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Sheng Y, Wang Y, Yang W, Wang XQ, Lu J, Pan B, Nan B, Liu Y, Ye F, Li C, Song J, Dou Y, Gao S, Liu Y. Semiconservative transmission of DNA N 6-adenine methylation in a unicellular eukaryote. Genome Res 2024; 34:740-756. [PMID: 38744529 DOI: 10.1101/gr.277843.123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Accepted: 04/15/2024] [Indexed: 05/16/2024]
Abstract
Although DNA N 6-adenine methylation (6mA) is best known in prokaryotes, its presence in eukaryotes has recently generated great interest. Biochemical and genetic evidence supports that AMT1, an MT-A70 family methyltransferase (MTase), is crucial for 6mA deposition in unicellular eukaryotes. Nonetheless, the 6mA transmission mechanism remains to be elucidated. Taking advantage of single-molecule real-time circular consensus sequencing (SMRT CCS), here we provide definitive evidence for semiconservative transmission of 6mA in Tetrahymena thermophila In wild-type (WT) cells, 6mA occurs at the self-complementary ApT dinucleotide, mostly in full methylation (full-6mApT); after DNA replication, hemi-methylation (hemi-6mApT) is transiently present on the parental strand, opposite to the daughter strand readily labeled by 5-bromo-2'-deoxyuridine (BrdU). In ΔAMT1 cells, 6mA predominantly occurs as hemi-6mApT. Hemi-to-full conversion in WT cells is fast, robust, and processive, whereas de novo methylation in ΔAMT1 cells is slow and sporadic. In Tetrahymena, regularly spaced 6mA clusters coincide with the linker DNA of nucleosomes arrayed in the gene body. Importantly, in vitro methylation of human chromatin by the reconstituted AMT1 complex recapitulates preferential targeting of hemi-6mApT sites in linker DNA, supporting AMT1's intrinsic and autonomous role in maintenance methylation. We conclude that 6mA is transmitted by a semiconservative mechanism: full-6mApT is split by DNA replication into hemi-6mApT, which is restored to full-6mApT by AMT1-dependent maintenance methylation. Our study dissects AMT1-dependent maintenance methylation and AMT1-independent de novo methylation, reveals a 6mA transmission pathway with a striking similarity to 5-methylcytosine (5mC) transmission at the CpG dinucleotide, and establishes 6mA as a bona fide eukaryotic epigenetic mark.
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Affiliation(s)
- Yalan Sheng
- MOE Key Laboratory of Evolution and Marine Biodiversity and Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao 266003, China
- Laboratory for Marine Biology and Biotechnology, Qingdao Marine Science and Technology Center, Qingdao 266237, China
| | - Yuanyuan Wang
- MOE Key Laboratory of Evolution and Marine Biodiversity and Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao 266003, China
- Laboratory for Marine Biology and Biotechnology, Qingdao Marine Science and Technology Center, Qingdao 266237, China
| | - Wentao Yang
- Department of Biochemistry and Molecular Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California 90033, USA
| | - Xue Qing Wang
- Department of Biochemistry and Molecular Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California 90033, USA
| | - Jiuwei Lu
- Department of Biochemistry, University of California Riverside, Riverside, California 92521, USA
| | - Bo Pan
- MOE Key Laboratory of Evolution and Marine Biodiversity and Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao 266003, China
- Laboratory for Marine Biology and Biotechnology, Qingdao Marine Science and Technology Center, Qingdao 266237, China
| | - Bei Nan
- MOE Key Laboratory of Evolution and Marine Biodiversity and Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao 266003, China
- Laboratory for Marine Biology and Biotechnology, Qingdao Marine Science and Technology Center, Qingdao 266237, China
| | - Yongqiang Liu
- MOE Key Laboratory of Evolution and Marine Biodiversity and Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao 266003, China
- Laboratory for Marine Biology and Biotechnology, Qingdao Marine Science and Technology Center, Qingdao 266237, China
| | - Fei Ye
- MOE Key Laboratory of Evolution and Marine Biodiversity and Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao 266003, China
- Laboratory for Marine Biology and Biotechnology, Qingdao Marine Science and Technology Center, Qingdao 266237, China
| | - Chun Li
- Division of Biostatistics, Department of Preventive Medicine, University of Southern California, Los Angeles, California 90033, USA
| | - Jikui Song
- Department of Biochemistry, University of California Riverside, Riverside, California 92521, USA
| | - Yali Dou
- Department of Biochemistry and Molecular Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California 90033, USA
| | - Shan Gao
- MOE Key Laboratory of Evolution and Marine Biodiversity and Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao 266003, China;
- Laboratory for Marine Biology and Biotechnology, Qingdao Marine Science and Technology Center, Qingdao 266237, China
| | - Yifan Liu
- Department of Biochemistry and Molecular Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California 90033, USA;
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Dennis AF, Xu Z, Clark DJ. Examining chromatin heterogeneity through PacBio long-read sequencing of M.EcoGII methylated genomes: an m6A detection efficiency and calling bias correcting pipeline. Nucleic Acids Res 2024; 52:e45. [PMID: 38634798 PMCID: PMC11109960 DOI: 10.1093/nar/gkae288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2024] [Revised: 03/23/2024] [Accepted: 04/04/2024] [Indexed: 04/19/2024] Open
Abstract
Recent studies have combined DNA methyltransferase footprinting of genomic DNA in nuclei with long-read sequencing, resulting in detailed chromatin maps for multi-kilobase stretches of genomic DNA from one cell. Theoretically, nucleosome footprints and nucleosome-depleted regions can be identified using M.EcoGII, which methylates adenines in any sequence context, providing a high-resolution map of accessible regions in each DNA molecule. Here, we report PacBio long-read sequence data for budding yeast nuclei treated with M.EcoGII and a bioinformatic pipeline which corrects for three key challenges undermining this promising method. First, detection of m6A in individual DNA molecules by the PacBio software is inefficient, resulting in false footprints predicted by random gaps of seemingly unmethylated adenines. Second, there is a strong bias against m6A base calling as AT content increases. Third, occasional methylation occurs within nucleosomes, breaking up their footprints. After correcting for these issues, our pipeline calculates a correlation coefficient-based score indicating the extent of chromatin heterogeneity within the cell population for every gene. Although the population average is consistent with that derived using other techniques, we observe a wide range of heterogeneity in nucleosome positions at the single-molecule level, probably reflecting cellular chromatin dynamics.
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Affiliation(s)
- Allison F Dennis
- Division of Developmental Biology, Eunice Kennedy-Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Zhuwei Xu
- Division of Developmental Biology, Eunice Kennedy-Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - David J Clark
- Division of Developmental Biology, Eunice Kennedy-Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
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3
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Helbrecht I, Heiter D, Yang W, Vincze T, Hanneman A, Lutz T, Ettwiller L, Bochtler M, Xu SY. Characterization of winged helix domain fusion endonucleases as N6-methyladenine-dependent type IV restriction systems. Front Microbiol 2024; 15:1286822. [PMID: 38655080 PMCID: PMC11037411 DOI: 10.3389/fmicb.2024.1286822] [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] [Received: 08/31/2023] [Accepted: 02/08/2024] [Indexed: 04/26/2024] Open
Abstract
Winged helix (wH) domains, also termed winged helix-turn-helix (wHTH) domains, are widespread in all kingdoms of life and have diverse roles. In the context of DNA binding and DNA modification sensing, some eukaryotic wH domains are known as sensors of non-methylated CpG. In contrast, the prokaryotic wH domains in DpnI and HhiV4I act as sensors of adenine methylation in the 6mApT (N6-methyladenine, 6mA, or N6mA) context. DNA-binding modes and interactions with the probed dinucleotide are vastly different in the two cases. Here, we show that the role of the wH domain as a sensor of adenine methylation is widespread in prokaryotes. We present previously uncharacterized examples of PD-(D/E)XK-wH (FcyTI, Psp4BI), PUA-wH-HNH (HtuIII), wH-GIY-YIG (Ahi29725I, Apa233I), and PLD-wH (Aba4572I, CbaI) fusion endonucleases that sense adenine methylation in the Dam+ Gm6ATC sequence contexts. Representatives of the wH domain endonuclease fusion families with the exception of the PLD-wH family could be purified, and an in vitro preference for adenine methylation in the Dam context could be demonstrated. Like most other modification-dependent restriction endonucleases (MDREs, also called type IV restriction systems), the new fusion endonucleases except those in the PD-(D/E)XK-wH family cleave close to but outside the recognition sequence. Taken together, our data illustrate the widespread combinatorial use of prokaryotic wH domains as adenine methylation readers. Other potential 6mA sensors in modified DNA are also discussed.
