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Ulrich RJ, Podkowik M, Tierce R, Irnov I, Putzel G, Samhadaneh N, Lacey KA, Boff D, Morales SM, Makita S, Karagounis TK, Zwack EE, Zhou C, Kim R, Drlica K, Pironti A, van Bakel H, Torres VJ, Shopsin B. Prophage-encoded methyltransferase drives adaptation of community-acquired methicillin-resistant Staphylococcus aureus. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.17.589803. [PMID: 38659881 PMCID: PMC11042277 DOI: 10.1101/2024.04.17.589803] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/26/2024]
Abstract
We recently described the evolution of a community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) USA300 variant responsible for an outbreak of skin and soft tissue infections. Acquisition of a mosaic version of the Φ11 prophage (mΦ11) that increases skin abscess size was an early step in CA-MRSA adaptation that primed the successful spread of the clone. The present report shows how prophage mΦ11 exerts its effect on virulence for skin infection without encoding a known toxin or fitness genes. Abscess size and skin inflammation were associated with DNA methylase activity of an mΦ11-encoded adenine methyltransferase (designated pamA). pamA increased expression of fibronectin-binding protein A (fnbA; FnBPA), and inactivation of fnbA eliminated the effect of pamA on abscess virulence without affecting strains lacking pamA. Thus, fnbA is a pamA-specific virulence factor. Mechanistically, pamA was shown to promote biofilm formation in vivo in skin abscesses, a phenotype linked to FnBPA's role in biofilm formation. Collectively, these data reveal a novel mechanism-epigenetic regulation of staphylococcal gene expression-by which phage can regulate virulence to drive adaptive leaps by S. aureus.
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Affiliation(s)
- Robert J. Ulrich
- Department of Medicine, NYU Grossman School of Medicine, New York, NY, USA
| | - Magdalena Podkowik
- Department of Medicine, NYU Grossman School of Medicine, New York, NY, USA
- Antimicrobial-Resistant Pathogens Program, NYU Grossman School of Medicine, New York, NY, USA
| | - Rebecca Tierce
- Division of Comparative Medicine, NYU Langone Health, New York, NY, USA
| | - Irnov Irnov
- Department of Microbiology, NYU Grossman School of Medicine, New York, NY, USA
| | - Gregory Putzel
- Antimicrobial-Resistant Pathogens Program, NYU Grossman School of Medicine, New York, NY, USA
- Department of Microbiology, NYU Grossman School of Medicine, New York, NY, USA
| | - Nora Samhadaneh
- Antimicrobial-Resistant Pathogens Program, NYU Grossman School of Medicine, New York, NY, USA
- Department of Microbiology, NYU Grossman School of Medicine, New York, NY, USA
| | - Keenan A. Lacey
- Department of Microbiology, NYU Grossman School of Medicine, New York, NY, USA
| | - Daiane Boff
- Department of Microbiology, NYU Grossman School of Medicine, New York, NY, USA
| | - Sabrina M. Morales
- Department of Medicine, NYU Grossman School of Medicine, New York, NY, USA
| | - Sohei Makita
- Department of Pathology, NYU Grossman School of Medicine, New York, NY, USA
| | - Theodora K. Karagounis
- Ronald O. Perelman Department of Dermatology, NYU Grossman School of Medicine, New York, NY, USA
| | - Erin E. Zwack
- Department of Microbiology, NYU Grossman School of Medicine, New York, NY, USA
| | - Chunyi Zhou
- Department of Microbiology, NYU Grossman School of Medicine, New York, NY, USA
| | - Randie Kim
- Ronald O. Perelman Department of Dermatology, NYU Grossman School of Medicine, New York, NY, USA
| | - Karl Drlica
- Department of Microbiology, Biochemistry & Molecular Genetics, New Jersey Medical School, Rutgers University, Newark, NJ, USA
- Department of Biochemistry and Molecular Pharmacology, NYU Grossman School of Medicine, New York, NY, USA
| | - Alejandro Pironti
- Antimicrobial-Resistant Pathogens Program, NYU Grossman School of Medicine, New York, NY, USA
- Department of Microbiology, NYU Grossman School of Medicine, New York, NY, USA
| | - Harm van Bakel
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Icahn Genomics Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Victor J. Torres
- Antimicrobial-Resistant Pathogens Program, NYU Grossman School of Medicine, New York, NY, USA
- Department of Microbiology, NYU Grossman School of Medicine, New York, NY, USA
- Department of Host-Microbe Interactions, St. Jude Children’s Research Hospital, Memphis, TN, USA
| | - Bo Shopsin
- Department of Medicine, NYU Grossman School of Medicine, New York, NY, USA
- Antimicrobial-Resistant Pathogens Program, NYU Grossman School of Medicine, New York, NY, USA
- Department of Microbiology, NYU Grossman School of Medicine, New York, NY, USA
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Pisciotta A, Sampino AM, Presentato A, Galardini M, Manteca A, Alduina R. The DNA cytosine methylome revealed two methylation motifs in the upstream regions of genes related to morphological and physiological differentiation in Streptomyces coelicolor A(3)2 M145. Sci Rep 2023; 13:7038. [PMID: 37120673 PMCID: PMC10148868 DOI: 10.1038/s41598-023-34075-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2023] [Accepted: 04/24/2023] [Indexed: 05/01/2023] Open
Abstract
DNA methylation is an epigenetic modification detected in both prokaryotic and eukaryotic genomic DNAs. In bacteria, the importance of 5-methylcytosine (m5C) in gene expression has been less investigated than in eukaryotic systems. Through dot-blot analysis employing m5C antibodies against chromosomal DNA, we have previously demonstrated that m5C influences the differentiation of Streptomyces coelicolor A(3)2 M145 in solid sporulating and liquid non-sporulating complex media. Here, we mapped the methylated cytosines of the M145 strain growing in the defined Maltose Glutamate (MG) liquid medium. Sequencing of the M145 genome after bisulfite treatment (BS-sequencing) evidenced 3360 methylated cytosines and the two methylation motifs, GGCmCGG and GCCmCG, in the upstream regions of 321 genes. Besides, the role of cytosine methylation was investigated using the hypo-methylating agent 5'-aza-2'-deoxycytidine (5-aza-dC) in S. coelicolor cultures, demonstrating that m5C affects both growth and antibiotic biosynthesis. Finally, quantitative reverse-transcription polymerase-chain-reaction (RT-qPCR) analysis of genes containing the methylation motifs in the upstream regions showed that 5-aza-dC treatment influenced their transcriptional levels and those of the regulatory genes for two antibiotics. To the best of our knowledge, this is the first study that reports the cytosine methylome of S. coelicolor M145, supporting the crucial role ascribed to cytosine methylation in controlling bacterial gene expression.
