1
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Forni D, Pozzoli U, Mozzi A, Cagliani R, Sironi M. Depletion of CpG dinucleotides in bacterial genomes may represent an adaptation to high temperatures. NAR Genom Bioinform 2024; 6:lqae088. [PMID: 39071851 PMCID: PMC11282364 DOI: 10.1093/nargab/lqae088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2024] [Revised: 06/17/2024] [Accepted: 07/18/2024] [Indexed: 07/30/2024] Open
Abstract
Dinucleotide biases have been widely investigated in the genomes of eukaryotes and viruses, but not in bacteria. We assembled a dataset of bacterial genomes (>15 000), which are representative of the genetic diversity in the kingdom Eubacteria, and we analyzed dinucleotide biases in relation to different traits. We found that TpA dinucleotides are the most depleted and that CpG dinucleotides show the widest dispersion. The abundances of both dinucleotides vary with genomic G + C content and show a very strong phylogenetic signal. After accounting for G + C content and phylogenetic inertia, we analyzed different bacterial lifestyle traits. We found that temperature preferences associate with the abundance of CpG dinucleotides, with thermophiles/hyperthemophiles being particularly depleted. Conversely, the TpA dinucleotide displays a bias that only depends on genomic G + C composition. Using predictions of intrinsic cyclizability we also show that CpG depletion may associate with higher DNA bendability in both thermophiles/hyperthermophiles and mesophiles, and that the former are predicted to have significantly more flexible genomes than the latter. We suggest that higher bendability is advantageous at high temperatures because it facilitates DNA positive supercoiling and that, through modulation of DNA mechanical properties, local or global CpG depletion controls genome organization, most likely not only in bacteria.
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Affiliation(s)
- Diego Forni
- Scientific Institute IRCCS E. MEDEA, Bioinformatics, 23842 Bosisio Parini, Italy
| | - Uberto Pozzoli
- Scientific Institute IRCCS E. MEDEA, Bioinformatics, 23842 Bosisio Parini, Italy
| | - Alessandra Mozzi
- Scientific Institute IRCCS E. MEDEA, Bioinformatics, 23842 Bosisio Parini, Italy
| | - Rachele Cagliani
- Scientific Institute IRCCS E. MEDEA, Bioinformatics, 23842 Bosisio Parini, Italy
| | - Manuela Sironi
- Scientific Institute IRCCS E. MEDEA, Bioinformatics, 23842 Bosisio Parini, Italy
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2
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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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3
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Forni D, Pozzoli U, Cagliani R, Sironi M. Dinucleotide biases in the genomes of prokaryotic and eukaryotic dsDNA viruses and their hosts. Mol Ecol 2024; 33:e17287. [PMID: 38263702 DOI: 10.1111/mec.17287] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 12/21/2023] [Accepted: 01/15/2024] [Indexed: 01/25/2024]
Abstract
The genomes of cellular organisms display CpG and TpA dinucleotide composition biases. Such biases have been poorly investigated in dsDNA viruses. Here, we show that in dsDNA virus, bacterial, and eukaryotic genomes, the representation of TpA and CpG dinucleotides is strongly dependent on genomic G + C content. Thus, the classical observed/expected ratios do not fully capture dinucleotide biases across genomes. Because a larger portion of the variance in TpA frequency was explained by G + C content, we explored which additional factors drive the distribution of CpG dinucleotides. Using the residuals of the linear regressions as a measure of dinucleotide abundance and ancestral state reconstruction across eukaryotic and prokaryotic virus trees, we identified an important role for phylogeny in driving CpG representation. Nonetheless, phylogenetic ANOVA analyses showed that few host associations also account for significant variations. Among eukaryotic viruses, most significant differences were observed between arthropod-infecting viruses and viruses that infect vertebrates or unicellular organisms. However, an effect of viral DNA methylation status (either driven by the host or by viral-encoded methyltransferases) is also likely. Among prokaryotic viruses, cyanobacteria-infecting phages resulted to be significantly CpG-depleted, whereas phages that infect bacteria in the genera Burkolderia and Staphylococcus were CpG-rich. Comparison with bacterial genomes indicated that this effect is largely driven by the general tendency for phages to resemble the host's genomic CpG content. Notably, such tendency is stronger for temperate than for lytic phages. Our data shed light into the processes that shape virus genome composition and inform manipulation strategies for biotechnological applications.
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Affiliation(s)
- Diego Forni
- Scientific Institute IRCCS E. MEDEA, Bioinformatics, Bosisio Parini, Italy
| | - Uberto Pozzoli
- Scientific Institute IRCCS E. MEDEA, Bioinformatics, Bosisio Parini, Italy
| | - Rachele Cagliani
- Scientific Institute IRCCS E. MEDEA, Bioinformatics, Bosisio Parini, Italy
| | - Manuela Sironi
- Scientific Institute IRCCS E. MEDEA, Bioinformatics, Bosisio Parini, Italy
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4
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Albert P, Varga B, Ferenc G, Kiss A. Conversion of the CG specific M.MpeI DNA methyltransferase into an enzyme predominantly methylating CCA and CCC sites. Nucleic Acids Res 2024; 52:1896-1908. [PMID: 38164970 PMCID: PMC10899764 DOI: 10.1093/nar/gkad1217] [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: 09/25/2023] [Revised: 12/04/2023] [Accepted: 12/19/2023] [Indexed: 01/03/2024] Open
Abstract
We used structure guided mutagenesis and directed enzyme evolution to alter the specificity of the CG specific bacterial DNA (cytosine-5) methyltransferase M.MpeI. Methylation specificity of the M.MpeI variants was characterized by digestions with methylation sensitive restriction enzymes and by measuring incorporation of tritiated methyl groups into double-stranded oligonucleotides containing single CC, CG, CA or CT sites. Site specific mutagenesis steps designed to disrupt the specific contacts between the enzyme and the non-substrate base pair of the target sequence (5'-CG/5'-CG) yielded M.MpeI variants with varying levels of CG specific and increasing levels of CA and CC specific MTase activity. Subsequent random mutagenesis of the target recognizing domain coupled with selection for non-CG specific methylation yielded a variant, which predominantly methylates CC dinucleotides, has very low activity on CG and CA sites, and no activity on CT sites. This M.MpeI variant contains a one amino acid deletion (ΔA323) and three substitutions (N324G, R326G and E305N) in the target recognition domain. The mutant enzyme has very strong preference for A and C in the 3' flanking position making it a CCA and CCC specific DNA methyltransferase.
