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Olina A, Agapov A, Yudin D, Sutormin D, Galivondzhyan A, Kuzmenko A, Severinov K, Aravin AA, Kulbachinskiy A. Bacterial Argonaute Proteins Aid Cell Division in the Presence of Topoisomerase Inhibitors in Escherichia coli. Microbiol Spectr 2023; 11:e0414622. [PMID: 37102866 PMCID: PMC10269773 DOI: 10.1128/spectrum.04146-22] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Accepted: 03/29/2023] [Indexed: 04/28/2023] Open
Abstract
Prokaryotic Argonaute (pAgo) proteins are guide-dependent nucleases that function in host defense against invaders. Recently, it was shown that TtAgo from Thermus thermophilus also participates in the completion of DNA replication by decatenating chromosomal DNA. Here, we show that two pAgos from cyanobacteria Synechococcus elongatus (SeAgo) and Limnothrix rosea (LrAgo) are active in heterologous Escherichia coli and aid cell division in the presence of the gyrase inhibitor ciprofloxacin, depending on the host double-strand break repair machinery. Both pAgos are preferentially loaded with small guide DNAs (smDNAs) derived from the sites of replication termination. Ciprofloxacin increases the amounts of smDNAs from the termination region and from the sites of genomic DNA cleavage by gyrase, suggesting that smDNA biogenesis depends on DNA replication and is stimulated by gyrase inhibition. Ciprofloxacin enhances asymmetry in the distribution of smDNAs around Chi sites, indicating that it induces double-strand breaks that serve as a source of smDNA during their processing by RecBCD. While active in E. coli, SeAgo does not protect its native host S. elongatus from ciprofloxacin. These results suggest that pAgo nucleases may help to complete replication of chromosomal DNA by promoting chromosome decatenation or participating in the processing of gyrase cleavage sites, and may switch their functional activities depending on the host species. IMPORTANCE Prokaryotic Argonautes (pAgos) are programmable nucleases with incompletely understood functions in vivo. In contrast to eukaryotic Argonautes, most studied pAgos recognize DNA targets. Recent studies suggested that pAgos can protect bacteria from invader DNA and counteract phage infection and may also have other functions including possible roles in DNA replication, repair, and gene regulation. Here, we have demonstrated that two cyanobacterial pAgos, SeAgo and LrAgo, can assist DNA replication and facilitate cell division in the presence of topoisomerase inhibitors in Escherichia coli. They are specifically loaded with small guide DNAs from the region of replication termination and protect the cells from the action of the gyrase inhibitor ciprofloxacin, suggesting that they help to complete DNA replication and/or repair gyrase-induced breaks. The results show that pAgo proteins may serve as a backup to topoisomerases under conditions unfavorable for DNA replication and may modulate the resistance of host bacterial strains to antibiotics.
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Affiliation(s)
- Anna Olina
- Institute of Molecular Genetics, National Research Center “Kurchatov Institute”, Moscow, Russia
| | - Aleksei Agapov
- Institute of Molecular Genetics, National Research Center “Kurchatov Institute”, Moscow, Russia
| | - Denis Yudin
- Institute of Molecular Genetics, National Research Center “Kurchatov Institute”, Moscow, Russia
| | - Dmitry Sutormin
- Skolkovo Institute of Science and Technology, Moscow, Russia
| | | | - Anton Kuzmenko
- Institute of Molecular Genetics, National Research Center “Kurchatov Institute”, Moscow, Russia
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, California, USA
| | | | - Alexei A. Aravin
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, California, USA
| | - Andrey Kulbachinskiy
- Institute of Molecular Genetics, National Research Center “Kurchatov Institute”, Moscow, Russia
- Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia
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Jiang H, Wang W, Wang W, Xue C, Wang L, Liu D, Wang R, Yu S, Wu ZS. Hairpin-inserted cross-shaped DNA nanoprobe for ultrasensitive microRNA detection based on built-in target analogue cycle amplification. Talanta 2022; 250:123717. [PMID: 35785608 DOI: 10.1016/j.talanta.2022.123717] [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: 03/24/2022] [Revised: 06/22/2022] [Accepted: 06/27/2022] [Indexed: 10/17/2022]
Abstract
It remains technically challenging to develop a sensitive assay system to isothermally amplify the signal for miRNA detection because of its low abundance in tested sample, sequence similarities and existence in complex biological environments. In this study, using miRNA-21 as target model, a hairpin-inserted cross-shaped DNA nanoprobe (CP) with four functional arms is constructed for the ultrasensitive detection of miRNA via one-step built-in target analogue (BTA) cycle-mediated signal amplification. BTA is pre-locked in one arm of CP probe and inactive. In the presence of target miRNA, BTA can be unlocked and initiate an isothermal amplification process. Utilizing as-designed CP probe, miRNA-21 can be detected to down to 500 fM, and the linear response range spans over five orders of magnitude. The nonspecific signal is less than 1% upon nontarget miRNAs. CP probe exhibits ∼six times enhancement in resistance to nuclease degradation and no obvious degradation-induced fluorescence change is detected during the assay period. The recovery yield ranges from 98.2~105.5% in FBS solution. Because of the high sensitivity, desirable specificity, strong anti-interference ability and substantial increase in nuclease resistance, CP probe is a promising tool for the detection of miRNAs in a complex biological milieu.
