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Campbell M, Barton IS, Roop RM, Chien P. Comparison of CcrM-dependent methylation in Caulobacter crescentus and Brucella abortus by nanopore sequencing. J Bacteriol 2024; 206:e0008324. [PMID: 38722176 PMCID: PMC11332171 DOI: 10.1128/jb.00083-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Accepted: 04/05/2024] [Indexed: 05/21/2024] Open
Abstract
Bacteria rely on DNA methylation for restriction-modification systems and epigenetic control of gene expression. Here, we use direct detection of methylated bases by nanopore sequencing to monitor global DNA methylation in Alphaproteobacteria, where use of this technique has not yet been reported. One representative of this order, Caulobacter crescentus, relies on DNA methylation to control cell cycle progression, but it is unclear whether other members of this order, such as Brucella abortus, depend on the same systems. We addressed these questions by first measuring CcrM-dependent DNA methylation in Caulobacter and showing excellent correlation between nanopore-based detection and previously published results. We then directly measure the impact of Lon-mediated CcrM degradation on the epigenome, verifying that loss of Lon results in pervasive methylation. We also show that the AlkB demethylase has no global impact on DNA methylation during normal growth. Next, we report on the global DNA methylation in B. abortus for the first time and find that CcrM-dependent methylation is reliant on Lon but impacts the two chromosomes differently. Finally, we explore the impact of the MucR transcription factor, known to compete with CcrM methylation, on the Brucella methylome and share the results with a publicly available visualization package. Our work demonstrates the utility of nanopore-based sequencing for epigenome measurements in Alphaproteobacteria and reveals new features of CcrM-dependent methylation in a zoonotic pathogen.IMPORTANCEDNA methylation plays an important role in bacteria, maintaining genome integrity and regulating gene expression. We used nanopore sequencing to directly measure methylated bases in Caulobacter crescentus and Brucella abortus. In Caulobacter, we showed that stabilization of the CcrM methyltransferase upon loss of the Lon protease results in prolific methylation and discovered that the putative methylase AlkB is unlikely to have a global physiological effect. We measured genome-wide methylation in Brucella for the first time, revealing a similar role for CcrM in cell-cycle methylation but a more complex regulation by the Lon protease than in Caulobacter. Finally, we show how the virulence factor MucR impacts DNA methylation patterns in Brucella.
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Affiliation(s)
- Maxwell Campbell
- Department of Biochemistry and Molecular Biology, University of Massachusetts Amherst, Amherst, Massachusetts, USA
| | - Ian Scott Barton
- Department of Microbiology and Immunology, Brody School of Medicine, East Carolina University, Greenville, South Carolina, USA
| | - R. Martin Roop
- Department of Microbiology and Immunology, Brody School of Medicine, East Carolina University, Greenville, South Carolina, USA
| | - Peter Chien
- Department of Biochemistry and Molecular Biology, University of Massachusetts Amherst, Amherst, Massachusetts, USA
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Campbell M, Barton IS, Roop RM, Chien P. Comparison of CcrM-dependent methylation in Caulobacter crescentus and Brucella abortus by nanopore sequencing. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.01.583015. [PMID: 38464217 PMCID: PMC10925313 DOI: 10.1101/2024.03.01.583015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/12/2024]
Abstract
Bacteria rely on DNA methylation for restriction-modification systems and epigenetic control of gene expression. Here, we use direct detection of methylated bases by nanopore sequencing to monitor global DNA methylation in Alphaproteobacteria, where use of this technique has not yet been reported. One representative of this order, Caulobacter crescentus, relies on DNA methylation to control cell cycle progression, but it is unclear whether other members of this order, such as Brucella abortus, depend on the same systems. We addressed these questions by first measuring CcrM-dependent DNA methylation in Caulobacter and show excellent correlation between nanopore-based detection and previously published results. We then directly measure the impact of Lon-mediated CcrM degradation on the epigenome, verifying that loss of Lon results in pervasive methylation. We also show that the AlkB demethylase has no global impact on DNA methylation during normal growth. Next, we report on the global DNA methylation in Brucella abortus for the first time and find that CcrM-dependent methylation is reliant on Lon but impacts the two chromosomes differently. Finally, we explore the impact of the MucR transcription factor, known to compete with CcrM methylation, on the Brucella methylome and share the results with a publicly available visualization package. Our work demonstrates the utility of nanopore-based sequencing for epigenome measurements in Alphaproteobacteria and reveals new features of CcrM-dependent methylation in a zoonotic pathogen.
