1
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Wojciechowski M, Czapinska H, Krwawicz J, Rafalski D, Bochtler M. Cytosine analogues as DNA methyltransferase substrates. Nucleic Acids Res 2024; 52:9267-9281. [PMID: 38966999 PMCID: PMC11347137 DOI: 10.1093/nar/gkae568] [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: 01/12/2023] [Revised: 05/23/2024] [Accepted: 06/20/2024] [Indexed: 07/06/2024] Open
Abstract
DNA methyltransferases are drug targets for myelodysplastic syndrome (MDS), chronic myelomonocytic leukemia (CMML), acute myelogenous leukemia (AML) and possibly β-hemoglobinopathies. We characterize the interaction of nucleoside analogues in DNA with a prokaryotic CpG-specific DNA methyltransferase (M.MpeI) as a model for mammalian DNMT1 methyltransferases. We tested DNA containing 5-hydroxymethylcytosine (5hmC), 5-hydroxycytosine (5OHC), 5-methyl-2-pyrimidinone (in the ribosylated form known as 5-methylzebularine, 5mZ), 5,6-dihydro-5-azacytosine (dhaC), 5-fluorocytosine (5FC), 5-chlorocytosine (5ClC), 5-bromocytosine (5BrC) and 5-iodocytosine (5IC). Covalent complex formation was by far most efficient for 5FC. Non-covalent complexes were most abundant for dhaC and 5mZ. Surprisingly, we observed methylation of 5IC and 5BrC, and to a lesser extent 5ClC and 5FC, in the presence, but not the absence of small molecule thiol nucleophiles. For 5IC and 5BrC, we demonstrated by mass spectrometry that the reactions were due to methyltransferase driven dehalogenation, followed by methylation. Crystal structures of M.MpeI-DNA complexes capture the 'in' conformation of the active site loop for analogues with small or rotatable (5mZ) 5-substituents and its 'out' form for bulky 5-substituents. Since very similar 'in' and 'out' loop conformations were also observed for DNMT1, it is likely that our conclusions generalize to other DNA methyltransferases.
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Affiliation(s)
- Marek Wojciechowski
- International Institute of Molecular and Cell Biology, Trojdena 4, 02-109 Warsaw, Poland
- Plant Breeding and Acclimatization Institute - National Research Institute, 05-870 Radzikow, Poland
| | - Honorata Czapinska
- 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
| | - Joanna Krwawicz
- 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
- Department of Biochemistry, University of Oxford, Oxford, UK
| | - Dominik Rafalski
- 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
| | - 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
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2
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Jurkowska RZ, Jeltsch A. Enzymology of Mammalian DNA Methyltransferases. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2022; 1389:69-110. [DOI: 10.1007/978-3-031-11454-0_4] [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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3
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Deep enzymology studies on DNA methyltransferases reveal novel connections between flanking sequences and enzyme activity. J Mol Biol 2021; 433:167186. [PMID: 34375615 DOI: 10.1016/j.jmb.2021.167186] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 08/01/2021] [Accepted: 08/03/2021] [Indexed: 11/22/2022]
Abstract
DNA interacting enzymes recognize their target sequences embedded in variable flanking sequence context. The influence of flanking sequences on enzymatic activities of DNA methyltransferases (DNMTs) can be systematically studied with "deep enzymology" approaches using pools of double-stranded DNA substrates, which contain target sites in random flanking sequence context. After incubation with DNMTs and bisulfite conversion, the methylation states and flanking sequences of individual DNA molecules are determined by NGS. Deep enzymology studies with different human and mouse DNMTs revealed strong influences of flanking sequences on the CpG and non-CpG methylation activity and structure of DNMT-DNA complexes. Differences in flanking sequence preferences of DNMT3A and DNMT3B were shown to be related to the prominent role of DNMT3B in the methylation of human SATII repeat elements. Mutational studies in DNMT3B discovered alternative interaction networks between the enzyme and the DNA leading to a partial equalization of the effects of different flanking sequences. Structural studies in DNMT1 revealed striking correlations between enzymatic activities and flanking sequence dependent conformational changes upon DNA binding. Correlation of the biochemical data with cellular methylation patterns demonstrated that flanking sequence preferences are an important parameter that influences genomic DNA methylation patterns together with other mechanisms targeting DNMTs to genomic sites.