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Affiliation(s)
- Annalisa Pisciotta
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (STEBICEF), University of Palermo, 90128, Palermo, Italy
| | - Alessia Maria Sampino
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (STEBICEF), University of Palermo, 90128, Palermo, Italy
| | - Alessandro Presentato
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (STEBICEF), University of Palermo, 90128, Palermo, Italy
| | - Marco Galardini
- Department of Biology, University of Florence, Florence, Italy
- EMBL-EBI, Wellcome Genome Campus, Cambridge, UK
- Institute for Molecular Bacteriology, TWINCORE, Centre for Experimental and Clinical Infection Research, A Joint Venture Between the Helmholtz Centre for Infection Research and the Hannover Medical School, Hannover, Germany
| | - Angel Manteca
- Área de Microbiología, Departamento de Biología Funcional, IUOPA and ISPA, Facultad de Medicina, Universidad de Oviedo, 33006, Oviedo, Spain
| | - Rosa Alduina
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (STEBICEF), University of Palermo, 90128, Palermo, Italy.
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DNA Methyltransferase Regulates Nitric Oxide Homeostasis and Virulence in a Chronically Adapted Pseudomonas aeruginosa Strain. mSystems 2022; 7:e0043422. [PMID: 36106744 PMCID: PMC9600465 DOI: 10.1128/msystems.00434-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Opportunistic pathogens such as Pseudomonas aeruginosa adapt their genomes rapidly during chronic infections. Understanding their epigenetic regulation may provide biomarkers for diagnosis and reveal novel regulatory mechanisms. We performed single-molecule real-time sequencing (SMRT-seq) to characterize the methylome of a chronically adapted P. aeruginosa clinical strain, TBCF10839. Two N6-methyladenine (6mA) methylation recognition motifs (RCCANNNNNNNTGAR and TRGANNNNNNTGC [modification sites are in bold]) were identified and predicted as new type I methylation sites using REBASE analysis. We confirmed that the motif TRGANNNNNNTGC was methylated by the methyltransferase (MTase) M.PaeTBCFII, according to methylation sensitivity assays in vivo and vitro. Transcriptomic analysis showed that a ΔpaeTBCFIIM knockout mutant significantly downregulated nitric oxide reductase (NOR) regulation and expression of coding genes such as nosR and norB, which contain methylated motifs in their promoters or coding regions. The ΔpaeTBCFIIM strain exhibited reduced intercellular survival capacity in NO-producing RAW264.7 macrophages and attenuated virulence in a Galleria mellonella infection model; the complemented strain recovered these defective phenotypes. Further phylogenetic analysis demonstrated that homologs of M.PaeTBCFII occur frequently in P. aeruginosa as well as other bacterial species. Our work therefore provided new insights into the relationship between DNA methylation, NO detoxification, and bacterial virulence, laying a foundation for further exploring the molecular mechanism of DNA methyltransferase in regulating the pathogenicity of P. aeruginosa. IMPORTANCE Pseudomonas aeruginosa is an opportunistic pathogen which causes acute and chronic infections that are difficult to treat. Comparative genomic analysis has showed broad genome diversity among P. aeruginosa clinical strains and revealed their different regulatory traits compared to the laboratory strains. While current investigation of the epigenetics of P. aeruginosa is still lacking, understanding epigenetic regulation may provide biomarkers for diagnosis and facilitate development of novel therapies. Denitrification capability is critical for microbial versatility in response to different environmental stress conditions, including the bacterial infection process, where nitric oxide (NO) can be generated by phagocytic cells. The denitrification regulation mechanisms have been studied intensively at genetic and biochemical levels. However, there is very little evidence about the epigenetic regulation of bacterial denitrification mechanism. P. aeruginosa TBCF10839 is a chronically host-adapted strain isolated from a cystic fibrosis (CF) patient with special antiphagocytosis characteristics. Here, we investigated the regulatory effect of an orphan DNA MTase, M.PaeTBCFII, in P. aeruginosa TBCF10839. We demonstrated that the DNA MTase regulates the transcription of denitrification genes represented by NOR and affects antiphagocytic ability in bacteria. In silico analysis suggested that DNA methylation modification may enhance gene expression by affecting the binding of transacting factors such as DNR and RpoN. Our findings not only deepen the understanding of the role of DNA MTase in transcriptional regulation in P. aeruginosa but also provide a theoretical foundation for the in-depth study of the molecular mechanism of the epigenetic regulation on denitrification, virulence, and host-pathogen interaction.
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Integration of the Salmonella Typhimurium Methylome and Transcriptome Reveals That DNA Methylation and Transcriptional Regulation Are Largely Decoupled under Virulence-Related Conditions. mBio 2022; 13:e0346421. [PMID: 35658533 PMCID: PMC9239280 DOI: 10.1128/mbio.03464-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Despite being in a golden age of bacterial epigenomics, little work has systematically examined the plasticity and functional impacts of the bacterial DNA methylome. Here, we leveraged single-molecule, real-time sequencing (SMRT-seq) to examine the m6A DNA methylome of two Salmonella enterica serovar Typhimurium strains: 14028s and a ΔmetJ mutant with derepressed methionine metabolism, grown in Luria broth or medium that simulates the intracellular environment. We found that the methylome is remarkably static: >95% of adenosine bases retain their methylation status across conditions. Integration of methylation with transcriptomic data revealed limited correlation between changes in methylation and gene expression. Further, examination of the transcriptome in ΔyhdJ bacteria lacking the m6A methylase with the most dynamic methylation pattern in our data set revealed little evidence of YhdJ-mediated gene regulation. Curiously, despite G(m6A)TC motifs being particularly resistant to change across conditions, incorporating dam mutants into our analyses revealed two examples where changes in methylation and transcription may be linked across conditions. This includes the novel finding that the ΔmetJ motility defect may be partially driven by hypermethylation of the chemotaxis gene tsr. Together, these data redefine the S. Typhimurium epigenome as a highly stable system that has rare but important roles in transcriptional regulation. Incorporating these lessons into future studies will be critical as we progress through the epigenomic era.