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Affiliation(s)
- Pál Albert
- Laboratory of DNA-Protein Interactions, Institute of Biochemistry, HUN-REN Biological Research Centre, 6726 Szeged, Hungary
- Doctoral School of Biology, Faculty of Science and Informatics, University of Szeged, 6726 Szeged, Hungary
| | - Bence Varga
- Laboratory of DNA-Protein Interactions, Institute of Biochemistry, HUN-REN Biological Research Centre, 6726 Szeged, Hungary
- Doctoral School of Biology, Faculty of Science and Informatics, University of Szeged, 6726 Szeged, Hungary
- Nucleic Acid Synthesis Laboratory, Institute of Plant Biology, HUN-REN Biological Research Centre, 6726 Szeged, Hungary
| | - Györgyi Ferenc
- Nucleic Acid Synthesis Laboratory, Institute of Plant Biology, HUN-REN Biological Research Centre, 6726 Szeged, Hungary
| | - Antal Kiss
- Laboratory of DNA-Protein Interactions, Institute of Biochemistry, HUN-REN Biological Research Centre, 6726 Szeged, Hungary
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5
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Sergeev AV, Loiko AG, Genatullina AI, Petrov AS, Kubareva EA, Dolinnaya NG, Gromova ES. Crosstalk between G-Quadruplexes and Dnmt3a-Mediated Methylation of the c-MYC Oncogene Promoter. Int J Mol Sci 2023; 25:45. [PMID: 38203216 PMCID: PMC10779317 DOI: 10.3390/ijms25010045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2023] [Revised: 12/15/2023] [Accepted: 12/17/2023] [Indexed: 01/12/2024] Open
Abstract
The methylation of cytosines at CpG sites in DNA, carried out de novo by DNA methyltransferase Dnmt3a, is a basic epigenetic modification involved in gene regulation and genome stability. Aberrant CpG methylation in gene promoters leads to oncogenesis. In oncogene promoters, CpG sites often colocalize with guanine-rich sequences capable of folding into G-quadruplexes (G4s). Our in vitro study aimed to investigate how parallel G4s formed by a sequence derived from the c-MYC oncogene promoter region affect the activity of the Dnmt3a catalytic domain (Dnmt3a-CD). For this purpose, we designed synthetic oligonucleotide constructs: a c-MYC G4-forming oligonucleotide and linear double-stranded DNA containing an embedded stable extrahelical c-MYC G4. The topology and thermal stability of G4 structures in these DNA models were analyzed using physicochemical techniques. We showed that Dnmt3a-CD specifically binds to an oligonucleotide containing c-MYC G4, resulting in inhibition of its methylation activity. c-MYC G4 formation in a double-stranded context significantly reduces Dnmt3a-CD-induced methylation of a CpG site located in close proximity to the quadruplex structure; this effect depends on the distance between the non-canonical structure and the specific CpG site. One would expect DNA hypomethylation near the G4 structure, while regions distant from this non-canonical form would maintain a regular pattern of high methylation levels. We hypothesize that the G4 structure sequesters the Dnmt3a-CD and impedes its proper binding to B-DNA, resulting in hypomethylation and activation of c-MYC transcription.
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Affiliation(s)
- Alexander V. Sergeev
- Department of Chemistry, Lomonosov Moscow State University, Leninskie Gory 1, 119991 Moscow, Russia; (A.V.S.); (A.G.L.); (A.I.G.); (A.S.P.); (N.G.D.); (E.S.G.)
| | - Andrei G. Loiko
- Department of Chemistry, Lomonosov Moscow State University, Leninskie Gory 1, 119991 Moscow, Russia; (A.V.S.); (A.G.L.); (A.I.G.); (A.S.P.); (N.G.D.); (E.S.G.)
| | - Adelya I. Genatullina
- Department of Chemistry, Lomonosov Moscow State University, Leninskie Gory 1, 119991 Moscow, Russia; (A.V.S.); (A.G.L.); (A.I.G.); (A.S.P.); (N.G.D.); (E.S.G.)
| | - Alexander S. Petrov
- Department of Chemistry, Lomonosov Moscow State University, Leninskie Gory 1, 119991 Moscow, Russia; (A.V.S.); (A.G.L.); (A.I.G.); (A.S.P.); (N.G.D.); (E.S.G.)
| | - Elena A. Kubareva
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Leninskie Gory 1, 119991 Moscow, Russia
| | - Nina G. Dolinnaya
- Department of Chemistry, Lomonosov Moscow State University, Leninskie Gory 1, 119991 Moscow, Russia; (A.V.S.); (A.G.L.); (A.I.G.); (A.S.P.); (N.G.D.); (E.S.G.)
| | - Elizaveta S. Gromova
- Department of Chemistry, Lomonosov Moscow State University, Leninskie Gory 1, 119991 Moscow, Russia; (A.V.S.); (A.G.L.); (A.I.G.); (A.S.P.); (N.G.D.); (E.S.G.)
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6
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Loo CE, Hix MA, Wang T, Cisneros GA, Kohli RM. Revealing Drivers for Carboxy- S-adenosyl-l-methionine Use by Neomorphic Variants of a DNA Methyltransferase. ACS Chem Biol 2023; 18:2224-2232. [PMID: 37379458 PMCID: PMC10592258 DOI: 10.1021/acschembio.3c00184] [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] [Indexed: 06/30/2023]
Abstract
Methylation of DNA plays a key role in diverse biological processes spanning from bacteria to mammals. DNA methyltransferases (MTases) typically employ S-adenosyl-l-methionine (SAM) as a critical cosubstrate and the relevant methyl donor for modification of the C5 position of cytosine. Recently, work on the CpG-specific bacterial MTase, M.MpeI, has shown that a single N374K point mutation can confer the enzyme with the neomorphic ability to use the sparse, naturally occurring metabolite carboxy-S-adenosyl-l-methionine (CxSAM) in order to generate the unnatural DNA modification, 5-carboxymethylcytosine (5cxmC). Here, we aimed to investigate the mechanistic basis for this DNA carboxymethyltransferase (CxMTase) activity by employing a combination of computational modeling and in vitro characterization. Modeling of substrate interactions with the enzyme variant allowed us to identify a favorable salt bridge between CxSAM and N374K that helps to rationalize selectivity of the CxMTase. Unexpectedly, we also discovered a potential role for a key active site E45 residue that makes a bidentate interaction with the ribosyl sugar of CxSAM, located on the opposite face of the CxMTase active site. Prompted by these modeling results, we further explored the space-opening E45D mutation and found that the E45D/N374K double mutant in fact inverts selectivity, preferring CxSAM over SAM in biochemical assays. These findings provide new insight into CxMTase active site architecture and may offer broader utility given the numerous opportunities offered by using SAM analogs for selective molecular labeling in concert with nucleic acid or even protein-modifying MTases.
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Affiliation(s)
- Christian E. Loo
- Graduate Group in Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Mark A. Hix
- Department of Chemistry, Wayne State University, Detroit, Michigan 48202, United States
| | - Tong Wang
- Graduate Group in Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - G. Andrés Cisneros
- Department of Physics, University of Texas at Dallas, Richardson, Texas 75801, United States; Department of Chemistry and Biochemistry, University of Texas at Dallas, Richardson, Texas 75801, United States
| | - Rahul M. Kohli
- Department of Medicine and Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
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7
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Avraham S, Schütz L, Käver L, Dankers A, Margalit S, Michaeli Y, Zirkin S, Torchinsky D, Gilat N, Bahr O, Nifker G, Koren-Michowitz M, Weinhold E, Ebenstein Y. Chemo-Enzymatic Fluorescence Labeling Of Genomic DNA For Simultaneous Detection Of Global 5-Methylcytosine And 5-Hydroxymethylcytosine. Chembiochem 2023; 24:e202300400. [PMID: 37518671 DOI: 10.1002/cbic.202300400] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Revised: 07/05/2023] [Accepted: 07/27/2023] [Indexed: 08/01/2023]
Abstract
5-Methylcytosine and 5-hydroxymethylcytosine are epigenetic modifications involved in gene regulation and cancer. We present a new, simple, and high-throughput platform for multi-color epigenetic analysis. The novelty of our approach is the ability to multiplex methylation and de-methylation signals in the same assay. We utilize an engineered methyltransferase enzyme that recognizes and labels all unmodified CpG sites with a fluorescent cofactor. In combination with the already established labeling of the de-methylation mark 5-hydroxymethylcytosine via enzymatic glycosylation, we obtained a robust platform for simultaneous epigenetic analysis of these marks. We assessed the global epigenetic levels in multiple samples of colorectal cancer and observed a 3.5-fold reduction in 5hmC levels but no change in DNA methylation levels between sick and healthy individuals. We also measured epigenetic modifications in chronic lymphocytic leukemia and observed a decrease in both modification levels (5-hydroxymethylcytosine: whole blood 30 %; peripheral blood mononuclear cells (PBMCs) 40 %. 5-methylcytosine: whole blood 53 %; PBMCs 48 %). Our findings propose using a simple blood test as a viable method for analysis, simplifying sample handling in diagnostics. Importantly, our results highlight the assay's potential for epigenetic evaluation of clinical samples, benefiting research and patient management.