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4
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Alves N, Neuparth T, Barros S, Santos MM. The anti-lipidemic drug simvastatin modifies epigenetic biomarkers in the amphipod Gammarus locusta. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2021; 209:111849. [PMID: 33387775 DOI: 10.1016/j.ecoenv.2020.111849] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 12/17/2020] [Accepted: 12/19/2020] [Indexed: 06/12/2023]
Abstract
The adverse effects of certain environmental chemicals have been recently associated with the modulation of the epigenome. Although changes in the epigenetic signature have yet to be integrated into hazard and risk assessment, they are interesting candidates to link environmental exposures and altered phenotypes, since these changes may be passed across multiple non-exposed generations. Here, we addressed the effects of simvastatin (SIM), one of the most prescribed pharmaceuticals in the world, on epigenetic regulation using the amphipod Gammarus locusta as a proxy, to support its integration into hazard and environmental risk assessment. SIM is a known modulator of the epigenome in mammalian cell lines and has been reported to impact G. locusta ecological endpoints at environmentally relevant levels. G. locusta juveniles were exposed to three SIM environmentally relevant concentrations (0.32, 1.6 and 8 µg L-1) for 15 days. Gene transcription levels of selected epigenetic regulators, i.e., dnmt1, dmap1, usp7, kat5 and uhrf1 were assessed, along with the quantification of DNA methylation levels and evaluation of key ecological endpoints: survival and growth. Exposure to 0.32 and 8 µg L-1 SIM induced significant downregulation of DNA methyltransferase 1 (dnmt1), concomitant with global DNA hypomethylation and growth impacts. Overall, this work is the first to validate the basal expression of key epigenetic regulators in a keystone marine crustacean, supporting the integration of epigenetic biomarkers into hazard assessment frameworks.
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Affiliation(s)
- Nélson Alves
- CIIMAR - Interdisciplinary Centre of Marine and Environmental Research, Endocrine Disruptors and Emerging Contaminants Group, University of Porto, Avenida General Norton de Matos S/N, 4450-208 Matosinhos, Portugal; FCUP - Department of Biology, Faculty of Sciences, University of Porto, Rua do Campo Alegre nº 1021/1055, 4169-007 Porto, Portugal
| | - Teresa Neuparth
- CIIMAR - Interdisciplinary Centre of Marine and Environmental Research, Endocrine Disruptors and Emerging Contaminants Group, University of Porto, Avenida General Norton de Matos S/N, 4450-208 Matosinhos, Portugal.
| | - Susana Barros
- CIIMAR - Interdisciplinary Centre of Marine and Environmental Research, Endocrine Disruptors and Emerging Contaminants Group, University of Porto, Avenida General Norton de Matos S/N, 4450-208 Matosinhos, Portugal
| | - Miguel M Santos
- CIIMAR - Interdisciplinary Centre of Marine and Environmental Research, Endocrine Disruptors and Emerging Contaminants Group, University of Porto, Avenida General Norton de Matos S/N, 4450-208 Matosinhos, Portugal; FCUP - Department of Biology, Faculty of Sciences, University of Porto, Rua do Campo Alegre nº 1021/1055, 4169-007 Porto, Portugal.
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5
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DNA sequence-dependent activity and base flipping mechanisms of DNMT1 regulate genome-wide DNA methylation. Nat Commun 2020; 11:3723. [PMID: 32709850 PMCID: PMC7381644 DOI: 10.1038/s41467-020-17531-8] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Accepted: 07/06/2020] [Indexed: 01/07/2023] Open
Abstract
DNA methylation maintenance by DNMT1 is an essential process in mammals but molecular mechanisms connecting DNA methylation patterns and enzyme activity remain elusive. Here, we systematically analyzed the specificity of DNMT1, revealing a pronounced influence of the DNA sequences flanking the target CpG site on DNMT1 activity. We determined DNMT1 structures in complex with preferred DNA substrates revealing that DNMT1 employs flanking sequence-dependent base flipping mechanisms, with large structural rearrangements of the DNA correlating with low catalytic activity. Moreover, flanking sequences influence the conformational dynamics of the active site and cofactor binding pocket. Importantly, we show that the flanking sequence preferences of DNMT1 highly correlate with genomic methylation in human and mouse cells, and 5-azacytidine triggered DNA demethylation is more pronounced at CpG sites with flanks disfavored by DNMT1. Overall, our findings uncover the intricate interplay between CpG-flanking sequence, DNMT1-mediated base flipping and the dynamic landscape of DNA methylation.