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Affiliation(s)
- Hao Jiang
- Cancer Metastasis Alert and Prevention Center, Fujian Provincial Key Laboratory of Cancer Metastasis Chemoprevention and Chemotherapy, Pharmaceutical Photocatalysis of State Key Laboratory of Photocatalysis on Energy and Environment, College of Chemistry, Fuzhou University, Fuzhou, 350002, China
| | - Wenqing Wang
- Cancer Metastasis Alert and Prevention Center, Fujian Provincial Key Laboratory of Cancer Metastasis Chemoprevention and Chemotherapy, Pharmaceutical Photocatalysis of State Key Laboratory of Photocatalysis on Energy and Environment, College of Chemistry, Fuzhou University, Fuzhou, 350002, China
| | - Weijun Wang
- Cancer Metastasis Alert and Prevention Center, Fujian Provincial Key Laboratory of Cancer Metastasis Chemoprevention and Chemotherapy, Pharmaceutical Photocatalysis of State Key Laboratory of Photocatalysis on Energy and Environment, College of Chemistry, Fuzhou University, Fuzhou, 350002, China; Hunan Provincial Key Laboratory of Phytohormones and Growth Development, College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha, 410128, China
| | - Chang Xue
- Cancer Metastasis Alert and Prevention Center, Fujian Provincial Key Laboratory of Cancer Metastasis Chemoprevention and Chemotherapy, Pharmaceutical Photocatalysis of State Key Laboratory of Photocatalysis on Energy and Environment, College of Chemistry, Fuzhou University, Fuzhou, 350002, China
| | - Lei Wang
- Cancer Metastasis Alert and Prevention Center, Fujian Provincial Key Laboratory of Cancer Metastasis Chemoprevention and Chemotherapy, Pharmaceutical Photocatalysis of State Key Laboratory of Photocatalysis on Energy and Environment, College of Chemistry, Fuzhou University, Fuzhou, 350002, China; Hunan Provincial Key Laboratory of Phytohormones and Growth Development, College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha, 410128, China
| | - Dengyou Liu
- Hunan Provincial Key Laboratory of Phytohormones and Growth Development, College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha, 410128, China.
| | - Ruozhong Wang
- Hunan Provincial Key Laboratory of Phytohormones and Growth Development, College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha, 410128, China
| | - Suhong Yu
- Cancer Metastasis Alert and Prevention Center, Fujian Provincial Key Laboratory of Cancer Metastasis Chemoprevention and Chemotherapy, Pharmaceutical Photocatalysis of State Key Laboratory of Photocatalysis on Energy and Environment, College of Chemistry, Fuzhou University, Fuzhou, 350002, China.
| | - Zai-Sheng Wu
- Cancer Metastasis Alert and Prevention Center, Fujian Provincial Key Laboratory of Cancer Metastasis Chemoprevention and Chemotherapy, Pharmaceutical Photocatalysis of State Key Laboratory of Photocatalysis on Energy and Environment, College of Chemistry, Fuzhou University, Fuzhou, 350002, China.
