:
NexxiotPrime Tower (Hardstrasse 201)ZurichSwitzerland
| | - Jens Georg
- Department of BioscienceTokyo University of AgricultureSetagaya‐kuTokyoJapan
| | - Shota Ohtake
- Faculty of Biology, Genetics and Experimental BioinformaticsUniversity of FreiburgFreiburgGermany
| | - Yutaka Sakamaki
- Faculty of Biology, Genetics and Experimental BioinformaticsUniversity of FreiburgFreiburgGermany
| | - Megumi Numakura
- Faculty of Biology, Genetics and Experimental BioinformaticsUniversity of FreiburgFreiburgGermany
| | - Munehiko Asayama
- School of Agriculture, Molecular GeneticsIbaraki UniversityIbarakiJapan
| | - Taku Chibazakura
- Faculty of Biology, Genetics and Experimental BioinformaticsUniversity of FreiburgFreiburgGermany
| | - Annegret Wilde
- Faculty of Biology, Molecular GeneticsUniversity of FreiburgFreiburgGermany
| | - Claudia Steglich
- Department of BioscienceTokyo University of AgricultureSetagaya‐kuTokyoJapan
| | - Wolfgang R. Hess
- Department of BioscienceTokyo University of AgricultureSetagaya‐kuTokyoJapan
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9
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Advances in Genetic Engineering in Improving Photosynthesis and Microalgal Productivity. Int J Mol Sci 2023; 24:ijms24031898. [PMID: 36768215 PMCID: PMC9915242 DOI: 10.3390/ijms24031898] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Revised: 01/10/2023] [Accepted: 01/16/2023] [Indexed: 01/21/2023] Open
Abstract
Even though sunlight energy far outweighs the energy required by human activities, its utilization is a key goal in the field of renewable energies. Microalgae have emerged as a promising new and sustainable feedstock for meeting rising food and feed demand. Because traditional methods of microalgal improvement are likely to have reached their limits, genetic engineering is expected to allow for further increases in the photosynthesis and productivity of microalgae. Understanding the mechanisms that control photosynthesis will enable researchers to identify targets for genetic engineering and, in the end, increase biomass yield, offsetting the costs of cultivation systems and downstream biomass processing. This review describes the molecular events that happen during photosynthesis and microalgal productivity through genetic engineering and discusses future strategies and the limitations of genetic engineering in microalgal productivity. We highlight the major achievements in manipulating the fundamental mechanisms of microalgal photosynthesis and biomass production, as well as promising approaches for making significant contributions to upcoming microalgal-based biotechnology.
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10
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Model-Based Design of Synthetic Antisense RNA for Predictable Gene Repression. METHODS IN MOLECULAR BIOLOGY (CLIFTON, N.J.) 2022; 2518:111-124. [PMID: 35666442 DOI: 10.1007/978-1-0716-2421-0_7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Our enhanced understanding of RNA folding and function has increased the use of small RNA regulators. Among these RNA regulators, synthetic antisense RNA (asRNA) is designed to contain an RNA sequence complementary to the target mRNA sequence, and the formation of double-stranded RNA (dsRNA) facilitates gene repression due to dsRNA degradation or prevention of ribosome access to the mRNA. Despite the simple complementarity rule, however, predictably tunable repression has been challenging when synthetic asRNAs are used. Here, the protocol for model-based asRNA design is described. This model can predict synthetic asRNA-mediated repression efficiency using two parameters: the change in free energy of complex formation (ΔGCF) and percent mismatch of the target binding region (TBR). The model has been experimentally validated in both Gram-positive and Gram-negative bacteria as well as for target genes in both plasmids and chromosomes. These asRNAs can be created by simply replacing the TBR sequence with one that is complementary to the target mRNA sequence of interest. In principle, this protocol can be applied to design and build asRNAs for predictable gene repression in various contexts, including multiple target genes and organisms, making asRNAs predictably tunable regulators for broad applications.
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11
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Kılıç M, Gollan PJ, Lepistö A, Isojärvi J, Sakurai I, Aro E, Mulo P. Gene expression and organization of thylakoid protein complexes in the PSII-less mutant of Synechocystis sp. PCC 6803. PLANT DIRECT 2022; 6:e409. [PMID: 35774619 PMCID: PMC9219013 DOI: 10.1002/pld3.409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 05/13/2022] [Accepted: 05/16/2022] [Indexed: 06/15/2023]
Abstract
Photosystems I and II (PSI and PSII) are the integral components of the photosynthetic electron transport chain that utilize light to provide chemical energy for CO2 fixation. In this study, we investigated how the deficiency of PSII affects the gene expression, accumulation, and organization of thylakoid protein complexes as well as physiological characteristics of Synechocystis sp. PCC 6803 by combining biochemical, biophysical, and transcriptomic approaches. RNA-seq analysis showed upregulated expression of genes encoding the PSII core proteins, and downregulation of genes associated with interaction between light-harvesting phycobilisomes and PSI. Two-dimensional separation of thylakoid protein complexes confirmed the lack of PSII complexes, yet unassembled PSII subunits were detected. The content of PsaB representing PSI was lower, while the content of cytochrome b6f complexes was higher in the PSII-less strain as compared with control (CS). Application of oxygraph measurements revealed higher rates of dark respiration and lower PSI activity in the mutant. The latter likely resulted from the detected decrease in the accumulation of PSI, PSI monomerization, increased proportion of energetically decoupled phycobilisomes in PSII-less cultures, and low abundance of phycocyanin. Merging the functional consequences of PSII depletion with differential protein and transcript accumulation in the mutant, in comparison to CS, identified signal transduction from the photosynthetic apparatus to the genome level.
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Affiliation(s)
- Mehmet Kılıç
- Molecular Plant Biology, Department of Life TechnologiesUniversity of TurkuTurkuFinland
| | - Peter J. Gollan
- Molecular Plant Biology, Department of Life TechnologiesUniversity of TurkuTurkuFinland
| | - Anniina Lepistö
- Molecular Plant Biology, Department of Life TechnologiesUniversity of TurkuTurkuFinland
| | - Janne Isojärvi
- Molecular Plant Biology, Department of Life TechnologiesUniversity of TurkuTurkuFinland
- Present address:
Turku PET CentreUniversity of TurkuTurkuFinland
| | - Isamu Sakurai
- Molecular Plant Biology, Department of Life TechnologiesUniversity of TurkuTurkuFinland
| | - Eva‐Mari Aro
- Molecular Plant Biology, Department of Life TechnologiesUniversity of TurkuTurkuFinland
| | - Paula Mulo
- Molecular Plant Biology, Department of Life TechnologiesUniversity of TurkuTurkuFinland
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12
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Li X, Xue C, Chen H, Zhang H, Wang Q. Small antisense RNA ThfR positively regulates Thf1 in Synechocystis sp. PCC 6803. JOURNAL OF PLANT PHYSIOLOGY 2022; 271:153642. [PMID: 35193088 DOI: 10.1016/j.jplph.2022.153642] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2021] [Revised: 02/05/2022] [Accepted: 02/07/2022] [Indexed: 06/14/2023]
Abstract
Thylakoid formation1 (Thf1), encoded by sll1414 (thf1), is a multifunctional protein conserved in all photosynthetic organisms. thf1 expression is highly induced by high light in Synechocystis during photosynthesis-related stress. In this study, differential RNA sequencing analysis of the Synechocystis sp. PCC 6803 revealed a small antisense RNA (asRNA) gene located on the reverse-complementary strand of the thf1 gene. The full length of this asRNA (designated ThfR) was determined by 5' and 3' RACE analysis. The accumulation of thf1 mRNA was up-regulated synchronously with the ThfR level during survival after high-light stress or nitrogen starvation. Under nitrogen starvation or high-light stress, compared with the wild type, a ThfR overexpression mutant demonstrated relatively more Thf1 protein content, while a ThfR reduced-expression mutant accumulated less Thf1 protein. Furthermore, the overexpression of ThfR enhanced the electron transport rate and the proliferation of cyanobacteria under high-light stress. These results, which we confirmed further using an Escherichia coli sRNA expression platform, suggest that the thf1 gene is positively regulated by ThfR, possibly through protection of the RAUUW element at the RNase E cleavage site. This study represents the first report, to our knowledge, of a cis-transcript antisense RNA that targets thf1 in Synechocystis sp. PCC 6803 and provides evidence that ThfR regulates photosynthesis by positively modulating thf1 under high-light conditions.
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Affiliation(s)
- Xiang Li
- Hefei National Laboratory for Physical Sciences at Microscale, The Chinese Academy of Sciences Key Laboratory of Innate Immunity and Chronic Disease, School of Basic Medical Sciences, Division of Life Science and Medicine, University of Science and Technology of China, Hefei, 230026, China; State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Kaifeng, 475004, China.
| | - Chunling Xue
- State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Kaifeng, 475004, China.
| | - Hui Chen
- State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Kaifeng, 475004, China.
| | - Huafeng Zhang
- Hefei National Laboratory for Physical Sciences at Microscale, The Chinese Academy of Sciences Key Laboratory of Innate Immunity and Chronic Disease, School of Basic Medical Sciences, Division of Life Science and Medicine, University of Science and Technology of China, Hefei, 230026, China.
| | - Qiang Wang
- State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Kaifeng, 475004, China.
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13
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Zhang J, Hess WR, Zhang C. "Life is short, and art is long": RNA degradation in cyanobacteria and model bacteria. MLIFE 2022; 1:21-39. [PMID: 38818322 PMCID: PMC10989914 DOI: 10.1002/mlf2.12015] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 03/03/2022] [Accepted: 03/03/2022] [Indexed: 06/01/2024]
Abstract
RNA turnover plays critical roles in the regulation of gene expression and allows cells to respond rapidly to environmental changes. In bacteria, the mechanisms of RNA turnover have been extensively studied in the models Escherichia coli and Bacillus subtilis, but not much is known in other bacteria. Cyanobacteria are a diverse group of photosynthetic organisms that have great potential for the sustainable production of valuable products using CO2 and solar energy. A better understanding of the regulation of RNA decay is important for both basic and applied studies of cyanobacteria. Genomic analysis shows that cyanobacteria have more than 10 ribonucleases and related proteins in common with E. coli and B. subtilis, and only a limited number of them have been experimentally investigated. In this review, we summarize the current knowledge about these RNA-turnover-related proteins in cyanobacteria. Although many of them are biochemically similar to their counterparts in E. coli and B. subtilis, they appear to have distinct cellular functions, suggesting a different mechanism of RNA turnover regulation in cyanobacteria. The identification of new players involved in the regulation of RNA turnover and the elucidation of their biological functions are among the future challenges in this field.
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Affiliation(s)
- Ju‐Yuan Zhang
- State Key Laboratory of Freshwater Ecology and Biotechnology and Key Laboratory of Algal Biology, Institute of HydrobiologyChinese Academy of SciencesWuhanChina
| | - Wolfgang R. Hess
- Genetics and Experimental Bioinformatics, Faculty of BiologyUniversity of FreiburgFreiburgGermany
| | - Cheng‐Cai Zhang
- State Key Laboratory of Freshwater Ecology and Biotechnology and Key Laboratory of Algal Biology, Institute of HydrobiologyChinese Academy of SciencesWuhanChina
- Institut WUT‐AMUAix‐Marseille University and Wuhan University of TechnologyWuhanChina
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14
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Hoffmann UA, Heyl F, Rogh SN, Wallner T, Backofen R, Hess WR, Steglich C, Wilde A. Transcriptome-wide in vivo mapping of cleavage sites for the compact cyanobacterial ribonuclease E reveals insights into its function and substrate recognition. Nucleic Acids Res 2021; 49:13075-13091. [PMID: 34871439 PMCID: PMC8682795 DOI: 10.1093/nar/gkab1161] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 10/26/2021] [Accepted: 11/16/2021] [Indexed: 12/13/2022] Open
Abstract
Ribonucleases are crucial enzymes in RNA metabolism and post-transcriptional regulatory processes in bacteria. Cyanobacteria encode the two essential ribonucleases RNase E and RNase J. Cyanobacterial RNase E is shorter than homologues in other groups of bacteria and lacks both the chloroplast-specific N-terminal extension as well as the C-terminal domain typical for RNase E of enterobacteria. In order to investigate the function of RNase E in the model cyanobacterium Synechocystis sp. PCC 6803, we engineered a temperature-sensitive RNase E mutant by introducing two site-specific mutations, I65F and the spontaneously occurred V94A. This enabled us to perform RNA-seq after the transient inactivation of RNase E by a temperature shift (TIER-seq) and to map 1472 RNase-E-dependent cleavage sites. We inferred a dominating cleavage signature consisting of an adenine at the -3 and a uridine at the +2 position within a single-stranded segment of the RNA. The data identified mRNAs likely regulated jointly by RNase E and an sRNA and potential 3' end-derived sRNAs. Our findings substantiate the pivotal role of RNase E in post-transcriptional regulation and suggest the redundant or concerted action of RNase E and RNase J in cyanobacteria.