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6
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Kinetics and mechanisms of mitotic inheritance of DNA methylation and their roles in aging-associated methylome deterioration. Cell Res 2020; 30:980-996. [PMID: 32581343 DOI: 10.1038/s41422-020-0359-9] [Citation(s) in RCA: 75] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2020] [Accepted: 05/27/2020] [Indexed: 12/16/2022] Open
Abstract
Mitotic inheritance of the DNA methylome is a challenging task for the maintenance of cell identity. Whether DNA methylation pattern in different genomic contexts can all be faithfully maintained is an open question. A replication-coupled DNA methylation maintenance model was proposed decades ago, but some observations suggest that a replication-uncoupled maintenance mechanism exists. However, the capacity and the underlying molecular events of replication-uncoupled maintenance are unclear. By measuring maintenance kinetics at the single-molecule level and assessing mutant cells with perturbation of various mechanisms, we found that the kinetics of replication-coupled maintenance are governed by the UHRF1-Ligase 1 and PCNA-DNMT1 interactions, whereas nucleosome occupancy and the interaction between UHRF1 and methylated H3K9 specifically regulate replication-uncoupled maintenance. Surprisingly, replication-uncoupled maintenance is sufficiently robust to largely restore the methylome when replication-coupled maintenance is severely impaired. However, solo-WCGW sites and other CpG sites displaying aging- and cancer-associated hypomethylation exhibit low maintenance efficiency, suggesting that although quite robust, mitotic inheritance of methylation is imperfect and that this imperfection may contribute to selective hypomethylation during aging and tumorigenesis.
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7
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Wang Y, Sheng Y, Liu Y, Zhang W, Cheng T, Duan L, Pan B, Qiao Y, Liu Y, Gao S. A distinct class of eukaryotic MT-A70 methyltransferases maintain symmetric DNA N6-adenine methylation at the ApT dinucleotides as an epigenetic mark associated with transcription. Nucleic Acids Res 2020; 47:11771-11789. [PMID: 31722409 PMCID: PMC7145601 DOI: 10.1093/nar/gkz1053] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2019] [Revised: 10/21/2019] [Accepted: 10/24/2019] [Indexed: 12/18/2022] Open
Abstract
Rediscovered as a potential eukaryotic epigenetic mark, DNA N6-adenine methylation (6mA) varies across species in abundance and its relationships with transcription. Here we characterize AMT1—representing a distinct MT-A70 family methyltransferase—in the ciliate Tetrahymena thermophila. AMT1 loss-of-function leads to severe defects in growth and development. Single Molecule, Real-Time (SMRT) sequencing reveals that AMT1 is required for the bulk of 6mA and all symmetric methylation at the ApT dinucleotides. The detection of hemi-methylated ApT sites suggests a semi-conservative mechanism for maintaining symmetric methylation. AMT1 affects expression of many genes; in particular, RAB46, encoding a Rab family GTPase involved in contractile vacuole function, is likely a direct target. The distribution of 6mA resembles H3K4 methylation and H2A.Z, two conserved epigenetic marks associated with RNA polymerase II transcription. Furthermore, strong 6mA and nucleosome positioning in wild-type cells is attenuated in ΔAMT1 cells. Our results support that AMT1-catalyzed 6mA is an integral part of the transcription-associated epigenetic landscape. AMT1 homologues are generally found in protists and basal fungi featuring ApT hyper-methylation associated with transcription, which are missing in animals, plants, and true fungi. This dichotomy of 6mA functions and the underlying molecular mechanisms may have implications in eukaryotic diversification.