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Affiliation(s)
- Igor Helbrecht
- New England Biolabs, Inc., Ipswich, MA, United States
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
- International Institute of Molecular and Cell Biology, Warsaw, Poland
| | - Daniel Heiter
- New England Biolabs, Inc., Ipswich, MA, United States
| | - Weiwei Yang
- New England Biolabs, Inc., Ipswich, MA, United States
| | - Tamas Vincze
- New England Biolabs, Inc., Ipswich, MA, United States
| | | | - Thomas Lutz
- New England Biolabs, Inc., Ipswich, MA, United States
| | | | - Matthias Bochtler
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
- International Institute of Molecular and Cell Biology, Warsaw, Poland
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4
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Dennis AF, Xu Z, Clark DJ. Examining chromatin heterogeneity through PacBio long-read sequencing of M.EcoGII methylated genomes: an m 6A detection efficiency and calling bias correcting pipeline. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.28.569045. [PMID: 38076871 PMCID: PMC10705563 DOI: 10.1101/2023.11.28.569045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/20/2023]
Abstract
Recent studies have combined DNA methyltransferase footprinting of genomic DNA in nuclei with long-read sequencing, resulting in detailed chromatin maps for multi-kilobase stretches of genomic DNA from one cell. Theoretically, nucleosome footprints and nucleosome-depleted regions can be identified using M.EcoGII, which methylates adenines in any sequence context, providing a high-resolution map of accessible regions in each DNA molecule. Here we report PacBio long-read sequence data for budding yeast nuclei treated with M.EcoGII and a bioinformatic pipeline which corrects for three key challenges undermining this promising method. First, detection of m6A in individual DNA molecules by the PacBio software is inefficient, resulting in false footprints predicted by random gaps of seemingly unmethylated adenines. Second, there is a strong bias against m6A base calling as AT content increases. Third, occasional methylation occurs within nucleosomes, breaking up their footprints. After correcting for these issues, our pipeline calculates a correlation coefficient-based score indicating the extent of chromatin heterogeneity within the cell population for every gene. Although the population average is consistent with that derived using other techniques, we observe a wide range of heterogeneity in nucleosome positions at the single-molecule level, probably reflecting cellular chromatin dynamics.
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Affiliation(s)
| | | | - David J. Clark
- Division of Developmental Biology, Eunice Kennedy-Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda MD 20892, USA
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5
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Dawe RK. Measuring open chromatin and DNA methylation in repeat arrays. NATURE PLANTS 2023; 9:1379-1380. [PMID: 37640934 DOI: 10.1038/s41477-023-01512-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/31/2023]
Affiliation(s)
- R Kelly Dawe
- Department of Plant Biology, University of Georgia, Athens, GA, USA.
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6
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Weng Z, Ruan F, Chen W, Chen Z, Xie Y, Luo M, Xie Z, Zhang C, Wang J, Sun Y, Fang Y, Guo M, Tan C, Chen W, Tong Y, Li Y, Wang H, Tang C. BIND&MODIFY: a long-range method for single-molecule mapping of chromatin modifications in eukaryotes. Genome Biol 2023; 24:61. [PMID: 36991510 PMCID: PMC10052867 DOI: 10.1186/s13059-023-02896-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Accepted: 03/15/2023] [Indexed: 03/31/2023] Open
Abstract
Epigenetic modifications of histones are associated with development and pathogenesis of disease. Existing approaches cannot provide insights into long-range interactions and represent the average chromatin state. Here we describe BIND&MODIFY, a method using long-read sequencing for profiling histone modifications and transcription factors on individual DNA fibers. We use recombinant fused protein A-M.EcoGII to tether methyltransferase M.EcoGII to protein binding sites to label neighboring regions by methylation. Aggregated BIND&MODIFY signal matches bulk ChIP-seq and CUT&TAG. BIND&MODIFY can simultaneously measure histone modification status, transcription factor binding, and CpG 5mC methylation at single-molecule resolution and also quantifies correlation between local and distal elements.
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Affiliation(s)
- Zhe Weng
- BGI Genomics, BGI-Shenzhen, Shenzhen, 518083, China
| | | | - Weitian Chen
- BGI Genomics, BGI-Shenzhen, Shenzhen, 518083, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Zhichao Chen
- BGI Genomics, BGI-Shenzhen, Shenzhen, 518083, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yeming Xie
- BGI Genomics, BGI-Shenzhen, Shenzhen, 518083, China
| | - Meng Luo
- BGI Genomics, BGI-Shenzhen, Shenzhen, 518083, China
| | - Zhe Xie
- BGI Genomics, BGI-Shenzhen, Shenzhen, 518083, China
- Department of Biology, Cell Biology and Physiology, University of Copenhagen 13, 2100, Copenhagen, Denmark
| | - Chen Zhang
- BGI Genomics, BGI-Shenzhen, Shenzhen, 518083, China
| | - Juan Wang
- BGI Genomics, BGI-Shenzhen, Shenzhen, 518083, China
| | - Yuxin Sun
- BGI Genomics, BGI-Shenzhen, Shenzhen, 518083, China
| | - Yitong Fang
- BGI Genomics, BGI-Shenzhen, Shenzhen, 518083, China
| | - Mei Guo
- BGI Genomics, BGI-Shenzhen, Shenzhen, 518083, China
| | - Chen Tan
- BGI Genomics, BGI-Shenzhen, Shenzhen, 518083, China
| | - Wenfang Chen
- BGI Genomics, BGI-Shenzhen, Shenzhen, 518083, China
| | - Yiqin Tong
- BGI Genomics, BGI-Shenzhen, Shenzhen, 518083, China
| | - Yaning Li
- BGI Genomics, BGI-Shenzhen, Shenzhen, 518083, China
| | - Hongqi Wang
- BGI Genomics, BGI-Shenzhen, Shenzhen, 518083, China
| | - Chong Tang
- BGI Genomics, BGI-Shenzhen, Shenzhen, 518083, China.
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7
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Lu X, Huang F, Cheng R, Zhu B. A Unique m6A-Dependent Restriction Endonuclease from an Archaeal Virus. Microbiol Spectr 2023:e0426222. [PMID: 36946751 PMCID: PMC10101028 DOI: 10.1128/spectrum.04262-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/23/2023] Open
Abstract
Prokaryotes possess numerous diverse defense systems to resist viral infections, while some viruses have also evolved antiviral defense systems to exclude other viruses in cases of multiple infections. Here, we report the first virus-derived modification-dependent restriction endonuclease (HHPV4I) from the archaeal virus HHPV4 (Haloarcula hispanica pleomorphic virus 4). HHPV4I contains an SRA domain, a winged helix (wH) domain, and an HNH domain; recognizes the Gm6ATC site; and specifically binds to Gm6ATC site-containing DNA. Both the wH domain and the HNH domain are responsible for DNA binding. Unlike the well-known m6A-specific restriction enzyme DpnI, HHPV4I only efficiently cleaves DNA with a fully methylated Gm6ATC site and cleaves DNA both upstream and downstream of the Gm6ATC sites on both DNA strands. Furthermore, HHPV4I preferentially cleaves DNA between VR bases (V = A/G/C, R = A/G) 4 to 20 nt away from the Gm6ATC site. Thus, the cleavage pattern of HHPV4I is distinct from those of all of the presently characterized restriction endonucleases. Mutations in the wH domain of HHPV4I do not alter m6A-dependent endonuclease activity, but they decrease recognition sequence specificity, thus expanding the cleaving capacity to more m6A-containing DNA sequences. The wH domain provides a target for searching, developing, and engineering novel m6A-dependent endonucleases. IMPORTANCE Many modification-dependent restriction endonucleases (MDREs) were identified in prokaryotes and recognized modified cytosine bases, such as 5-methylcytosine (5mC), 5-hydroxymethylcytosine (5hmC), and glucosyl-5-hydroxymethylcytosine (g5hmC). The first virus-derived MDRE (HHPV4I) from the archaeal virus HHPV4 was identified in this study. The viral MDRE suggested a new strategy employed by the virus to exclude other viruses in the case of multiple replications. HHPV4I is a novel N6-methyladenine (m6A)-dependent restriction endonuclease, while the cleavage pattern of HHPV4I is distinct from the well-known m6A-dependent restriction endonuclease DpnI. HHPV4I recognizes Gm6ATC sites and cleaves DNA both upstream and downstream of the Gm6ATC sites on both DNA strands. It preferentially cleaves DNA between VR bases (V = A/G/C, R = A/G) 4 to 20 nt away from the Gm6ATC sites. Furthermore, mutations in the HHPV4I wH domain can alter the sequence specificity without impeding the m6A-dependent DNA cleavage activity, providing a target for engineering more m6A-dependent endonucleases with different sequence specificities.