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Furuta Y, Miura F, Ichise T, Nakayama SMM, Ikenaka Y, Zorigt T, Tsujinouchi M, Ishizuka M, Ito T, Higashi H. A GCDGC-specific DNA (cytosine-5) methyltransferase that methylates the GCWGC sequence on both strands and the GCSGC sequence on one strand. PLoS One 2022; 17:e0265225. [PMID: 35312710 PMCID: PMC8936443 DOI: 10.1371/journal.pone.0265225] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Accepted: 02/24/2022] [Indexed: 11/18/2022] Open
Abstract
5-Methylcytosine is one of the major epigenetic marks of DNA in living organisms. Some bacterial species possess DNA methyltransferases that modify cytosines on both strands to produce fully-methylated sites or on either strand to produce hemi-methylated sites. In this study, we characterized a DNA methyltransferase that produces two sequences with different methylation patterns: one methylated on both strands and another on one strand. M.BatI is the orphan DNA methyltransferase of Bacillus anthracis coded in one of the prophages on the chromosome. Analysis of M.BatI modified DNA by bisulfite sequencing revealed that the enzyme methylates the first cytosine in sequences of 5ʹ-GCAGC-3ʹ, 5ʹ-GCTGC-3ʹ, and 5ʹ-GCGGC-3ʹ, but not of 5ʹ-GCCGC-3ʹ. This resulted in the production of fully-methylated 5ʹ-GCWGC-3ʹ and hemi-methylated 5ʹ-GCSGC-3ʹ. M.BatI also showed toxicity when expressed in E. coli, which was caused by a mechanism other than DNA modification activity. Homologs of M.BatI were found in other Bacillus species on different prophage like regions, suggesting the spread of the gene by several different phages. The discovery of the DNA methyltransferase with unique modification target specificity suggested unrevealed diversity of target sequences of bacterial cytosine DNA methyltransferase.
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Affiliation(s)
- Yoshikazu Furuta
- Division of Infection and Immunity, International Institute for Zoonosis Control, Hokkaido University, Sapporo, Japan
- * E-mail:
| | - Fumihito Miura
- Department of Biochemistry, Kyushu University Graduate School of Medical Sciences, Fukuoka, Japan
| | - Takahiro Ichise
- Laboratory of Toxicology, Department of Environmental Veterinary Sciences, School of Veterinary Medicine, Hokkaido University, Sapporo, Japan
| | - Shouta M. M. Nakayama
- Laboratory of Toxicology, Department of Environmental Veterinary Sciences, School of Veterinary Medicine, Hokkaido University, Sapporo, Japan
| | - Yoshinori Ikenaka
- Laboratory of Toxicology, Department of Environmental Veterinary Sciences, School of Veterinary Medicine, Hokkaido University, Sapporo, Japan
- Water Research Group, Unit for Environmental Sciences and Management, North-West University, Potchefstroom, South Africa
| | - Tuvshinzaya Zorigt
- Division of Infection and Immunity, International Institute for Zoonosis Control, Hokkaido University, Sapporo, Japan
| | - Mai Tsujinouchi
- Division of Infection and Immunity, International Institute for Zoonosis Control, Hokkaido University, Sapporo, Japan
| | - Mayumi Ishizuka
- Laboratory of Toxicology, Department of Environmental Veterinary Sciences, School of Veterinary Medicine, Hokkaido University, Sapporo, Japan
| | - Takashi Ito
- Department of Biochemistry, Kyushu University Graduate School of Medical Sciences, Fukuoka, Japan
| | - Hideaki Higashi
- Division of Infection and Immunity, International Institute for Zoonosis Control, Hokkaido University, Sapporo, Japan
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Lewis EB, Chen E, Culyba MJ. DNA cytosine methylation at the lexA promoter of Escherichia coli is stationary phase specific. G3 (BETHESDA, MD.) 2022; 12:6444991. [PMID: 34849799 PMCID: PMC9210283 DOI: 10.1093/g3journal/jkab409] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Accepted: 11/18/2021] [Indexed: 01/09/2023]
Abstract
The bacterial DNA damage response pathway (SOS response) is composed of a network of genes regulated by a single transcriptional repressor, LexA. The lexA promoter, itself, contains two LexA operators, enabling negative feedback. In Escherichia coli, the downstream operator contains a conserved DNA cytosine methyltransferase (Dcm) site that is predicted to be methylated to 5-methylcytosine (5mC) specifically during stationary phase growth, suggesting a regulatory role for DNA methylation in the SOS response. To test this, we quantified 5mC at the lexA locus, and then examined the effect of LexA on Dcm activity, as well as the impact of this 5mC mark on LexA binding, lexA transcription, and SOS response induction. We found that 5mC at the lexA promoter is specific to stationary phase growth, but that it does not affect lexA expression. Our data support a model where LexA binding at the promoter inhibits Dcm activity without an effect on the SOS regulon.
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Affiliation(s)
- Elizabeth B Lewis
- Division of Infectious Diseases, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
| | - Edwin Chen
- Division of Infectious Diseases, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
| | - Matthew J Culyba
- Division of Infectious Diseases, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
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DNA Methylation in Prokaryotes. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2022; 1389:21-43. [DOI: 10.1007/978-3-031-11454-0_2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Meng B, Epp N, Wijaya W, Mrázek J, Hoover TR. Methylation Motifs in Promoter Sequences May Contribute to the Maintenance of a Conserved m5C Methyltransferase in Helicobacter pylori. Microorganisms 2021; 9:microorganisms9122474. [PMID: 34946076 PMCID: PMC8706393 DOI: 10.3390/microorganisms9122474] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Revised: 11/23/2021] [Accepted: 11/25/2021] [Indexed: 01/22/2023] Open
Abstract
DNA methylomes of Helicobacter pylori strains are complex due to the large number of DNA methyltransferases (MTases) they possess. H. pylori J99 M.Hpy99III is a 5-methylcytosine (m5C) MTase that converts GCGC motifs to Gm5CGC. Homologs of M.Hpy99III are found in essentially all H. pylori strains. Most of these homologs are orphan MTases that lack a cognate restriction endonuclease, and their retention in H. pylori strains suggest they have roles in gene regulation. To address this hypothesis, green fluorescent protein (GFP) reporter genes were constructed with six putative promoters that had a GCGC motif in the extended −10 region, and the expression of the reporter genes was compared in wild-type H. pylori G27 and a mutant lacking the M.Hpy99III homolog (M.HpyGIII). The expression of three of the GFP reporter genes was decreased significantly in the mutant lacking M.HpyGIII. In addition, the growth rate of the H. pylori G27 mutant lacking M.HpyGIII was reduced markedly compared to that of the wild type. These findings suggest that the methylation of the GCGC motif in many H. pylori GCGC-containing promoters is required for the robust expression of genes controlled by these promoters, which may account for the universal retention of M.Hpy99III homologs in H. pylori strains.
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Affiliation(s)
- Bowen Meng
- Department of Microbiology, University of Georgia, Athens, GA 30602, USA; (B.M.); (N.E.); (W.W.)
| | - Naomi Epp
- Department of Microbiology, University of Georgia, Athens, GA 30602, USA; (B.M.); (N.E.); (W.W.)
| | - Winsen Wijaya
- Department of Microbiology, University of Georgia, Athens, GA 30602, USA; (B.M.); (N.E.); (W.W.)
| | - Jan Mrázek
- Department of Microbiology and Institute of Bioinformatics, University of Georgia, Athens, GA 30602, USA;
| | - Timothy R. Hoover
- Department of Microbiology, University of Georgia, Athens, GA 30602, USA; (B.M.); (N.E.); (W.W.)