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Affiliation(s)
- Sigal Avraham
- Department of Chemistry, Raymond and Beverly SacklerFaculty of Exact Sciences, Department of Biomedical Engineering, Tel Aviv University Tel Aviv-Yafo, 6997801, Tel Aviv, Israel
- School of Chemistry,Ramat Aviv, Tel Aviv University, Tel Aviv, 6997801, Israel
| | - Leonie Schütz
- Institute of Organic Chemistry, RWTH Aachen University, 52056, Aachen, Germany
| | - Larissa Käver
- Institute of Organic Chemistry, RWTH Aachen University, 52056, Aachen, Germany
| | - Andreas Dankers
- Institute of Organic Chemistry, RWTH Aachen University, 52056, Aachen, Germany
| | - Sapir Margalit
- Department of Chemistry, Raymond and Beverly SacklerFaculty of Exact Sciences, Department of Biomedical Engineering, Tel Aviv University Tel Aviv-Yafo, 6997801, Tel Aviv, Israel
| | - Yael Michaeli
- Department of Chemistry, Raymond and Beverly SacklerFaculty of Exact Sciences, Department of Biomedical Engineering, Tel Aviv University Tel Aviv-Yafo, 6997801, Tel Aviv, Israel
- School of Chemistry,Ramat Aviv, Tel Aviv University, Tel Aviv, 6997801, Israel
| | - Shahar Zirkin
- Department of Chemistry, Raymond and Beverly SacklerFaculty of Exact Sciences, Department of Biomedical Engineering, Tel Aviv University Tel Aviv-Yafo, 6997801, Tel Aviv, Israel
- School of Chemistry,Ramat Aviv, Tel Aviv University, Tel Aviv, 6997801, Israel
| | - Dmitry Torchinsky
- Department of Chemistry, Raymond and Beverly SacklerFaculty of Exact Sciences, Department of Biomedical Engineering, Tel Aviv University Tel Aviv-Yafo, 6997801, Tel Aviv, Israel
- School of Chemistry,Ramat Aviv, Tel Aviv University, Tel Aviv, 6997801, Israel
| | - Noa Gilat
- Department of Chemistry, Raymond and Beverly SacklerFaculty of Exact Sciences, Department of Biomedical Engineering, Tel Aviv University Tel Aviv-Yafo, 6997801, Tel Aviv, Israel
- School of Chemistry,Ramat Aviv, Tel Aviv University, Tel Aviv, 6997801, Israel
| | - Omer Bahr
- Department of Chemistry, Raymond and Beverly SacklerFaculty of Exact Sciences, Department of Biomedical Engineering, Tel Aviv University Tel Aviv-Yafo, 6997801, Tel Aviv, Israel
- School of Chemistry,Ramat Aviv, Tel Aviv University, Tel Aviv, 6997801, Israel
| | - Gil Nifker
- Department of Chemistry, Raymond and Beverly SacklerFaculty of Exact Sciences, Department of Biomedical Engineering, Tel Aviv University Tel Aviv-Yafo, 6997801, Tel Aviv, Israel
- School of Chemistry,Ramat Aviv, Tel Aviv University, Tel Aviv, 6997801, Israel
| | | | - Elmar Weinhold
- Institute of Organic Chemistry, RWTH Aachen University, 52056, Aachen, Germany
| | - Yuval Ebenstein
- Department of Chemistry, Raymond and Beverly SacklerFaculty of Exact Sciences, Department of Biomedical Engineering, Tel Aviv University Tel Aviv-Yafo, 6997801, Tel Aviv, Israel
- School of Chemistry,Ramat Aviv, Tel Aviv University, Tel Aviv, 6997801, Israel
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8
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Trexler M, Bányai L, Kerekes K, Patthy L. Evolution of termination codons of proteins and the TAG-TGA paradox. Sci Rep 2023; 13:14294. [PMID: 37653005 PMCID: PMC10471768 DOI: 10.1038/s41598-023-41410-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Accepted: 08/25/2023] [Indexed: 09/02/2023] Open
Abstract
In most eukaryotes and prokaryotes TGA is used at a significantly higher frequency than TAG as termination codon of protein-coding genes. Although this phenomenon has been recognized several years ago, there is no generally accepted explanation for the TAG-TGA paradox. Our analyses of human mutation data revealed that out of the eighteen sense codons that can give rise to a nonsense codon by single base substitution, the CGA codon is exceptional: it gives rise to the TGA stop codon at an order of magnitude higher rate than the other codons. Here we propose that the TAG-TGA paradox is due to methylation and hypermutabilty of CpG dinucleotides. In harmony with this explanation, we show that the coding genomes of organisms with strong CpG methylation have a significant bias for TGA whereas those from organisms that lack CpG methylation use TGA and TAG termination codons with similar probability.
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Affiliation(s)
- Mária Trexler
- Institute of Enzymology, Research Centre for Natural Sciences, Budapest, 1117, Hungary
| | - László Bányai
- Institute of Enzymology, Research Centre for Natural Sciences, Budapest, 1117, Hungary
| | - Krisztina Kerekes
- Institute of Enzymology, Research Centre for Natural Sciences, Budapest, 1117, Hungary
| | - László Patthy
- Institute of Enzymology, Research Centre for Natural Sciences, Budapest, 1117, Hungary.