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Affiliation(s)
- Xueling Lu
- Key Laboratory of Molecular Biophysics, the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Fengtao Huang
- Key Laboratory of Molecular Biophysics, the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, China
- Shenzhen Huazhong University of Science and Technology Research Institute, Shenzhen, China
| | - Rui Cheng
- Key Laboratory of Molecular Biophysics, the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Bin Zhu
- Key Laboratory of Molecular Biophysics, the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, China
- Shenzhen Huazhong University of Science and Technology Research Institute, Shenzhen, China
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Gao Q, Lu S, Wang Y, He L, Wang M, Jia R, Chen S, Zhu D, Liu M, Zhao X, Yang Q, Wu Y, Zhang S, Huang J, Mao S, Ou X, Sun D, Tian B, Cheng A. Bacterial DNA methyltransferase: A key to the epigenetic world with lessons learned from proteobacteria. Front Microbiol 2023; 14:1129437. [PMID: 37032876 PMCID: PMC10073500 DOI: 10.3389/fmicb.2023.1129437] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Accepted: 02/27/2023] [Indexed: 04/11/2023] Open
Abstract
Epigenetics modulates expression levels of various important genes in both prokaryotes and eukaryotes. These epigenetic traits are heritable without any change in genetic DNA sequences. DNA methylation is a universal mechanism of epigenetic regulation in all kingdoms of life. In bacteria, DNA methylation is the main form of epigenetic regulation and plays important roles in affecting clinically relevant phenotypes, such as virulence, host colonization, sporulation, biofilm formation et al. In this review, we survey bacterial epigenomic studies and focus on the recent developments in the structure, function, and mechanism of several highly conserved bacterial DNA methylases. These methyltransferases are relatively common in bacteria and participate in the regulation of gene expression and chromosomal DNA replication and repair control. Recent advances in sequencing techniques capable of detecting methylation signals have enabled the characterization of genome-wide epigenetic regulation. With their involvement in critical cellular processes, these highly conserved DNA methyltransferases may emerge as promising targets for developing novel epigenetic inhibitors for biomedical applications.
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Affiliation(s)
- Qun Gao
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan, China
| | - Shuwei Lu
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Yuwei Wang
- Key Laboratory of Livestock and Poultry Provenance Disease Research in Mianyang, Sichuan, China
| | - Longgui He
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Mingshu Wang
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan, China
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Renyong Jia
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan, China
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Shun Chen
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan, China
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Dekang Zhu
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan, China
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Mafeng Liu
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan, China
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Xinxin Zhao
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan, China
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Qiao Yang
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan, China
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Ying Wu
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan, China
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Shaqiu Zhang
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan, China
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Juan Huang
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan, China
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Sai Mao
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan, China
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Xumin Ou
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan, China
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Di Sun
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan, China
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Bin Tian
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan, China
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Anchun Cheng
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan, China
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
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9
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Evolutionary History of RNA Modifications at N6-Adenosine Originating from the R-M System in Eukaryotes and Prokaryotes. BIOLOGY 2022; 11:biology11020214. [PMID: 35205080 PMCID: PMC8868631 DOI: 10.3390/biology11020214] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Revised: 01/13/2022] [Accepted: 01/24/2022] [Indexed: 12/11/2022]
Abstract
Simple Summary The m6A is the most abundant and well-studied modification of mRNA, and plays an important role in transcription and translation. It is known to be evolutionarily conserved machinery present in the last eukaryotic common ancestor (LECA). The writers and erasers responsible for adding or removing m6A belong to specific protein families, respectively, suggesting that these members are evolutionarily related. However, only some of these mRNA m6A modification-associated proteins have been studied from an evolutionary perspective, while there has been no comprehensive and systematic analysis of the distributions and evolutionary history of N6mA-associated proteins in the three kingdoms of life. In this study, we identified orthologues of all the reported N6mA-associated proteins in 88 organisms from three kingdoms of life and comprehensively reconstructed the evolutionary history of the RNA N6mA modification machinery. The results demonstrate that RNA N6mA-MTases are derived from at least two different types of prokaryotic DNA MTases (class α and β MTases). As the m6A reader, YTH proteins may be acquired by LECA from an individual prokaryotic YTH-domain protein that evolved from the N-terminals of an R-M system endonuclease. In addition, the origin of eukaryotic ALKBH family proteins is inferred to be driven by at least two occasions of independent HTG from the bacterial ALKB family. Abstract Methylation at the N6-position of adenosine (N6mA) on mRNA (m6A) is one of the most widespread, highly selective and dynamically regulated RNA modifications and plays an important role in transcription and translation. In the present study, a comprehensive analysis of phylogenetic relationships, conserved domain sequence characteristics and protein structure comparisons were employed to explore the distribution of RNA N6mA modification (m6A, m6,6A, m6Am, m6, 6Am and m6t6A)-associated proteins (writers, readers and erasers) in three kingdoms of life and reveal the evolutionary history of these modifications. These findings further confirmed that the restriction-modification (R-M) system is the origin of DNA and RNA N6mA modifications. Among them, the existing mRNA m6A modification system derived from the last eukaryotic common ancestor (LECA) is the evolutionary product of elements from the last universal common ancestor (LUCA) or driven by horizontal gene transfer (HGT) from bacterial elements. The subsequent massive gene gains and losses contribute to the development of unique and diverse functions in distinct species. Particularly, RNA methyltransferases (MTases) as the writer responsible for adding N6mA marks on mRNA and ncRNAs may have evolved from class α and β prokaryotic “orphan” MTases originating from the R-M system. The reader, YTH proteins that specifically recognize the m6A deposit, may be acquired by LECA from an individual prokaryotic YTH-domain protein that evolved from N-terminals of an R-M system endonuclease. The eraser, which emerged from the ALKB family (ALKBH5 and FTO) in eukaryotes, may be driven by independent HTG from bacterial ALKB proteins. The evolutionary history of RNA N6mA modifications was inferred in the present study, which will deepen our understanding of these modifications in different species.
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Brothers M, Rine J. Distinguishing between recruitment and spread of silent chromatin structures in Saccharomyces cerevisiae. eLife 2022; 11:75653. [PMID: 35073254 PMCID: PMC8830885 DOI: 10.7554/elife.75653] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Accepted: 01/21/2022] [Indexed: 11/13/2022] Open
Abstract
The formation of heterochromatin at HML, HMR, and telomeres in Saccharomyces cerevisiae involves two main steps: Recruitment of Sir proteins to silencers and their spread throughout the silenced domain. We developed a method to study these two processes at single base-pair resolution. Using a fusion protein between the heterochromatin protein Sir3 and the non-site-specific bacterial adenine methyltransferase M.EcoGII, we mapped sites of Sir3-chromatin interactions genome-wide using long-read Nanopore sequencing to detect adenines methylated by the fusion protein and by ChIP-seq to map the distribution of Sir3-M.EcoGII. A silencing-deficient mutant of Sir3 lacking its Bromo-Adjacent Homology (BAH) domain, sir3-bah∆, was still recruited to HML, HMR, and telomeres. However, in the absence of the BAH domain, it was unable to spread away from those recruitment sites. Overexpression of Sir3 did not lead to further spreading at HML, HMR, and most telomeres. A few exceptional telomeres, like 6R, exhibited a small amount of Sir3 spreading, suggesting that boundaries at telomeres responded variably to Sir3 overexpression. Finally, by using a temperature-sensitive allele of SIR3 fused to M.ECOGII, we tracked the positions first methylated after induction and found that repression of genes at HML and HMR began before Sir3 occupied the entire locus.
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Affiliation(s)
- Molly Brothers
- Department of Molecular and Cell Biology, University of California, Berkeley
| | - Jasper Rine
- Department of Molecular and Cell Biology, University of California, Berkeley
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11
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Marinov GK, Shipony Z, Kundaje A, Greenleaf WJ. Single-Molecule Multikilobase-Scale Profiling of Chromatin Accessibility Using m6A-SMAC-Seq and m6A-CpG-GpC-SMAC-Seq. Methods Mol Biol 2022; 2458:269-298. [PMID: 35103973 PMCID: PMC9531602 DOI: 10.1007/978-1-0716-2140-0_15] [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] [Indexed: 06/14/2023]
Abstract
A hallmark feature of active cis-regulatory elements (CREs) in eukaryotes is their nucleosomal depletion and, accordingly, higher accessibility to enzymatic treatment. This property has been the basis of a number of sequencing-based assays for genome-wide identification and tracking the activity of CREs across different biological conditions, such as DNAse-seq, ATAC-seq , NOMeseq, and others. However, the fragmentation of DNA inherent to many of these assays and the limited read length of short-read sequencing platforms have so far not allowed the simultaneous measurement of the chromatin accessibility state of CREs located distally from each other. The combination of labeling accessible DNA with DNA modifications and nanopore sequencing has made it possible to develop such assays. Here, we provide a detailed protocol for carrying out the SMAC-seq assay (Single-Molecule long-read Accessible Chromatin mapping sequencing), in its m6A-SMAC-seq and m6A-CpG-GpC-SMAC-seq variants, together with methods for data processing and analysis, and discuss key experimental and analytical considerations for working with SMAC-seq datasets.