- Correspondence: ; Tel.: +1-706-542-2675
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10
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Carvalho A, Mazel D, Baharoglu Z. Deficiency in cytosine DNA methylation leads to high chaperonin expression and tolerance to aminoglycosides in Vibrio cholerae. PLoS Genet 2021; 17:e1009748. [PMID: 34669693 PMCID: PMC8559950 DOI: 10.1371/journal.pgen.1009748] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Revised: 11/01/2021] [Accepted: 10/04/2021] [Indexed: 12/11/2022] Open
Abstract
Antibiotic resistance has become a major global issue. Understanding the molecular mechanisms underlying microbial adaptation to antibiotics is of keen importance to fight Antimicrobial Resistance (AMR). Aminoglycosides are a class of antibiotics that target the small subunit of the bacterial ribosome, disrupting translational fidelity and increasing the levels of misfolded proteins in the cell. In this work, we investigated the role of VchM, a DNA methyltransferase, in the response of the human pathogen Vibrio cholerae to aminoglycosides. VchM is a V. cholerae specific orphan m5C DNA methyltransferase that generates cytosine methylation at 5'-RCCGGY-3' motifs. We show that deletion of vchM, although causing a growth defect in absence of stress, allows V. cholerae cells to cope with aminoglycoside stress at both sub-lethal and lethal concentrations of these antibiotics. Through transcriptomic and genetic approaches, we show that groESL-2 (a specific set of chaperonin-encoding genes located on the second chromosome of V. cholerae), are upregulated in cells lacking vchM and are needed for the tolerance of vchM mutant to lethal aminoglycoside treatment, likely by fighting aminoglycoside-induced misfolded proteins. Interestingly, preventing VchM methylation of the four RCCGGY sites located in groESL-2 region, leads to a higher expression of these genes in WT cells, showing that the expression of these chaperonins is modulated in V. cholerae by DNA methylation.
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Affiliation(s)
- André Carvalho
- Département Génomes et Génétique, Institut Pasteur, UMR3525, CNRS, Unité Plasticité du Génome Bactérien, Paris, France
- Sorbonne Université, Collège doctoral, F-75005 Paris, France
| | - Didier Mazel
- Département Génomes et Génétique, Institut Pasteur, UMR3525, CNRS, Unité Plasticité du Génome Bactérien, Paris, France
| | - Zeynep Baharoglu
- Département Génomes et Génétique, Institut Pasteur, UMR3525, CNRS, Unité Plasticité du Génome Bactérien, Paris, France
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Mehershahi KS, Chen SL. DNA methylation by three Type I restriction modification systems of Escherichia coli does not influence gene regulation of the host bacterium. Nucleic Acids Res 2021; 49:7375-7388. [PMID: 34181709 PMCID: PMC8287963 DOI: 10.1093/nar/gkab530] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 06/01/2021] [Accepted: 06/22/2021] [Indexed: 12/13/2022] Open
Abstract
DNA methylation is a common epigenetic mark that influences transcriptional regulation, and therefore cellular phenotype, across all domains of life. In particular, both orphan methyltransferases and those from phasevariable restriction modification systems (RMSs) have been co-opted to regulate virulence epigenetically in many bacteria. We now show that three distinct non-phasevariable Type I RMSs in Escherichia coli have no measurable impact on gene expression, in vivo virulence, or any of 1190 in vitro growth phenotypes. We demonstrated this using both Type I RMS knockout mutants as well as heterologous installation of Type I RMSs into two E. coli strains. These data provide three clear and currently rare examples of restriction modification systems that have no impact on their host organism’s gene regulation. This leads to the possibility that other such nonregulatory methylation systems may exist, broadening our view of the potential role that RMSs may play in bacterial evolution.
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Affiliation(s)
- Kurosh S Mehershahi
- NUHS Infectious Diseases Translational Research Programme, Department of Medicine, Division of Infectious Diseases, Yong Loo Lin School of Medicine, Singapore 119228
| | - Swaine L Chen
- NUHS Infectious Diseases Translational Research Programme, Department of Medicine, Division of Infectious Diseases, Yong Loo Lin School of Medicine, Singapore 119228.,Laboratory of Bacterial Genomics, Genome Institute of Singapore, Singapore 138672
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Anton BP, Roberts RJ. Beyond Restriction Modification: Epigenomic Roles of DNA Methylation in Prokaryotes. Annu Rev Microbiol 2021; 75:129-149. [PMID: 34314594 DOI: 10.1146/annurev-micro-040521-035040] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The amount of bacterial and archaeal genome sequence and methylome data has greatly increased over the last decade, enabling new insights into the functional roles of DNA methylation in these organisms. Methyltransferases (MTases), the enzymes responsible for DNA methylation, are exchanged between prokaryotes through horizontal gene transfer and can function either as part of restriction-modification systems or in apparent isolation as single (orphan) genes. The patterns of DNA methylation they confer on the host chromosome can have significant effects on gene expression, DNA replication, and other cellular processes. Some processes require very stable patterns of methylation, resulting in conservation of persistent MTases in a particular lineage. Other processes require patterns that are more dynamic yet more predictable than what is afforded by horizontal gene transfer and gene loss, resulting in phase-variable or recombination-driven MTase alleles. In this review, we discuss what is currently known about the functions of DNA methylation in prokaryotes in light of these evolutionary patterns. Expected final online publication date for the Annual Review of Microbiology, Volume 75 is October 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Brian P Anton
- New England Biolabs, Ipswich, Massachusetts 01938, USA; ,
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Gaultney RA, Vincent AT, Lorioux C, Coppée JY, Sismeiro O, Varet H, Legendre R, Cockram CA, Veyrier F, Picardeau M. 4-Methylcytosine DNA modification is critical for global epigenetic regulation and virulence in the human pathogen Leptospira interrogans. Nucleic Acids Res 2020; 48:12102-12115. [PMID: 33301041 PMCID: PMC7708080 DOI: 10.1093/nar/gkaa966] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Revised: 10/01/2020] [Accepted: 10/13/2020] [Indexed: 12/25/2022] Open
Abstract
In bacteria, DNA methylation can be facilitated by 'orphan' DNA methyltransferases lacking cognate restriction endonucleases, but whether and how these enzymes control key cellular processes are poorly understood. The effects of a specific modification, 4-methylcytosine (4mC), are even less clear, as this epigenetic marker is unique to bacteria and archaea, whereas the bulk of epigenetic research is currently performed on eukaryotes. Here, we characterize a 4mC methyltransferase from the understudied pathogen Leptospira spp. Inactivating this enzyme resulted in complete abrogation of CTAG motif methylation, leading to genome-wide dysregulation of gene expression. Mutants exhibited growth defects, decreased adhesion to host cells, higher susceptibility to LPS-targeting antibiotics, and, importantly, were no longer virulent in an acute infection model. Further investigation resulted in the discovery of at least one gene, that of an ECF sigma factor, whose transcription was altered in the methylase mutant and, subsequently, by mutation of the CTAG motifs in the promoter of the gene. The genes that comprise the regulon of this sigma factor were, accordingly, dysregulated in the methylase mutant and in a strain overexpressing the sigma factor. Our results highlight the importance of 4mC in Leptospira physiology, and suggest the same of other understudied species.