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Affiliation(s)
- Ute A Hoffmann
- Molecular Genetics of Prokaryotes, Institute of Biology III, University of Freiburg, 79104 Freiburg, Germany
| | - Florian Heyl
- Bioinformatics Group, Department of Computer Science, University of Freiburg, 79110 Freiburg, Germany
| | - Said N Rogh
- Molecular Genetics of Prokaryotes, Institute of Biology III, University of Freiburg, 79104 Freiburg, Germany
| | - Thomas Wallner
- Molecular Genetics of Prokaryotes, Institute of Biology III, University of Freiburg, 79104 Freiburg, Germany
| | - Rolf Backofen
- Bioinformatics Group, Department of Computer Science, University of Freiburg, 79110 Freiburg, Germany.,Signalling Research Centres BIOSS and CIBSS, University of Freiburg, 79104 Freiburg, Germany
| | - Wolfgang R Hess
- Genetics and Experimental Bioinformatics, Faculty of Biology, University of Freiburg, 79104 Freiburg, Germany
| | - Claudia Steglich
- Genetics and Experimental Bioinformatics, Faculty of Biology, University of Freiburg, 79104 Freiburg, Germany
| | - Annegret Wilde
- Molecular Genetics of Prokaryotes, Institute of Biology III, University of Freiburg, 79104 Freiburg, Germany
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15
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Klähn S, Mikkat S, Riediger M, Georg J, Hess WR, Hagemann M. Integrative analysis of the salt stress response in cyanobacteria. Biol Direct 2021; 16:26. [PMID: 34906211 PMCID: PMC8670252 DOI: 10.1186/s13062-021-00316-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Accepted: 11/29/2021] [Indexed: 12/24/2022] Open
Abstract
Microorganisms evolved specific acclimation strategies to thrive in environments of high or fluctuating salinities. Here, salt acclimation in the model cyanobacterium Synechocystis sp. PCC 6803 was analyzed by integrating transcriptomic, proteomic and metabolomic data. A dynamic reorganization of the transcriptome occurred during the first hours after salt shock, e.g. involving the upregulation of genes to activate compatible solute biochemistry balancing osmotic pressure. The massive accumulation of glucosylglycerol then had a measurable impact on the overall carbon and nitrogen metabolism. In addition, we observed the coordinated induction of putative regulatory RNAs and of several proteins known for their involvement in other stress responses. Overall, salt-induced changes in the proteome and transcriptome showed good correlations, especially among the stably up-regulated proteins and their transcripts. We define an extended salt stimulon comprising proteins directly or indirectly related to compatible solute metabolism, ion and water movements, and a distinct set of regulatory RNAs involved in post-transcriptional regulation. Our comprehensive data set provides the basis for engineering cyanobacterial salt tolerance and to further understand its regulation.
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Affiliation(s)
- Stephan Klähn
- Department of Solar Materials, Helmholtz-Centre for Environmental Research - UFZ, Leipzig, Germany
- Faculty of Biology, Genetics and Experimental Bioinformatics, University of Freiburg, Freiburg, Germany
| | - Stefan Mikkat
- Core Facility Proteome Analysis, Rostock University Medical Center, Rostock, Germany
| | - Matthias Riediger
- Faculty of Biology, Genetics and Experimental Bioinformatics, University of Freiburg, Freiburg, Germany
| | - Jens Georg
- Faculty of Biology, Genetics and Experimental Bioinformatics, University of Freiburg, Freiburg, Germany
| | - Wolfgang R. Hess
- Faculty of Biology, Genetics and Experimental Bioinformatics, University of Freiburg, Freiburg, Germany
| | - Martin Hagemann
- Department of Plant Physiology, Institute of Biosciences, University of Rostock, A.-Einstein-Str. 3, 18059 Rostock, Germany
- Department Life, Light and Matter, University of Rostock, Rostock, Germany
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16
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Zhan J, Steglich C, Scholz I, Hess WR, Kirilovsky D. Inverse regulation of light harvesting and photoprotection is mediated by a 3'-end-derived sRNA in cyanobacteria. THE PLANT CELL 2021; 33:358-380. [PMID: 33793852 PMCID: PMC8136909 DOI: 10.1093/plcell/koaa030] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Accepted: 12/01/2020] [Indexed: 06/12/2023]
Abstract
Phycobilisomes (PBSs), the principal cyanobacterial antenna, are among the most efficient macromolecular structures in nature, and are used for both light harvesting and directed energy transfer to the photosynthetic reaction center. However, under unfavorable conditions, excess excitation energy needs to be rapidly dissipated to avoid photodamage. The orange carotenoid protein (OCP) senses light intensity and induces thermal energy dissipation under stress conditions. Hence, its expression must be tightly controlled; however, the molecular mechanism of this regulation remains to be elucidated. Here, we describe the discovery of a posttranscriptional regulatory mechanism in Synechocystis sp. PCC 6803 in which the expression of the operon encoding the allophycocyanin subunits of the PBS is directly and in an inverse fashion linked to the expression of OCP. This regulation is mediated by ApcZ, a small regulatory RNA that is derived from the 3'-end of the tetracistronic apcABC-apcZ operon. ApcZ inhibits ocp translation under stress-free conditions. Under most stress conditions, apc operon transcription decreases and ocp translation increases. Thus, a key operon involved in the collection of light energy is functionally connected to the expression of a protein involved in energy dissipation. Our findings support the view that regulatory RNA networks in bacteria evolve through the functionalization of mRNA 3'-UTRs.
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Affiliation(s)
- Jiao Zhan
- Université Paris-Saclay, Commissariat à l’Énergie Atomiques et aux Énergies Alternatives, Centre National de la Recherche Scientifique (CEA, CNRS), Institute for Integrative Biology of the Cell (I2BC), 91198 Gif sur Yvette, France
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Claudia Steglich
- Faculty of Biology, Institute of Biology III, University of Freiburg, D-79104 Freiburg im Breisgau, Germany
| | - Ingeborg Scholz
- Faculty of Biology, Institute of Biology III, University of Freiburg, D-79104 Freiburg im Breisgau, Germany
| | - Wolfgang R Hess
- Faculty of Biology, Institute of Biology III, University of Freiburg, D-79104 Freiburg im Breisgau, Germany
| | - Diana Kirilovsky
- Université Paris-Saclay, Commissariat à l’Énergie Atomiques et aux Énergies Alternatives, Centre National de la Recherche Scientifique (CEA, CNRS), Institute for Integrative Biology of the Cell (I2BC), 91198 Gif sur Yvette, France
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17
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Kim H, Wang H, Ki JS. Chloroacetanilides inhibit photosynthesis and disrupt the thylakoid membranes of the dinoflagellate Prorocentrum minimum as revealed with metazachlor treatment. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2021; 211:111928. [PMID: 33476845 DOI: 10.1016/j.ecoenv.2021.111928] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 01/08/2021] [Accepted: 01/09/2021] [Indexed: 06/12/2023]
Abstract
The chloroacetanilides are among the most commonly used herbicides worldwide, which contaminate aquatic environments and affect aquatic phototrophs. Their sub-lethal toxicity has been evaluated using freshwater algae; however, the modes of cellular toxicity and levels of toxicity to marine organisms are not fully understood. In the present study, we assessed the cellular and molecular effects of chloroacetanilides on marine phototrophs using the dinoflagellate Prorocentrum minimum and the herbicide metazachlor (MZC). The MZC treatment led to a considerable reduction in cell number and pigment, and the EC50 of MZC was calculated to be 0.647 mg/L. The photosynthetic parameters, Fv/Fm and chlorophyll fluorescence significantly decreased with MZC exposure time in a dose-dependent manner. In addition, MZC significantly induced photosynthesis genes, including PmpsbA, PmpsaA, and PmatpB, and the antioxidant PmGST, but not PmKatG. These findings were well matched to reactive oxygen species (ROS) production in MZC-treated cells. Interestingly, we observed inflated vacuoles, undivided chloroplasts, and breakdown of thylakoid membranes in MZC-treated cells. These results support the hypothesis that MZC severely damages chloroplasts, resulting in dysfunction of the dinoflagellate photosynthesis and possibly marine phototrophs in the environment.
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Affiliation(s)
- Hansol Kim
- Department of Biotechnology, Sangmyung University, Seoul 03016, South Korea
| | - Hui Wang
- Department of Biotechnology, Sangmyung University, Seoul 03016, South Korea
| | - Jang-Seu Ki
- Department of Biotechnology, Sangmyung University, Seoul 03016, South Korea.
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18
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Tightening the Screws on PsbA in Cyanobacteria. Trends Genet 2020; 37:211-215. [PMID: 32977998 DOI: 10.1016/j.tig.2020.08.018] [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: 06/30/2020] [Revised: 08/18/2020] [Accepted: 08/20/2020] [Indexed: 11/22/2022]
Abstract
Cyanobacterial genomes encode several isoforms of the D1 (PsbA) subunit of Photosystem II (PSII). The distinct regulation of each isoform ensures adaptation under changing environmental conditions. Uncovering the missing elements of signal transduction pathways and psbA gene expression could open new avenues in engineering programs of cyanobacterial strains.
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19
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Mao F, He Y, Gin KYH. Antioxidant responses in cyanobacterium Microcystis aeruginosa caused by two commonly used UV filters, benzophenone-1 and benzophenone-3, at environmentally relevant concentrations. JOURNAL OF HAZARDOUS MATERIALS 2020; 396:122587. [PMID: 32335379 DOI: 10.1016/j.jhazmat.2020.122587] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2019] [Revised: 03/20/2020] [Accepted: 03/24/2020] [Indexed: 06/11/2023]
Abstract
Benzophenone-type ultraviolet filters (BPs) have recently been recognized as emerging organic contaminants. In the present study, the cyanobacterium Microcystis aeruginosa was exposed to environmentally relevant levels (0.01-1000 μg L-1) of benzophenone-1 (BP-1) and benzophenone-3 (BP-3) for seven days. A battery of tested endpoints associated with photosynthetic pigments and oxidative stress was employed for a better understanding of the mode of action. The tested cyanobacterium could uptake the two BPs (27.4-54.9%) from culture media. The two BPs were able to inhibit the production of chlorophyll a (chl-a) and promote the accumulation of carotenoids, leading to unaffected chl-a autofluorescence. Slightly increased malondialdehyde (MDA) contents suggested that BP-1 and BP-3 caused moderate oxidative stress. BP-1 stimulated the activities of superoxide dismutase (SOD), glutathione reductase (GR) and glutathione S-transferase (GST) in M. aeruginosa while BP-3 increased the activities of SOD, GST, and glutathione (GSH), showing a concentration- and time-dependent relationship. The activities of other biomarkers, such as catalase (CAT) and glutathione peroxidase (GPx) fluctuated depending on exposure time and concentration. The overall results suggested that the two BPs can trigger moderate oxidative stress in M. aeruginosa and the tested cyanobacterium was capable of alleviating stress by different mechanisms.