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Affiliation(s)
| | - Zohar Shipony
- Department of Genetics, Stanford University, Stanford, CA, USA.
| | - Anshul Kundaje
- Department of Genetics, Stanford University, Stanford, CA, USA
- Department of Computer Science, Stanford University, Stanford, CA, USA
| | - William J Greenleaf
- Department of Genetics, Stanford University, Stanford, CA, USA
- Center for Personal Dynamic Regulomes, Stanford University, Stanford, CA, USA
- Department of Applied Physics, Stanford University, Stanford, CA, USA
- Chan Zuckerberg Biohub, San Francisco, CA, USA
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12
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Recent Advances on DNA Base Flipping: A General Mechanism for Writing, Reading, and Erasing DNA Modifications. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2022; 1389:295-315. [DOI: 10.1007/978-3-031-11454-0_12] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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13
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Bruneaux M, Kronholm I, Ashrafi R, Ketola T. Roles of adenine methylation and genetic mutations in adaptation to different temperatures in Serratia marcescens. Epigenetics 2021; 17:861-881. [PMID: 34519613 DOI: 10.1080/15592294.2021.1966215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Abstract
Epigenetic modifications can contribute to adaptation, but the relative contributions of genetic and epigenetic variation are unknown. Previous studies on the role of epigenetic changes in adaptation in eukaryotes have nearly exclusively focused on cytosine methylation (m5C), while prokaryotes exhibit a richer system of methyltransferases targetting adenines (m6A) or cytosines (m4C, m5C). DNA methylation in prokaryotes has many roles, but its potential role in adaptation still needs further investigation. We collected phenotypic, genetic, and epigenetic data using single molecule real-time sequencing of clones of the bacterium Serratia marcescens that had undergone experimental evolution in contrasting temperatures to investigate the relationship between environment and genetic, epigenetic, and phenotypic changes. The genomic distribution of GATC motifs, which were the main target for m6A methylation, and of variable m6A epiloci pointed to a potential link between m6A methylation and regulation of gene expression in S. marcescens. Evolved strains, while genetically homogeneous, exhibited many polymorphic m6A epiloci. There was no strong support for a genetic control of methylation changes in our experiment, and no clear evidence of parallel environmentally induced or environmentally selected methylation changes at specific epiloci was found. Both genetic and epigenetic variants were associated with some phenotypic traits. Overall, our results suggest that both genetic and adenine methylation changes have the potential to contribute to phenotypic adaptation in S. marcescens, but that any environmentally induced epigenetic change occurring in our experiment would probably have been quite labile.
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Affiliation(s)
- Matthieu Bruneaux
- Department of Biological and Environmental Science, University of Jyväskylä, Jyväskylä, Finland
| | - Ilkka Kronholm
- Department of Biological and Environmental Science, University of Jyväskylä, Jyväskylä, Finland
| | - Roghaieh Ashrafi
- Department of Biological and Environmental Science, University of Jyväskylä, Jyväskylä, Finland
| | - Tarmo Ketola
- Department of Biological and Environmental Science, University of Jyväskylä, Jyväskylä, Finland
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Zaworski J, Dagva O, Kingston AW, Fomenkov A, Morgan RD, Bossi L, Raleigh EA. Genome archaeology of two laboratory Salmonella enterica enterica sv Typhimurium. G3 (BETHESDA, MD.) 2021; 11:jkab226. [PMID: 34544129 PMCID: PMC8496262 DOI: 10.1093/g3journal/jkab226] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Accepted: 06/29/2021] [Indexed: 11/25/2022]
Abstract
The Salmonella research community has used strains and bacteriophages over decades, exchanging useful new isolates among laboratories for the study of cell surface antigens, metabolic pathways and restriction-modification (RM) studies. Here we present the sequences of two laboratory Salmonella strains (STK005, an isolate of LB5000; and its descendant ER3625). In the ancestry of LB5000, segments of ∼15 and ∼42 kb were introduced from Salmonella enterica sv Abony 803 into S. enterica sv Typhimurium LT2, forming strain SD14; this strain is thus a hybrid of S. enterica isolates. Strains in the SD14 lineage were used to define flagellar antigens from the 1950s to the 1970s, and to define three RM systems from the 1960s to the 1980s. LB5000 was also used as a host in phage typing systems used by epidemiologists. In the age of cheaper and easier sequencing, this resource will provide access to the sequence that underlies the extensive literature.
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Affiliation(s)
- Julie Zaworski
- Research Department, New England Biolabs, Ipswich, MA 01938-2723, USA
| | - Oyut Dagva
- Research Department, New England Biolabs, Ipswich, MA 01938-2723, USA
| | | | - Alexey Fomenkov
- Research Department, New England Biolabs, Ipswich, MA 01938-2723, USA
| | - Richard D Morgan
- Research Department, New England Biolabs, Ipswich, MA 01938-2723, USA
| | - Lionello Bossi
- CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), University Paris-Saclay, Gif-sur-Yvette 91198, France
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Rahman MM, Tollefsbol TO. Targeting cancer epigenetics with CRISPR-dCAS9: Principles and prospects. Methods 2021; 187:77-91. [PMID: 32315755 PMCID: PMC7572534 DOI: 10.1016/j.ymeth.2020.04.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Revised: 04/15/2020] [Accepted: 04/15/2020] [Indexed: 12/11/2022] Open
Abstract
Cancer therapeutics is an ever-evolving field due to incessant demands for effective and precise treatment options. Over the last few decades, cancer treatment strategies have shifted somewhat from surgery to targeted precision medicine. CRISPR-dCas9 is an emerging version of precision cancer therapy that has been adapted from the prokaryotic CRISPR-Cas system. Once ligated to epigenetic effectors (EE), CRISPR-dCas9 can function as an epigenetic editing tool and CRISPR-dCas9-EE complexes could be exploited to alter cancerous epigenetic features associated with different cancer hallmarks. In this article, we discuss the rationale of epigenetic editing as a therapeutic strategy against cancer. We also outline how sgRNA-dCas9 was derived from the CRISPR-Cas system. In addition, the current status of sgRNA-dCas9 use (in vivo and in vitro) in cancer is updated with a molecular illustration of CRISPR-dCas9-mediated epigenetic and transcriptional modulation. As sgRNA-dCas9 is still at the developmental phase, challenges are inherent to its use. We evaluate major challenges in targeting cancer with sgRNA-dCas9 such as off-target effects, lack of sgRNA designing rubrics, target site selection dilemmas and deficient sgRNA-dCas9 delivery systems. Finally, we appraise the sgRNA-dCas9 as a prospective cancer therapeutic by summarizing ongoing improvements of sgRNA-dCas9 methodology.
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Affiliation(s)
- Mohammad Mijanur Rahman
- Department of Biology, University of Alabama at Birmingham, 1300 University Boulevard, Birmingham, AL 35294, USA.
| | - Trygve O Tollefsbol
- Department of Biology, University of Alabama at Birmingham, 1300 University Boulevard, Birmingham, AL 35294, USA; Comprehensive Center for Healthy Aging, University of Alabama Birmingham, 1530 3rd Avenue South, Birmingham, AL 35294, USA; Comprehensive Cancer Center, University of Alabama Birmingham, 1802 6th Avenue South, Birmingham, AL 35294, USA; Nutrition Obesity Research Center, University of Alabama Birmingham, 1675 University Boulevard, Birmingham, AL 35294, USA; Comprehensive Diabetes Center, University of Alabama Birmingham, 1825 University Boulevard, Birmingham, AL 35294, USA.
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16
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Prokaryotic DNA methylation and its functional roles. J Microbiol 2021; 59:242-248. [DOI: 10.1007/s12275-021-0674-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 01/29/2021] [Accepted: 02/01/2021] [Indexed: 12/31/2022]
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17
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Vandenbussche I, Sass A, Van Nieuwerburgh F, Pinto-Carbó M, Mannweiler O, Eberl L, Coenye T. Detection of cytosine methylation in Burkholderia cenocepacia by single-molecule real-time sequencing and whole-genome bisulfite sequencing. MICROBIOLOGY-SGM 2021; 167. [PMID: 33565960 DOI: 10.1099/mic.0.001027] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Research on prokaryotic epigenetics, the study of heritable changes in gene expression independent of sequence changes, led to the identification of DNA methylation as a versatile regulator of diverse cellular processes. Methylation of adenine bases is often linked to regulation of gene expression in bacteria, but cytosine methylation is also frequently observed. In this study, we present a complete overview of the cytosine methylome in Burkholderia cenocepacia, an opportunistic respiratory pathogen in cystic fibrosis patients. Single-molecule real-time (SMRT) sequencing was used to map all 4mC-modified cytosines, as analysis of the predicted MTases in the B. cenocepacia genome revealed the presence of a 4mC-specific phage MTase, M.BceJII, targeting GGCC sequences. Methylation motif GCGGCCGC was identified, and out of 6850 motifs detected across the genome, 2051 (29.9 %) were methylated at the fifth position. Whole-genome bisulfite sequencing (WGBS) was performed to map 5mC methylation and 1635 5mC-modified cytosines were identified in CpG motifs. A comparison of the genomic positions of the modified bases called by each method revealed no overlap, which confirmed the authenticity of the detected 4mC and 5mC methylation by SMRT sequencing and WGBS, respectively. Large inter-strain variation of the 4mC-methylated cytosines was observed when B. cenocepacia strains J2315 and K56-2 were compared, which suggests that GGCC methylation patterns in B. cenocepacia are strain-specific. It seems likely that 4mC methylation of GGCC is not involved in regulation of gene expression but rather is a remnant of bacteriophage invasion, in which methylation of the phage genome was crucial for protection against restriction-modification systems of B. cenocepacia.