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9
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Xiong J, Chen KK, Xie NB, Ji TT, Yu SY, Tang F, Xie C, Feng YQ, Yuan BF. Bisulfite-Free and Single-Base Resolution Detection of Epigenetic DNA Modification of 5-Methylcytosine by Methyltransferase-Directed Labeling with APOBEC3A Deamination Sequencing. Anal Chem 2022; 94:15489-15498. [DOI: 10.1021/acs.analchem.2c03808] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Jun Xiong
- School of Public Health, Department of Radiation and Medical Oncology, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan 430071, China
- Sauvage Center for Molecular Sciences, College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, China
| | - Ke-Ke Chen
- Sauvage Center for Molecular Sciences, College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, China
| | - Neng-Bin Xie
- School of Public Health, Department of Radiation and Medical Oncology, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan 430071, China
- Sauvage Center for Molecular Sciences, College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, China
| | - Tong-Tong Ji
- Sauvage Center for Molecular Sciences, College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, China
| | - Si-Yu Yu
- School of Public Health, Department of Radiation and Medical Oncology, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan 430071, China
| | - Feng Tang
- Sauvage Center for Molecular Sciences, College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, China
| | - Conghua Xie
- School of Public Health, Department of Radiation and Medical Oncology, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan 430071, China
| | - Yu-Qi Feng
- School of Public Health, Department of Radiation and Medical Oncology, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan 430071, China
- Sauvage Center for Molecular Sciences, College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, China
| | - Bi-Feng Yuan
- School of Public Health, Department of Radiation and Medical Oncology, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan 430071, China
- Sauvage Center for Molecular Sciences, College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, China
- Research Center of Public Health, Renmin Hospital of Wuhan University, Wuhan 430060, China
- Cancer Precision Diagnosis and Treatment and Translational Medicine Hubei Engineering Research Center, Zhongnan Hospital of Wuhan University, Wuhan Research Center for Infectious Diseases and Cancer, Chinese Academy of Medical Sciences, Wuhan 430071, China
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10
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Loiko AG, Sergeev AV, Genatullina AI, Monakhova MV, Kubareva EA, Dolinnaya NG, Gromova ES. Impact of G-Quadruplex Structures on Methylation of Model Substrates by DNA Methyltransferase Dnmt3a. Int J Mol Sci 2022; 23:ijms231810226. [PMID: 36142137 PMCID: PMC9499004 DOI: 10.3390/ijms231810226] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2022] [Revised: 08/28/2022] [Accepted: 09/02/2022] [Indexed: 11/17/2022] Open
Abstract
In mammals, de novo methylation of cytosines in DNA CpG sites is performed by DNA methyltransferase Dnmt3a. Changes in the methylation status of CpG islands are critical for gene regulation and for the progression of some cancers. Recently, the potential involvement of DNA G-quadruplexes (G4s) in methylation control has been found. Here, we provide evidence for a link between G4 formation and the function of murine DNA methyltransferase Dnmt3a and its individual domains. As DNA models, we used (i) an isolated G4 formed by oligonucleotide capable of folding into parallel quadruplex and (ii) the same G4 inserted into a double-stranded DNA bearing several CpG sites. Using electrophoretic mobility shift and fluorescence polarization assays, we showed that the Dnmt3a catalytic domain (Dnmt3a-CD), in contrast to regulatory PWWP domain, effectively binds the G4 structure formed in both DNA models. The G4-forming oligonucleotide displaced the DNA substrate from its complex with Dnmt3a-CD, resulting in a dramatic suppression of the enzyme activity. In addition, a direct impact of G4 inserted into the DNA duplex on the methylation of a specific CpG site was revealed. Possible mechanisms of G4-mediated epigenetic regulation may include Dnmt3a sequestration at G4 and/or disruption of Dnmt3a oligomerization on the DNA surface.
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Affiliation(s)
- Andrei G. Loiko
- Department of Chemistry, Lomonosov Moscow State University, Leninskie Gory 1, 119991 Moscow, Russia
- Correspondence: (A.G.L.); (A.V.S.)
| | - Alexander V. Sergeev
- Department of Chemistry, Lomonosov Moscow State University, Leninskie Gory 1, 119991 Moscow, Russia
- Correspondence: (A.G.L.); (A.V.S.)
| | - Adelya I. Genatullina
- Department of Chemistry, Lomonosov Moscow State University, Leninskie Gory 1, 119991 Moscow, Russia
| | - Mayya V. Monakhova
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Leninskie Gory 1, 119991 Moscow, Russia
| | - Elena A. Kubareva
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Leninskie Gory 1, 119991 Moscow, Russia
| | - Nina G. Dolinnaya
- Department of Chemistry, Lomonosov Moscow State University, Leninskie Gory 1, 119991 Moscow, Russia
| | - Elizaveta S. Gromova
- Department of Chemistry, Lomonosov Moscow State University, Leninskie Gory 1, 119991 Moscow, Russia
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11
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Genome-Wide Association Study of Nucleotide Variants Associated with Resistance to Nine Antimicrobials in Mycoplasma bovis. Microorganisms 2022; 10:microorganisms10071366. [PMID: 35889084 PMCID: PMC9320666 DOI: 10.3390/microorganisms10071366] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Revised: 06/30/2022] [Accepted: 07/01/2022] [Indexed: 12/03/2022] Open
Abstract
Antimicrobial resistance (AMR) studies of Mycoplasma bovis have generally focused on specific loci versus using a genome-wide association study (GWAS) approach. A GWAS approach, using two different models, was applied to 194 Mycoplasma bovis genomes. Both a fixed effects linear model (FEM) and a linear mixed model (LMM) identified associations between nucleotide variants (NVs) and antimicrobial susceptibility testing (AST) phenotypes. The AMR phenotypes represented fluoroquinolones, tetracyclines, phenicols, and macrolides. Both models identified known and novel NVs associated (Bonferroni adjusted p < 0.05) with AMR. Fluoroquinolone resistance was associated with multiple NVs, including previously identified mutations in gyrA and parC. NVs in the 30S ribosomal protein 16S were associated with tetracycline resistance, whereas NVs in 5S rRNA, 23S rRNA, and 50S ribosomal proteins were associated with phenicol and macrolide resistance. For all antimicrobial classes, resistance was associated with NVs in genes coding for ABC transporters and other membrane proteins, tRNA-ligases, peptidases, and transposases, suggesting a NV-based multifactorial model of AMR in M. bovis. This study was the largest collection of North American M. bovis isolates used with a GWAS for the sole purpose of identifying novel and non-antimicrobial-target NVs associated with AMR.
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12
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Dordet-Frisoni E, Vandecasteele C, Contarin R, Sagné E, Baranowski E, Klopp C, Nouvel LX, Citti C. Impacts of Mycoplasma agalactiae restriction-modification systems on pan-epigenome dynamics and genome plasticity. Microb Genom 2022; 8. [PMID: 35576144 PMCID: PMC9465063 DOI: 10.1099/mgen.0.000829] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
DNA methylations play an important role in the biology of bacteria. Often associated with restriction modification (RM) systems, they are important drivers of bacterial evolution interfering in horizontal gene transfer events by providing a defence against foreign DNA invasion or by favouring genetic transfer through production of recombinogenic DNA ends. Little is known regarding the methylome of the Mycoplasma genus, which encompasses several pathogenic species with small genomes. Here, genome-wide detection of DNA methylations was conducted using single molecule real-time (SMRT) and bisulphite sequencing in several strains of Mycoplasma agalactiae, an important ruminant pathogen and a model organism. Combined with whole-genome analysis, this allowed the identification of 19 methylated motifs associated with three orphan methyltransferases (MTases) and eight RM systems. All systems had a homolog in at least one phylogenetically distinct Mycoplasma spp. Our study also revealed that several superimposed genetic events may participate in the M. agalactiae dynamic epigenomic landscape. These included (i) DNA shuffling and frameshift mutations that affect the MTase and restriction endonuclease content of a clonal population and (ii) gene duplication, erosion, and horizontal transfer that modulate MTase and RM repertoires of the species. Some of these systems were experimentally shown to play a major role in mycoplasma conjugative, horizontal DNA transfer. While the versatility of DNA methylation may contribute to regulating essential biological functions at cell and population levels, RM systems may be key in mycoplasma genome evolution and adaptation by controlling horizontal gene transfers.