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Yan S, Zhen J, Li Y, Huang Y, Ai X, Li Y, Stojkoska A, Huang X, Ruan C, Li J, Fan L, Xie J. Mycobacterium Lrp/AsnC family transcriptional factor modulates the arginase pathway as both a sensor and a transcriptional repressor. J Genet Genomics 2021; 48:1020-1031. [PMID: 34696992 DOI: 10.1016/j.jgg.2021.06.018] [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: 10/19/2020] [Revised: 06/20/2021] [Accepted: 06/22/2021] [Indexed: 12/26/2022]
Abstract
L-Arginine is the precursor of nitric oxide (NO), a host immune effector against intracellular pathogens including Mycobacterium tuberculosis (M. tb). Pathogens including M. tb have evolved various strategies targeting arginine to block the production of NO for better survival and proliferation. However, L-arginine metabolism and regulation in Mycobacterium are poorly understood. Here, we report the identification of M. smegmatis MSMEG_1415 (homolog of M. tb Rv2324) as an arginine-responsive transcriptional factor regulating the arginase pathway. In the absence of L-arginine, MSMEG_1415 acts as a repressor to inhibit the transcription of the roc (for arginine, ornithine catabolism) gene cluster, thereby switching off the arginase pathway. Treatment with L-arginine relieves the transcriptional inhibition of MSMEG_1415 on the roc gene cluster to activate the arginase pathway. Moreover, the L-arginine-MSMEG_1415 complex activates the transcription of the roc gene cluster by recognizing and binding a 15-bp palindrome motif, thereby preventing the excess accumulation of L-arginine in M. smegmatis. Physiologically, MSMEG_1415 confers mycobacteria resistance to starvation and fluoroquinolones exposure, suggestive of its important role in M. smegmatis persistence. The results uncover a unique regulatory mechanism of arginine metabolism in mycobacteria and identify M. tb Rv2324 as an attractive candidate target for the design of drugs against tuberculosis.
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Affiliation(s)
- Shuangquan Yan
- Institute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Ministry of Education Eco-Environment of the Three Gorges Reservoir Region, School of Life Sciences, Southwest University, Chongqing 400715, China
| | - Junfeng Zhen
- Institute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Ministry of Education Eco-Environment of the Three Gorges Reservoir Region, School of Life Sciences, Southwest University, Chongqing 400715, China
| | - Yuzhu Li
- Institute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Ministry of Education Eco-Environment of the Three Gorges Reservoir Region, School of Life Sciences, Southwest University, Chongqing 400715, China
| | - Yu Huang
- Institute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Ministry of Education Eco-Environment of the Three Gorges Reservoir Region, School of Life Sciences, Southwest University, Chongqing 400715, China
| | - Xuefeng Ai
- Institute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Ministry of Education Eco-Environment of the Three Gorges Reservoir Region, School of Life Sciences, Southwest University, Chongqing 400715, China
| | - Yue Li
- Institute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Ministry of Education Eco-Environment of the Three Gorges Reservoir Region, School of Life Sciences, Southwest University, Chongqing 400715, China
| | - Andrea Stojkoska
- Institute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Ministry of Education Eco-Environment of the Three Gorges Reservoir Region, School of Life Sciences, Southwest University, Chongqing 400715, China
| | - Xue Huang
- Institute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Ministry of Education Eco-Environment of the Three Gorges Reservoir Region, School of Life Sciences, Southwest University, Chongqing 400715, China
| | - Cao Ruan
- Institute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Ministry of Education Eco-Environment of the Three Gorges Reservoir Region, School of Life Sciences, Southwest University, Chongqing 400715, China
| | - Jiang Li
- Institute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Ministry of Education Eco-Environment of the Three Gorges Reservoir Region, School of Life Sciences, Southwest University, Chongqing 400715, China
| | - Lin Fan
- Shanghai Clinic and Research Center of Tuberculosis, Shanghai Pulmonary Hospital, Tongji University School of Medicine, Shanghai Key Laboratory of Tuberculosis, Shanghai 200433, China.
| | - Jianping Xie
- Institute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Ministry of Education Eco-Environment of the Three Gorges Reservoir Region, School of Life Sciences, Southwest University, Chongqing 400715, China.