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Affiliation(s)
- Ian Vandenbussche
- Laboratory of Pharmaceutical Microbiology, Ghent University, Ghent, Belgium
| | - Andrea Sass
- Laboratory of Pharmaceutical Microbiology, Ghent University, Ghent, Belgium
| | | | - Marta Pinto-Carbó
- Department of Plant and Microbial Microbiology, University of Zurich, Zurich, Switzerland
| | - Olga Mannweiler
- Department of Plant and Microbial Microbiology, University of Zurich, Zurich, Switzerland
| | - Leo Eberl
- Department of Plant and Microbial Microbiology, University of Zurich, Zurich, Switzerland
| | - Tom Coenye
- Laboratory of Pharmaceutical Microbiology, Ghent University, Ghent, Belgium
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Fomenkov A, Sun Z, Murray IA, Ruse C, McClung C, Yamaichi Y, Raleigh EA, Roberts RJ. Plasmid replication-associated single-strand-specific methyltransferases. Nucleic Acids Res 2021; 48:12858-12873. [PMID: 33270887 PMCID: PMC7736820 DOI: 10.1093/nar/gkaa1163] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Revised: 11/10/2020] [Accepted: 11/12/2020] [Indexed: 01/01/2023] Open
Abstract
Analysis of genomic DNA from pathogenic strains of Burkholderia cenocepacia J2315 and Escherichia coli O104:H4 revealed the presence of two unusual MTase genes. Both are plasmid-borne ORFs, carried by pBCA072 for B. cenocepacia J2315 and pESBL for E. coli O104:H4. Pacific Biosciences SMRT sequencing was used to investigate DNA methyltransferases M.BceJIII and M.EcoGIX, using artificial constructs. Mating properties of engineered pESBL derivatives were also investigated. Both MTases yield promiscuous m6A modification of single strands, in the context SAY (where S = C or G and Y = C or T). Strikingly, this methylation is asymmetric in vivo, detected almost exclusively on one DNA strand, and is incomplete: typically, around 40% of susceptible motifs are modified. Genetic and biochemical studies suggest that enzyme action depends on replication mode: DNA Polymerase I (PolI)-dependent ColE1 and p15A origins support asymmetric modification, while the PolI-independent pSC101 origin does not. An MTase-PolI complex may enable discrimination of PolI-dependent and independent plasmid origins. M.EcoGIX helps to establish pESBL in new hosts by blocking the action of restriction enzymes, in an orientation-dependent fashion. Expression and action appear to occur on the entering single strand in the recipient, early in conjugal transfer, until lagging-strand replication creates the double-stranded form.
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Affiliation(s)
| | - Zhiyi Sun
- New England Biolabs Inc., 240 County Road, Ipswich, MA, USA
| | - Iain A Murray
- New England Biolabs Inc., 240 County Road, Ipswich, MA, USA
| | - Cristian Ruse
- New England Biolabs Inc., 240 County Road, Ipswich, MA, USA
| | | | - Yoshiharu Yamaichi
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), Gif-sur-Yvette, France
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19
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Enzymatic characterization of three human RNA adenosine methyltransferases reveals diverse substrate affinities and reaction optima. J Biol Chem 2021; 296:100270. [PMID: 33428944 PMCID: PMC7948815 DOI: 10.1016/j.jbc.2021.100270] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Revised: 01/06/2021] [Accepted: 01/07/2021] [Indexed: 11/22/2022] Open
Abstract
RNA methylations of varied RNA species (mRNA, tRNA, rRNA, non-coding RNA) generate a range of modified nucleotides, including N6-methyladenosine. Here we study the enzymology of three human RNA methyltransferases that methylate the adenosine amino group in diverse contexts, when it is: the first transcribed nucleotide after the mRNA cap (PCIF1), at position 1832 of 18S rRNA (MettL5-Trm112 complex), and within a hairpin in the 3′ UTR of the S-adenosyl-l-methionine synthetase (MettL16). Among these three enzymes, the catalytic efficiency ranges from PCIF1, with the fastest turnover rate of >230 h−1 μM−1 on mRNA cap analog, down to MettL16, which has the lowest rate of ∼3 h−1 μM−1 acting on an RNA hairpin. Both PCIF1 and MettL5 have a binding affinity (Km) of ∼1 μM or less for both substrates of SAM and RNA, whereas MettL16 has significantly lower binding affinities for both (Km >0.4 mM for SAM and ∼10 μM for RNA). The three enzymes are active over a wide pH range (∼5.4–9.4) and have different preferences for ionic strength. Sodium chloride at 200 mM markedly diminished methylation activity of MettL5-Trm112 complex, whereas MettL16 had higher activity in the range of 200 to 500 mM NaCl. Zinc ion inhibited activities of all three enzymes. Together, these results illustrate the diversity of RNA adenosine methyltransferases in their enzymatic mechanisms and substrate specificities and underline the need for assay optimization in their study.
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Abdulhay NJ, McNally CP, Hsieh LJ, Kasinathan S, Keith A, Estes LS, Karimzadeh M, Underwood JG, Goodarzi H, Narlikar GJ, Ramani V. Massively multiplex single-molecule oligonucleosome footprinting. eLife 2020; 9:59404. [PMID: 33263279 PMCID: PMC7735760 DOI: 10.7554/elife.59404] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Accepted: 11/24/2020] [Indexed: 01/10/2023] Open
Abstract
Our understanding of the beads-on-a-string arrangement of nucleosomes has been built largely on high-resolution sequence-agnostic imaging methods and sequence-resolved bulk biochemical techniques. To bridge the divide between these approaches, we present the single-molecule adenine methylated oligonucleosome sequencing assay (SAMOSA). SAMOSA is a high-throughput single-molecule sequencing method that combines adenine methyltransferase footprinting and single-molecule real-time DNA sequencing to natively and nondestructively measure nucleosome positions on individual chromatin fibres. SAMOSA data allows unbiased classification of single-molecular 'states' of nucleosome occupancy on individual chromatin fibres. We leverage this to estimate nucleosome regularity and spacing on single chromatin fibres genome-wide, at predicted transcription factor binding motifs, and across human epigenomic domains. Our analyses suggest that chromatin is comprised of both regular and irregular single-molecular oligonucleosome patterns that differ subtly in their relative abundance across epigenomic domains. This irregularity is particularly striking in constitutive heterochromatin, which has typically been viewed as a conformationally static entity. Our proof-of-concept study provides a powerful new methodology for studying nucleosome organization at a previously intractable resolution and offers up new avenues for modeling and visualizing higher order chromatin structure.
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Affiliation(s)
- Nour J Abdulhay
- Department of Biochemistry & Biophysics, University of California San Francisco, San Francisco, United States
| | - Colin P McNally
- Department of Biochemistry & Biophysics, University of California San Francisco, San Francisco, United States
| | - Laura J Hsieh
- Department of Biochemistry & Biophysics, University of California San Francisco, San Francisco, United States
| | | | - Aidan Keith
- Department of Biochemistry & Biophysics, University of California San Francisco, San Francisco, United States
| | - Laurel S Estes
- Department of Biochemistry & Biophysics, University of California San Francisco, San Francisco, United States
| | - Mehran Karimzadeh
- Department of Biochemistry & Biophysics, University of California San Francisco, San Francisco, United States.,Vector Institute, Toronto, United States
| | | | - Hani Goodarzi
- Department of Biochemistry & Biophysics, University of California San Francisco, San Francisco, United States.,Bakar Computational Health Sciences Institute, San Francisco, United States
| | - Geeta J Narlikar
- Department of Biochemistry & Biophysics, University of California San Francisco, San Francisco, United States
| | - Vijay Ramani
- Department of Biochemistry & Biophysics, University of California San Francisco, San Francisco, United States.,Bakar Computational Health Sciences Institute, San Francisco, United States
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Woodcock CB, Horton JR, Zhang X, Blumenthal RM, Cheng X. Beta class amino methyltransferases from bacteria to humans: evolution and structural consequences. Nucleic Acids Res 2020; 48:10034-10044. [PMID: 32453412 PMCID: PMC7544214 DOI: 10.1093/nar/gkaa446] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 05/12/2020] [Accepted: 05/14/2020] [Indexed: 01/09/2023] Open
Abstract
S-adenosyl-l-methionine dependent methyltransferases catalyze methyl transfers onto a wide variety of target molecules, including DNA and RNA. We discuss a family of methyltransferases, those that act on the amino groups of adenine or cytosine in DNA, have conserved motifs in a particular order in their amino acid sequence, and are referred to as class beta MTases. Members of this class include M.EcoGII and M.EcoP15I from Escherichia coli, Caulobacter crescentus cell cycle-regulated DNA methyltransferase (CcrM), the MTA1-MTA9 complex from the ciliate Oxytricha, and the mammalian MettL3-MettL14 complex. These methyltransferases all generate N6-methyladenine in DNA, with some members having activity on single-stranded DNA as well as RNA. The beta class of methyltransferases has a unique multimeric feature, forming either homo- or hetero-dimers, allowing the enzyme to use division of labor between two subunits in terms of substrate recognition and methylation. We suggest that M.EcoGII may represent an ancestral form of these enzymes, as its activity is independent of the nucleic acid type (RNA or DNA), its strandedness (single or double), and its sequence (aside from the target adenine).