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Affiliation(s)
- Emilie Dordet-Frisoni
- IHAP, Université de Toulouse, INRAE, ENVT, Toulouse, France.,Present address: INTHERES, Université de Toulouse, INRAE, ENVT, Toulouse, France
| | | | | | - Eveline Sagné
- IHAP, Université de Toulouse, INRAE, ENVT, Toulouse, France
| | | | - Christophe Klopp
- INRAE, UR875 MIAT, Sigenae, BioInfo Genotoul, BioInfoMics, F-31326 Auzeville, France
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13
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Furuta Y, Miura F, Ichise T, Nakayama SMM, Ikenaka Y, Zorigt T, Tsujinouchi M, Ishizuka M, Ito T, Higashi H. A GCDGC-specific DNA (cytosine-5) methyltransferase that methylates the GCWGC sequence on both strands and the GCSGC sequence on one strand. PLoS One 2022; 17:e0265225. [PMID: 35312710 PMCID: PMC8936443 DOI: 10.1371/journal.pone.0265225] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Accepted: 02/24/2022] [Indexed: 11/18/2022] Open
Abstract
5-Methylcytosine is one of the major epigenetic marks of DNA in living organisms. Some bacterial species possess DNA methyltransferases that modify cytosines on both strands to produce fully-methylated sites or on either strand to produce hemi-methylated sites. In this study, we characterized a DNA methyltransferase that produces two sequences with different methylation patterns: one methylated on both strands and another on one strand. M.BatI is the orphan DNA methyltransferase of Bacillus anthracis coded in one of the prophages on the chromosome. Analysis of M.BatI modified DNA by bisulfite sequencing revealed that the enzyme methylates the first cytosine in sequences of 5ʹ-GCAGC-3ʹ, 5ʹ-GCTGC-3ʹ, and 5ʹ-GCGGC-3ʹ, but not of 5ʹ-GCCGC-3ʹ. This resulted in the production of fully-methylated 5ʹ-GCWGC-3ʹ and hemi-methylated 5ʹ-GCSGC-3ʹ. M.BatI also showed toxicity when expressed in E. coli, which was caused by a mechanism other than DNA modification activity. Homologs of M.BatI were found in other Bacillus species on different prophage like regions, suggesting the spread of the gene by several different phages. The discovery of the DNA methyltransferase with unique modification target specificity suggested unrevealed diversity of target sequences of bacterial cytosine DNA methyltransferase.
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Affiliation(s)
- Yoshikazu Furuta
- Division of Infection and Immunity, International Institute for Zoonosis Control, Hokkaido University, Sapporo, Japan
- * E-mail:
| | - Fumihito Miura
- Department of Biochemistry, Kyushu University Graduate School of Medical Sciences, Fukuoka, Japan
| | - Takahiro Ichise
- Laboratory of Toxicology, Department of Environmental Veterinary Sciences, School of Veterinary Medicine, Hokkaido University, Sapporo, Japan
| | - Shouta M. M. Nakayama
- Laboratory of Toxicology, Department of Environmental Veterinary Sciences, School of Veterinary Medicine, Hokkaido University, Sapporo, Japan
| | - Yoshinori Ikenaka
- Laboratory of Toxicology, Department of Environmental Veterinary Sciences, School of Veterinary Medicine, Hokkaido University, Sapporo, Japan
- Water Research Group, Unit for Environmental Sciences and Management, North-West University, Potchefstroom, South Africa
| | - Tuvshinzaya Zorigt
- Division of Infection and Immunity, International Institute for Zoonosis Control, Hokkaido University, Sapporo, Japan
| | - Mai Tsujinouchi
- Division of Infection and Immunity, International Institute for Zoonosis Control, Hokkaido University, Sapporo, Japan
| | - Mayumi Ishizuka
- Laboratory of Toxicology, Department of Environmental Veterinary Sciences, School of Veterinary Medicine, Hokkaido University, Sapporo, Japan
| | - Takashi Ito
- Department of Biochemistry, Kyushu University Graduate School of Medical Sciences, Fukuoka, Japan
| | - Hideaki Higashi
- Division of Infection and Immunity, International Institute for Zoonosis Control, Hokkaido University, Sapporo, Japan
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14
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Khandia R, Ali Khan A, Alexiou A, Povetkin SN, Nikolaevna VM. Codon Usage Analysis of Pro-Apoptotic Bim Gene Isoforms. J Alzheimers Dis 2022; 86:1711-1725. [DOI: 10.3233/jad-215691] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Background: Bim is a Bcl-2 homology 3 (BH3)-only proteins, a group of pro-apoptotic proteins involved in physiological and pathological conditions. Both the overexpression and under-expression of Bim protein are associated with the diseased condition, and various isoforms of Bim protein are present with differential apoptotic potential. Objective: The present study attempted to envisage the association of various molecular signatures with the codon choices of Bim isoforms. Methods: Molecular signatures like composition, codon usage, nucleotide skews, the free energy of mRNA transcript, physical properties of proteins, codon adaptation index, relative synonymous codon usage, and dinucleotide odds ratio were determined and analyzed for their associations with codon choices of Bim gene. Results: Skew analysis of the Bim gene indicated the preference of C nucleotide over G, A, and T and preference of G over T and A nucleotides was observed. An increase in C content at the first and third codon position increased gene expression while it decreased at the second codon position. Compositional constraints on nucleotide C at all three codon positions affected gene expression. The analysis revealed an exceptionally high usage of CpC dinucleotide in all the envisaged 31 isoforms of Bim. We correlated it with the requirement of rapid demethylation machinery to fine-tune the Bimgene expression. Also, mutational pressure played a dominant role in shaping codon usage bias in Bim isoforms. Conclusion: An exceptionally high usage of CpC dinucleotide in all the envisaged 31 isoforms of Bim indicates a high order selectional force to fine tune Bim gene expression.
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Affiliation(s)
- Rekha Khandia
- Department of Biochemistry and Genetics, Barkatullah University, Bhopal, India
| | - Azmat Ali Khan
- Pharmaceutical Biotechnology Laboratory, Department of Pharmaceutical Chemistry, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
| | - Athanasios Alexiou
- Novel Global Community Educational Foundation, Australia & AFNP Med, Austria
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15
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Matsumoto S, Tateishi-Karimata H, Sugimoto N. DNA methylation is regulated by both the stability and topology of G-quadruplex. Chem Commun (Camb) 2022; 58:12459-12462. [DOI: 10.1039/d2cc04383a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The methylation reaction was regulated by not only the stability of G4 but also the topology of G4.