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Affiliation(s)
| | - Antony T Vincent
- Bacterial Symbionts Evolution, INRS-Centre Armand-Frappier, Laval, Quebec, Canada
| | - Céline Lorioux
- Unité Biologie des Spirochètes, Institut Pasteur, Paris, France
| | - Jean-Yves Coppée
- Transcriptome and Epigenome Platform, Biomics, Center for Technological Resources and Research (C2RT), Institut Pasteur, Paris, France
| | - Odile Sismeiro
- Transcriptome and Epigenome Platform, Biomics, Center for Technological Resources and Research (C2RT), Institut Pasteur, Paris, France
| | - Hugo Varet
- Transcriptome and Epigenome Platform, Biomics, Center for Technological Resources and Research (C2RT), Institut Pasteur, Paris, France
- Bioinformatics and Biostatistics Hub, Department of Computational Biology, USR 3756 CNRS, Institut Pasteur, Paris, France
| | - Rachel Legendre
- Transcriptome and Epigenome Platform, Biomics, Center for Technological Resources and Research (C2RT), Institut Pasteur, Paris, France
- Bioinformatics and Biostatistics Hub, Department of Computational Biology, USR 3756 CNRS, Institut Pasteur, Paris, France
| | | | - Frédéric J Veyrier
- Bacterial Symbionts Evolution, INRS-Centre Armand-Frappier, Laval, Quebec, Canada
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14
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Jensen TØ, Tellgren-Roth C, Redl S, Maury J, Jacobsen SAB, Pedersen LE, Nielsen AT. Genome-wide systematic identification of methyltransferase recognition and modification patterns. Nat Commun 2019; 10:3311. [PMID: 31427571 PMCID: PMC6700114 DOI: 10.1038/s41467-019-11179-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Accepted: 06/27/2019] [Indexed: 01/25/2023] Open
Abstract
Genome-wide analysis of DNA methylation patterns using single molecule real-time DNA sequencing has boosted the number of publicly available methylomes. However, there is a lack of tools coupling methylation patterns and the corresponding methyltransferase genes. Here we demonstrate a high-throughput method for coupling methyltransferases with their respective motifs, using automated cloning and analysing the methyltransferases in vectors carrying a strain-specific cassette containing all potential target sites. To validate the method, we analyse the genomes of the thermophile Moorella thermoacetica and the mesophile Acetobacterium woodii, two acetogenic bacteria having substantially modified genomes with 12 methylation motifs and a total of 23 methyltransferase genes. Using our method, we characterize the 23 methyltransferases, assign motifs to the respective enzymes and verify activity for 11 of the 12 motifs. Single molecule real-time DNA sequencing allows genome-wide identification of DNA methylation patterns. Here, Jensen et al. present a high-throughput method that allows rapid coupling of DNA methylation patterns with their corresponding methyltransferase genes in bacteria.
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Affiliation(s)
- Torbjørn Ølshøj Jensen
- The Novo Nordisk Foundation Center for Biosustainability (CfB), Technical University of Denmark (DTU), DK-2800, Lyngby, Denmark
| | - Christian Tellgren-Roth
- Uppsala Genome Center, National Genomics Infrastructure, SciLifeLab, SE-751 08, Uppsala, Sweden
| | - Stephanie Redl
- The Novo Nordisk Foundation Center for Biosustainability (CfB), Technical University of Denmark (DTU), DK-2800, Lyngby, Denmark.,Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Jérôme Maury
- The Novo Nordisk Foundation Center for Biosustainability (CfB), Technical University of Denmark (DTU), DK-2800, Lyngby, Denmark
| | | | - Lasse Ebdrup Pedersen
- The Novo Nordisk Foundation Center for Biosustainability (CfB), Technical University of Denmark (DTU), DK-2800, Lyngby, Denmark
| | - Alex Toftgaard Nielsen
- The Novo Nordisk Foundation Center for Biosustainability (CfB), Technical University of Denmark (DTU), DK-2800, Lyngby, Denmark.
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15
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Conrad JW, Harwood VJ. Comparison of DNA Methylation in Vibrio vulnificus Cells Grown in Human Serum with Those Grown in Seawater. Microbiol Resour Announc 2019; 8:e00419-19. [PMID: 31320429 PMCID: PMC6639608 DOI: 10.1128/mra.00419-19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Accepted: 06/13/2019] [Indexed: 11/20/2022] Open
Abstract
The chromosomal methylation statuses of the highly virulent Vibrio vulnificus strain CMCP6 grown in human serum and in seawater are compared here. Growth in seawater resulted in ∼4 times as much methylation as that in human serum, primarily N4-methylcytosines.
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Affiliation(s)
- James W Conrad
- Department of Integrative Biology, University of South Florida, Tampa, Florida, USA
| | - Valerie J Harwood
- Department of Integrative Biology, University of South Florida, Tampa, Florida, USA
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16
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Peschek N, Hoyos M, Herzog R, Förstner KU, Papenfort K. A conserved RNA seed-pairing domain directs small RNA-mediated stress resistance in enterobacteria. EMBO J 2019; 38:e101650. [PMID: 31313835 PMCID: PMC6694218 DOI: 10.15252/embj.2019101650] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Revised: 05/31/2019] [Accepted: 06/09/2019] [Indexed: 12/20/2022] Open
Abstract
Small regulatory RNAs (sRNAs) are crucial components of many stress response systems. The envelope stress response (ESR) of Gram‐negative bacteria is a paradigm for sRNA‐mediated stress management and involves, among other factors, the alternative sigma factor E (σE) and one or more sRNAs. In this study, we identified the MicV sRNA as a new member of the σE regulon in Vibrio cholerae. We show that MicV acts redundantly with another sRNA, VrrA, and that both sRNAs share a conserved seed‐pairing domain allowing them to regulate multiple target mRNAs. V. cholerae lacking σE displayed increased sensitivity toward antimicrobials, and over‐expression of either of the sRNAs suppressed this phenotype. Laboratory selection experiments using a library of synthetic sRNA regulators revealed that the seed‐pairing domain of σE‐dependent sRNAs is strongly enriched among sRNAs identified under membrane‐damaging conditions and that repression of OmpA is crucial for sRNA‐mediated stress relief. Together, our work shows that MicV and VrrA act as global regulators in the ESR of V. cholerae and provides evidence that bacterial sRNAs can be functionally annotated by their seed‐pairing sequences.