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Affiliation(s)
- Feijian Mao
- NUS Environmental Research Institute, National University of Singapore, 5A Engineering Drive 1, #02-01, Singapore 117411, Singapore
| | - Yiliang He
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Karina Yew-Hoong Gin
- NUS Environmental Research Institute, National University of Singapore, 5A Engineering Drive 1, #02-01, Singapore 117411, Singapore; Department of Civil and Environmental Engineering, National University of Singapore, 1 Engineering Drive 2, E1A 07-03, Singapore 117576, Singapore.
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20
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Mironov KS, Kupriyanova EV, Shumskaya M, Los DA. Alcohol stress on cyanobacterial membranes: New insights revealed by transcriptomics. Gene 2020; 764:145055. [PMID: 32882332 DOI: 10.1016/j.gene.2020.145055] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 07/22/2020] [Accepted: 08/12/2020] [Indexed: 11/18/2022]
Abstract
Cyanobacteria are model photosynthetic prokaryotic organisms often used in biotechnology to produce biofuels including alcohols. The effect of alcohols on cyanobacterial cell physiology and specifically on membrane fluidity is poorly understood. Previous research on various primary aliphatic alcohols found that alcohols with a short hydrocarbon chain (C1-C3) do not affect expression of genes related to membrane physical state. In addition, less water-soluble alcohols with a hydrocarbon chain longer than C8 are found to have a reduced ability to reach cellular membranes hence do not drastically change membrane physical state or induce expression of stress-responsive genes. Therefore, hexan-1-ol (C6) is suggested to have the most profound effect on cyanobacterial membrane physical state. Here, we studied the effects of hexan-1-ol on the cyanobacterium Synechocystis sp. PCC 6803 transcriptome. The transcriptome data obtained is compared to the previously reported analysis of gene expression induced by benzyl alcohol and butan-1-ol. The set of genes whose expression is induced after exposure to all three studied alcohols is identified. The expression under alcohol stress for several general stress response operons is analyzed, and examples of antisense interactions of RNA are investigated.
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Affiliation(s)
- Kirill S Mironov
- Department of Molecular Biosystems, K.A. Timiryazev Institute of Plant Physiology, Russian Academy of Science, Botanicheskaya str., 35, Moscow 127276, Russian Federation.
| | - Elena V Kupriyanova
- Department of Molecular Biosystems, K.A. Timiryazev Institute of Plant Physiology, Russian Academy of Science, Botanicheskaya str., 35, Moscow 127276, Russian Federation
| | - Maria Shumskaya
- Department of Biology, School of Natural Sciences, Kean University, 1000 Morris Ave, Union, NJ 07083, USA
| | - Dmitry A Los
- Department of Molecular Biosystems, K.A. Timiryazev Institute of Plant Physiology, Russian Academy of Science, Botanicheskaya str., 35, Moscow 127276, Russian Federation
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21
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Kim H, Wang H, Abassi S, Ki JS. The herbicide alachlor severely affects photosystem function and photosynthetic gene expression in the marine dinoflagellate Prorocentrum minimum. JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART. B, PESTICIDES, FOOD CONTAMINANTS, AND AGRICULTURAL WASTES 2020; 55:620-629. [PMID: 32364417 DOI: 10.1080/03601234.2020.1755198] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Alachlor is one of the most widely used herbicides and can remain in agricultural soils and wastewater. The toxicity of alachlor to marine life has been rarely studied; therefore, we evaluated the physiological and transcriptional responses in the marine dinoflagellate Prorocentrum minimum. The herbicide led to considerable decreases in P. minimum cell numbers and pigment contents. The EC50 was determined to be 0.373 mg/L. Photosynthesis efficiency and chlorophyll autofluorescence dramatically decreased with increasing alachlor dose and exposure time. Real-time PCR analysis showed that the photosynthesis-related genes PmpsbA, PmatpB, and PmrbcL were induced the most by alachlor; the transcriptional level of each gene varied with time. PmrbcL expression increased after 30 min of alachlor treatment, whereas PmatpB and PmpsbA increased after 24 h. The PmpsbA expression level was highest (5.0 times compared to control) after 6 h of alachlor treatment. There was no significant change in PmpsaA expression with varying treatment time or concentration. Additionally, there was no notable change in the expression of antioxidant genes PmGST and PmKatG, or in ROS accumulation. These suggest that alachlor may affect microalgal photosystem function, with little oxidative stress, causing severe physiological damage to the cells, and even cell death.
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Affiliation(s)
- Hansol Kim
- Department of Biotechnology, Sangmyung University, Seoul, South Korea
| | - Hui Wang
- Department of Biotechnology, Sangmyung University, Seoul, South Korea
| | - Sofia Abassi
- Department of Biotechnology, Sangmyung University, Seoul, South Korea
| | - Jang-Seu Ki
- Department of Biotechnology, Sangmyung University, Seoul, South Korea
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22
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He P, Cai X, Chen K, Fu X. Identification of small RNAs involved in nitrogen fixation in Anabaena sp. PCC 7120 based on RNA-seq under steady state conditions. ANN MICROBIOL 2020. [DOI: 10.1186/s13213-020-01557-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Abstract
Purpose
Anabaena sp. PCC7120 is a genetically tractable model organism for nitrogen fixation and photosynthesis research. The importance of small regulatory RNAs (sRNAs) as mediators of a number of cellular processes in bacteria has begun to be recognized. Bacterial sRNA binds to target genes through base pairing, and play a regulatory role. Many studies have shown that bacterial sRNA can regulate cell stress response, carbon and nitrogen fixation, and so on. However, little is known about sRNAs in Anabaena sp. PCC 7120 regarded to nitrogen fixation under later steady state.
Methods
To provide a comprehensive study of sRNAs in this model organism, the sRNA (< 200 nt) extracted from Anabaena sp. PCC 7120 under nitrogen step-down treatment of 12 days, together with the sRNA from the control, was analyzed using deep RNA sequencing. Possible target genes regulated by all identified putative sRNAs were predicted by IntaRNA and further analyzed for functional categorizations for biological pathways.
Result
Totally, 14,132 transcripts were produced from the de novo assembly. Among them, transcripts that are located either in the intergenic region or antisense strand were kept, which resulted in 1219 sRNA candidates, for further analysis. RPKM-based differential expression analysis showed that 418 sRNAs were significantly differentially expressed between the samples from control (nitrogen addition, N+) and nitrogen depletion, (N−). Among them, 303 sRNAs were significantly upregulated, whereas 115 sRNAs were significantly downregulated. RT-PCR of 18 randomly chosen sRNAs showed a similar pattern as RNA-seq result, which confirmed the reliability of the RNA-seq data. In addition, the possible target genes regulated by unique sRNAs of Anabaena sp. PCC 7120 under nitrogen addition (N+) condition or that under nitrogen depletion (N−) condition were analyzed for functional categorization and biological pathways, which provided the evidences that sRNAs were indeed involved in many different metabolic pathways.
Conclusion
The information from the present study provides a valuable reference for understanding the sRNA-mediated regulation of the nitrogen fixation in Anabaena PCC 7120 under steady state conditions.
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23
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Lambrecht SJ, Steglich C, Hess WR. A minimum set of regulators to thrive in the ocean. FEMS Microbiol Rev 2020; 44:232-252. [DOI: 10.1093/femsre/fuaa005] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Accepted: 02/19/2020] [Indexed: 12/25/2022] Open
Abstract
ABSTRACT
Marine cyanobacteria of the genus Prochlorococcus thrive in high cell numbers throughout the euphotic zones of the world's subtropical and tropical oligotrophic oceans, making them some of the most ecologically relevant photosynthetic microorganisms on Earth. The ecological success of these free-living phototrophs suggests that they are equipped with a regulatory system competent to address many different stress situations. However, Prochlorococcus genomes are compact and streamlined, with the majority encoding only five different sigma factors, five to six two-component systems and eight types of other transcriptional regulators. Here, we summarize the existing information about the functions of these protein regulators, about transcriptomic responses to defined stress conditions, and discuss the current knowledge about riboswitches, RNA-based regulation and the roles of certain metabolites as co-regulators. We focus on the best-studied isolate, Prochlorococcus MED4, but extend to other strains and ecotypes when appropriate, and we include some information gained from metagenomic and metatranscriptomic analyses.
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Affiliation(s)
- S Joke Lambrecht
- Genetics and Experimental Bioinformatics, Institute of Biology III, Faculty of Biology, University of Freiburg, Schänzlestr. 1, D-79104 Freiburg, Germany
| | - Claudia Steglich
- Genetics and Experimental Bioinformatics, Institute of Biology III, Faculty of Biology, University of Freiburg, Schänzlestr. 1, D-79104 Freiburg, Germany
| | - Wolfgang R Hess
- Genetics and Experimental Bioinformatics, Institute of Biology III, Faculty of Biology, University of Freiburg, Schänzlestr. 1, D-79104 Freiburg, Germany
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24
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Lejars M, Hajnsdorf E. The world of asRNAs in Gram-negative and Gram-positive bacteria. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2020; 1863:194489. [PMID: 31935527 DOI: 10.1016/j.bbagrm.2020.194489] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Accepted: 01/09/2020] [Indexed: 12/19/2022]
Abstract
Bacteria exhibit an amazing diversity of mechanisms controlling gene expression to both maintain essential functions and modulate accessory functions in response to environmental cues. Over the years, it has become clear that bacterial regulation of gene expression is still far from fully understood. This review focuses on antisense RNAs (asRNAs), a class of RNA regulators defined by their location in cis and their perfect complementarity with their targets, as opposed to small RNAs (sRNAs) which act in trans with only short regions of complementarity. For a long time, only few functional asRNAs in bacteria were known and were almost exclusively found on mobile genetic elements (MGEs), thus, their importance among the other regulators was underestimated. However, the extensive application of transcriptomic approaches has revealed the ubiquity of asRNAs in bacteria. This review aims to present the landscape of studied asRNAs in bacteria by comparing 67 characterized asRNAs from both Gram-positive and Gram-negative bacteria. First we describe the inherent ambiguity in the existence of asRNAs in bacteria, second, we highlight their diversity and their involvement in all aspects of bacterial life. Finally we compare their location and potential mode of action toward their target between Gram-negative and Gram-positive bacteria and present tendencies and exceptions that could lead to a better understanding of asRNA functions.
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Affiliation(s)
- Maxence Lejars
- UMR8261, CNRS, Université de Paris, Institut de Biologie Physico-Chimique, 75005 Paris, France.
| | - Eliane Hajnsdorf
- UMR8261, CNRS, Université de Paris, Institut de Biologie Physico-Chimique, 75005 Paris, France.
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25
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Muro-Pastor AM, Hess WR. Regulatory RNA at the crossroads of carbon and nitrogen metabolism in photosynthetic cyanobacteria. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2019; 1863:194477. [PMID: 31884117 DOI: 10.1016/j.bbagrm.2019.194477] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2019] [Revised: 12/16/2019] [Accepted: 12/22/2019] [Indexed: 12/17/2022]
Abstract
Cyanobacteria are photosynthetic bacteria that populate widely different habitats. Accordingly, cyanobacteria exhibit a wide spectrum of lifestyles, physiologies, and morphologies and possess genome sizes and gene numbers which may vary by up to a factor of ten within the phylum. Consequently, large differences exist between individual species in the size and complexity of their regulatory networks. Several non-coding RNAs have been identified that play crucial roles in the acclimation responses of cyanobacteria to changes in the environment. Some of these regulatory RNAs are conserved throughout the cyanobacterial phylum, while others exist only in a few taxa. Here we give an overview on characterized regulatory RNAs in cyanobacteria, with a focus on regulators of photosynthesis, carbon and nitrogen metabolism. However, chances are high that these regulators represent just the tip of the iceberg.