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Affiliation(s)
- Saki Matsumoto
- FIBER (Frontier Institute for Biomolecular Engineering Research), Konan University, 7-1-20 Minatojima-Minamimachi, Chuo-ku, Kobe 650-0047, Japan
| | - Hisae Tateishi-Karimata
- FIBER (Frontier Institute for Biomolecular Engineering Research), Konan University, 7-1-20 Minatojima-Minamimachi, Chuo-ku, Kobe 650-0047, Japan
| | - Naoki Sugimoto
- FIBER (Frontier Institute for Biomolecular Engineering Research), Konan University, 7-1-20 Minatojima-Minamimachi, Chuo-ku, Kobe 650-0047, Japan
- FIRST (Graduate School of Frontiers of Innovative Research in Science and Technology), Konan University, 7-1-20 Minatojima-Minamimachi, Chuo-ku, Kobe 650-0047, Japan
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16
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Nascimento Araujo CD, Amorim AT, Barbosa MS, Alexandre JCPL, Campos GB, Macedo CL, Marques LM, Timenetsky J. Evaluating the presence of Mycoplasma hyorhinis, Fusobacterium nucleatum, and Helicobacter pylori in biopsies of patients with gastric cancer. Infect Agent Cancer 2021; 16:70. [PMID: 34949212 PMCID: PMC8705184 DOI: 10.1186/s13027-021-00410-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Accepted: 12/13/2021] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND Gastric cancer is the third leading cause of cancer-related deaths worldwide and has been associated with infections that may promote tumour progression. Accordingly, we analysed the presence of Mollicutes, Mycoplasma hyorhinis, Fusobacterium nucleatum and Helicobacter pylori in gastric cancer tissues and evaluated their correlation with clinicopathological factors. METHODS Using a commercial kit, DNA were extracted from 120 gastric samples embedded in paraffin: 80 from patients with gastric cancer and 40 from cancer free patients, dating from 2006 to 2016. Mollicutes and H. pylori were detected by PCR; F. nucleatum and M. hyorhinis were detected by qPCR, together with immunohistochemistry for the latter bacteria. RESULTS Mollicutes were detected in the case and control groups (12% and 2.5%) and correlated with the papillary histologic pattern (P = 0.003), likely due to cell transformation promoted by Mollicutes. M. hyorhinis was detected in the case and control group but was not considered a cancer risk factor. H. pylori was detected at higher loads in the case compared to the control group (8% and 22%, P = 0.008) and correlated with metastasis (P = 0.024), lymphatic invasion (P = 0.033), tumour of diffused type (P = 0.028), and histopathological grading G1/G2 (P = 0.008). F. nucleatum was the most abundant bacteria in the case group, but was also detected in the control group (26% and 2.5%). It increased the cancer risk factor (P = 0.045, OR = 10.562, CI95% = 1.057-105.521), and correlated with old age (P = 0.030) and tumour size (P = 0.053). Bacterial abundance was significantly different between groups (P = 0.001). CONCLUSION Our findings could improve the control and promote our understanding of opportunistic bacteria and their relevance to malignant phenotypes.
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Affiliation(s)
- Camila do Nascimento Araujo
- Department of Microbiology, Institute of Biomedical Sciences, ICB/USP, University of São Paulo, São Paulo, Brazil
| | - Aline Teixeira Amorim
- Department of Microbiology, Institute of Biomedical Sciences, ICB/USP, University of São Paulo, São Paulo, Brazil
| | - Maysa Santos Barbosa
- Department of Microbiology, Institute of Biomedical Sciences, ICB/USP, University of São Paulo, São Paulo, Brazil
| | | | - Guilherme Barreto Campos
- Department of Microbiology, Institute of Biomedical Sciences, ICB/USP, University of São Paulo, São Paulo, Brazil.,Multidisciplinary Health Institute /Campus Anísio Teixeira, IMS/CAT - UFBA, Federal University of Bahia, Vitória da Conquista, Brazil
| | - Cláudia Leal Macedo
- Micro - Pathological Anatomy and Cytopathology Service, Vitória da Conquista, Brazil
| | - Lucas Miranda Marques
- Department of Microbiology, Institute of Biomedical Sciences, ICB/USP, University of São Paulo, São Paulo, Brazil. .,Multidisciplinary Health Institute /Campus Anísio Teixeira, IMS/CAT - UFBA, Federal University of Bahia, Vitória da Conquista, Brazil.
| | - Jorge Timenetsky
- Department of Microbiology, Institute of Biomedical Sciences, ICB/USP, University of São Paulo, São Paulo, Brazil
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17
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Z-DNA as a Tool for Nuclease-Free DNA Methyltransferase Assay. Int J Mol Sci 2021; 22:ijms222111990. [PMID: 34769422 PMCID: PMC8585049 DOI: 10.3390/ijms222111990] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 10/29/2021] [Accepted: 10/30/2021] [Indexed: 01/16/2023] Open
Abstract
Methylcytosines in mammalian genomes are the main epigenetic molecular codes that switch off the repertoire of genes in cell-type and cell-stage dependent manners. DNA methyltransferases (DMT) are dedicated to managing the status of cytosine methylation. DNA methylation is not only critical in normal development, but it is also implicated in cancers, degeneration, and senescence. Thus, the chemicals to control DMT have been suggested as anticancer drugs by reprogramming the gene expression profile in malignant cells. Here, we report a new optical technique to characterize the activity of DMT and the effect of inhibitors, utilizing the methylation-sensitive B-Z transition of DNA without bisulfite conversion, methylation-sensing proteins, and polymerase chain reaction amplification. With the high sensitivity of single-molecule FRET, this method detects the event of DNA methylation in a single DNA molecule and circumvents the need for amplification steps, permitting direct interpretation. This method also responds to hemi-methylated DNA. Dispensing with methylation-sensitive nucleases, this method preserves the molecular integrity and methylation state of target molecules. Sparing methylation-sensing nucleases and antibodies helps to avoid errors introduced by the antibody’s incomplete specificity or variable activity of nucleases. With this new method, we demonstrated the inhibitory effect of several natural bio-active compounds on DMT. All taken together, our method offers quantitative assays for DMT and DMT-related anticancer drugs.
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18
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Ge J, Qiu X. Expression, purification, characterization of DNA binding activity and crystallization of a putative type II DNA Cytosine-5-methyltransferase from Microcystis aeruginosa. Protein Expr Purif 2021; 189:105988. [PMID: 34634480 DOI: 10.1016/j.pep.2021.105988] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2021] [Revised: 09/01/2021] [Accepted: 10/04/2021] [Indexed: 11/25/2022]
Abstract
DNA 5-methylcytosine modification plays an important role in the regulation of a variety of biological functions in both prokaryotic and eukaryotic organisms. Previous studies show that DNA Cytosine-5-methylation is predominantly associated with restriction-modification system in bacteria. IPF4390 is deduced to be a putative type II DNA Cytosine-5 methyltransferase from a fresh water cyanobacterium, Microcystis aeruginosa. Both its substrate sequence specificity and catalytic mechanism need to be revealed. In this study, the cloning, expression, purification, DNA binding assays and crystallization of IPF4390 are reported. Results of DNA binding assays demonstrate that IPF4390 can specifically recognize and bind two double-stranded DNAs containing GGNCC (N = A, T, C or G) sequences (HgiBI: 5'-ATAAGGACCAATA-3'; TdeIII: 5'-ATAAGGGCCAATA-3'). Therefore, IPF4390 is probably capable of blocking endonuclease cleavage once restriction sites containing these sequences. Moreover, the crystal of IPF4390 in the presence of TdeIII was obtained, and its X-ray diffraction data were collected and scaled to a maximum resolution of 2.46 Å.
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Affiliation(s)
- Junyi Ge
- Ministry of Education Key Laboratory of Applied Marine Biotechnology, Ningbo University, Ningbo, Zhejiang Province, 315800, China
| | - Xiaoting Qiu
- Ministry of Education Key Laboratory of Applied Marine Biotechnology, Ningbo University, Ningbo, Zhejiang Province, 315800, China; Institute of Marine Biotechnology, College of Food and Pharmaceutical Sciences, Ningbo University, Ningbo, Zhejiang Province, 315800, China; Li Dak Sum Yip Yio Chin Kenneth Li Marine Biopharmaceutical Research Center, Ningbo University, Ningbo, Zhejiang Province, 315800, China.