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Abstract
RNA degradation is an important process that affects the final concentration of individual mRNAs, affecting protein expression and cellular physiology. Studies of how RNA is degraded increase our knowledge of this fundamental process as well as enable the creation of genetic tools to manipulate RNA stability. By studying global transcript turnover, we searched for sequence elements that correlated with transcript (in)stability and used these sequences to guide tool design. This study probes global RNA turnover in a cyanobacterium, Synechococcus sp. strain PCC 7002, that both has a unique array of RNases that facilitate RNA degradation and is an industrially relevant strain that could be used to convert CO2 and sunlight into useful products. RNA degradation is an important process that influences the ultimate concentration of individual proteins inside cells. While the main enzymes that facilitate this process have been identified, global maps of RNA turnover are available for only a few species. Even in these cases, there are few sequence elements that are known to enhance or destabilize a native transcript; even fewer confer the same effect when added to a heterologous transcript. To address this knowledge gap, we assayed genome-wide RNA degradation in the cyanobacterium Synechococcus sp. strain PCC 7002 by collecting total RNA samples after stopping nascent transcription with rifampin. We quantified the abundance of each position in the transcriptome as a function of time using RNA-sequencing data and later analyzed the global mRNA decay map using machine learning principles. Half-lives, calculated on a per-ORF (open reading frame) basis, were extremely short, with a median half-life of only 0.97 min. Despite extremely rapid turnover of most mRNA, transcripts encoding proteins involved in photosynthesis were both highly expressed and highly stable. Upon inspection of these stable transcripts, we identified an enriched motif in the 3′ untranslated region (UTR) that had similarity to Rho-independent terminators. We built statistical models for half-life prediction and used them to systematically identify sequence motifs in both 5′ and 3′ UTRs that correlate with stabilized transcripts. We found that transcripts linked to a terminator containing a poly(U) tract had a longer half-life than both those without a poly(U) tract and those without a terminator. IMPORTANCE RNA degradation is an important process that affects the final concentration of individual mRNAs, affecting protein expression and cellular physiology. Studies of how RNA is degraded increase our knowledge of this fundamental process as well as enable the creation of genetic tools to manipulate RNA stability. By studying global transcript turnover, we searched for sequence elements that correlated with transcript (in)stability and used these sequences to guide tool design. This study probes global RNA turnover in a cyanobacterium, Synechococcus sp. strain PCC 7002, that both has a unique array of RNases that facilitate RNA degradation and is an industrially relevant strain that could be used to convert CO2 and sunlight into useful products.
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Sengupta A, Madhu S, Wangikar PP. A Library of Tunable, Portable, and Inducer-Free Promoters Derived from Cyanobacteria. ACS Synth Biol 2020; 9:1790-1801. [PMID: 32551554 DOI: 10.1021/acssynbio.0c00152] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Cyanobacteria are emerging as hosts for various biotechnological applications. The ability to engineer these photosynthetic prokaryotes greatly depends on the availability of well-characterized promoters. Inducer-free promoters of a range of activities may be desirable for the eventual large-scale, outdoor cultivations. Further, several native promoters of cyanobacteria are repressed by high carbon dioxide or light, and it would be of interest to alter this property. We started with PrbcL and PcpcB, the well-characterized native promoters of the model cyanobacterium Synechococcus elongatus PCC 7942, found upstream of the two abundantly expressed genes, Ribulose-1,5-Bisphosphate Carboxylase/Oxygenase, and phycocyanin β-1 subunit, respectively. The library of 48 promoters created via error-prone PCR of these 300-bp-long native promoters showed 2 orders of magnitude dynamic range with activities that were both lower and higher than those of the wild-type promoters. A few mutants of the PrbcL showed greater strength than PcpcB, which is widely considered a superstrong promoter. A number of mutant promoters did not show repression by high CO2 or light, typically found for PrbcL and PcpcB, respectively. Further, the wild-type and mutant promoters showed comparable activities in the fast-growing and stress-tolerant strains S. elongatus PCC 11801 and PCC 11802, suggesting that the library can be used in different cyanobacteria. Interestingly, the majority of the promoters showed strong expression in E. coli, thus adding to the repertoire of inducer-free promoters for this heterotrophic workhorse. Our results have implications in the metabolic engineering of cyanobacteria and E. coli.
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Xu M, Lawrence JG, Durand D. Selection, periodicity and potential function for Highly Iterative Palindrome-1 (HIP1) in cyanobacterial genomes. Nucleic Acids Res 2019; 46:2265-2278. [PMID: 29432573 PMCID: PMC5861425 DOI: 10.1093/nar/gky075] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2017] [Accepted: 01/25/2018] [Indexed: 02/05/2023] Open
Abstract
Highly Iterated Palindrome 1 (HIP1, GCGATCGC) is hyper-abundant in most cyanobacterial genomes. In some cyanobacteria, average HIP1 abundance exceeds one motif per gene. Such high abundance suggests a significant role in cyanobacterial biology. However, 20 years of study have not revealed whether HIP1 has a function, much less what that function might be. We show that HIP1 is 15- to 300-fold over-represented in genomes analyzed. More importantly, HIP1 sites are conserved both within and between open reading frames, suggesting that their overabundance is maintained by selection rather than by continual replenishment by neutral processes, such as biased DNA repair. This evidence for selection suggests a functional role for HIP1. No evidence was found to support a functional role as a peptide or RNA motif or a role in the regulation of gene expression. Rather, we demonstrate that the distribution of HIP1 along cyanobacterial chromosomes is significantly periodic, with periods ranging from 10 to 90 kb, consistent in scale with periodicities reported for co-regulated, co-expressed and evolutionarily correlated genes. The periodicity we observe is also comparable in scale to chromosomal interaction domains previously described in other bacteria. In this context, our findings imply HIP1 functions associated with chromosome and nucleoid structure.