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Affiliation(s)
- Alicia M Muro-Pastor
- Instituto de Bioquímica Vegetal y Fotosíntesis, Consejo Superior de Investigaciones Científicas and Universidad de Sevilla, Américo Vespucio 49, E-41092 Sevilla, Spain
| | - Wolfgang R Hess
- University of Freiburg, Faculty of Biology, Genetics and Experimental Bioinformatics, Schänzlestr. 1, D-79104 Freiburg, Germany; University of Freiburg, Freiburg Institute for Advanced Studies, Albertstr. 19, D-79104 Freiburg, Germany.
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26
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Olmedo-Verd E, Brenes-Álvarez M, Vioque A, Muro-Pastor AM. A Heterocyst-Specific Antisense RNA Contributes to Metabolic Reprogramming in Nostoc sp. PCC 7120. PLANT & CELL PHYSIOLOGY 2019; 60:1646-1655. [PMID: 31093664 DOI: 10.1093/pcp/pcz087] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Accepted: 04/28/2019] [Indexed: 06/09/2023]
Abstract
Upon nitrogen deficiency, some filamentous cyanobacteria differentiate specialized cells, called heterocysts, devoted to N2 fixation. Heterocysts appear regularly spaced along the filaments and exhibit structural and metabolic adaptations, such as loss of photosynthetic CO2 fixation or increased respiration, to provide a proper microaerobic environment for its specialized function. Heterocyst development is under transcriptional control of the global nitrogen regulator NtcA and the specific regulator HetR. Transcription of a large number of genes is induced or repressed upon nitrogen deficiency specifically in cells undergoing differentiation. In recent years, the HetR regulon has been described to include heterocyst-specific trans-acting small RNAs and antisense RNAs (asRNAs), suggesting that there is an additional layer of post-transcriptional regulation involved in heterocyst development. Here, we characterize in the cyanobacterium Nostoc (Anabaena) sp. PCC 7120 an asRNA, that we call as_glpX, transcribed within the glpX gene encoding the Calvin cycle bifunctional enzyme sedoheptulose-1,7-bisphosphatase/fructose-1,6-bisphosphatase (SBPase). Transcription of as_glpX is restricted to heterocysts and is induced very early during the process of differentiation. Expression of as_glpX RNA promotes the cleavage of the glpX mRNA by RNase III, resulting in a reduced amount of SBPase. Therefore, the early expression of this asRNA could contribute to the quick shut-down of CO2 fixation in those cells in the filament that are undergoing differentiation into heterocysts. In summary, as_glpX is the first naturally occurring asRNA shown to rapidly and dynamically regulate metabolic transformation in Nostoc heterocysts. The use of antisense transcripts to manipulate gene expression specifically in heterocysts could became a useful tool for metabolic engineering in cyanobacteria.
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Affiliation(s)
- Elvira Olmedo-Verd
- Instituto de Bioquímica Vegetal y Fotosíntesis, Universidad de Sevilla and CSIC, Américo Vespucio 49, 41092 Sevilla, Spain
| | - Manuel Brenes-Álvarez
- Instituto de Bioquímica Vegetal y Fotosíntesis, Universidad de Sevilla and CSIC, Américo Vespucio 49, 41092 Sevilla, Spain
| | - Agustín Vioque
- Instituto de Bioquímica Vegetal y Fotosíntesis, Universidad de Sevilla and CSIC, Américo Vespucio 49, 41092 Sevilla, Spain
| | - Alicia M Muro-Pastor
- Instituto de Bioquímica Vegetal y Fotosíntesis, Universidad de Sevilla and CSIC, Américo Vespucio 49, 41092 Sevilla, Spain
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Abstract
As the transcriptional and post-transcriptional regulators of gene expression, small RNAs (sRNAs) play important roles in every domain of life in organisms. It has been discovered gradually that bacteria possess multiple means of gene regulation using RNAs. They have been continuously used as model organisms for photosynthesis, metabolism, biotechnology, evolution, and nitrogen fixation for many decades. Cyanobacteria, one of the most ancient life forms, constitute all kinds of photoautotrophic bacteria and exist in almost any environment on this planet. It is believed that a complex RNA-based regulatory mechanism functions in cyanobacteria to help them adapt to changes and stresses in diverse environments. Although lagging far behind other model microorganisms, such as yeast and Escherichia coli, more and more non-coding regulatory sRNAs have been recognized in cyanobacteria during the past decades. In this article, by focusing on cyanobacterial sRNAs, the approaches for detection and targeting of sRNAs will be summarized, four major mechanisms and regulatory functions will be generalized, eight types of cis-encoded sRNA and four types of trans-encoded sRNAs will be reviewed in detail, and their possible physiological functions will be further discussed.
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Affiliation(s)
- Jinlu Hu
- School of Life Sciences, Northwestern Polytechnical University, Xi'an, China
| | - Qiang Wang
- Key Laboratory of Algal Biology, Institute of Hydrobiology, The Chinese Academy of Sciences, Wuhan, China.,University of the Chinese Academy of Sciences, Beijing, China
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28
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Abstract
ABSTRACT
Although bacterial genomes are usually densely protein-coding, genome-wide mapping approaches of transcriptional start sites revealed that a significant fraction of the identified promoters drive the transcription of noncoding RNAs. These can be
trans
-acting RNAs, mainly originating from intergenic regions and, in many studied examples, possessing regulatory functions. However, a significant fraction of these noncoding RNAs consist of natural antisense transcripts (asRNAs), which overlap other transcriptional units. Naturally occurring asRNAs were first observed to play a role in bacterial plasmid replication and in bacteriophage λ more than 30 years ago. Today’s view is that asRNAs abound in all three domains of life. There are several examples of asRNAs in bacteria with clearly defined functions. Nevertheless, many asRNAs appear to result from pervasive initiation of transcription, and some data point toward global functions of such widespread transcriptional activity, explaining why the search for a specific regulatory role is sometimes futile. In this review, we give an overview about the occurrence of antisense transcription in bacteria, highlight particular examples of functionally characterized asRNAs, and discuss recent evidence pointing at global relevance in RNA processing and transcription-coupled DNA repair.
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Bi Y, Pei G, Sun T, Chen Z, Chen L, Zhang W. Regulation Mechanism Mediated by Trans-Encoded sRNA Nc117 in Short Chain Alcohols Tolerance in Synechocystis sp. PCC 6803. Front Microbiol 2018; 9:863. [PMID: 29780373 PMCID: PMC5946031 DOI: 10.3389/fmicb.2018.00863] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Accepted: 04/13/2018] [Indexed: 11/13/2022] Open
Abstract
Microbial small RNAs (sRNAs) play essential roles against many stress conditions in cyanobacteria. However, little is known on their regulatory mechanisms on biofuels tolerance. In our previous sRNA analysis, a trans-encoded sRNA Nc117 was found involved in the tolerance to ethanol and 1-butanol in Synechocystis sp. PCC 6803. However, its functional mechanism is yet to be determined. In this study, functional characterization of sRNA Nc117 was performed. Briefly, the exact length of the trans-encoded sRNA Nc117 was determined to be 102 nucleotides using 3′ RACE, and the positive regulation of Nc117 on short chain alcohols tolerance was further confirmed. Then, computational target prediction and transcriptomic analysis were integrated to explore the potential targets of Nc117. A total of 119 up-regulated and 116 down-regulated genes were identified in nc117 overexpression strain compared with the wild type by comparative transcriptomic analysis, among which the upstream regions of five genes were overlapped with those predicted by computational target approach. Based on the phenotype analysis of gene deletion and overexpression strains under short chain alcohols stress, one gene slr0007 encoding D-glycero-alpha-D-manno-heptose 1-phosphate guanylyltransferase was determined as a potential target of Nc117, suggesting that the synthesis of LPS or S-layer glycoprotein may be responsible for the tolerance enhancement. As the first reported trans-encoded sRNA positively regulating biofuels tolerance in cyanobacteria, this study not only provided evidence for a new regulatory mechanism of trans-encoded sRNA in cyanobacteria, but also valuable information for rational construction of high-tolerant cyanobacterial chassis.
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Affiliation(s)
- Yanqi Bi
- Laboratory of Synthetic Microbiology, School of Chemical Engineering and Technology, Tianjin University, Tianjin, China.,Key Laboratory of Systems Bioengineering, Ministry of Education of the People's Republic of China, Tianjin, China.,Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, China
| | - Guangsheng Pei
- Laboratory of Synthetic Microbiology, School of Chemical Engineering and Technology, Tianjin University, Tianjin, China.,Key Laboratory of Systems Bioengineering, Ministry of Education of the People's Republic of China, Tianjin, China.,Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, China
| | - Tao Sun
- Laboratory of Synthetic Microbiology, School of Chemical Engineering and Technology, Tianjin University, Tianjin, China.,Key Laboratory of Systems Bioengineering, Ministry of Education of the People's Republic of China, Tianjin, China.,Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, China
| | - Zixi Chen
- Laboratory of Synthetic Microbiology, School of Chemical Engineering and Technology, Tianjin University, Tianjin, China.,Key Laboratory of Systems Bioengineering, Ministry of Education of the People's Republic of China, Tianjin, China.,Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, China
| | - Lei Chen
- Laboratory of Synthetic Microbiology, School of Chemical Engineering and Technology, Tianjin University, Tianjin, China.,Key Laboratory of Systems Bioengineering, Ministry of Education of the People's Republic of China, Tianjin, China.,Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, China
| | - Weiwen Zhang
- Laboratory of Synthetic Microbiology, School of Chemical Engineering and Technology, Tianjin University, Tianjin, China.,Key Laboratory of Systems Bioengineering, Ministry of Education of the People's Republic of China, Tianjin, China.,Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, China.,Center for Biosafety Research and Strategy, Tianjin University, Tianjin, China
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Hu J, Zhan J, Chen H, He C, Cang H, Wang Q. The Small Regulatory Antisense RNA PilR Affects Pilus Formation and Cell Motility by Negatively Regulating pilA11 in Synechocystis sp. PCC 6803. Front Microbiol 2018; 9:786. [PMID: 29740417 PMCID: PMC5924778 DOI: 10.3389/fmicb.2018.00786] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2018] [Accepted: 04/06/2018] [Indexed: 01/19/2023] Open
Abstract
Pili are found on the surface of many bacteria and play important roles in cell motility, pathogenesis, biofilm formation, and sensing and reacting to environmental changes. Cell motility in the model cyanobacterium Synechocystis sp. PCC 6803 relies on expression of the putative pilA9-pilA10-pilA11-slr2018 operon. In this study, we identified the antisense RNA PilR encoded in the noncoding strand of the prepilin-encoding gene pilA11. Analysis of overexpressor [PilR(+)] and suppressor [PilR(-)] mutant strains revealed that PilR is a direct negative regulator of PilA11 protein. Although overexpression of PilR did not affect cell growth, it greatly reduced levels of pilA11 mRNA and protein and decreased both the thickness and number of pili, resulting in limited cell motility and small, distinct colonies. Suppression of PilR had the opposite effect. A hypothetical model on the regulation of pilA9-pilA10-pilA11-slr2018 operon expression by PilR was proposed. These results add a layer of complexity to the mechanisms controlling pilA11 gene expression and cell motility, and provide novel insights into how sRNA and the intergenic region secondary structures can work together to discoordinatly regulate target gene in an operon in cyanobacterium.