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19
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Wang T, Loo CE, Kohli RM. Enzymatic approaches for profiling cytosine methylation and hydroxymethylation. Mol Metab 2021; 57:101314. [PMID: 34375743 PMCID: PMC8829811 DOI: 10.1016/j.molmet.2021.101314] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/27/2021] [Revised: 07/26/2021] [Accepted: 08/03/2021] [Indexed: 12/20/2022] Open
Abstract
Background In mammals, modifications to cytosine bases, particularly in cytosine-guanine (CpG) dinucleotide contexts, play a major role in shaping the epigenome. The canonical epigenetic mark is 5-methylcytosine (5mC), but oxidized versions of 5mC, including 5-hydroxymethylcytosine (5hmC), are now known to be important players in epigenomic dynamics. Understanding the functional role of these modifications in gene regulation, normal development, and pathological conditions requires the ability to localize these modifications in genomic DNA. The classical approach for sequencing cytosine modifications has involved differential deamination via the chemical sodium bisulfite; however, bisulfite is destructive, limiting its utility in important biological or clinical settings where detection of low frequency populations is critical. Additionally, bisulfite fails to resolve 5mC from 5hmC. Scope of review To summarize how enzymatic rather than chemical approaches can be leveraged to localize and resolve different cytosine modifications in a non-destructive manner. Major conclusions Nature offers a suite of enzymes with biological roles in cytosine modification in organisms spanning from bacteriophages to mammals. These enzymatic activities include methylation by DNA methyltransferases, oxidation of 5mC by TET family enzymes, hypermodification of 5hmC by glucosyltransferases, and the generation of transition mutations from cytosine to uracil by DNA deaminases. Here, we describe how insights into the natural reactivities of these DNA-modifying enzymes can be leveraged to convert them into powerful biotechnological tools. Application of these enzymes in sequencing can be accomplished by relying on their natural activity, exploiting their ability to discriminate between cytosine modification states, reacting them with functionalized substrate analogs to introduce chemical handles, or engineering the DNA-modifying enzymes to take on new reactivities. We describe how these enzymatic reactions have been combined and permuted to localize DNA modifications with high specificity and without the destructive limitations posed by chemical methods for epigenetic sequencing. Chemical sequencing methods damage DNA and can confound cytosine modifications. DNA modifying enzymes offer non-destructive and selective biotechnological tools. DNA deaminases, methyltransferases, oxygenases and glucosyltransferases can be used. Permuting enzymes with various activities can reveal distinct cytosine states. Engineered enzymes utilizing unnatural co-substrates expand sequencing scope.
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Affiliation(s)
- Tong Wang
- Graduate Group in Biochemistry and Molecular Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Christian E Loo
- Graduate Group in Biochemistry and Molecular Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Rahul M Kohli
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA; Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA; Epigenetics Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
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20
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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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21
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Discovery of an Unnatural DNA Modification Derived from a Natural Secondary Metabolite. Cell Chem Biol 2020; 28:97-104.e4. [PMID: 33053370 DOI: 10.1016/j.chembiol.2020.09.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 08/19/2020] [Accepted: 09/23/2020] [Indexed: 02/06/2023]
Abstract
Despite widespread interest for understanding how modified bases have evolved their contemporary functions, limited experimental evidence exists for measuring how close an organism is to accidentally creating a new, modified base within the framework of its existing genome. Here, we describe the biochemical and structural basis for how a single-point mutation in E. coli's naturally occurring cytosine methyltransferase can surprisingly endow a neomorphic ability to create the unnatural DNA base, 5-carboxymethylcytosine (5cxmC), in vivo. Mass spectrometry, bacterial genetics, and structure-guided biochemistry reveal this base to be exclusively derived from the natural but sparse secondary metabolite carboxy-S-adenosyl-L-methionine (CxSAM). Our discovery of a new, unnatural DNA modification reveals insights into the substrate selectivity of DNA methyltransferase enzymes, offers a promising new biotechnological tool for the characterization of the mammalian epigenome, and provides an unexpected model for how neomorphic bases could arise in nature from repurposed host metabolites.
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22
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Nye TM, van Gijtenbeek LA, Stevens AG, Schroeder JW, Randall JR, Matthews LA, Simmons LA. Methyltransferase DnmA is responsible for genome-wide N6-methyladenosine modifications at non-palindromic recognition sites in Bacillus subtilis. Nucleic Acids Res 2020; 48:5332-5348. [PMID: 32324221 PMCID: PMC7261158 DOI: 10.1093/nar/gkaa266] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 04/02/2020] [Accepted: 04/06/2020] [Indexed: 12/20/2022] Open
Abstract
The genomes of organisms from all three domains of life harbor endogenous base modifications in the form of DNA methylation. In bacterial genomes, methylation occurs on adenosine and cytidine residues to include N6-methyladenine (m6A), 5-methylcytosine (m5C), and N4-methylcytosine (m4C). Bacterial DNA methylation has been well characterized in the context of restriction-modification (RM) systems, where methylation regulates DNA incision by the cognate restriction endonuclease. Relative to RM systems less is known about how m6A contributes to the epigenetic regulation of cellular functions in Gram-positive bacteria. Here, we characterize site-specific m6A modifications in the non-palindromic sequence GACGmAG within the genomes of Bacillus subtilis strains. We demonstrate that the yeeA gene is a methyltransferase responsible for the presence of m6A modifications. We show that methylation from YeeA does not function to limit DNA uptake during natural transformation. Instead, we identify a subset of promoters that contain the methylation consensus sequence and show that loss of methylation within promoter regions causes a decrease in reporter expression. Further, we identify a transcriptional repressor that preferentially binds an unmethylated promoter used in the reporter assays. With these results we suggest that m6A modifications in B. subtilis function to promote gene expression.
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Affiliation(s)
- Taylor M Nye
- Department of Molecular, Cellular, and Developmental Biology University of Michigan, Ann Arbor, MI 48109-1055, USA
| | - Lieke A van Gijtenbeek
- Department of Molecular, Cellular, and Developmental Biology University of Michigan, Ann Arbor, MI 48109-1055, USA
| | - Amanda G Stevens
- Department of Molecular, Cellular, and Developmental Biology University of Michigan, Ann Arbor, MI 48109-1055, USA
| | - Jeremy W Schroeder
- Department of Molecular, Cellular, and Developmental Biology University of Michigan, Ann Arbor, MI 48109-1055, USA
| | - Justin R Randall
- Department of Molecular, Cellular, and Developmental Biology University of Michigan, Ann Arbor, MI 48109-1055, USA
| | - Lindsay A Matthews
- Department of Molecular, Cellular, and Developmental Biology University of Michigan, Ann Arbor, MI 48109-1055, USA
| | - Lyle A Simmons
- Department of Molecular, Cellular, and Developmental Biology University of Michigan, Ann Arbor, MI 48109-1055, USA
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Denzer L, Schroten H, Schwerk C. From Gene to Protein-How Bacterial Virulence Factors Manipulate Host Gene Expression During Infection. Int J Mol Sci 2020; 21:ijms21103730. [PMID: 32466312 PMCID: PMC7279228 DOI: 10.3390/ijms21103730] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 05/19/2020] [Accepted: 05/20/2020] [Indexed: 02/06/2023] Open
Abstract
Bacteria evolved many strategies to survive and persist within host cells. Secretion of bacterial effectors enables bacteria not only to enter the host cell but also to manipulate host gene expression to circumvent clearance by the host immune response. Some effectors were also shown to evade the nucleus to manipulate epigenetic processes as well as transcription and mRNA procession and are therefore classified as nucleomodulins. Others were shown to interfere downstream with gene expression at the level of mRNA stability, favoring either mRNA stabilization or mRNA degradation, translation or protein stability, including mechanisms of protein activation and degradation. Finally, manipulation of innate immune signaling and nutrient supply creates a replicative niche that enables bacterial intracellular persistence and survival. In this review, we want to highlight the divergent strategies applied by intracellular bacteria to evade host immune responses through subversion of host gene expression via bacterial effectors. Since these virulence proteins mimic host cell enzymes or own novel enzymatic functions, characterizing their properties could help to understand the complex interactions between host and pathogen during infections. Additionally, these insights could propose potential targets for medical therapy.