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Affiliation(s)
- Minli Xu
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA 15213, USA
| | - Jeffrey G Lawrence
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Dannie Durand
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA 15213, USA.,Department of Computer Science, Carnegie Mellon University, Pittsburgh, PA 15213, USA
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Scholz I, Lott SC, Behler J, Gärtner K, Hagemann M, Hess WR. Divergent methylation of CRISPR repeats and cas genes in a subtype I-D CRISPR-Cas-system. BMC Microbiol 2019; 19:147. [PMID: 31262257 PMCID: PMC6604393 DOI: 10.1186/s12866-019-1526-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Accepted: 06/20/2019] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND The presence and activity of CRISPR-Cas defense systems is a hallmark of many prokaryotic microorganisms. Here, the distribution of sequences related to the highly iterated palindrome 1 (HIP1) element and the DNA methylation of CGATCG motifs embedded within HIP1 as a vital part of the CRISPR1 repeat sequence was analyzed in the cyanobacterium Synechocystis sp. PCC 6803. Previously suggested functions of HIP1 include organization of chromosomal structure, DNA recombination or gene regulation, all of which could be relevant in CRISPR-Cas functionality. RESULTS The CRISPR1 repeat-spacer array contains more than 50 CGATCG elements that are double-methylated (5mCG6mATCG) by the enzymes M.Ssp6803I and M.Ssp6803III. Hence, more than 200 possible methylation events cluster over a stretch of 3600 bp of double-stranded DNA. Bisulfite sequencing showed that these motifs were highly methylated at the m5CGATCG positions whereas specific motifs within the CRISPR1 cas genes were hypomethylated suggesting a lowered accessibility for the DNA methylase to these regions. Assays for conjugation and CRISPR1-mediated DNA interference revealed a 50% drop in conjugation efficiency in the mutant lacking the 5mC methylation of CGATCG motifs, while the highly efficient DNA interference activity was not affected by the lack of m5CGATCG DNA-methylation, nor was the capability to differentiate between self and non-self targets based on the protospacer adjacent motifs (PAMs) GTA and GTC versus the non-PAM AGC. A third DNA methylation mediated by M.Ssp6803II modifies the first cytosine in the motif GGCC yielding GGm4CC. We found a remarkable absence of GGCC motifs and hence the corresponding methylation over an 11 kb stretch encompassing all the cas genes involved in interference and crRNA maturation but not adaptation of the CRISPR1 system. CONCLUSIONS The lack of GGCC tetranucleotides along the CRISPR1 interference and maturation genes supports the reported hybrid character of subtype I-D CRISPR-Cas systems. We report tight and very high 5mC methylation of the CRISPR1 repeat sequences. Nevertheless, cells lacking the 5mC methylation activity were unaffected in their CRISPR1-mediated interference response but the efficiency of conjugation was reduced by 50%. These results point to an unknown role of m5CGATCG DNA-methylation marks in conjugation and DNA transformation.
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Affiliation(s)
- Ingeborg Scholz
- Faculty of Biology, Genetics an Experimental Bioinformatics, University of Freiburg, Schänzlestr. 1, D-79104 Freiburg, Germany
| | - Steffen C. Lott
- Faculty of Biology, Genetics an Experimental Bioinformatics, University of Freiburg, Schänzlestr. 1, D-79104 Freiburg, Germany
| | - Juliane Behler
- Faculty of Biology, Genetics an Experimental Bioinformatics, University of Freiburg, Schänzlestr. 1, D-79104 Freiburg, Germany
| | - Katrin Gärtner
- University of Rostock, Institute of Biosciences, Plant Physiology, A.-Einstein-Str. 3, D-18059 Rostock, Germany
| | - Martin Hagemann
- University of Rostock, Institute of Biosciences, Plant Physiology, A.-Einstein-Str. 3, D-18059 Rostock, Germany
| | - Wolfgang R. Hess
- Faculty of Biology, Genetics an Experimental Bioinformatics, University of Freiburg, Schänzlestr. 1, D-79104 Freiburg, Germany
- University of Freiburg, Freiburg Institute for Advanced Studies, Albertstr. 19, D-79104 Freiburg, Germany