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Affiliation(s)
- Yuanyuan Wang
- Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao 266003, China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266003, China.,MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China
| | - Yalan Sheng
- Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao 266003, China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266003, China.,MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China
| | - Yongqiang Liu
- Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao 266003, China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266003, China.,MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China
| | - Wenxin Zhang
- School of Life Science, Anhui Agricultural University, Hefei 230036, China
| | - Ting Cheng
- Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao 266003, China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266003, China.,MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China
| | - Lili Duan
- Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao 266003, China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266003, China.,MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China
| | - Bo Pan
- Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao 266003, China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266003, China.,MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China
| | - Yu Qiao
- Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao 266003, China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266003, China.,MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China
| | - Yifan Liu
- Department of Pathology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Shan Gao
- Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao 266003, China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266003, China.,MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China
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8
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Dumesic PA, Stoddard CI, Catania S, Narlikar GJ, Madhani HD. ATP Hydrolysis by the SNF2 Domain of Dnmt5 Is Coupled to Both Specific Recognition and Modification of Hemimethylated DNA. Mol Cell 2020; 79:127-139.e4. [PMID: 32437639 DOI: 10.1016/j.molcel.2020.04.029] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2020] [Revised: 03/23/2020] [Accepted: 03/24/2020] [Indexed: 01/01/2023]
Abstract
C.neoformans Dnmt5 is an unusually specific maintenance-type CpG methyltransferase (DNMT) that mediates long-term epigenome evolution. It harbors a DNMT domain and SNF2 ATPase domain. We find that the SNF2 domain couples substrate specificity to an ATPase step essential for DNA methylation. Coupling occurs independent of nucleosomes. Hemimethylated DNA preferentially stimulates ATPase activity, and mutating Dnmt5's ATP-binding pocket disproportionately reduces ATPase stimulation by hemimethylated versus unmethylated substrates. Engineered DNA substrates that stabilize a reaction intermediate by mimicking a "flipped-out" conformation of the target cytosine bypass the SNF2 domain's requirement for hemimethylation. This result implies that ATP hydrolysis by the SNF2 domain is coupled to the DNMT domain conformational changes induced by preferred substrates. These findings establish a new role for a SNF2 ATPase: controlling an adjoined enzymatic domain's substrate recognition and catalysis. We speculate that this coupling contributes to the exquisite specificity of Dnmt5 via mechanisms related to kinetic proofreading.
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Affiliation(s)
- Phillip A Dumesic
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Caitlin I Stoddard
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Sandra Catania
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Geeta J Narlikar
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94158, USA.
| | - Hiten D Madhani
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94158, USA; Chan-Zuckerberg Biohub, San Francisco, CA 94158, USA.
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9
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Jeltsch A, Broche J, Bashtrykov P. Molecular Processes Connecting DNA Methylation Patterns with DNA Methyltransferases and Histone Modifications in Mammalian Genomes. Genes (Basel) 2018; 9:genes9110566. [PMID: 30469440 PMCID: PMC6266221 DOI: 10.3390/genes9110566] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Revised: 11/13/2018] [Accepted: 11/16/2018] [Indexed: 12/20/2022] Open
Abstract
DNA methylation is an essential part of the epigenome chromatin modification network, which also comprises several covalent histone protein post-translational modifications. All these modifications are highly interconnected, because the writers and erasers of one mark, DNA methyltransferases (DNMTs) and ten eleven translocation enzymes (TETs) in the case of DNA methylation, are directly or indirectly targeted and regulated by other marks. Here, we have collected information about the genomic distribution and variability of DNA methylation in human and mouse DNA in different genomic elements. After summarizing the impact of DNA methylation on genome evolution including CpG depletion, we describe the connection of DNA methylation with several important histone post-translational modifications, including methylation of H3K4, H3K9, H3K27, and H3K36, but also with nucleosome remodeling. Moreover, we present the mechanistic features of mammalian DNA methyltransferases and their associated factors that mediate the crosstalk between DNA methylation and chromatin modifications. Finally, we describe recent advances regarding the methylation of non-CpG sites, methylation of adenine residues in human cells and methylation of mitochondrial DNA. At several places, we highlight controversial findings or open questions demanding future experimental work.
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Affiliation(s)
- Albert Jeltsch
- Institute of Biochemistry and Technical Biochemistry, Department of Biochemistry, University of Stuttgart, 70569 Stuttgart, Germany.
| | - Julian Broche
- Institute of Biochemistry and Technical Biochemistry, Department of Biochemistry, University of Stuttgart, 70569 Stuttgart, Germany.
| | - Pavel Bashtrykov
- Institute of Biochemistry and Technical Biochemistry, Department of Biochemistry, University of Stuttgart, 70569 Stuttgart, Germany.