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Affiliation(s)
- Jinlu Hu
- School of Life Sciences, Northwestern Polytechnical University, Xi'an, China
| | - Jiao Zhan
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
| | - Hui Chen
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China.,Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology of China, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
| | - Chenliu He
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
| | - Huaixing Cang
- School of Life Sciences, Northwestern Polytechnical University, Xi'an, China
| | - Qiang Wang
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
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The host-encoded RNase E endonuclease as the crRNA maturation enzyme in a CRISPR-Cas subtype III-Bv system. Nat Microbiol 2018; 3:367-377. [PMID: 29403013 DOI: 10.1038/s41564-017-0103-5] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Accepted: 12/20/2017] [Indexed: 02/08/2023]
Abstract
Specialized RNA endonucleases for the maturation of clustered regularly interspaced short palindromic repeat (CRISPR)-derived RNAs (crRNAs) are critical in CRISPR-CRISPR-associated protein (Cas) defence mechanisms. The Cas6 and Cas5d enzymes are the RNA endonucleases in many class 1 CRISPR-Cas systems. In some class 2 systems, maturation and effector functions are combined within a single enzyme or maturation proceeds through the combined actions of RNase III and trans-activating CRISPR RNAs (tracrRNAs). Three separate CRISPR-Cas systems exist in the cyanobacterium Synechocystis sp. PCC 6803. Whereas Cas6-type enzymes act in two of these systems, the third, which is classified as subtype III-B variant (III-Bv), lacks cas6 homologues. Instead, the maturation of crRNAs proceeds through the activity of endoribonuclease E, leaving unusual 13- and 14-nucleotide-long 5'-handles. Overexpression of RNase E leads to overaccumulation and knock-down to the reduced accumulation of crRNAs in vivo, suggesting that RNase E is the limiting factor for CRISPR complex formation. Recognition by RNase E depends on a stem-loop in the CRISPR repeat, whereas base substitutions at the cleavage site trigger the appearance of secondary products, consistent with a two-step recognition and cleavage mechanism. These results suggest the adaptation of an otherwise very conserved housekeeping enzyme to accommodate new substrates and illuminate the impressive plasticity of CRISPR-Cas systems that enables them to function in particular genomic environments.
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32
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Puxty RJ, Evans DJ, Millard AD, Scanlan DJ. Energy limitation of cyanophage development: implications for marine carbon cycling. ISME JOURNAL 2018; 12:1273-1286. [PMID: 29379179 PMCID: PMC5931967 DOI: 10.1038/s41396-017-0043-3] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/07/2017] [Revised: 11/25/2017] [Accepted: 12/09/2017] [Indexed: 11/16/2022]
Abstract
Marine cyanobacteria are responsible for ~25% of the fixed carbon that enters the ocean biosphere. It is thought that abundant co-occurring viruses play an important role in regulating population dynamics of cyanobacteria and thus the cycling of carbon in the oceans. Despite this, little is known about how viral infections ‘play-out’ in the environment, particularly whether infections are resource or energy limited. Photoautotrophic organisms represent an ideal model to test this since available energy is modulated by the incoming light intensity through photophosphorylation. Therefore, we exploited phototrophy of the environmentally relevant marine cyanobacterium Synechococcus and monitored growth of a cyanobacterial virus (cyanophage). We found that light intensity has a marked effect on cyanophage infection dynamics, but that this is not manifest by a change in DNA synthesis. Instead, cyanophage development appears energy limited for the synthesis of proteins required during late infection. We posit that acquisition of auxiliary metabolic genes (AMGs) involved in light-dependent photosynthetic reactions acts to overcome this limitation. We show that cyanophages actively modulate expression of these AMGs in response to light intensity and provide evidence that such regulation may be facilitated by a novel mechanism involving light-dependent splicing of a group I intron in a photosynthetic AMG. Altogether, our data offers a mechanistic link between diurnal changes in irradiance and observed community level responses in metabolism, i.e., through an irradiance-dependent, viral-induced release of dissolved organic matter (DOM).
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Affiliation(s)
- Richard J Puxty
- School of Life Sciences, University of Warwick, Coventry, West Midlands, CV4 7AL, UK
| | - David J Evans
- School of Biology and BSRC, Biomolecular Sciences Building, North Haugh, St Andrews, KY16 9AJ, UK
| | - Andrew D Millard
- Department of Infection, Immunity and Inflammation, University of Leicester, Leicester, LE1 9HNL, UK
| | - David J Scanlan
- School of Life Sciences, University of Warwick, Coventry, West Midlands, CV4 7AL, UK.
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33
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Wang B, Eckert C, Maness PC, Yu J. A Genetic Toolbox for Modulating the Expression of Heterologous Genes in the Cyanobacterium Synechocystis sp. PCC 6803. ACS Synth Biol 2018; 7:276-286. [PMID: 29232504 DOI: 10.1021/acssynbio.7b00297] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Cyanobacteria, genetic models for photosynthesis research for decades, have recently become attractive hosts for producing renewable fuels and chemicals, owing to their genetic tractability, relatively fast growth, and their ability to utilize sunlight, fix carbon dioxide, and in some cases, fix nitrogen. Despite significant advances, there is still an urgent demand for synthetic biology tools in order to effectively manipulate genetic circuits in cyanobacteria. In this study, we have compared a total of 17 natural and chimeric promoters, focusing on expression of the ethylene-forming enzyme (EFE) in the cyanobacterium Synechocystis sp. PCC 6803. We report the finding that the E. coli σ70 promoter Ptrc is superior compared to the previously reported strong promoters, such as PcpcB and PpsbA, for the expression of EFE. In addition, we found that the EFE expression level was very sensitive to the 5'-untranslated region upstream of the open reading frame. A library of ribosome binding sites (RBSs) was rationally designed and was built and systematically characterized. We demonstrate a strategy complementary to the RBS prediction software to facilitate the rational design of an RBS library to optimize the gene expression in cyanobacteria. Our results show that the EFE expression level is dramatically enhanced through these synthetic biology tools and is no longer the rate-limiting step for cyanobacterial ethylene production. These systematically characterized promoters and the RBS design strategy can serve as useful tools to tune gene expression levels and to identify and mitigate metabolic bottlenecks in cyanobacteria.
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Affiliation(s)
- Bo Wang
- Biosciences
Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, Colorado 80401, United States
| | - Carrie Eckert
- Biosciences
Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, Colorado 80401, United States
- Renewable
and Sustainable Energy Institute, University of Colorado, Boulder, 4001 Discovery Drive, Boulder, Colorado 80303, United States
| | - Pin-Ching Maness
- Biosciences
Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, Colorado 80401, United States
| | - Jianping Yu
- Biosciences
Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, Colorado 80401, United States
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34
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Zhan J, Wang Q. Photoresponse Mechanism in Cyanobacteria: Key Factor in Photoautotrophic Chassis. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1080:75-96. [PMID: 30091092 DOI: 10.1007/978-981-13-0854-3_4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
As the oldest oxygenic photoautotrophic prokaryotes, cyanobacteria have outstanding advantages as the chassis cell in the research field of synthetic biology. Cognition of photosynthetic mechanism, including the photoresponse mechanism under high-light (HL) conditions, is important for optimization of the cyanobacteria photoautotrophic chassis for synthesizing biomaterials as "microbial cell factories." Cyanobacteria are well-established model organisms for the study of oxygenic photosynthesis and have evolved various acclimatory responses to HL conditions to protect the photosynthetic apparatus from photodamage. Here, we reviewed the latest progress in the mechanism of HL acclimation in cyanobacteria. The subsequent acclimatory responses and the corresponding molecular mechanisms are included: (1) acclimatory responses of PSII and PSI; (2) the degradation of phycobilisome; (3) induction of the photoprotective mechanisms such as state transitions, OCP-dependent non-photochemical quenching, and the induction of HLIP family; and (4) the regulation mechanisms of the gene expression under HL.
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Affiliation(s)
- Jiao Zhan
- Key Laboratory of Algal Biology, Institute of Hydrobiology, The Chinese Academy of Sciences, Wuhan, Hubei, China
| | - Qiang Wang
- Key Laboratory of Algal Biology, Institute of Hydrobiology, The Chinese Academy of Sciences, Wuhan, Hubei, China.
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35
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Song X, Wang Y, Diao J, Li S, Chen L, Zhang W. Direct Photosynthetic Production of Plastic Building Block Chemicals from CO 2. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1080:215-238. [PMID: 30091097 DOI: 10.1007/978-981-13-0854-3_9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Hydroxy acids have attracted attention as building block chemicals due to their roles as precursors for the production of various pharmaceuticals, vitamins, antibiotics, and flavor compounds as well as monomers for biodegradable plastic polyesters. The current approach to hydroxy acid production relies on nonrenewable fossil resources such as petroleum for raw materials, raising issues such as the rising costs of starting materials and environmental incompatibility. Recently, synthetic biology approaches based on the rational design and reconstruction of new biological systems were implemented to produce chemicals from a variety of renewable substrates. In addition to research using heterotrophic organic carbon-dependent Escherichia coli or yeasts, photosynthetic microorganisms such as cyanobacteria possessing the ability to absorb solar radiation and fix carbon dioxide (CO2) as a sole carbon source have been engineered into a new type of microbial cell factory to directly produce hydroxy acids from CO2. In this chapter, recent progress regarding the direct photosynthetic production of three important hydroxy acids-3-hydroxypropionate (3-HP), 3-hydroxybutyrate (3-HB), and 3-hydroxyvalerate (3-HV)-from CO2 in cyanobacteria is summarized and discussed.
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Affiliation(s)
- Xinyu Song
- Center for Biosafety Research and Strategy, Tianjin University, Tianjin, China.,Laboratory of Synthetic Microbiology, School of Chemical Engineering & Technology, Tianjin University, Tianjin, China.,Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin, China.,SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, China.,School of Environmental Science and Engineering, Tianjin University, Tianjin, China
| | - Yunpeng Wang
- Laboratory of Synthetic Microbiology, School of Chemical Engineering & Technology, Tianjin University, Tianjin, China.,Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin, China.,SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, China
| | - Jinjin Diao
- Laboratory of Synthetic Microbiology, School of Chemical Engineering & Technology, Tianjin University, Tianjin, China.,Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin, China.,SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, China
| | - Shubin Li
- Laboratory of Synthetic Microbiology, School of Chemical Engineering & Technology, Tianjin University, Tianjin, China.,Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin, China.,SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, China
| | - Lei Chen
- Laboratory of Synthetic Microbiology, School of Chemical Engineering & Technology, Tianjin University, Tianjin, China.,Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin, China.,SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, China
| | - Weiwen Zhang
- Center for Biosafety Research and Strategy, Tianjin University, Tianjin, China. .,Laboratory of Synthetic Microbiology, School of Chemical Engineering & Technology, Tianjin University, Tianjin, China. .,Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin, China. .,SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, China.
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Tan X, Hou S, Song K, Georg J, Klähn S, Lu X, Hess WR. The primary transcriptome of the fast-growing cyanobacterium Synechococcus elongatus UTEX 2973. BIOTECHNOLOGY FOR BIOFUELS 2018; 11:218. [PMID: 30127850 PMCID: PMC6091082 DOI: 10.1186/s13068-018-1215-8] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Accepted: 07/25/2018] [Indexed: 05/04/2023]
Abstract
BACKGROUND Cyanobacteria have shown promising potential for the production of various biofuels and chemical feedstocks. Synechococcus elongatus UTEX 2973 is a fast-growing strain with pronounced tolerance to high temperatures and illumination. Hence, this strain appears to be ideal for the development of photosynthetic biotechnology. However, molecular insights on how this strain can rapidly accumulate biomass and carbohydrates under high-light and high-temperature conditions are lacking. RESULTS Differential RNA-Sequencing (dRNA-Seq) enabled the genome-wide identification of 4808 transcription start sites (TSSs) in S. elongatus UTEX 2973 using a background reduction algorithm. High light promoted the transcription of genes associated with central metabolic pathways, whereas the highly induced small RNA (sRNA) PsrR1 likely contributed to the repression of phycobilisome genes and the accelerated glycogen accumulation rates measured under this condition. Darkness caused transcriptome remodeling with a decline in the expression of genes for carbon fixation and other major metabolic pathways and an increase in the expression of genes for glycogen catabolism and Calvin cycle inhibitor CP12. Two of the identified TSSs drive the transcription of highly abundant sRNAs in darkness. One of them is widely conserved throughout the cyanobacterial phylum. Its gene is fused to a protein-coding gene in some species, illustrating the evolutionary origin of sRNAs from an mRNA 3'-end. CONCLUSIONS Our comprehensive set of genome-wide mapped TSSs, sRNAs and promoter activities will be valuable for projects requiring precise information about the control of transcription aimed at metabolic engineering and the elucidation of stress acclimation mechanisms in this promising strain.