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Affiliation(s)
- Nikolai Peschek
- Faculty of Biology I, Department of Microbiology, Ludwig-Maximilians-University of Munich, Martinsried, Germany.,Munich Center for Integrated Protein Science (CIPSM), Munich, Germany
| | - Mona Hoyos
- Faculty of Biology I, Department of Microbiology, Ludwig-Maximilians-University of Munich, Martinsried, Germany
| | - Roman Herzog
- Faculty of Biology I, Department of Microbiology, Ludwig-Maximilians-University of Munich, Martinsried, Germany
| | - Konrad U Förstner
- Institute of Information Science, TH Köln - University of Applied Sciences, Cologne, Germany.,ZB MED - Information Centre for Life Sciences, Cologne, Germany
| | - Kai Papenfort
- Faculty of Biology I, Department of Microbiology, Ludwig-Maximilians-University of Munich, Martinsried, Germany.,Munich Center for Integrated Protein Science (CIPSM), Munich, Germany
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17
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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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18
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Park HJ, Jung B, Lee J, Han SW. Functional characterization of a putative DNA methyltransferase, EadM, in Xanthomonas axonopodis pv. glycines by proteomic and phenotypic analyses. Sci Rep 2019; 9:2446. [PMID: 30792399 PMCID: PMC6385262 DOI: 10.1038/s41598-019-38650-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Accepted: 01/02/2019] [Indexed: 11/13/2022] Open
Abstract
Xanthomonas axonopodis pv. glycines (Xag) is a phytopathogenic bacterium causing bacterial pustule disease in soybean. Functions of DNA methyltransferases have been characterized in animal pathogenic bacteria, but are poorly understood in plant pathogens. Here, we report that functions of a putative DNA methyltransferase, EadM, in Xag. An EadM-overexpressing strain, Xag(EadM), was less virulent than the wild-type carrying an empty vector, Xag(EV). Interestingly, the viable cell numbers of Xag(EadM) were much lower (10-fold) than those of Xag(EV) at the same optical density. Comparative proteomic analysis revealed that proteins involved in cell wall/membrane/envelope and iron-transport were more abundant. Based on proteomic analysis we carried out diverse phenotypic assays. Scanning electron microscopy revealed abnormal bacterial envelopes in Xag(EadM). Additionally, Xag(EadM) showed decreased stress tolerance against ciprofloxacin and sorbitol, but enhanced resistance to desiccation. Exopolysaccharide production in Xag(EadM) was also decreased. Production of siderophores, which are iron-chelators, was much higher in Xag(EadM). As in Xag, Escherichia coli expressing EadM showed significantly reduced (1000-fold) viable cell numbers at the same optical density. Thus, EadM is associated with virulence, envelope biogenesis, stress tolerance, exopolysaccharide production, and siderophore production. Our results provide valuable and fundamental information regarding DNA methyltransferase functions and their related cellular mechanisms in plant pathogenic bacteria.
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Affiliation(s)
- Hye-Jee Park
- Department of Integrative Plant Science, Chung-Ang University, Anseong, 17546, Republic of Korea
| | - Boknam Jung
- Department of Applied Biology, Dong-A University, Busan, 49315, Republic of Korea
| | - Jungkwan Lee
- Department of Applied Biology, Dong-A University, Busan, 49315, Republic of Korea
| | - Sang-Wook Han
- Department of Integrative Plant Science, Chung-Ang University, Anseong, 17546, Republic of Korea.
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19
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The RNA degradosome promotes tRNA quality control through clearance of hypomodified tRNA. Proc Natl Acad Sci U S A 2019; 116:1394-1403. [PMID: 30622183 DOI: 10.1073/pnas.1814130116] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
The factors and mechanisms that govern tRNA stability in bacteria are not well understood. Here, we investigated the influence of posttranscriptional modification of bacterial tRNAs (tRNA modification) on tRNA stability. We focused on ThiI-generated 4-thiouridine (s4U), a modification found in bacterial and archaeal tRNAs. Comprehensive quantification of Vibrio cholerae tRNAs revealed that the abundance of some tRNAs is decreased in a ΔthiI strain in a stationary phase-specific manner. Multiple mechanisms, including rapid degradation of a subset of hypomodified tRNAs, account for the reduced abundance of tRNAs in the absence of thiI Through transposon insertion sequencing, we identified additional tRNA modifications that promote tRNA stability and bacterial viability. Genetic analysis of suppressor mutants as well as biochemical analyses revealed that rapid degradation of hypomodified tRNA is mediated by the RNA degradosome. Elongation factor Tu seems to compete with the RNA degradosome, protecting aminoacyl tRNAs from decay. Together, our observations describe a previously unrecognized bacterial tRNA quality control system in which hypomodification sensitizes tRNAs to decay mediated by the RNA degradosome.
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20
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Poulter RTM, Ho J, Handley T, Taiaroa G, Butler MI. Comparison between complete genomes of an isolate of Pseudomonas syringae pv. actinidiae from Japan and a New Zealand isolate of the pandemic lineage. Sci Rep 2018; 8:10915. [PMID: 30026612 PMCID: PMC6053426 DOI: 10.1038/s41598-018-29261-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Accepted: 07/09/2018] [Indexed: 11/21/2022] Open
Abstract
The modern pandemic of the bacterial kiwifruit pathogen Pseudomonas syringae pv actinidiae (Psa) is caused by a particular Psa lineage. To better understand the genetic basis of the virulence of this lineage, we compare the completely assembled genome of a pandemic New Zealand strain with that of the Psa type strain first isolated in Japan in 1983. Aligning the two genomes shows numerous translocations, constrained so as to retain the appropriate orientation of the Architecture Imparting Sequences (AIMs). There are several large horizontally acquired regions, some of which include Type I, Type II or Type III restriction systems. The activity of these systems is reflected in the methylation patterns of the two strains. The pandemic strain carries an Integrative Conjugative Element (ICE) located at a tRNA-Lys site. Two other complex elements are also present at tRNA-Lys sites in the genome. These elements are derived from ICE but have now acquired some alternative secretion function. There are numerous types of mobile element in the two genomes. Analysis of these elements reveals no evidence of recombination between the two Psa lineages.
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Affiliation(s)
| | - Joycelyn Ho
- Department of Biochemistry, University of Otago, Dunedin, New Zealand
| | - Thomas Handley
- Department of Biochemistry, University of Otago, Dunedin, New Zealand
| | - George Taiaroa
- Department of Biochemistry, University of Otago, Dunedin, New Zealand
| | - Margi I Butler
- Department of Biochemistry, University of Otago, Dunedin, New Zealand.