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10
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Gowher H, Jeltsch A. Mammalian DNA methyltransferases: new discoveries and open questions. Biochem Soc Trans 2018; 46:1191-1202. [PMID: 30154093 PMCID: PMC6581191 DOI: 10.1042/bst20170574] [Citation(s) in RCA: 108] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Revised: 07/12/2018] [Accepted: 07/13/2018] [Indexed: 11/17/2022]
Abstract
As part of the epigenetic network, DNA methylation is a major regulator of chromatin structure and function. In mammals, it mainly occurs at palindromic CpG sites, but asymmetric methylation at non-CpG sites is also observed. Three enzymes are involved in the generation and maintenance of DNA methylation patterns. DNMT1 has high preference for hemimethylated CpG sites, and DNMT3A and DNMT3B equally methylate unmethylated and hemimethylated DNA, and also introduce non-CpG methylation. Here, we review recent observations and novel insights into the structure and function of mammalian DNMTs (DNA methyltransferases), including new structures of DNMT1 and DNMT3A, data on their mechanism, regulation by post-translational modifications and on the function of DNMTs in cells. In addition, we present news findings regarding the allosteric regulation and targeting of DNMTs by chromatin modifications and chromatin proteins. In combination, the recent publications summarized here impressively illustrate the intensity of ongoing research in this field. They provide a deeper understanding of key mechanistic properties of DNMTs, but they also document still unsolved issues, which need to be addressed in future research.
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Affiliation(s)
- Humaira Gowher
- Department of Biochemistry, Purdue University, West Lafayette, IN 47907, U.S.A
| | - Albert Jeltsch
- Institute of Biochemistry and Technical Biochemistry, Department of Biochemistry, University of Stuttgart, Stuttgart, Germany
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11
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Zhou W, Dinh HQ, Ramjan Z, Weisenberger DJ, Nicolet CM, Shen H, Laird PW, Berman BP. DNA methylation loss in late-replicating domains is linked to mitotic cell division. Nat Genet 2018; 50:591-602. [PMID: 29610480 PMCID: PMC5893360 DOI: 10.1038/s41588-018-0073-4] [Citation(s) in RCA: 219] [Impact Index Per Article: 31.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2017] [Accepted: 01/24/2018] [Indexed: 12/31/2022]
Abstract
DNA methylation loss occurs frequently in cancer genomes, primarily within lamina-associated, late-replicating regions termed Partially Methylated Domains (PMDs). We profiled 39 diverse primary tumors and 8 matched adjacent tissues using Whole-Genome Bisulfite Sequencing (WGBS), and analyzed them alongside 343 additional human and 206 mouse WGBS datasets. We identified a local CpG sequence context associated with preferential hypomethylation in PMDs. Analysis of CpGs in this context (“Solo-WCGWs”) revealed previously undetected PMD hypomethylation in almost all healthy tissue types. PMD hypomethylation increased with age, beginning during fetal development, and appeared to track the accumulation of cell divisions. In cancer, PMD hypomethylation depth correlated with somatic mutation density and cell-cycle gene expression, consistent with its reflection of mitotic history, and suggesting its application as a mitotic clock. We propose that late replication leads to lifelong progressive methylation loss, which acts as a biomarker for cellular aging and which may contribute to oncogenesis.
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Affiliation(s)
- Wanding Zhou
- Center for Epigenetics, Van Andel Research Institute, Grand Rapids, MI, USA
| | - Huy Q Dinh
- Center for Bioinformatics and Functional Genomics, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | | | - Daniel J Weisenberger
- USC Norris Comprehensive Cancer Center, University of Southern California, Los Angeles, CA, USA
| | - Charles M Nicolet
- USC Norris Comprehensive Cancer Center, University of Southern California, Los Angeles, CA, USA
| | - Hui Shen
- Center for Epigenetics, Van Andel Research Institute, Grand Rapids, MI, USA.
| | - Peter W Laird
- Center for Epigenetics, Van Andel Research Institute, Grand Rapids, MI, USA.
| | - Benjamin P Berman
- Center for Bioinformatics and Functional Genomics, Cedars-Sinai Medical Center, Los Angeles, CA, USA.
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12
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Ravichandran M, Jurkowska RZ, Jurkowski TP. Target specificity of mammalian DNA methylation and demethylation machinery. Org Biomol Chem 2018; 16:1419-1435. [DOI: 10.1039/c7ob02574b] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
We review here the molecular mechanisms employed by DNMTs and TET enzymes that are responsible for shaping the DNA methylation pattern of a mammalian cell.