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Affiliation(s)
- Xiaoming Tan
- Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, No. 189 Songling Road, Qingdao, 266101 China
- Genetics and Experimental Bioinformatics, Faculty of Biology, University of Freiburg, Schänzlestraße 1, 79104 Freiburg, Germany
- Present Address: College of Life Sciences, Hubei University, 368 Youyi Avenue, Wuchang District, Wuhan, 430062 China
| | - Shengwei Hou
- Genetics and Experimental Bioinformatics, Faculty of Biology, University of Freiburg, Schänzlestraße 1, 79104 Freiburg, Germany
| | - Kuo Song
- Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, No. 189 Songling Road, Qingdao, 266101 China
- Genetics and Experimental Bioinformatics, Faculty of Biology, University of Freiburg, Schänzlestraße 1, 79104 Freiburg, Germany
| | - Jens Georg
- Genetics and Experimental Bioinformatics, Faculty of Biology, University of Freiburg, Schänzlestraße 1, 79104 Freiburg, Germany
| | - Stephan Klähn
- Genetics and Experimental Bioinformatics, Faculty of Biology, University of Freiburg, Schänzlestraße 1, 79104 Freiburg, Germany
- Department of Solar Materials, Helmholtz Centre for Environmental Research-UFZ, Permoserstraße 15, 04318 Leipzig, Germany
| | - Xuefeng Lu
- Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, No. 189 Songling Road, Qingdao, 266101 China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, No. 1 Wenhai Road, Qingdao, 266237 China
| | - Wolfgang R. Hess
- Genetics and Experimental Bioinformatics, Faculty of Biology, University of Freiburg, Schänzlestraße 1, 79104 Freiburg, Germany
- Freiburg Institute for Advanced Studies, University of Freiburg, Albertstraße 19, 79104 Freiburg, Germany
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Pei G, Sun T, Chen S, Chen L, Zhang W. Systematic and functional identification of small non-coding RNAs associated with exogenous biofuel stress in cyanobacterium Synechocystis sp. PCC 6803. BIOTECHNOLOGY FOR BIOFUELS 2017; 10:57. [PMID: 28286552 PMCID: PMC5341163 DOI: 10.1186/s13068-017-0743-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Accepted: 02/28/2017] [Indexed: 06/06/2023]
Abstract
BACKGROUND The unicellular model cyanobacterium Synechocystis sp. PCC 6803 is considered a promising microbial chassis for biofuel production. However, its low tolerance to biofuel toxicity limits its potential application. Although recent studies showed that bacterial small RNAs (sRNAs) play important roles in regulating cellular processes in response to various stresses, the role of sRNAs in resisting exogenous biofuels is yet to be determined. RESULTS Based on genome-wide sRNA sequencing combined with systematic analysis of previous transcriptomic and proteomic data under the same biofuel or environmental perturbations, we report the identification of 133 trans-encoded sRNA transcripts with high-resolution mapping of sRNAs in Synechocystis, including 23 novel sRNAs identified for the first time. In addition, according to quantitative expression analysis and sRNA regulatory network prediction, sRNAs potentially involved in biofuel tolerance were identified and functionally confirmed by constructing sRNA overexpression or suppression strains of Synechocystis. Notably, overexpression of sRNA Nc117 revealed an improved tolerance to ethanol and butanol, while suppression of Nc117 led to increased sensitivity. CONCLUSIONS The study provided the first comprehensive responses to exogenous biofuels at the sRNA level in Synechocystis and opens an avenue to engineering sRNA regulatory elements for improved biofuel tolerance in the cyanobacterium Synechocystis.
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Affiliation(s)
- Guangsheng Pei
- Laboratory of Synthetic Microbiology, School of Chemical Engineering & Technology, Tianjin University, Tianjin, 300072 People’s Republic of China
- Key Laboratory of Systems Bioengineering, Ministry of Education of China, Tianjin, 300072 People’s Republic of China
- Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, People’s Republic of China
| | - Tao Sun
- Laboratory of Synthetic Microbiology, School of Chemical Engineering & Technology, Tianjin University, Tianjin, 300072 People’s Republic of China
- Key Laboratory of Systems Bioengineering, Ministry of Education of China, Tianjin, 300072 People’s Republic of China
- Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, People’s Republic of China
| | - Shuo Chen
- Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, People’s Republic of China
| | - Lei Chen
- Laboratory of Synthetic Microbiology, School of Chemical Engineering & Technology, Tianjin University, Tianjin, 300072 People’s Republic of China
- Key Laboratory of Systems Bioengineering, Ministry of Education of China, Tianjin, 300072 People’s Republic of China
- Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, People’s Republic of China
| | - Weiwen Zhang
- Laboratory of Synthetic Microbiology, School of Chemical Engineering & Technology, Tianjin University, Tianjin, 300072 People’s Republic of China
- Key Laboratory of Systems Bioengineering, Ministry of Education of China, Tianjin, 300072 People’s Republic of China
- Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, People’s Republic of China
- Center for Biosafety Research and Strategy, Tianjin University, Tianjin, People’s Republic of China
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Sun T, Pei G, Wang J, Chen L, Zhang W. A novel small RNA CoaR regulates coenzyme A biosynthesis and tolerance of Synechocystis sp. PCC6803 to 1-butanol possibly via promoter-directed transcriptional silencing. BIOTECHNOLOGY FOR BIOFUELS 2017; 10:42. [PMID: 28239414 PMCID: PMC5319066 DOI: 10.1186/s13068-017-0727-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Accepted: 02/09/2017] [Indexed: 05/24/2023]
Abstract
BACKGROUND Microbial small RNAs (sRNAs) have been proposed as valuable regulatory elements for optimizing cellular metabolism for industrial purposes. However, little information is currently available on functional relevance of sRNAs to biofuels tolerance in cyanobacteria. RESULTS Here, we described the identification and functional characterization of a novel 124 nt sRNA Ncl1460 involved in tolerance to biofuel 1-butanol in Synechocystis sp. PCC 6803. The expression of Ncl1460 was verified by blotting assay and its length was determined through 3' RACE. Further analysis showed that Ncl1460 was a negative regulator of slr0847 (coaD) and slr0848 operon responsible for coenzyme A (CoA) synthesis possibly via promoter-directed transcriptional silencing mechanisms which has been widely discovered in eukaryote; thus Ncl1460 was designated as CoaR (CoA Biosynthesis Regulatory sRNA). The possible interaction between CoaR and target genes was suggested by CoA quantification and green fluorescent protein assays. Finally, a quantitative proteomics analysis showed that CoaR regulated tolerance to 1-butanol possibly by down-regulating CoA biosynthesis, resulting in a decrease of fatty acid metabolism and energy metabolism. CONCLUSIONS As the first reported sRNA involved CoA synthesis and 1-butanol tolerance in cyanobacteria, this study provides not only novel insights in regulating mechanisms of essential pathways in cyanobacteria, but also valuable target for biofuels tolerance and productivity modifications.
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Affiliation(s)
- Tao Sun
- Laboratory of Synthetic Microbiology, School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072 People’s Republic of China
- Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin, 300072 People’s Republic of China
- SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, 300072 People’s Republic of China
| | - Guangsheng Pei
- Laboratory of Synthetic Microbiology, School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072 People’s Republic of China
- Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin, 300072 People’s Republic of China
- SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, 300072 People’s Republic of China
| | - Jiangxin Wang
- Shenzhen Engineering Lab for Marine Algal Biotechnology, College of Life Science, Shenzhen University, Shenzhen, 518060 People’s Republic of China
| | - Lei Chen
- Laboratory of Synthetic Microbiology, School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072 People’s Republic of China
- Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin, 300072 People’s Republic of China
- SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, 300072 People’s Republic of China
| | - Weiwen Zhang
- Laboratory of Synthetic Microbiology, School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072 People’s Republic of China
- Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin, 300072 People’s Republic of China
- SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, 300072 People’s Republic of China
- Center for Biosafety Research and Strategy, Tianjin University, Tianjin, People’s Republic of China
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Hu J, Li T, Xu W, Zhan J, Chen H, He C, Wang Q. Small Antisense RNA RblR Positively Regulates RuBisCo in Synechocystis sp. PCC 6803. Front Microbiol 2017; 8:231. [PMID: 28261186 PMCID: PMC5306279 DOI: 10.3389/fmicb.2017.00231] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2016] [Accepted: 02/01/2017] [Indexed: 11/21/2022] Open
Abstract
Small regulatory RNAs (sRNAs) function as transcriptional and post-transcriptional regulators of gene expression in organisms from all domains of life. Cyanobacteria are thought to have developed a complex RNA-based regulatory mechanism. In the current study, by genome-wide analysis of differentially expressed small RNAs in Synechocystis sp. PCC 6803 under high light conditions, we discovered an asRNA (RblR) that is 113nt in length and completely complementary to its target gene rbcL, which encodes the large chain of RuBisCO, the enzyme that catalyzes carbon fixation. Further analysis of the RblR(+)/(−) mutants revealed that RblR acts as a positive regulator of rbcL under various stress conditions; Suppressing RblR adversely affects carbon assimilation and thus the yield, and those phenotypes of both the wild type and the overexpressor could be downgraded to the suppressor level by carbonate depletion, indicated a regulatory role of RblR in CO2 assimilation. In addition, a real-time expression platform in Escherichia coli was setup and which confirmed that RblR promoted the translation of the rbcL mRNA into the RbcL protein. The present study is the first report of a regulatory RNA that targets RbcL in Synechocystis sp. PCC 6803, and provides strong evidence that RblR regulates photosynthesis by positively modulating rbcL expression in Synechocystis.
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Affiliation(s)
- Jinlu Hu
- School of Life Sciences, Northwestern Polytechnical University Xi'an, China
| | - Tianpei Li
- Key Laboratory of Algal Biology, Institute of Hydrobiology, the Chinese Academy of SciencesWuhan, China; University of the Chinese Academy of SciencesBeijing, China
| | - Wen Xu
- Crop Designing Centre, Henan Academy of Agricultural Sciences Zhengzhou, China
| | - Jiao Zhan
- Key Laboratory of Algal Biology, Institute of Hydrobiology, the Chinese Academy of Sciences Wuhan, China
| | - Hui Chen
- Key Laboratory of Algal Biology, Institute of Hydrobiology, the Chinese Academy of Sciences Wuhan, China
| | - Chenliu He
- Key Laboratory of Algal Biology, Institute of Hydrobiology, the Chinese Academy of Sciences Wuhan, China
| | - Qiang Wang
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, the Chinese Academy of Sciences Wuhan, China
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Westermark S, Steuer R. Toward Multiscale Models of Cyanobacterial Growth: A Modular Approach. Front Bioeng Biotechnol 2016; 4:95. [PMID: 28083530 PMCID: PMC5183639 DOI: 10.3389/fbioe.2016.00095] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Accepted: 12/09/2016] [Indexed: 11/29/2022] Open
Abstract
Oxygenic photosynthesis dominates global primary productivity ever since its evolution more than three billion years ago. While many aspects of phototrophic growth are well understood, it remains a considerable challenge to elucidate the manifold dependencies and interconnections between the diverse cellular processes that together facilitate the synthesis of new cells. Phototrophic growth involves the coordinated action of several layers of cellular functioning, ranging from the photosynthetic light reactions and the electron transport chain, to carbon-concentrating mechanisms and the assimilation of inorganic carbon. It requires the synthesis of new building blocks by cellular metabolism, protection against excessive light, as well as diurnal regulation by a circadian clock and the orchestration of gene expression and cell division. Computational modeling allows us to quantitatively describe these cellular functions and processes relevant for phototrophic growth. As yet, however, computational models are mostly confined to the inner workings of individual cellular processes, rather than describing the manifold interactions between them in the context of a living cell. Using cyanobacteria as model organisms, this contribution seeks to summarize existing computational models that are relevant to describe phototrophic growth and seeks to outline their interactions and dependencies. Our ultimate aim is to understand cellular functioning and growth as the outcome of a coordinated operation of diverse yet interconnected cellular processes.