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Gärtner K, Klähn S, Watanabe S, Mikkat S, Scholz I, Hess WR, Hagemann M. Cytosine N4-Methylation via M.Ssp6803II Is Involved in the Regulation of Transcription, Fine- Tuning of DNA Replication and DNA Repair in the Cyanobacterium Synechocystis sp. PCC 6803. Front Microbiol 2019; 10:1233. [PMID: 31231331 PMCID: PMC6560206 DOI: 10.3389/fmicb.2019.01233] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Accepted: 05/17/2019] [Indexed: 12/15/2022] Open
Abstract
DNA methylation plays a crucial role for gene regulation among eukaryotes, but its regulatory function is less documented in bacteria. In the cyanobacterium Synechocystis sp. PCC 6803 five DNA methyltransferases have been identified. Among them, M.Ssp6803II is responsible for the specific methylation of the first cytosine in the frequently occurring motif GGCC, leading to N4-methylcytosine (GGm4CC). The mutation of the corresponding gene sll0729 led to lowered chlorophyll/phycocyanin ratio and slower growth. Transcriptomics only showed altered expression of sll0470 and sll1526, two genes encoding hypothetical proteins. Moreover, prolonged cultivation revealed instability of the initially obtained phenotype. Colonies with normal pigmentation and wild-type-like growth regularly appeared on agar plates. These colonies represent suppressor mutants, because the sll0729 gene was still completely inactivated and the GGCC sites remained unmethylated. The suppressor strains showed smaller cell size, lowered DNA content per cell, and decreased tolerance against UV compared to wild type. Promoter assays revealed that the transcription of the sll0470 gene was still stimulated in the suppressor clones. Proteomics identified decreased levels of DNA topoisomerase 4 subunit A in suppressor cells. Collectively, these results indicate that GGm4CC methylation is involved in the regulation of gene expression, in the fine-tuning of DNA replication, and DNA repair mechanisms.
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Affiliation(s)
- Katrin Gärtner
- Department of Plant Physiology, University of Rostock, Rostock, Germany
| | - Stephan Klähn
- Faculty of Biology, Genetics & Experimental Bioinformatics, University of Freiburg, Freiburg im Breisgau, Germany
- Department of Solar Materials, Helmholtz-Centre for Environmental Research, Leipzig, Germany
| | - Satoru Watanabe
- Department of Bioscience, Tokyo University of Agriculture, Tokyo, Japan
| | - Stefan Mikkat
- Core Facility Proteome Analysis, University Medicine Rostock, Rostock, Germany
| | - Ingeborg Scholz
- Faculty of Biology, Genetics & Experimental Bioinformatics, University of Freiburg, Freiburg im Breisgau, Germany
| | - Wolfgang R. Hess
- Faculty of Biology, Genetics & Experimental Bioinformatics, University of Freiburg, Freiburg im Breisgau, Germany
- Freiburg Institute for Advanced Studies, University of Freiburg, Freiburg im Breisgau, Germany
| | - Martin Hagemann
- Department of Plant Physiology, University of Rostock, Rostock, Germany
- Department Life, Light and Matter, University of Rostock, Rostock, Germany
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Sengupta A, Sunder AV, Sohoni SV, Wangikar PP. Fine-Tuning Native Promoters of Synechococcus elongatus PCC 7942 To Develop a Synthetic Toolbox for Heterologous Protein Expression. ACS Synth Biol 2019; 8:1219-1223. [PMID: 30973704 DOI: 10.1021/acssynbio.9b00066] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The cyanobacterium Synechococcus elongatus PCC 7942 is a potential photosynthetic cell-factory. In this study, two native promoters from S. elongatus PCC 7942 driving the expression of abundant cyanobacterial proteins phycocyanin (P cpcB7942) and RuBisCO (P rbc7942) were characterized in relation to their sequence features, expression levels, diurnal behavior, and regulation by light and CO2, major abiotic factors important for cyanobacterial growth. P cpcB7942 was repressed under high light intensity, but cultivation at higher CO2 concentration was able to recover promoter activity. On the other hand, P rbc7942 was repressed by elevated CO2 with a negative regulatory region between 300 and 225 bp. Removal of this region flipped the effect of CO2 with Rbc225 being activated only at high CO2 concentration, besides leading to the loss of circadian rhythm. The results from this study on promoter features and regulation will help expand the repertoire of tools for pathway engineering in cyanobacteria.