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Affiliation(s)
| | | | - T. P. Jurkowski
- Universität Stuttgart
- Abteilung Biochemie
- Institute für Biochemie und Technische Biochemie
- Stuttgart D-70569
- Germany
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13
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Jeltsch A, Jurkowska RZ. Allosteric control of mammalian DNA methyltransferases - a new regulatory paradigm. Nucleic Acids Res 2016; 44:8556-8575. [PMID: 27521372 PMCID: PMC5062992 DOI: 10.1093/nar/gkw723] [Citation(s) in RCA: 142] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Accepted: 08/08/2016] [Indexed: 12/23/2022] Open
Abstract
In mammals, DNA methylation is introduced by the DNMT1, DNMT3A and DNMT3B methyltransferases, which are all large multi-domain proteins containing a catalytic C-terminal domain and an N-terminal part with regulatory functions. Recently, two novel regulatory principles of DNMTs were uncovered. It was shown that their catalytic activity is under allosteric control of N-terminal domains with autoinhibitory function, the RFT and CXXC domains in DNMT1 and the ADD domain in DNMT3. Moreover, targeting and activity of DNMTs were found to be regulated in a concerted manner by interactors and posttranslational modifications (PTMs). In this review, we describe the structures and domain composition of the DNMT1 and DNMT3 enzymes, their DNA binding, catalytic mechanism, multimerization and the processes controlling their stability in cells with a focus on their regulation and chromatin targeting by PTMs, interactors and chromatin modifications. We propose that the allosteric regulation of DNMTs by autoinhibitory domains acts as a general switch for the modulation of the function of DNMTs, providing numerous possibilities for interacting proteins, nucleic acids or PTMs to regulate DNMT activity and targeting. The combined regulation of DNMT targeting and catalytic activity contributes to the precise spatiotemporal control of DNMT function and genome methylation in cells.
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Affiliation(s)
- Albert Jeltsch
- Institute of Biochemistry, Pfaffenwaldring 55, Faculty of Chemistry, University of Stuttgart, D-70569 Stuttgart, Germany
| | - Renata Z Jurkowska
- BioMed X Innovation Center, Im Neuenheimer Feld 583, D-69120 Heidelberg, Germany
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14
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Joshi M, Rajpathak SN, Narwade SC, Deobagkar D. Ensemble-Based Virtual Screening and Experimental Validation of Inhibitors Targeting a Novel Site of Human DNMT1. Chem Biol Drug Des 2016; 88:5-16. [PMID: 26850820 DOI: 10.1111/cbdd.12741] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Revised: 01/16/2016] [Accepted: 01/31/2016] [Indexed: 12/29/2022]
Abstract
Human DNA methyltransferase1 (hDNMT1) is responsible for preserving DNA methylation patterns that play important regulatory roles in differentiation and development. Misregulation of DNA methylation has thus been linked to many syndromes, life style diseases, and cancers. Developing specific inhibitors of hDNMT1 is an important challenge in the area since the currently targeted cofactor and substrate binding site share structural features with various proteins. In this work, we generated a structural model of the active form of hDNMT1 and identified that the 5-methylcytosine (5-mC) binding site of the hDNMT1 is structurally unique to the protein. This site has been previously demonstrated to be critical for methylation activity. We further performed multiple nanosecond time scale atomistic molecular dynamics simulations of the structural model followed by virtual screening of the Asinex database to identify inhibitors targeting the 5-mC site. Two compounds were discovered that inhibited hDNMT1 in vitro, one of which also showed inhibition in vivo corroborating the screening procedure. This study thus identifies and attempts to validate for the first time a unique site of hDNMT1 that could be harnessed for rationally designing highly selective and potent hypomethylating agents.
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Affiliation(s)
- Manali Joshi
- Bioinformatics Centre, S. P. Pune University, Ganeshkhind Road, Pune, Maharashtra, 411007, India
| | - Shriram N Rajpathak
- Center of Advanced Studies, Department of Zoology, S. P. Pune University, Ganeshkhind Road, Pune, Maharashtra, 411007, India
| | - Santosh C Narwade
- Center of Advanced Studies, Department of Zoology, S. P. Pune University, Ganeshkhind Road, Pune, Maharashtra, 411007, India
| | - Deepti Deobagkar
- Bioinformatics Centre, S. P. Pune University, Ganeshkhind Road, Pune, Maharashtra, 411007, India.,Center of Advanced Studies, Department of Zoology, S. P. Pune University, Ganeshkhind Road, Pune, Maharashtra, 411007, India
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15
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Jurkowska RZ, Jeltsch A. Enzymology of Mammalian DNA Methyltransferases. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 945:87-122. [PMID: 27826836 DOI: 10.1007/978-3-319-43624-1_5] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
DNA methylation is currently one of the hottest topics in basic and biomedical research. Despite tremendous progress in understanding the structures and biochemical properties of the mammalian DNA nucleotide methyltransferases (DNMTs), principles of their regulation in cells have only begun to be uncovered. In mammals, DNA methylation is introduced by the DNMT1, DNMT3A, and DNMT3B enzymes, which are all large multi-domain proteins. These enzymes contain a catalytic C-terminal domain with a characteristic cytosine-C5 methyltransferase fold and an N-terminal part with different domains that interacts with other proteins and chromatin and is involved in targeting and regulation of the DNMTs. The subnuclear localization of the DNMT enzymes plays an important role in their biological function: DNMT1 is localized to replicating DNA via interaction with PCNA and UHRF1. DNMT3 enzymes bind to heterochromatin via protein multimerization and are targeted to chromatin by their ADD and PWWP domains. Recently, a novel regulatory mechanism has been discovered in DNMTs, as latest structural and functional data demonstrated that the catalytic activities of all three enzymes are under tight allosteric control of their N-terminal domains having autoinhibitory functions. This mechanism provides numerous possibilities for the precise regulation of the methyltransferases via controlling the binding and release of autoinhibitory domains by protein factors, noncoding RNAs, or by posttranslational modifications of the DNMTs. In this chapter, we summarize key enzymatic properties of DNMTs, including their specificity and processivity, and afterward we focus on the regulation of their activity and targeting via allosteric processes, protein interactors, and posttranslational modifications.