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Affiliation(s)
- Stefanie Westermark
- Fachinstitut für Theoretische Biologie (ITB), Institut für Biologie, Humboldt-Universität zu Berlin , Berlin , Germany
| | - Ralf Steuer
- Fachinstitut für Theoretische Biologie (ITB), Institut für Biologie, Humboldt-Universität zu Berlin , Berlin , Germany
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41
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Baumgartner D, Kopf M, Klähn S, Steglich C, Hess WR. Small proteins in cyanobacteria provide a paradigm for the functional analysis of the bacterial micro-proteome. BMC Microbiol 2016; 16:285. [PMID: 27894276 PMCID: PMC5126843 DOI: 10.1186/s12866-016-0896-z] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Accepted: 11/14/2016] [Indexed: 12/21/2022] Open
Abstract
Background Despite their versatile functions in multimeric protein complexes, in the modification of enzymatic activities, intercellular communication or regulatory processes, proteins shorter than 80 amino acids (μ-proteins) are a systematically underestimated class of gene products in bacteria. Photosynthetic cyanobacteria provide a paradigm for small protein functions due to extensive work on the photosynthetic apparatus that led to the functional characterization of 19 small proteins of less than 50 amino acids. In analogy, previously unstudied small ORFs with similar degrees of conservation might encode small proteins of high relevance also in other functional contexts. Results Here we used comparative transcriptomic information available for two model cyanobacteria, Synechocystis sp. PCC 6803 and Synechocystis sp. PCC 6714 for the prediction of small ORFs. We found 293 transcriptional units containing candidate small ORFs ≤80 codons in Synechocystis sp. PCC 6803, also including the known mRNAs encoding small proteins of the photosynthetic apparatus. From these transcriptional units, 146 are shared between the two strains, 42 are shared with the higher plant Arabidopsis thaliana and 25 with E. coli. To verify the existence of the respective μ-proteins in vivo, we selected five genes as examples to which a FLAG tag sequence was added and re-introduced them into Synechocystis sp. PCC 6803. These were the previously annotated gene ssr1169, two newly defined genes norf1 and norf4, as well as nsiR6(nitrogen stress-induced RNA 6) and hliR1(high light-inducible RNA 1) , which originally were considered non-coding. Upon activation of expression via the Cu2+.responsive petE promoter or from the native promoters, all five proteins were detected in Western blot experiments. Conclusions The distribution and conservation of these five genes as well as their regulation of expression and the physico-chemical properties of the encoded proteins underline the likely great bandwidth of small protein functions in bacteria and makes them attractive candidates for functional studies.
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Affiliation(s)
- Desiree Baumgartner
- University of Freiburg, Faculty of Biology, Genetics and Experimental Bioinformatics, Schänzlestr. 1, D-79104, Freiburg, Germany
| | - Matthias Kopf
- University of Freiburg, Faculty of Biology, Genetics and Experimental Bioinformatics, Schänzlestr. 1, D-79104, Freiburg, Germany.,Present Address: Molecular Health GmbH, Kurfürsten-Anlage 21, 69115, Heidelberg, Germany
| | - Stephan Klähn
- University of Freiburg, Faculty of Biology, Genetics and Experimental Bioinformatics, Schänzlestr. 1, D-79104, Freiburg, Germany
| | - Claudia Steglich
- University of Freiburg, Faculty of Biology, Genetics and Experimental Bioinformatics, Schänzlestr. 1, D-79104, Freiburg, Germany
| | - Wolfgang R Hess
- University of Freiburg, Faculty of Biology, Genetics and Experimental Bioinformatics, Schänzlestr. 1, D-79104, Freiburg, Germany.
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Englund E, Liang F, Lindberg P. Evaluation of promoters and ribosome binding sites for biotechnological applications in the unicellular cyanobacterium Synechocystis sp. PCC 6803. Sci Rep 2016; 6:36640. [PMID: 27857166 PMCID: PMC5114575 DOI: 10.1038/srep36640] [Citation(s) in RCA: 87] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2016] [Accepted: 10/17/2016] [Indexed: 01/21/2023] Open
Abstract
For effective metabolic engineering, a toolbox of genetic components that enables predictable control of gene expression is needed. Here we present a systematic study of promoters and ribosome binding sites in the unicellular cyanobacterium Synechocystis sp. PCC 6803. A set of metal ion inducible promoters from Synechocystis were compared to commonly used constitutive promoters, by measuring fluorescence of a reporter protein in a standardized setting to allow for accurate comparisons of promoter activity. The most versatile and useful promoter was found to be PnrsB, which from a relatively silent expression could be induced almost 40-fold, nearly up to the activity of the strong psbA2 promoter. By varying the concentrations of the two metal ion inducers Ni2+ and Co2+, expression from the promoter was highly tunable, results that were reproduced with PnrsB driving ethanol production. The activities of several ribosomal binding sites were also measured, and tested in parallel in Synechocystis and Escherichia coli. The results of the study add useful information to the Synechocystis genetic toolbox for biotechnological applications.
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Affiliation(s)
- Elias Englund
- Department of Chemistry - Ångström, Uppsala University, Box 523, SE-751 20 Uppsala, Sweden
| | - Feiyan Liang
- Department of Chemistry - Ångström, Uppsala University, Box 523, SE-751 20 Uppsala, Sweden
| | - Pia Lindberg
- Department of Chemistry - Ångström, Uppsala University, Box 523, SE-751 20 Uppsala, Sweden
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de Porcellinis AJ, Klähn S, Rosgaard L, Kirsch R, Gutekunst K, Georg J, Hess WR, Sakuragi Y. The Non-Coding RNA Ncr0700/PmgR1 is Required for Photomixotrophic Growth and the Regulation of Glycogen Accumulation in the Cyanobacterium Synechocystis sp. PCC 6803. PLANT & CELL PHYSIOLOGY 2016; 57:2091-2103. [PMID: 27440548 DOI: 10.1093/pcp/pcw128] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Accepted: 07/12/2016] [Indexed: 06/06/2023]
Abstract
Carbohydrate metabolism is a tightly regulated process in photosynthetic organisms. In the cyanobacterium Synechocystis sp. PCC 6803, the photomixotrophic growth protein A (PmgA) is involved in the regulation of glucose and storage carbohydrate (i.e. glycogen) metabolism, while its biochemical activity and possible factors acting downstream of PmgA are unknown. Here, a genome-wide microarray analysis of a ΔpmgA strain identified the expression of 36 protein-coding genes and 42 non-coding transcripts as significantly altered. From these, the non-coding RNA Ncr0700 was identified as the transcript most strongly reduced in abundance. Ncr0700 is widely conserved among cyanobacteria. In Synechocystis its expression is inversely correlated with light intensity. Similarly to a ΔpmgA mutant, a Δncr0700 deletion strain showed an approximately 2-fold increase in glycogen content under photoautotrophic conditions and wild-type-like growth. Moreover, its growth was arrested by 38 h after a shift to photomixotrophic conditions. Ectopic expression of Ncr0700 in Δncr0700 and ΔpmgA restored the glycogen content and photomixotrophic growth to wild-type levels. These results indicate that Ncr0700 is required for photomixotrophic growth and the regulation of glycogen accumulation, and acts downstream of PmgA. Hence Ncr0700 is renamed here as PmgR1 for photomixotrophic growth RNA 1.
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Affiliation(s)
- Alice J de Porcellinis
- Copenhagen Plant Science Center, Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Frederiksberg, DK-1871, Denmark
- These authors contributed equally to this work
| | - Stephan Klähn
- Genetics and Experimental Bioinformatics, Faculty of Biology, University of Freiburg, Schänzlestr. 1, Freiburg, D-79104, Germany
- These authors contributed equally to this work
| | - Lisa Rosgaard
- Copenhagen Plant Science Center, Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Frederiksberg, DK-1871, Denmark
- Present address: R&D Renescience Thermal Power, DONG Energy, Skærbæk-7000 Fredericia, Denmark
| | - Rebekka Kirsch
- Botanical Institute, Christian-Albrechts-University, Am Botanischen Garten 5, Kiel, D-24118, Germany
| | - Kirstin Gutekunst
- Botanical Institute, Christian-Albrechts-University, Am Botanischen Garten 5, Kiel, D-24118, Germany
| | - Jens Georg
- Genetics and Experimental Bioinformatics, Faculty of Biology, University of Freiburg, Schänzlestr. 1, Freiburg, D-79104, Germany
| | - Wolfgang R Hess
- Genetics and Experimental Bioinformatics, Faculty of Biology, University of Freiburg, Schänzlestr. 1, Freiburg, D-79104, Germany
| | - Yumiko Sakuragi
- Copenhagen Plant Science Center, Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Frederiksberg, DK-1871, Denmark
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Chromatin remodelling and antisense-mediated up-regulation of the developmental switch gene eud-1 control predatory feeding plasticity. Nat Commun 2016; 7:12337. [PMID: 27487725 PMCID: PMC4976200 DOI: 10.1038/ncomms12337] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Accepted: 06/23/2016] [Indexed: 12/27/2022] Open
Abstract
Phenotypic plasticity has been suggested to act through developmental switches, but little is known about associated molecular mechanisms. In the nematode Pristionchus pacificus, the sulfatase eud-1 was identified as part of a developmental switch controlling mouth-form plasticity governing a predatory versus bacteriovorous mouth-form decision. Here we show that mutations in the conserved histone-acetyltransferase Ppa-lsy-12 and the methyl-binding-protein Ppa-mbd-2 mimic the eud-1 phenotype, resulting in the absence of one mouth-form. Mutations in both genes cause histone modification defects and reduced eud-1 expression. Surprisingly, Ppa-lsy-12 mutants also result in the down-regulation of an antisense-eud-1 RNA. eud-1 and antisense-eud-1 are co-expressed and further experiments suggest that antisense-eud-1 acts through eud-1 itself. Indeed, overexpression of the antisense-eud-1 RNA increases the eud-1-sensitive mouth-form and extends eud-1 expression. In contrast, this effect is absent in eud-1 mutants indicating that antisense-eud-1 positively regulates eud-1. Thus, chromatin remodelling and antisense-mediated up-regulation of eud-1 control feeding plasticity in Pristionchus.
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Sinetova MA, Los DA. New insights in cyanobacterial cold stress responses: Genes, sensors, and molecular triggers. Biochim Biophys Acta Gen Subj 2016; 1860:2391-2403. [PMID: 27422804 DOI: 10.1016/j.bbagen.2016.07.006] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Revised: 06/16/2016] [Accepted: 07/09/2016] [Indexed: 10/21/2022]
Abstract
BACKGROUND Cold stress strongly induces the expression of ~100 genes in cyanobacteria. Some of these genes are necessary to protect cellular functions by adjustment of membranes, as well as transcriptional and translational machineries. About a half of cold-induced genes are not functionally characterized. A part of cold-induced genes is under control of a two-component regulatory system, consisting of histidine kinase Hik33 and response regulator Rre26. The mechanism(s) that control another part of cold-inducible genes are still unknown. SCOPE OF REVIEW The aim of this review is to summarise the latest findings in cyanobacterial cold-stress responses including transcriptomics, cold sensing, and molecular triggers. MAJOR CONCLUSIONS A feedback loop between the membrane fluidity and transcription of genes for fatty acid desaturases operates via the transmembrane red-light-activated cold sensor Hik33, which perceives cold-induced membrane rigidification as a change in its thickness. The cold-induced kinase activity of Hik33 is facilitated by interaction with a small protein, Ssl3451 - the third contributor to a canonical two-component regulatory system, which may explain the ability of some cyanobacterial histidine kinases to interact with different response regulators under different stress conditions. Other regulatory systems that control cold-stress responses operate via Ser/Thr protein kinase, SpkE, and via temperature-dependent changes in DNA supercoiling. Transcriptomic analysis shows that universal triggers of stress responses are reactive oxygen species and changes in redox status of plastoquinone pool. GENERAL SIGNIFICANCE Deeper understanding of molecular mechanisms of temperature sensing and regulation of cold-stress responses in photosynthetic cells provide a background for generation of cold-resistant crops.