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Affiliation(s)
- Clayton B Woodcock
- Department of Epigenetics and Molecular Carcinogenesis, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - John R Horton
- Department of Epigenetics and Molecular Carcinogenesis, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Xing Zhang
- Department of Epigenetics and Molecular Carcinogenesis, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Robert M Blumenthal
- Department of Medical Microbiology and Immunology, and Program in Bioinformatics, The University of Toledo College of Medicine and Life Sciences, Toledo, OH 43614, USA
| | - Xiaodong Cheng
- Department of Epigenetics and Molecular Carcinogenesis, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
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Srivastava A, Murugaiyan J, Garcia JAL, De Corte D, Hoetzinger M, Eravci M, Weise C, Kumar Y, Roesler U, Hahn MW, Grossart HP. Combined Methylome, Transcriptome and Proteome Analyses Document Rapid Acclimatization of a Bacterium to Environmental Changes. Front Microbiol 2020; 11:544785. [PMID: 33042055 PMCID: PMC7522526 DOI: 10.3389/fmicb.2020.544785] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2020] [Accepted: 08/18/2020] [Indexed: 11/13/2022] Open
Abstract
Polynucleobacter asymbioticus strain QLW-P1DMWA-1T represents a group of highly successful heterotrophic ultramicrobacteria that is frequently very abundant (up to 70% of total bacterioplankton) in freshwater habitats across all seven continents. This strain was originally isolated from a shallow Alpine pond characterized by rapid changes in water temperature and elevated UV radiation due to its location at an altitude of 1300 m. To elucidate the strain’s adjustment to fluctuating environmental conditions, we recorded changes occurring in its transcriptomic and proteomic profiles under contrasting experimental conditions by simulating thermal conditions in winter and summer as well as high UV irradiation. To analyze the potential connection between gene expression and regulation via methyl group modification of the genome, we also analyzed its methylome. The methylation pattern differed between the three treatments, pointing to its potential role in differential gene expression. An adaptive process due to evolutionary pressure in the genus was deduced by calculating the ratios of non-synonymous to synonymous substitution rates for 20 Polynucleobacter spp. genomes obtained from geographically diverse isolates. The results indicate purifying selection.
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Affiliation(s)
- Abhishek Srivastava
- Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Stechlin, Germany.,Department of Functional and Evolutionary Ecology, University of Vienna, Vienna, Austria
| | - Jayaseelan Murugaiyan
- Centre for Infectious Medicine, Institute for Animal Health and Environmental Hygiene, Freie Universität Berlin, Berlin, Germany.,Department of Biotechnology, SRM University-AP, Guntur, India
| | - Juan A L Garcia
- Department of Functional and Evolutionary Ecology, University of Vienna, Vienna, Austria
| | - Daniele De Corte
- Research and Development Center for Marine Biosciences, Japan Agency for Marine-Earth Science and Technology, Yokosuka, Japan
| | - Matthias Hoetzinger
- Department of Biology and Environmental Science, Linnaeus University, Kalmar, Sweden
| | - Murat Eravci
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, Berlin, Germany
| | - Christoph Weise
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, Berlin, Germany
| | - Yadhu Kumar
- Eurofins Genomics Europe Sequencing GmbH, Konstanz, Germany
| | - Uwe Roesler
- Centre for Infectious Medicine, Institute for Animal Health and Environmental Hygiene, Freie Universität Berlin, Berlin, Germany
| | - Martin W Hahn
- Research Department for Limnology, University of Innsbruck, Mondsee, Austria
| | - Hans-Peter Grossart
- Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Stechlin, Germany.,Institute for Biochemistry and Biology, Potsdam University, Potsdam, Germany
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23
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Stergachis AB, Debo BM, Haugen E, Churchman LS, Stamatoyannopoulos JA. Single-molecule regulatory architectures captured by chromatin fiber sequencing. Science 2020; 368:1449-1454. [PMID: 32587015 DOI: 10.1126/science.aaz1646] [Citation(s) in RCA: 77] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2019] [Revised: 01/12/2020] [Accepted: 04/24/2020] [Indexed: 12/14/2022]
Abstract
Gene regulation is chiefly determined at the level of individual linear chromatin molecules, yet our current understanding of cis-regulatory architectures derives from fragmented sampling of large numbers of disparate molecules. We developed an approach for precisely stenciling the structure of individual chromatin fibers onto their composite DNA templates using nonspecific DNA N6-adenine methyltransferases. Single-molecule long-read sequencing of chromatin stencils enabled nucleotide-resolution readout of the primary architecture of multikilobase chromatin fibers (Fiber-seq). Fiber-seq exposed widespread plasticity in the linear organization of individual chromatin fibers and illuminated principles guiding regulatory DNA actuation, the coordinated actuation of neighboring regulatory elements, single-molecule nucleosome positioning, and single-molecule transcription factor occupancy. Our approach and results open new vistas on the primary architecture of gene regulation.
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Affiliation(s)
- Andrew B Stergachis
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
| | - Brian M Debo
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.,Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA, USA
| | - Eric Haugen
- Altius Institute for Biomedical Sciences, Seattle, WA, USA
| | - L Stirling Churchman
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA, USA
| | - John A Stamatoyannopoulos
- Altius Institute for Biomedical Sciences, Seattle, WA, USA. .,Departments of Genome Sciences and Medicine, University of Washington, Seattle, WA, USA
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24
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Shipony Z, Marinov GK, Swaffer MP, Sinnott-Armstrong NA, Skotheim JM, Kundaje A, Greenleaf WJ. Long-range single-molecule mapping of chromatin accessibility in eukaryotes. Nat Methods 2020; 17:319-327. [PMID: 32042188 PMCID: PMC7968351 DOI: 10.1038/s41592-019-0730-2] [Citation(s) in RCA: 60] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Accepted: 12/22/2019] [Indexed: 02/06/2023]
Abstract
Mapping open chromatin regions has emerged as a widely used tool for identifying active regulatory elements in eukaryotes. However, existing approaches, limited by reliance on DNA fragmentation and short-read sequencing, cannot provide information about large-scale chromatin states or reveal coordination between the states of distal regulatory elements. We have developed a method for profiling the accessibility of individual chromatin fibers, a single-molecule long-read accessible chromatin mapping sequencing assay (SMAC-seq), enabling the simultaneous, high-resolution, single-molecule assessment of chromatin states at multikilobase length scales. Our strategy is based on combining the preferential methylation of open chromatin regions by DNA methyltransferases with low sequence specificity, in this case EcoGII, an N6-methyladenosine (m6A) methyltransferase, and the ability of nanopore sequencing to directly read DNA modifications. We demonstrate that aggregate SMAC-seq signals match bulk-level accessibility measurements, observe single-molecule nucleosome and transcription factor protection footprints, and quantify the correlation between chromatin states of distal genomic elements.
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Affiliation(s)
- Zohar Shipony
- Department of Genetics, Stanford University, Stanford, CA, USA
| | | | | | | | - Jan M Skotheim
- Department of Biology, Stanford University, Stanford, CA, USA
| | - Anshul Kundaje
- Department of Genetics, Stanford University, Stanford, CA, USA
- Department of Computer Science, Stanford University, Stanford, CA, USA
| | - William J Greenleaf
- Department of Genetics, Stanford University, Stanford, CA, USA.
- Department of Applied Physics, Stanford University, Stanford, CA, USA.
- Chan Zuckerberg Biohub, San Francisco, CA, USA.
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25
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Umlauf D, Sobecki M, Crabbe L. Methyl Adenine Identification (MadID): High-Resolution Detection of Protein-DNA Interactions. Methods Mol Biol 2020; 2175:123-138. [PMID: 32681488 DOI: 10.1007/978-1-0716-0763-3_10] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
Mapping the binding sites of DNA- or chromatin-interacting proteins is essential to understand many essential biological processes. Methyl Adenine Identification (MadID) is a proximity methylation-based assay that allows the visualization, quantification, and identification of binding sites from DNA-interacting proteins in eukaryotic cells. Chromatin-binding proteins of interest are fused to the newly described bacterial methyltransferase M.EcoGII. This enzyme catalyzes the methylation of adenine residues with no sequence specificity. Consequently, adenines within and in the vicinity of the protein binding sites will be decorated with a methyl group (m6A), a modification that can be further detected using different methods. M.EcoGII-dependent DNA methylation can be monitored in situ using immunostaining, at the genome-wide level using a combination of m6A-specific immunoprecipitation and whole-genome sequencing, or locally at DNA regions of interest purified by chromatin immunoprecipitation or probe-based capture techniques. MadID is conceptually similar to DNA adenine methyltransferase identification (DamID) that relies on the methylation of GATC motifs. However, MadID provides a higher resolution, deeper coverage, and opens ways for identification of binding sites in genomic regions that were largely inaccessible such as telomeres, centromeres, and repeated elements.