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Affiliation(s)
- Renata Z Jurkowska
- BioMed X Innovation Center, Im Neuenheimer Feld 583, Heidelberg, D-69120, Germany.
| | - Albert Jeltsch
- Institute of Biochemistry, Faculty of Chemistry, University of Stuttgart, Pfaffenwaldring 55, Stuttgart, D-70569, Germany.
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16
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Jeltsch A, Jurkowska RZ. New concepts in DNA methylation. Trends Biochem Sci 2014; 39:310-8. [PMID: 24947342 DOI: 10.1016/j.tibs.2014.05.002] [Citation(s) in RCA: 293] [Impact Index Per Article: 26.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2014] [Revised: 05/15/2014] [Accepted: 05/18/2014] [Indexed: 02/08/2023]
Abstract
The widely-cited model of maintenance of DNA methylation at CpG sites implies that DNA methylation is introduced by the Dnmt3 de novo DNA methyltransferases during early development, and methylation at hemimethylated CpG sites is specifically maintained by the Dnmt1 maintenance methyltransferase. However, substantial experimental evidence from the past decade indicates that this simple model needs to be revised. DNA methylation can be described by a dynamic stochastic model, in which DNA methylation at each site is determined by the local activity of DNA methyltransferases (Dnmts), DNA demethylases, and the DNA replication rate. Through the targeting and regulation of these enzymes, DNA methylation is controlled by the network of chromatin marks.
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Affiliation(s)
- Albert Jeltsch
- Institute of Biochemistry, Stuttgart University, Pfaffenwaldring 55, D-70569 Stuttgart, Germany.
| | - Renata Z Jurkowska
- Institute of Biochemistry, Stuttgart University, Pfaffenwaldring 55, D-70569 Stuttgart, Germany
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17
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Bashtrykov P, Rajavelu A, Hackner B, Ragozin S, Carell T, Jeltsch A. Targeted mutagenesis results in an activation of DNA methyltransferase 1 and confirms an autoinhibitory role of its RFTS domain. Chembiochem 2014; 15:743-8. [PMID: 24532244 DOI: 10.1002/cbic.201300740] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2013] [Indexed: 12/21/2022]
Abstract
The N-terminal regulatory part of DNA methyltransferase 1 (Dnmt1) contains a replication foci targeting sequence (RFTS) domain, which is involved in the recruitment of Dnmt1 to replication forks. The RFTS domain has been observed in a crystal structure to bind to the catalytic domain of the enzyme and block its catalytic centre. Removal of the RFTS domain led to activation of Dnmt1, thus suggesting an autoinhibitory role of this domain. Here, we destabilised the interaction of the RFTS domain with the catalytic domain by site-directed mutagenesis and purified the corresponding Dnmt1 variants. Our data show that these mutations resulted in an up to fourfold increase in Dnmt1 methylation activity in vitro. Activation of Dnmt1 was not accompanied by a change in its preference for methylation of hemimethylated CpG sites. We also show that the Dnmt1 E572R/D575R variant has a higher DNA methylation activity in human cells after transfection into HCT116 cells, which are hypomorphic for Dnmt1. Our findings strongly support the autoinhibitory role of the RFTS domain, and indicate that it contributes to the regulation of Dnmt1 activity in cells.