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Affiliation(s)
- Maxwell Campbell
- Department of Biochemistry and Molecular Biology, University of Massachusetts Amherst, Amherst, MA
| | - Ian Scott Barton
- Department of Microbiology and Immunology, Brody School of Medicine, East Carolina University, Greenville, NC
| | - R. Martin Roop
- Department of Microbiology and Immunology, Brody School of Medicine, East Carolina University, Greenville, NC
| | - Peter Chien
- Department of Biochemistry and Molecular Biology, University of Massachusetts Amherst, Amherst, MA
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Wu X, Yu C, Mu W, Gu Z, Feng Y, Zhang Y. The structural mechanism for transcription activation by Caulobacter crescentus GcrA. Nucleic Acids Res 2023; 51:1960-1970. [PMID: 36715319 PMCID: PMC9976885 DOI: 10.1093/nar/gkad016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Revised: 12/28/2022] [Accepted: 01/05/2023] [Indexed: 01/31/2023] Open
Abstract
Canonical bacterial transcription activators bind to their cognate cis elements at the upstream of transcription start site (TSS) in a form of dimer. Caulobacter crescentus GcrA, a non-canonical transcription activator, can activate transcription from promoters harboring its cis element at the upstream or downstream of TSS in a form of monomer. We determined two cryo-EM structures of C. crescentus GcrA-bound transcription activation complexes, GcrA TACU and GcrA TACD, which comprise GcrA, RNAP, σ70 and promoter DNA with GcrA cis elements at either the upstream or downstream of TSS at 3.6 and 3.8 Å, respectively. In the GcrA-TACU structure, GcrA makes bipartite interactions with both σ70 domain 2 (σ702) and its cis element, while in the GcrA-TACD structure, GcrA retains interaction with σ702 but loses the interaction with its cis element. Our results suggest that GcrA likely forms a functionally specialized GcrA-RNAP-σA holoenzyme, in which GcrA first locates its cis element and then facilitates RNAP to load on core promoter at its proximal region. The sequence-specific interaction of GcrA and DNA is disrupted either at the stage of RPo formation or promoter escape depending on the location of GcrA cis elements relative to TSS.
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Affiliation(s)
- Xiaoxian Wu
- Key Laboratory of Synthetic Biology, Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
| | - Chengzhi Yu
- Key Laboratory of Synthetic Biology, Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Wenhui Mu
- Key Laboratory of Plant Stress Biology, State Key Laboratory of Cotton Biology, School of Life Sciences, Henan University, Kaifeng 475004, China
| | - Zhanxi Gu
- Key Laboratory of Synthetic Biology, Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yu Feng
- Department of Biophysics, and Department of Infectious Disease of Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Yu Zhang
- Key Laboratory of Synthetic Biology, Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
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Koppenhöfer S, Tomasch J, Lang AS. Shared properties of gene transfer agent and core genes revealed by comparative genomics of Alphaproteobacteria. Microb Genom 2022; 8:mgen000890. [PMID: 36350115 PMCID: PMC9836097 DOI: 10.1099/mgen.0.000890] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Gene transfer agents (GTAs) are phage-like particles that transfer pieces of cellular genomic DNA to other cells. Homologues of the Rhodobacter capsulatus GTA (RcGTA) structural genes are widely distributed in the Alphaproteobacteria and particularly well conserved in the order Rhodobacterales. Possible reasons for their widespread conservation are still being discussed. It has been suggested that these alphaproteobacterial elements originate from a prophage that was present in an ancestral bacterium and subsequently evolved into a GTA that is now widely maintained in extant descendant lineages. Here, we analysed genomic properties that might relate to the conservation of these alphaproteobacterial GTAs. This revealed that the chromosomal locations of the GTA gene clusters are biased. They primarily occur on the leading strand of DNA replication, at large distances from long repetitive elements, and thus are in regions of lower plasticity, and in areas of extreme GC skew, which also accumulate core genes. These extreme GC skew regions arise from the preferential use of codons with an excess of G over C, a distinct phenomenon from the elevated GC content that has previously been found to be associated with GTA genes. The observed properties, along with their high level of conservation, show that GTA genes share multiple features with core genes in the examined lineages of the Alphaproteobacteria.