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Affiliation(s)
- David Umlauf
- LBCMCP, Centre de Biologie Integrative (CBI), CNRS, Université de Toulouse, Toulouse, France
| | - Michal Sobecki
- Institute of Anatomy, University of Zurich, Zurich, Switzerland
| | - Laure Crabbe
- LBCMCP, Centre de Biologie Integrative (CBI), CNRS, Université de Toulouse, Toulouse, France.
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26
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Lutz T, Flodman K, Copelas A, Czapinska H, Mabuchi M, Fomenkov A, He X, Bochtler M, Xu SY. A protein architecture guided screen for modification dependent restriction endonucleases. Nucleic Acids Res 2019; 47:9761-9776. [PMID: 31504772 PMCID: PMC6765204 DOI: 10.1093/nar/gkz755] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Revised: 08/18/2019] [Accepted: 08/31/2019] [Indexed: 11/15/2022] Open
Abstract
Modification dependent restriction endonucleases (MDREs) often have separate catalytic and modification dependent domains. We systematically looked for previously uncharacterized fusion proteins featuring a PUA or DUF3427 domain and HNH or PD-(D/E)XK catalytic domain. The enzymes were clustered by similarity of their putative modification sensing domains into several groups. The TspA15I (VcaM4I, CmeDI), ScoA3IV (MsiJI, VcaCI) and YenY4I groups, all featuring a PUA superfamily domain, preferentially cleaved DNA containing 5-methylcytosine or 5-hydroxymethylcytosine. ScoA3V, also featuring a PUA superfamily domain, but of a different clade, exhibited 6-methyladenine stimulated nicking activity. With few exceptions, ORFs for PUA-superfamily domain containing endonucleases were not close to DNA methyltransferase ORFs, strongly supporting modification dependent activity of the endonucleases. DUF3427 domain containing fusion proteins had very little or no endonuclease activity, despite the presence of a putative PD-(D/E)XK catalytic domain. However, their expression potently restricted phage T4gt in Escherichia coli cells. In contrast to the ORFs for PUA domain containing endonucleases, the ORFs for DUF3427 fusion proteins were frequently found in defense islands, often also featuring DNA methyltransferases.
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Affiliation(s)
- Thomas Lutz
- New England Biolabs, Inc. 240 County Road, Ipswich, MA 01938, USA
| | - Kiersten Flodman
- New England Biolabs, Inc. 240 County Road, Ipswich, MA 01938, USA
| | - Alyssa Copelas
- New England Biolabs, Inc. 240 County Road, Ipswich, MA 01938, USA
| | - Honorata Czapinska
- International Institute of Molecular and Cell Biology, Trojdena 4, 02-109 Warsaw, Poland
| | - Megumu Mabuchi
- New England Biolabs, Inc. 240 County Road, Ipswich, MA 01938, USA
| | - Alexey Fomenkov
- New England Biolabs, Inc. 240 County Road, Ipswich, MA 01938, USA
| | - Xinyi He
- State Key Laboratory of Microbial Metabolism, School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, 200240 Shanghai, China
| | - Matthias Bochtler
- International Institute of Molecular and Cell Biology, Trojdena 4, 02-109 Warsaw, Poland.,Institute of Biochemistry and Biophysics PAS, Pawinskiego 5a, 02-106 Warsaw, Poland
| | - Shuang-Yong Xu
- New England Biolabs, Inc. 240 County Road, Ipswich, MA 01938, USA
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27
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Abstract
In all domains of life, genomes contain epigenetic information superimposed over the nucleotide sequence. Epigenetic signals control DNA-protein interactions and can cause phenotypic change in the absence of mutation. A nearly universal mechanism of epigenetic signalling is DNA methylation. In bacteria, DNA methylation has roles in genome defence, chromosome replication and segregation, nucleoid organization, cell cycle control, DNA repair and regulation of transcription. In many bacterial species, DNA methylation controls reversible switching (phase variation) of gene expression, a phenomenon that generates phenotypic cell variants. The formation of epigenetic lineages enables the adaptation of bacterial populations to harsh or changing environments and modulates the interaction of pathogens with their eukaryotic hosts.
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28
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Sobecki M, Souaid C, Boulay J, Guerineau V, Noordermeer D, Crabbe L. MadID, a Versatile Approach to Map Protein-DNA Interactions, Highlights Telomere-Nuclear Envelope Contact Sites in Human Cells. Cell Rep 2019; 25:2891-2903.e5. [PMID: 30517874 PMCID: PMC6293860 DOI: 10.1016/j.celrep.2018.11.027] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Revised: 09/26/2018] [Accepted: 11/04/2018] [Indexed: 11/19/2022] Open
Abstract
Mapping the binding sites of DNA- or chromatin-interacting proteins is essential to understanding biological processes. DNA adenine methyltransferase identification (DamID) has emerged as a comprehensive method to map genome-wide occupancy of proteins of interest. A caveat of DamID is the specificity of Dam methyltransferase for GATC motifs that are not homogenously distributed in the genome. Here, we developed an optimized method named MadID, using proximity labeling of DNA by the methyltransferase M.EcoGII. M.EcoGII mediates N6-adenosine methylation in any DNA sequence context, resulting in deeper and unbiased coverage of the genome. We demonstrate, using m6A-specific immunoprecipitation and deep sequencing, that MadID is a robust method to identify protein-DNA interactions at the whole-genome level. Using MadID, we revealed contact sites between human telomeres, repetitive sequences devoid of GATC sites, and the nuclear envelope. Overall, MadID opens the way to identification of binding sites in genomic regions that were largely inaccessible. MadID: mapping of protein-DNA interactions in vivo using proximity labeling Deeper and unbiased genome-wide coverage using M.EcoGII, a methyltransferase Identification of binding sites in previously inaccessible regions of the genome Identification of telomere-nuclear envelope contact sites
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Affiliation(s)
- Michal Sobecki
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, Université Paris-Saclay, 91198 Gif-sur-Yvette Cedex, France
| | - Charbel Souaid
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, Université Paris-Saclay, 91198 Gif-sur-Yvette Cedex, France
| | - Jocelyne Boulay
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, Université Paris-Saclay, 91198 Gif-sur-Yvette Cedex, France
| | - Vincent Guerineau
- Institut de Chimie des Substances Naturelles, CNRS UPR2301, Université Paris-Sud, Université Paris-Saclay, Avenue de la Terrasse, 91198 Gif-sur-Yvette Cedex, France
| | - Daan Noordermeer
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, Université Paris-Saclay, 91198 Gif-sur-Yvette Cedex, France
| | - Laure Crabbe
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, Université Paris-Saclay, 91198 Gif-sur-Yvette Cedex, France; LBCMCP, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS/UPS, 31062 Toulouse Cedex, France.
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29
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The cell cycle-regulated DNA adenine methyltransferase CcrM opens a bubble at its DNA recognition site. Nat Commun 2019; 10:4600. [PMID: 31601797 PMCID: PMC6787082 DOI: 10.1038/s41467-019-12498-7] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Accepted: 09/11/2019] [Indexed: 11/09/2022] Open
Abstract
The Caulobacter crescentus cell cycle-regulated DNA methyltransferase (CcrM) methylates the adenine of hemimethylated GANTC after replication. Here we present the structure of CcrM in complex with double-stranded DNA containing the recognition sequence. CcrM contains an N-terminal methyltransferase domain and a C-terminal nonspecific DNA-binding domain. CcrM is a dimer, with each monomer contacting primarily one DNA strand: the methyltransferase domain of one molecule binds the target strand, recognizes the target sequence, and catalyzes methyl transfer, while the C-terminal domain of the second molecule binds the non-target strand. The DNA contacts at the 5-base pair recognition site results in dramatic DNA distortions including bending, unwinding and base flipping. The two DNA strands are pulled apart, creating a bubble comprising four recognized base pairs. The five bases of the target strand are recognized meticulously by stacking contacts, van der Waals interactions and specific Watson–Crick polar hydrogen bonds to ensure high enzymatic specificity. CcrM is a cell cycle-regulated DNA methyltransferase that methylates an adenine within a specific sequence following replication in the gram negative bacterium Caulobacter crescentus. Here the authors present a crystal structure of DNA-bound CcrM that reveals the molecular mechanism leading to sequence-specific methylation.