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Affiliation(s)
- Pavel Bashtrykov
- Institute of Biochemistry, Faculty of Chemistry, University Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart (Germany)
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18
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Bashtrykov P, Jankevicius G, Jurkowska RZ, Ragozin S, Jeltsch A. The UHRF1 protein stimulates the activity and specificity of the maintenance DNA methyltransferase DNMT1 by an allosteric mechanism. J Biol Chem 2013; 289:4106-15. [PMID: 24368767 DOI: 10.1074/jbc.m113.528893] [Citation(s) in RCA: 90] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The ubiquitin-like, containing PHD and RING finger domains protein 1 (UHRF1) is essential for maintenance DNA methylation by DNA methyltransferase 1 (DNMT1). UHRF1 has been shown to recruit DNMT1 to replicated DNA by the ability of its SET and RING-associated (SRA) domain to bind to hemimethylated DNA. Here, we demonstrate that UHRF1 also increases the activity of DNMT1 by almost 5-fold. This stimulation is mediated by a direct interaction of both proteins through the SRA domain of UHRF1 and the replication focus targeting sequence domain of DNMT1, and it does not require DNA binding by the SRA domain. Disruption of the interaction between DNMT1 and UHRF1 by replacement of key residues in the replication focus targeting sequence domain led to a strong reduction of DNMT1 stimulation. Additionally, the interaction with UHRF1 increased the specificity of DNMT1 for methylation of hemimethylated CpG sites. These findings show that apart from the targeting of DNMT1 to the replicated DNA UHRF1 increases the activity and specificity of DNMT1, thus exerting a multifaceted influence on the maintenance of DNA methylation.
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Affiliation(s)
- Pavel Bashtrykov
- From the Institute of Biochemistry, Faculty of Chemistry, University Stuttgart, D-70569 Stuttgart, Germany and
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19
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Genomic Imprinting - der Kampf der Geschlechter auf molekularer Ebene. Angew Chem Int Ed Engl 2013. [DOI: 10.1002/ange.201307005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Jurkowska RZ, Jeltsch A. Genomic Imprinting-The Struggle of the Genders at the Molecular Level. Angew Chem Int Ed Engl 2013; 52:13524-36. [DOI: 10.1002/anie.201307005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2013] [Indexed: 11/10/2022]
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Abstract
Base excision repair (BER) corrects DNA damage from oxidation, deamination and alkylation. Such base lesions cause little distortion to the DNA helix structure. BER is initiated by a DNA glycosylase that recognizes and removes the damaged base, leaving an abasic site that is further processed by short-patch repair or long-patch repair that largely uses different proteins to complete BER. At least 11 distinct mammalian DNA glycosylases are known, each recognizing a few related lesions, frequently with some overlap in specificities. Impressively, the damaged bases are rapidly identified in a vast excess of normal bases, without a supply of energy. BER protects against cancer, aging, and neurodegeneration and takes place both in nuclei and mitochondria. More recently, an important role of uracil-DNA glycosylase UNG2 in adaptive immunity was revealed. Furthermore, other DNA glycosylases may have important roles in epigenetics, thus expanding the repertoire of BER proteins.
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Affiliation(s)
- Hans E Krokan
- Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology, N-7489 Trondheim, Norway.
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CpG underrepresentation and the bacterial CpG-specific DNA methyltransferase M.MpeI. Proc Natl Acad Sci U S A 2012; 110:105-10. [PMID: 23248272 DOI: 10.1073/pnas.1207986110] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Cytosine methylation promotes deamination. In eukaryotes, CpG methylation is thought to account for CpG underrepresentation. Whether scarcity of CpGs in prokaryotic genomes is diagnostic for methylation is not clear. Here, we report that Mycoplasms tend to be CpG depleted and to harbor a family of constitutively expressed or phase variable CpG-specific DNA methyltransferases. The very CpG poor Mycoplasma penetrans and its constitutively active CpG-specific methyltransferase M.MpeI were chosen for further characterization. Genome-wide sequencing of bisulfite-converted DNA indicated that M.MpeI methylated CpG target sites both in vivo and in vitro in a locus-nonselective manner. A crystal structure of M.MpeI with DNA at 2.15-Å resolution showed that the substrate base was flipped and that its place in the DNA stack was taken by a glutamine residue. A phenylalanine residue was intercalated into the "weak" CpG step of the nonsubstrate strand, indicating mechanistic similarities in the recognition of the short CpG target sequence by prokaryotic and eukaryotic DNA methyltransferases.
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