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Affiliation(s)
- Sonja Koppenhöfer
- Department of Biology, Memorial University of Newfoundland, St John’s, Newfoundland and Labrador, Canada
| | - Jürgen Tomasch
- Laboratory of Anoxygenic Phototrophs, Institute of Microbiology of the Czech Academy of Science – Centre Algatech, Třeboň, Czech Republic
| | - Andrew S. Lang
- Department of Biology, Memorial University of Newfoundland, St John’s, Newfoundland and Labrador, Canada,*Correspondence: Andrew S. Lang,
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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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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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Tomasch J, Koppenhöfer S, Lang AS. Connection Between Chromosomal Location and Function of CtrA Phosphorelay Genes in Alphaproteobacteria. Front Microbiol 2021; 12:662907. [PMID: 33995326 PMCID: PMC8116508 DOI: 10.3389/fmicb.2021.662907] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Accepted: 04/09/2021] [Indexed: 12/28/2022] Open
Abstract
Most bacterial chromosomes are circular, with replication starting at one origin (ori) and proceeding on both replichores toward the terminus (ter). Several studies have shown that the location of genes relative to ori and ter can have profound effects on regulatory networks and physiological processes. The CtrA phosphorelay is a gene regulatory system conserved in most alphaproteobacteria. It was first discovered in Caulobacter crescentus where it controls replication and division into a stalked and a motile cell in coordination with other factors. The locations of the ctrA gene and targets of this response regulator on the chromosome affect their expression through replication-induced DNA hemi-methylation and specific positioning along a CtrA activity gradient in the dividing cell, respectively. Here we asked to what extent the location of CtrA regulatory network genes might be conserved in the alphaproteobacteria. We determined the locations of the CtrA phosphorelay and associated genes in closed genomes with unambiguously identifiable ori from members of five alphaproteobacterial orders. The location of the phosphorelay genes was the least conserved in the Rhodospirillales followed by the Sphingomonadales. In the Rhizobiales a trend toward certain chromosomal positions could be observed. Compared to the other orders, the CtrA phosphorelay genes were conserved closer to ori in the Caulobacterales. In contrast, the genes were highly conserved closer to ter in the Rhodobacterales. Our data suggest selection pressure results in differential positioning of CtrA phosphorelay and associated genes in alphaproteobacteria, particularly in the orders Rhodobacterales, Caulobacterales and Rhizobiales that is worth deeper investigation.
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Affiliation(s)
- Jürgen Tomasch
- Department of Molecular Bacteriology, Helmholtz-Center for Infection Research, Braunschweig, Germany
| | - Sonja Koppenhöfer
- Department of Biology, Memorial University of Newfoundland, St. John's, NL, Canada
| | - Andrew S Lang
- Department of Biology, Memorial University of Newfoundland, St. John's, NL, Canada
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Wang W, Ding B, Lou W, Lin S. Promoter Hypomethylation and miR-145-5p Downregulation- Mediated HDAC11 Overexpression Promotes Sorafenib Resistance and Metastasis of Hepatocellular Carcinoma Cells. Front Cell Dev Biol 2020; 8:724. [PMID: 32903337 PMCID: PMC7434871 DOI: 10.3389/fcell.2020.00724] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2020] [Accepted: 07/14/2020] [Indexed: 12/14/2022] Open
Abstract
Sorafenib resistance and tumor metastasis account for poor outcome of hepatocellular carcinoma (HCC). Histone deacetylase 11 (HDAC11) has been reported to exert oncogenic effects in several types of human cancer, but its specific functions and detailed mechanisms in HCC are not fully elucidated. Here we identified HDAC11 as a potential oncogene and promising biomarker in HCC by in silico analysis. Histone deacetylase 11 was upregulated in sorafenib-resistant SMMC7721 compared with its parental cell. Knockdown of HDAC11 suppressed proliferation and sorafenib resistance, which may be due to inhibition of drug metabolism cytochrome P450 predicted by gene-set enrichment analysis. Histone deacetylase expression was higher in highly metastatic MHCC97H than lowly metastatic MHCC97L. Downregulation of HDAC11 significantly attenuated the migrated and invaded abilities of HCC cells. Histone deacetylase 11 was directly targeted and suppressed by miR-145-5p. Inhibition of miR-145-5p enhanced sorafenib resistance and metastasis of HCC, and these effects could be attenuated by knockdown of HDAC11. The promoter methylation level of HDAC11 was markedly decreased in HCC tissues compared with normal controls. Administration of 5’-Aza-2’-deoxycytidine, a DNA methyltransferase inhibitor, facilitated HDAC11 expression in HCC cells. Our data indicate a role of miR-145-5p/HDAC11 axis in regulation of sorafenib resistance and metastasis in HCC.
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Affiliation(s)
- Wenlong Wang
- Intensive Care Unit, Hangzhou Hospital of Traditional Chinese Medicine, Hangzhou, China
| | - Bisha Ding
- Program of Innovative Cancer Therapeutics, Division of Hepatobiliary and Pancreatic Surgery, Department of Surgery, First Affiliated Hospital, College of Medicine, Key Laboratory of Combined Multi-Organ Transplantation, Ministry of Public Health, Key Laboratory of Organ Transplantation, Zhejiang University, Hangzhou, China
| | - Weiyang Lou
- Department of Breast Surgery, First Affiliated Hospital, College of Medicine, Zhejiang University, Zhejiang, China
| | - Shengyou Lin
- Department of Oncology, Hangzhou Hospital of Traditional Chinese Medicine, Hangzhou, China
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