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30
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Beh LY, Debelouchina GT, Clay DM, Thompson RE, Lindblad KA, Hutton ER, Bracht JR, Sebra RP, Muir TW, Landweber LF. Identification of a DNA N6-Adenine Methyltransferase Complex and Its Impact on Chromatin Organization. Cell 2019; 177:1781-1796.e25. [PMID: 31104845 DOI: 10.1016/j.cell.2019.04.028] [Citation(s) in RCA: 64] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Revised: 01/31/2019] [Accepted: 04/12/2019] [Indexed: 11/27/2022]
Abstract
DNA N6-adenine methylation (6mA) has recently been described in diverse eukaryotes, spanning unicellular organisms to metazoa. Here, we report a DNA 6mA methyltransferase complex in ciliates, termed MTA1c. It consists of two MT-A70 proteins and two homeobox-like DNA-binding proteins and specifically methylates dsDNA. Disruption of the catalytic subunit, MTA1, in the ciliate Oxytricha leads to genome-wide loss of 6mA and abolishment of the consensus ApT dimethylated motif. Mutants fail to complete the sexual cycle, which normally coincides with peak MTA1 expression. We investigate the impact of 6mA on nucleosome occupancy in vitro by reconstructing complete, full-length Oxytricha chromosomes harboring 6mA in native or ectopic positions. We show that 6mA directly disfavors nucleosomes in vitro in a local, quantitative manner, independent of DNA sequence. Furthermore, the chromatin remodeler ACF can overcome this effect. Our study identifies a diverged DNA N6-adenine methyltransferase and defines the role of 6mA in chromatin organization.
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Affiliation(s)
- Leslie Y Beh
- Departments of Biochemistry & Molecular Biophysics and Biological Sciences, Columbia University, New York, NY 10032, USA; Department of Chemistry, Princeton University, Princeton, NJ 08544, USA; Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ 08544, USA
| | | | - Derek M Clay
- Departments of Biochemistry & Molecular Biophysics and Biological Sciences, Columbia University, New York, NY 10032, USA
| | - Robert E Thompson
- Department of Chemistry, Princeton University, Princeton, NJ 08544, USA
| | - Kelsi A Lindblad
- Departments of Biochemistry & Molecular Biophysics and Biological Sciences, Columbia University, New York, NY 10032, USA
| | - Elizabeth R Hutton
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ 08544, USA
| | - John R Bracht
- Department of Biology, American University, Washington, DC 20016, USA
| | - Robert P Sebra
- Icahn Institute and Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Tom W Muir
- Department of Chemistry, Princeton University, Princeton, NJ 08544, USA.
| | - Laura F Landweber
- Departments of Biochemistry & Molecular Biophysics and Biological Sciences, Columbia University, New York, NY 10032, USA.
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31
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Flodman K, Tsai R, Xu MY, Corrêa IR, Copelas A, Lee YJ, Xu MQ, Weigele P, Xu SY. Type II Restriction of Bacteriophage DNA With 5hmdU-Derived Base Modifications. Front Microbiol 2019; 10:584. [PMID: 30984133 PMCID: PMC6449724 DOI: 10.3389/fmicb.2019.00584] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2019] [Accepted: 03/07/2019] [Indexed: 11/13/2022] Open
Abstract
To counteract bacterial defense systems, bacteriophages (phages) make extensive base modifications (substitutions) to block endonuclease restriction. Here we evaluated Type II restriction of three thymidine (T or 5-methyldeoxyuridine, 5mdU) modified phage genomes: Pseudomonas phage M6 with 5-(2-aminoethyl)deoxyuridine (5-NedU), Salmonella phage ViI (Vi1) with 5-(2-aminoethoxy)methyldeoxyuridine (5-NeOmdU) and Delftia phage phi W-14 (a.k.a. ΦW-14) with α-putrescinylthymidine (putT). Among >200 commercially available restriction endonucleases (REases) tested, phage M6, ViI, and phi W-14 genomic DNAs (gDNA) show resistance against 48.4, 71.0, and 68.8% of Type II restrictions, respectively. Inspection of the resistant sites indicates the presence of conserved dinucleotide TG or TC (TS, S=C, or G), implicating the specificity of TS sequence as the target that is converted to modified base in the genomes. We also tested a number of DNA methyltransferases (MTases) on these phage DNAs and found some MTases can fully or partially modify the DNA to confer more resistance to cleavage by REases. Phage M6 restriction fragments can be efficiently ligated by T4 DNA ligase. Phi W-14 restriction fragments show apparent reduced rate in E. coli exonuclease III degradation. This work extends previous studies that hypermodified T derived from 5hmdU provides additional resistance to host-encoded restrictions, in parallel to modified cytosines, guanine, and adenine in phage genomes. The results reported here provide a general guidance to use REases to map and clone phage DNA with hypermodified thymidine.
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Affiliation(s)
| | - Rebecca Tsai
- New England Biolabs, Inc., Ipswich, MA, United States
| | - Michael Y Xu
- New England Biolabs, Inc., Ipswich, MA, United States
| | - Ivan R Corrêa
- New England Biolabs, Inc., Ipswich, MA, United States
| | | | - Yan-Jiun Lee
- New England Biolabs, Inc., Ipswich, MA, United States
| | - Ming-Qun Xu
- New England Biolabs, Inc., Ipswich, MA, United States
| | - Peter Weigele
- New England Biolabs, Inc., Ipswich, MA, United States
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32
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TaDa! Analysing cell type-specific chromatin in vivo with Targeted DamID. Curr Opin Neurobiol 2019; 56:160-166. [PMID: 30844670 DOI: 10.1016/j.conb.2019.01.021] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Accepted: 01/23/2019] [Indexed: 01/16/2023]
Abstract
The emergence of neuronal diversity during development of the nervous system relies on dynamic changes in the epigenetic landscape of neural stem cells and their progeny. Targeted DamID (TaDa) is proving invaluable in identifying the genome-wide binding sites of chromatin-associated proteins in vivo, without fixation, cell isolation, or immunoprecipitation. The simplicity and efficiency of the technique have led to an ever-expanding TaDa toolbox. These tools enable profiling of gene expression and chromatin accessibility, as well as the identification of the genome-wide binding sites of chromatin complexes, transcription factors and RNAs. Here, we review these new developments, with particular emphasis on the use of TaDa in studying neuronal specification.
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33
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McIntyre ABR, Alexander N, Grigorev K, Bezdan D, Sichtig H, Chiu CY, Mason CE. Single-molecule sequencing detection of N6-methyladenine in microbial reference materials. Nat Commun 2019; 10:579. [PMID: 30718479 PMCID: PMC6362088 DOI: 10.1038/s41467-019-08289-9] [Citation(s) in RCA: 96] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Accepted: 12/19/2018] [Indexed: 11/17/2022] Open
Abstract
The DNA base modification N6-methyladenine (m6A) is involved in many pathways related to the survival of bacteria and their interactions with hosts. Nanopore sequencing offers a new, portable method to detect base modifications. Here, we show that a neural network can improve m6A detection at trained sequence contexts compared to previously published methods using deviations between measured and expected current values as each adenine travels through a pore. The model, implemented as the mCaller software package, can be extended to detect known or confirm suspected methyltransferase target motifs based on predictions of methylation at untrained contexts. We use PacBio, Oxford Nanopore, methylated DNA immunoprecipitation sequencing (MeDIP-seq), and whole-genome bisulfite sequencing data to generate and orthogonally validate methylomes for eight microbial reference species. These well-characterized microbial references can serve as controls in the development and evaluation of future methods for the identification of base modifications from single-molecule sequencing data.
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Affiliation(s)
- Alexa B R McIntyre
- Department of Physiology and Biophysics, Weill Cornell Medicine, New York, 10065, NY, USA
- Tri-Institutional Training Program in Computational Biology and Medicine, New York, 10065, NY, USA
| | - Noah Alexander
- Department of Physiology and Biophysics, Weill Cornell Medicine, New York, 10065, NY, USA
| | - Kirill Grigorev
- Department of Physiology and Biophysics, Weill Cornell Medicine, New York, 10065, NY, USA
| | - Daniela Bezdan
- Department of Physiology and Biophysics, Weill Cornell Medicine, New York, 10065, NY, USA
| | - Heike Sichtig
- US Food and Drug Administration, Silver Spring, 20993, MD, USA
| | - Charles Y Chiu
- Department of Laboratory Medicine, University of California San Francisco, San Francisco, 94107, CA, USA
- UCSF-Abbott Viral Diagnostics and Discovery Center, San Francisco, 94107, CA, USA
| | - Christopher E Mason
- Department of Physiology and Biophysics, Weill Cornell Medicine, New York, 10065, NY, USA.
- The HRH Prince Alwaleed Bin Talal Bin Abdulaziz Alsaud Institute for Computational Biomedicine, Weill Cornell Medicine, New York, 10021, NY, USA.
- The Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, 10021, NY, USA.
- The WorldQuant Initiative for Quantitative Prediction, Weill Cornell Medicine, New York, 10021, NY, USA.
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