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Hagemann M, Gärtner K, Scharnagl M, Bolay P, Lott SC, Fuss J, Huettel B, Reinhardt R, Klähn S, Hess WR. Identification of the DNA methyltransferases establishing the methylome of the cyanobacterium Synechocystis sp. PCC 6803. DNA Res 2018; 25:343-352. [PMID: 29444255 PMCID: PMC6105098 DOI: 10.1093/dnares/dsy006] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Accepted: 01/24/2018] [Indexed: 11/12/2022] Open
Abstract
DNA methylation in bacteria is important for defense against foreign DNA, but is also involved in DNA repair, replication, chromosome partitioning, and regulatory processes. Thus, characterization of the underlying DNA methyltransferases in genetically tractable bacteria is of paramount importance. Here, we characterized the methylome and orphan methyltransferases in the model cyanobacterium Synechocystis sp. PCC 6803. Single molecule real-time (SMRT) sequencing revealed four DNA methylation recognition sequences in addition to the previously known motif m5CGATCG, which is recognized by M.Ssp6803I. For three of the new recognition sequences, we identified the responsible methyltransferases. M.Ssp6803II, encoded by the sll0729 gene, modifies GGm4CC, M.Ssp6803III, encoded by slr1803, represents the cyanobacterial dam-like methyltransferase modifying Gm6ATC, and M.Ssp6803V, encoded by slr6095 on plasmid pSYSX, transfers methyl groups to the bipartite motif GGm6AN7TTGG/CCAm6AN7TCC. The remaining methylation recognition sequence GAm6AGGC is probably recognized by methyltransferase M.Ssp6803IV encoded by slr6050. M.Ssp6803III and M.Ssp6803IV were essential for the viability of Synechocystis, while the strains lacking M.Ssp6803I and M.Ssp6803V showed growth similar to the wild type. In contrast, growth was strongly diminished of the Δsll0729 mutant lacking M.Ssp6803II. These data provide the basis for systematic studies on the molecular mechanisms impacted by these methyltransferases.
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Affiliation(s)
- Martin Hagemann
- Institute of Biosciences, Plant Physiology, University of Rostock, Rostock, Germany
| | - Katrin Gärtner
- Institute of Biosciences, Plant Physiology, University of Rostock, Rostock, Germany
| | - Matthias Scharnagl
- Institute of Biosciences, Plant Physiology, University of Rostock, Rostock, Germany
| | - Paul Bolay
- Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Steffen C Lott
- Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Janina Fuss
- Max Planck-Genome-Centre Cologne, Max Planck Institute for Plant Breeding Research, Köln, Germany
| | - Bruno Huettel
- Max Planck-Genome-Centre Cologne, Max Planck Institute for Plant Breeding Research, Köln, Germany
| | - Richard Reinhardt
- Max Planck-Genome-Centre Cologne, Max Planck Institute for Plant Breeding Research, Köln, Germany
| | - Stephan Klähn
- Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Wolfgang R Hess
- Faculty of Biology, University of Freiburg, Freiburg, Germany
- Freiburg Institute for Advanced Studies, University of Freiburg, Germany
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Sengupta A, Pakrasi HB, Wangikar PP. Recent advances in synthetic biology of cyanobacteria. Appl Microbiol Biotechnol 2018; 102:5457-5471. [PMID: 29744631 DOI: 10.1007/s00253-018-9046-x] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Revised: 04/23/2018] [Accepted: 04/24/2018] [Indexed: 12/11/2022]
Abstract
Cyanobacteria are attractive hosts that can be engineered for the photosynthetic production of fuels, fine chemicals, and proteins from CO2. Moreover, the responsiveness of these photoautotrophs towards different environmental signals, such as light, CO2, diurnal cycle, and metals make them potential hosts for the development of biosensors. However, engineering these hosts proves to be a challenging and lengthy process. Synthetic biology can make the process of biological engineering more predictable through the use of standardized biological parts that are well characterized and tools to assemble them. While significant progress has been made with model heterotrophic organisms, many of the parts and tools are not portable in cyanobacteria. Therefore, efforts are underway to develop and characterize parts derived from cyanobacteria. In this review, we discuss the reported parts and tools with the objective to develop cyanobacteria as cell factories or biosensors. We also discuss the issues related to characterization, tunability, portability, and the need to develop enabling technologies to engineer this "green" chassis.
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Affiliation(s)
- Annesha Sengupta
- Department of Chemical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India
| | - Himadri B Pakrasi
- Department of Biology, Washington University, St. Louis, MO, USA.,Department of Energy, Environmental and Chemical Engineering, Washington University, St. Louis, MO, USA
| | - Pramod P Wangikar
- Department of Chemical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India. .,DBT-Pan IIT Center for Bioenergy, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India. .,Wadhwani Research Center for Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India.