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Affiliation(s)
- Maria A Sinetova
- Institute of Plant Physiology, Russian Academy of Sciences, Botanicheskaya Street 35, 127276 Moscow, Russian Federation
| | - Dmitry A Los
- Institute of Plant Physiology, Russian Academy of Sciences, Botanicheskaya Street 35, 127276 Moscow, Russian Federation.
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Lidbury I, Kröber E, Zhang Z, Zhu Y, Murrell JC, Chen Y, Schäfer H. A mechanism for bacterial transformation of dimethylsulfide to dimethylsulfoxide: a missing link in the marine organic sulfur cycle. Environ Microbiol 2016; 18:2754-66. [PMID: 27114231 DOI: 10.1111/1462-2920.13354] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Accepted: 04/19/2016] [Indexed: 11/30/2022]
Abstract
The volatile organosulfur compound, dimethylsulfide (DMS), plays an important role in climate regulation and global sulfur biogeochemical cycles. Microbial oxidation of DMS to dimethylsulfoxide (DMSO) represents a major sink of DMS in surface seawater, yet the underlying molecular mechanisms and key microbial taxa involved are not known. Here, we reveal that Ruegeria pomeroyi, a model marine heterotrophic bacterium, can oxidize DMS to DMSO using trimethylamine monooxygenase (Tmm). Purified Tmm oxidizes DMS to DMSO at a 1:1 ratio. Mutagenesis of the tmm gene in R. pomeroyi completely abolished DMS oxidation and subsequent DMSO formation. Expression of Tmm and DMS oxidation in R. pomeroyi is methylamine-dependent and regulated at the post-transcriptional level. Considering that Tmm is present in approximately 20% of bacterial cells inhabiting marine surface waters, particularly the marine Roseobacter clade and the SAR11 clade, our observations contribute to a mechanistic understanding of biological DMSO production in surface seawater.
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Affiliation(s)
- Ian Lidbury
- School of Life Sciences, Gibbet Hill Campus, University of Warwick, Coventry, CV4 7AL, UK
| | - Eileen Kröber
- School of Life Sciences, Gibbet Hill Campus, University of Warwick, Coventry, CV4 7AL, UK
| | - Zhidong Zhang
- Institute of Microbiology, Xinjiang Academy of Agriculture Sciences, Urumqi, 830091, China
| | - Yijun Zhu
- School of Life Sciences, Gibbet Hill Campus, University of Warwick, Coventry, CV4 7AL, UK
| | - J Colin Murrell
- School of Environmental Sciences, University of East Anglia, Norwich Research Park, NR4 7TJ, Norwich, UK
| | - Yin Chen
- School of Life Sciences, Gibbet Hill Campus, University of Warwick, Coventry, CV4 7AL, UK
| | - Hendrik Schäfer
- School of Life Sciences, Gibbet Hill Campus, University of Warwick, Coventry, CV4 7AL, UK
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Vishnu US, Sankarasubramanian J, Gunasekaran P, Sridhar J, Rajendhran J. Omics of Brucella: Species-Specific sRNA-Mediated Gene Ontology Regulatory Networks Identified by Computational Biology. OMICS-A JOURNAL OF INTEGRATIVE BIOLOGY 2016; 20:375-85. [DOI: 10.1089/omi.2016.0034] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Affiliation(s)
- Udayakumar S. Vishnu
- Department of Genetics, School of Biological Sciences, Madurai Kamaraj University, Madurai, India
| | | | - Paramasamy Gunasekaran
- Department of Genetics, School of Biological Sciences, Madurai Kamaraj University, Madurai, India
| | - Jayavel Sridhar
- Department of Biotechnology, DDE, Madurai Kamaraj University, Madurai, India
| | - Jeyaprakash Rajendhran
- Department of Genetics, School of Biological Sciences, Madurai Kamaraj University, Madurai, India
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Čuklina J, Hahn J, Imakaev M, Omasits U, Förstner KU, Ljubimov N, Goebel M, Pessi G, Fischer HM, Ahrens CH, Gelfand MS, Evguenieva-Hackenberg E. Genome-wide transcription start site mapping of Bradyrhizobium japonicum grown free-living or in symbiosis - a rich resource to identify new transcripts, proteins and to study gene regulation. BMC Genomics 2016; 17:302. [PMID: 27107716 PMCID: PMC4842269 DOI: 10.1186/s12864-016-2602-9] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Accepted: 03/25/2016] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND Differential RNA-sequencing (dRNA-seq) is indispensable for determination of primary transcriptomes. However, using dRNA-seq data to map transcriptional start sites (TSSs) and promoters genome-wide is a bioinformatics challenge. We performed dRNA-seq of Bradyrhizobium japonicum USDA 110, the nitrogen-fixing symbiont of soybean, and developed algorithms to map TSSs and promoters. RESULTS A specialized machine learning procedure for TSS recognition allowed us to map 15,923 TSSs: 14,360 in free-living bacteria, 4329 in symbiosis with soybean and 2766 in both conditions. Further, we provide proteomic evidence for 4090 proteins, among them 107 proteins corresponding to new genes and 178 proteins with N-termini different from the existing annotation (72 and 109 of them with TSS support, respectively). Guided by proteomics evidence, previously identified TSSs and TSSs experimentally validated here, we assign a score threshold to flag 14 % of the mapped TSSs as a class of lower confidence. However, this class of lower confidence contains valid TSSs of low-abundant transcripts. Moreover, we developed a de novo algorithm to identify promoter motifs upstream of mapped TSSs, which is publicly available, and found motifs mainly used in symbiosis (similar to RpoN-dependent promoters) or under both conditions (similar to RpoD-dependent promoters). Mapped TSSs and putative promoters, proteomic evidence and updated gene annotation were combined into an annotation file. CONCLUSIONS The genome-wide TSS and promoter maps along with the extended genome annotation of B. japonicum represent a valuable resource for future systems biology studies and for detailed analyses of individual non-coding transcripts and ORFs. Our data will also provide new insights into bacterial gene regulation during the agriculturally important symbiosis between rhizobia and legumes.
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Affiliation(s)
- Jelena Čuklina
- />AA Kharkevich Institute for Information Transmission Problems, Russian Academy of Sciences, Bolshoi Karetny pereulok 19, Moscow, 127051 Russia
- />Moscow Institute of Physics and Technology, Institutskiy pereulok 9, Dolgoprudnyy, Moscow region 141700 Russia
- />Present Address: Institute of Molecular Systems Biology, ETH Zürich, Auguste-Piccard Hof 1, CH-8093 Zürich, Switzerland
| | - Julia Hahn
- />Institute of Microbiology and Molecular Biology, University of Giessen, Heinrich-Buff-Ring 26-32, D-35392 Giessen, Germany
| | - Maxim Imakaev
- />Department of Physics, Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge, MA 02139 USA
| | - Ulrich Omasits
- />Agroscope, Institute for Plant Production Sciences, Research Group Molecular Diagnostics, Genomics and Bioinformatics & Swiss Institute of Bioinformatics (SIB), Schloss 1, CH-8820 Wädenswil, Switzerland
| | - Konrad U. Förstner
- />Core Unit Systems Medicine, University of Würzburg, Josef-Schneider-Str. 2 Bau D15, D-97080 Würzburg, Germany
| | - Nikolay Ljubimov
- />Lomonosov Moscow State University, Faculty of Computational Mathematics and Cybernetics, Leninskie Gory, 2-nd educational building, Moscow, 119991 Russia
| | - Melanie Goebel
- />Institute of Microbiology and Molecular Biology, University of Giessen, Heinrich-Buff-Ring 26-32, D-35392 Giessen, Germany
| | - Gabriella Pessi
- />ETH, Institute of Microbiology, Vladimir-Prelog-Weg 4, CH-8093 Zürich, Switzerland
- />Present Address: Department of Plant and Microbial Biology University of Zürich, Zollikerstrasse 107, CH-8008 Zürich, Switzerland
| | - Hans-Martin Fischer
- />ETH, Institute of Microbiology, Vladimir-Prelog-Weg 4, CH-8093 Zürich, Switzerland
| | - Christian H. Ahrens
- />Agroscope, Institute for Plant Production Sciences, Research Group Molecular Diagnostics, Genomics and Bioinformatics & Swiss Institute of Bioinformatics (SIB), Schloss 1, CH-8820 Wädenswil, Switzerland
| | - Mikhail S. Gelfand
- />AA Kharkevich Institute for Information Transmission Problems, Russian Academy of Sciences, Bolshoi Karetny pereulok 19, Moscow, 127051 Russia
- />Department of Bioengineering and Bioinformatics, Lomonosov Moscow State University, Vorobievy Gory 73-1, Moscow, 119991 Russia
| | - Elena Evguenieva-Hackenberg
- />Institute of Microbiology and Molecular Biology, University of Giessen, Heinrich-Buff-Ring 26-32, D-35392 Giessen, Germany
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Hernández-Prieto MA, Semeniuk TA, Giner-Lamia J, Futschik ME. The Transcriptional Landscape of the Photosynthetic Model Cyanobacterium Synechocystis sp. PCC6803. Sci Rep 2016; 6:22168. [PMID: 26923200 PMCID: PMC4770689 DOI: 10.1038/srep22168] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2015] [Accepted: 02/09/2016] [Indexed: 01/03/2023] Open
Abstract
Cyanobacteria exhibit a great capacity to adapt to different environmental conditions through changes in gene expression. Although this plasticity has been extensively studied in the model cyanobacterium Synechocystis sp. PCC 6803, a detailed analysis of the coordinated transcriptional adaption across varying conditions is lacking. Here, we report a meta-analysis of 756 individual microarray measurements conducted in 37 independent studies-the most comprehensive study of the Synechocystis transcriptome to date. Using stringent statistical evaluation, we characterized the coordinated adaptation of Synechocystis' gene expression on systems level. Evaluation of the data revealed that the photosynthetic apparatus is subjected to greater changes in expression than other cellular components. Nevertheless, network analyses indicated a significant degree of transcriptional coordination of photosynthesis and various metabolic processes, and revealed the tight co-regulation of components of photosystems I, II and phycobilisomes. Detailed inspection of the integrated data led to the discovery a variety of regulatory patterns and novel putative photosynthetic genes. Intriguingly, global clustering analyses suggested contrasting transcriptional response of metabolic and regulatory genes stress to conditions. The integrated Synechocystis transcriptome can be accessed and interactively analyzed via the CyanoEXpress website (http://cyanoexpress.sysbiolab.eu).
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Affiliation(s)
- Miguel A. Hernández-Prieto
- Systems Biology and Bioinformatics Laboratory, Centre of Marine Sciences, University of Algarve, 8005-139 Faro, Portugal
| | - Trudi Ann Semeniuk
- Systems Biology and Bioinformatics Laboratory, Centre of Marine Sciences, University of Algarve, 8005-139 Faro, Portugal
| | - Joaquín Giner-Lamia
- Systems Biology and Bioinformatics Laboratory, Centre of Marine Sciences, University of Algarve, 8005-139 Faro, Portugal
| | - Matthias E. Futschik
- Systems Biology and Bioinformatics Laboratory, Centre of Marine Sciences, University of Algarve, 8005-139 Faro, Portugal
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Cyanobacterial chassis engineering for enhancing production of biofuels and chemicals. Appl Microbiol Biotechnol 2016; 100:3401-13. [DOI: 10.1007/s00253-016-7374-2] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Revised: 01/29/2016] [Accepted: 02/01/2016] [Indexed: 10/22/2022]
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