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21
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Abstract
Vibrio is a genus of ubiquitous bacteria found in a wide variety of aquatic and marine habitats; of the >100 described Vibrio spp., ~12 cause infections in humans. Vibrio cholerae can cause cholera, a severe diarrhoeal disease that can be quickly fatal if untreated and is typically transmitted via contaminated water and person-to-person contact. Non-cholera Vibrio spp. (for example, Vibrio parahaemolyticus, Vibrio alginolyticus and Vibrio vulnificus) cause vibriosis - infections normally acquired through exposure to sea water or through consumption of raw or undercooked contaminated seafood. Non-cholera bacteria can lead to several clinical manifestations, most commonly mild, self-limiting gastroenteritis, with the exception of V. vulnificus, an opportunistic pathogen with a high mortality that causes wound infections that can rapidly lead to septicaemia. Treatment for Vibrio spp. infection largely depends on the causative pathogen: for example, rehydration therapy for V. cholerae infection and debridement of infected tissues for V. vulnificus-associated wound infections, with antibiotic therapy for severe cholera and systemic infections. Although cholera is preventable and effective oral cholera vaccines are available, outbreaks can be triggered by natural or man-made events that contaminate drinking water or compromise access to safe water and sanitation. The incidence of vibriosis is rising, perhaps owing in part to the spread of Vibrio spp. favoured by climate change and rising sea water temperature.
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22
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Erickson KE, Winkler JD, Nguyen DT, Gill RT, Chatterjee A. The Tolerome: A Database of Transcriptome-Level Contributions to Diverse Escherichia coli Resistance and Tolerance Phenotypes. ACS Synth Biol 2017; 6:2302-2315. [PMID: 29017328 DOI: 10.1021/acssynbio.7b00235] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Tolerance and resistance are complex biological phenotypes that are desirable bioengineering goals for those seeking to design industrial strains or prevent the spread of antibiotic resistance. Over decades of research, a wealth of information has been generated to attempt to decode a molecular basis for tolerance, but to fully achieve the goal of engineering tolerance, researchers must be able to easily learn from a variety of data sources. To this end, we here describe a resource designed to enable scrutiny of diverse tolerance phenotypes. We have curated hundreds of gene expression studies exploring the response of Escherichia coli to chemical and environmental perturbations, from antibiotics to biofuels and solvents and more. Overall, our efforts give rise to a database encompassing more than 56 000 gene expression changes across 89 different stress conditions. This resource is designed for compatibility with the Resistome database, which includes more than 5000 strains with mutations conferring resistance or sensitivity but no transcriptomic data. Thus, the work here results in the first combined resource specialized to tolerance and resistance in E. coli that supports investigations across genomic, transcriptomic, and phenotypic levels. We leverage the database to identify promising bioengineering targets by searching globally across multiple stress conditions as well as by narrowing the focus to fewer conditions of interest, such as biofuel stress and antibiotic stress. We discuss some of the most frequently differentially expressed or coexpressed genes, and predict which transcription factors and sigma factors most likely contribute to gene expression profiles in a wide array of conditions. We also compare profiles from sensitive and resistant strains, gaining knowledge of how responses differ per overrepresented gene ontology terms. Finally, we search for genes that are frequently differentially expressed but not mutated, with the expectation that these may present interesting targets for future engineering efforts. The curated data presented here is publicly available, and should be advantageous to those studying a variety of bacterial tolerance phenotypes.
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Affiliation(s)
- Keesha E. Erickson
- Chemical & Biological Engineering, University of Colorado, Boulder, Colorado 80301, United States
| | - James D. Winkler
- Chemical & Biological Engineering, University of Colorado, Boulder, Colorado 80301, United States
| | - Danh T. Nguyen
- Chemical & Biological Engineering, University of Colorado, Boulder, Colorado 80301, United States
| | - Ryan T. Gill
- Chemical & Biological Engineering, University of Colorado, Boulder, Colorado 80301, United States
| | - Anushree Chatterjee
- Chemical & Biological Engineering, University of Colorado, Boulder, Colorado 80301, United States
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23
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Srikhanta YN, Gorrell RJ, Power PM, Tsyganov K, Boitano M, Clark TA, Korlach J, Hartland EL, Jennings MP, Kwok T. Methylomic and phenotypic analysis of the ModH5 phasevarion of Helicobacter pylori. Sci Rep 2017; 7:16140. [PMID: 29170397 PMCID: PMC5700931 DOI: 10.1038/s41598-017-15721-x] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Accepted: 10/31/2017] [Indexed: 12/20/2022] Open
Abstract
The Helicobacter pylori phase variable gene modH, typified by gene HP1522 in strain 26695, encodes a N6-adenosine type III DNA methyltransferase. Our previous studies identified multiple strain-specific modH variants (modH1 – modH19) and showed that phase variation of modH5 in H. pylori P12 influenced expression of motility-associated genes and outer membrane protein gene hopG. However, the ModH5 DNA recognition motif and the mechanism by which ModH5 controls gene expression were unknown. Here, using comparative single molecule real-time sequencing, we identify the DNA site methylated by ModH5 as 5′-Gm6ACC-3′. This motif is vastly underrepresented in H. pylori genomes, but overrepresented in a number of virulence genes, including motility-associated genes, and outer membrane protein genes. Motility and the number of flagella of H. pylori P12 wild-type were significantly higher than that of isogenic modH5 OFF or ΔmodH5 mutants, indicating that phase variable switching of modH5 expression plays a role in regulating H. pylori motility phenotypes. Using the flagellin A (flaA) gene as a model, we show that ModH5 modulates flaA promoter activity in a GACC methylation-dependent manner. These findings provide novel insights into the role of ModH5 in gene regulation and how it mediates epigenetic regulation of H. pylori motility.
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Affiliation(s)
- Yogitha N Srikhanta
- Department of Microbiology, Monash University, Clayton, 3800, Victoria, Australia.,Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Parkville, 3010, Victoria, Australia.,Infection and Immunity Program, Biomedicine Discovery Institute, Monash University, Clayton, 3800, Victoria, Australia
| | - Rebecca J Gorrell
- Department of Microbiology, Monash University, Clayton, 3800, Victoria, Australia.,Infection and Immunity Program, Biomedicine Discovery Institute, Monash University, Clayton, 3800, Victoria, Australia.,Department of Biochemistry and Molecular Biology, Monash University, Clayton, 3800, Victoria, Australia.,Cancer Program, Biomedicine Discovery Institute, Monash University, Clayton, 3800, Victoria, Australia
| | - Peter M Power
- Institute for Glycomics, Griffith University, Gold Coast, Queensland, 4222, Australia
| | - Kirill Tsyganov
- Bioinformatics Platform, Monash University, Clayton, 3800, Victoria, Australia
| | | | | | | | - Elizabeth L Hartland
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Parkville, 3010, Victoria, Australia.,Department of Molecular and Translational Science, Hudson Institute of Medical Research, Monash University, Clayton, 3800, Victoria, Australia
| | - Michael P Jennings
- Institute for Glycomics, Griffith University, Gold Coast, Queensland, 4222, Australia.
| | - Terry Kwok
- Department of Microbiology, Monash University, Clayton, 3800, Victoria, Australia. .,Infection and Immunity Program, Biomedicine Discovery Institute, Monash University, Clayton, 3800, Victoria, Australia. .,Department of Biochemistry and Molecular Biology, Monash University, Clayton, 3800, Victoria, Australia. .,Cancer Program, Biomedicine Discovery Institute, Monash University, Clayton, 3800, Victoria, Australia.