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Cassier-Chauvat C, Veaudor T, Chauvat F. Comparative Genomics of DNA Recombination and Repair in Cyanobacteria: Biotechnological Implications. Front Microbiol 2016; 7:1809. [PMID: 27881980 PMCID: PMC5101192 DOI: 10.3389/fmicb.2016.01809] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Accepted: 10/27/2016] [Indexed: 12/16/2022] Open
Abstract
Cyanobacteria are fascinating photosynthetic prokaryotes that are regarded as the ancestors of the plant chloroplast; the purveyors of oxygen and biomass for the food chain; and promising cell factories for an environmentally friendly production of chemicals. In colonizing most waters and soils of our planet, cyanobacteria are inevitably challenged by environmental stresses that generate DNA damages. Furthermore, many strains engineered for biotechnological purposes can use DNA recombination to stop synthesizing the biotechnological product. Hence, it is important to study DNA recombination and repair in cyanobacteria for both basic and applied research. This review reports what is known in a few widely studied model cyanobacteria and what can be inferred by mining the sequenced genomes of morphologically and physiologically diverse strains. We show that cyanobacteria possess many E. coli-like DNA recombination and repair genes, and possibly other genes not yet identified. E. coli-homolog genes are unevenly distributed in cyanobacteria, in agreement with their wide genome diversity. Many genes are extremely well conserved in cyanobacteria (mutMS, radA, recA, recFO, recG, recN, ruvABC, ssb, and uvrABCD), even in small genomes, suggesting that they encode the core DNA repair process. In addition to these core genes, the marine Prochlorococcus and Synechococcus strains harbor recBCD (DNA recombination), umuCD (mutational DNA replication), as well as the key SOS genes lexA (regulation of the SOS system) and sulA (postponing of cell division until completion of DNA reparation). Hence, these strains could possess an E. coli-type SOS system. In contrast, several cyanobacteria endowed with larger genomes lack typical SOS genes. For examples, the two studied Gloeobacter strains lack alkB, lexA, and sulA; and Synechococcus PCC7942 has neither lexA nor recCD. Furthermore, the Synechocystis PCC6803 lexA product does not regulate DNA repair genes. Collectively, these findings indicate that not all cyanobacteria have an E. coli-type SOS system. Also interestingly, several cyanobacteria possess multiple copies of E. coli-like DNA repair genes, such as Acaryochloris marina MBIC11017 (2 alkB, 3 ogt, 7 recA, 3 recD, 2 ssb, 3 umuC, 4 umuD, and 8 xerC), Cyanothece ATCC51142 (2 lexA and 4 ruvC), and Nostoc PCC7120 (2 ssb and 3 xerC).
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Affiliation(s)
- Corinne Cassier-Chauvat
- Institute for Integrative Biology of the Cell, CEA, Centre Nationnal de la Recherche Scientifique (CNRS), Universite Paris-Sud, Université Paris-Saclay Gif-sur-Yvette Cedex, France
| | - Théo Veaudor
- Institute for Integrative Biology of the Cell, CEA, Centre Nationnal de la Recherche Scientifique (CNRS), Universite Paris-Sud, Université Paris-Saclay Gif-sur-Yvette Cedex, France
| | - Franck Chauvat
- Institute for Integrative Biology of the Cell, CEA, Centre Nationnal de la Recherche Scientifique (CNRS), Universite Paris-Sud, Université Paris-Saclay Gif-sur-Yvette Cedex, France
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Regulation of the scp Genes in the Cyanobacterium Synechocystis sp. PCC 6803--What is New? Molecules 2015; 20:14621-37. [PMID: 26274949 PMCID: PMC6331805 DOI: 10.3390/molecules200814621] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Revised: 08/05/2015] [Accepted: 08/07/2015] [Indexed: 11/18/2022] Open
Abstract
In the cyanobacterium Synechocystis sp. PCC 6803 there are five genes encoding small CAB-like (SCP) proteins, which have been shown to be up-regulated under stress. Analyses of the promoter sequences of the scp genes revealed the existence of an NtcA binding motif in two scp genes, scpB and scpE. Binding of NtcA, the key transcriptional regulator during nitrogen stress, to the promoter regions was shown by electrophoretic mobility shift assay. The metabolite 2-oxoglutarate did not increase the affinity of NtcA for binding to the promoters of scpB and scpE. A second motif, the HIP1 palindrome 5ʹ GGCGATCGCC 3ʹ, was detected in the upstream regions of scpB and scpC. The transcription factor encoded by sll1130 has been suggested to recognize this motif to regulate heat-responsive genes. Our data suggest that HIP1 is not a regulatory element within the scp genes. Further, the presence of the high light regulatory (HLR1) motif was confirmed in scpB-E, in accordance to their induced transcriptions in cells exposed to high light. The HLR1 motif was newly discovered in eight additional genes.
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