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24
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Identification of a Pseudomonas aeruginosa PAO1 DNA Methyltransferase, Its Targets, and Physiological Roles. mBio 2017; 8:mBio.02312-16. [PMID: 28223461 PMCID: PMC5358918 DOI: 10.1128/mbio.02312-16] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
DNA methylation is widespread among prokaryotes, and most DNA methylation reactions are catalyzed by adenine DNA methyltransferases, which are part of restriction-modification (R-M) systems. R-M systems are known for their role in the defense against foreign DNA; however, DNA methyltransferases also play functional roles in gene regulation. In this study, we used single-molecule real-time (SMRT) sequencing to uncover the genome-wide DNA methylation pattern in the opportunistic pathogen Pseudomonas aeruginosa PAO1. We identified a conserved sequence motif targeted by an adenine methyltransferase of a type I R-M system and quantified the presence of N6-methyladenine using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Changes in the PAO1 methylation status were dependent on growth conditions and affected P. aeruginosa pathogenicity in a Galleria mellonella infection model. Furthermore, we found that methylated motifs in promoter regions led to shifts in sense and antisense gene expression, emphasizing the role of enzymatic DNA methylation as an epigenetic control of phenotypic traits in P. aeruginosa. Since the DNA methylation enzymes are not encoded in the core genome, our findings illustrate how the acquisition of accessory genes can shape the global P. aeruginosa transcriptome and thus may facilitate adaptation to new and challenging habitats. With the introduction of advanced technologies, epigenetic regulation by DNA methyltransferases in bacteria has become a subject of intense studies. Here we identified an adenosine DNA methyltransferase in the opportunistic pathogen Pseudomonas aeruginosa PAO1, which is responsible for DNA methylation of a conserved sequence motif. The methylation level of all target sequences throughout the PAO1 genome was approximated to be in the range of 65 to 85% and was dependent on growth conditions. Inactivation of the methyltransferase revealed an attenuated-virulence phenotype in the Galleria mellonella infection model. Furthermore, differential expression of more than 90 genes was detected, including the small regulatory RNA prrF1, which contributes to a global iron-sparing response via the repression of a set of gene targets. Our finding of a methylation-dependent repression of the antisense transcript of the prrF1 small regulatory RNA significantly expands our understanding of the regulatory mechanisms underlying active DNA methylation in bacteria.
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25
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Abstract
UNLABELLED Transposon insertion sequencing (TIS; also known as TnSeq) is a potent approach commonly used to comprehensively define the genetic loci that contribute to bacterial fitness in diverse environments. A key presumption underlying analyses of TIS datasets is that loci with a low frequency of transposon insertions contribute to fitness. However, it is not known whether factors such as nucleoid binding proteins can alter the frequency of transposon insertion and thus whether TIS output may systematically reflect factors that are independent of the role of the loci in fitness. Here, we investigated whether the histone-like nucleoid structuring (H-NS) protein, which preferentially associates with AT-rich sequences, modulates the frequency of Mariner transposon insertion in the Vibrio cholerae genome, using comparative analysis of TIS results from wild-type (wt) and Δhns V. cholerae strains. These analyses were overlaid on gene classification based on GC content as well as on extant genome-wide identification of H-NS binding loci. Our analyses revealed a significant dearth of insertions within AT-rich loci in wt V. cholerae that was not apparent in the Δhns insertion library. Additionally, we observed a striking correlation between genetic loci that are overrepresented in the Δhns insertion library relative to their insertion frequency in wt V. cholerae and loci previously found to physically interact with H-NS. Collectively, our findings reveal that factors other than genetic fitness can systematically modulate the frequency of transposon insertions in TIS studies and add a cautionary note to interpretation of TIS data, particularly for AT-rich sequences. IMPORTANCE Transposon insertion sequencing (TIS) is often used to assess the relative frequency with which genetic loci can be disrupted, which is taken as an indicator of their importance for bacterial fitness. Here, we report that biological factors other than the relative levels of fitness of insertion mutants can influence TIS output. We found that the presence of the DNA binding protein H-NS, which preferentially recognizes AT-rich sequences, is linked to significant underrepresentation of mutations within AT-rich loci in transposon insertion libraries. Furthermore, there is a marked correspondence between loci bound by H-NS and loci with an increased frequency of disruption in a Δhns insertion library relative to a wt library. Our data suggest that factors other than genetic fitness (e.g., DNA binding proteins such as H-NS) can systematically modulate the frequency of transposon insertions in TIS studies and add a note of caution for interpretation of TIS data.
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Casadesús J. Bacterial DNA Methylation and Methylomes. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 945:35-61. [PMID: 27826834 DOI: 10.1007/978-3-319-43624-1_3] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
Formation of C5-methylcytosine, N4-methylcytosine, and N6-methyladenine in bacterial genomes is postreplicative and involves transfer of a methyl group from S-adenosyl-methionine to a base embedded in a specific DNA sequence context. Most bacterial DNA methyltransferases belong to restriction-modification systems; in addition, "solitary" or "orphan" DNA methyltransferases are frequently found in the genomes of bacteria and phage. Base methylation can affect the interaction of DNA-binding proteins with their cognate sites, either by a direct effect (e.g., steric hindrance) or by changes in DNA topology. In both Alphaproteobacteria and Gammaproteobacteria, the roles of DNA base methylation are especially well known for N6-methyladenine, including control of chromosome replication, nucleoid segregation, postreplicative correction of DNA mismatches, cell cycle-coupled transcription, formation of bacterial cell lineages, and regulation of bacterial virulence. Technical procedures that permit genome-wide analysis of DNA methylation are nowadays expanding our knowledge of the extent, evolution, and physiological significance of bacterial DNA methylation.
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Affiliation(s)
- Josep Casadesús
- Departamento de Genética, Universidad de Sevilla, Apartado 1095, Seville, 41080, Spain.
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Chao MC, Zhu S, Kimura S, Davis BM, Schadt EE, Fang G, Waldor MK. Correction: A Cytosine Methytransferase Modulates the Cell Envelope Stress Response in the Cholera Pathogen. PLoS Genet 2015; 11:e1005739. [PMID: 26657207 PMCID: PMC4747549 DOI: 10.1371/journal.pgen.1005739] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
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