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Wilkinson AA, Jagu E, Ubych K, Coulthard S, Rushton AE, Kennefick J, Su Q, Neely RK, Fernandez-Trillo P. Site-Selective and Rewritable Labeling of DNA through Enzymatic, Reversible, and Click Chemistries. ACS CENTRAL SCIENCE 2020; 6:525-534. [PMID: 32342002 PMCID: PMC7181315 DOI: 10.1021/acscentsci.9b01023] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Indexed: 05/02/2023]
Abstract
Current methods for bioconjugation rely on the introduction of stable linkers that lack the required versatility to perform sequential functionalizations. However, sequential manipulations are an increasing requirement in chemical biology because they can underpin multiple analyses of the same sample to provide a wider understanding of cell behavior. Here, we present a new method to site-selectively write, remove, and rewrite chemical functionality to a biomolecule, DNA in this case. Our method combines the precision and robustness of methyltransferase-directed labeling with the reversibility of acyl hydrazones and the efficiency of click chemistry. Underpinning the method is a new S-adenosyl-l-methionine derivative to site-selectively label DNA with a bifunctional chemical handle containing an acyl hydrazone-linker and a terminal azide. Functional tags are conjugated via the azide and can be removed (i.e., untagged) when needed at the acyl hydrazone via exchange with hydroxyl amine. The formed hydrazide-labeled DNA is a versatile intermediate that can be either rewritten to reset the original chemical handle or covalently reacted with a permanent tag. This ability to write, tag, untag, and permanently tag DNA is exploited to sequentially introduce two fluorescent dyes on DNA. Finally, we demonstrate the potential of the method by developing a protocol to sort labeled DNA using magnetic beads, with subsequent amplification of the sorted DNA sample for further analysis. The presented method opens new avenues for site-selective bioconjugation and should underpin integrative approaches in chemical biology where sequential functionalizations of the same sample are required.
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Affiliation(s)
- Andrew A Wilkinson
- School of Chemistry, University of Birmingham, Edgbaston, Birmingham, U.K., B15 2TT
| | - Elodie Jagu
- School of Chemistry, University of Birmingham, Edgbaston, Birmingham, U.K., B15 2TT
| | - Krystian Ubych
- School of Chemistry, University of Birmingham, Edgbaston, Birmingham, U.K., B15 2TT
| | - Steven Coulthard
- School of Chemistry, University of Birmingham, Edgbaston, Birmingham, U.K., B15 2TT
| | - Ashleigh E Rushton
- School of Chemistry, University of Birmingham, Edgbaston, Birmingham, U.K., B15 2TT
| | - Jack Kennefick
- School of Chemistry, University of Birmingham, Edgbaston, Birmingham, U.K., B15 2TT
| | - Qiang Su
- School of Chemistry, University of Birmingham, Edgbaston, Birmingham, U.K., B15 2TT
| | - Robert K Neely
- School of Chemistry, University of Birmingham, Edgbaston, Birmingham, U.K., B15 2TT
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25
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Role of Mycoplasma Chaperone DnaK in Cellular Transformation. Int J Mol Sci 2020; 21:ijms21041311. [PMID: 32075244 PMCID: PMC7072988 DOI: 10.3390/ijms21041311] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Revised: 02/04/2020] [Accepted: 02/12/2020] [Indexed: 12/25/2022] Open
Abstract
Studies of the human microbiome have elucidated an array of complex interactions between prokaryotes and their hosts. However, precise bacterial pathogen-cancer relationships remain largely elusive, although several bacteria, particularly those establishing persistent intra-cellular infections, like mycoplasmas, can alter host cell cycles, affect apoptotic pathways, and stimulate the production of inflammatory substances linked to DNA damage, thus potentially promoting abnormal cell growth and transformation. Consistent with this idea, in vivo experiments in several chemically induced or genetically deficient mouse models showed that germ-free conditions reduce colonic tumor formation. We demonstrate that mycoplasma DnaK, a chaperone protein belonging to the Heath shock protein (Hsp)-70 family, binds Poly-(ADP-ribose) Polymerase (PARP)-1, a protein that plays a critical role in the pathways involved in recognition of DNA damage and repair, and reduces its catalytic activity. It also binds USP10, a key p53 regulator, reducing p53 stability and anti-cancer functions. Finally, we showed that bystander, uninfected cells take up exogenous DnaK-suggesting a possible paracrine function in promoting cellular transformation, over and above direct mycoplasma infection. We propose that mycoplasmas, and perhaps certain other bacteria with closely related DnaK, may have oncogenic activity, mediated through the inhibition of DNA repair and p53 functions, and may be involved in the initiation of some cancers but not necessarily involved nor necessarily even be present in later stages.
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Kamuju V, Kumar S, Khan WH, Vivekanandan P. Hypervirulent Clostridium difficile ribotypes are CpG depleted. Virulence 2019; 9:1422-1425. [PMID: 30176154 PMCID: PMC6141142 DOI: 10.1080/21505594.2018.1509669] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
Affiliation(s)
- Vinay Kamuju
- a Department of Biochemical Engineering and Biotechnology , Indian Institute of Technology Delhi , New Delhi , India
| | - Santosh Kumar
- a Department of Biochemical Engineering and Biotechnology , Indian Institute of Technology Delhi , New Delhi , India
| | - Wajihul Hasan Khan
- b Kusuma School of Biological Sciences , Indian Institute of Technology Delhi , New Delhi , India
| | - Perumal Vivekanandan
- b Kusuma School of Biological Sciences , Indian Institute of Technology Delhi , New Delhi , India
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27
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Abstract
Mycoplasmas are intrinsically resistant to antimicrobials targeting the cell wall (fosfomycin, glycopeptides, or β-lactam antibiotics) and to sulfonamides, first-generation quinolones, trimethoprim, polymixins, and rifampicin. The antibiotics most frequently used to control mycoplasmal infections in animals are macrolides and tetracyclines. Lincosamides, fluoroquinolones, pleuromutilins, phenicols, and aminoglycosides can also be active. Standardization of methods used for determination of susceptibility levels is difficult since no quality control strains are available and because of species-specific growth requirements. Reduced susceptibility levels or resistances to several families of antimicrobials have been reported in field isolates of pathogenic Mycoplasma species of major veterinary interest: M. gallisepticum and M. synoviae in poultry; M. hyopneumoniae, M. hyorhinis, and M. hyosynoviae in swine; M. bovis in cattle; and M. agalactiae in small ruminants. The highest resistances are observed for macrolides, followed by tetracyclines. Most strains remain susceptible to fluoroquinolones. Pleuromutilins are the most effective antibiotics in vitro. Resistance frequencies vary according to the Mycoplasma species but also according to the countries or groups of animals from which the samples were taken. Point mutations in the target genes of different antimicrobials have been identified in resistant field isolates, in vitro-selected mutants, or strains reisolated after an experimental infection followed by one or several treatments: DNA-gyrase and topoisomerase IV for fluoroquinolones; 23S rRNA for macrolides, lincosamides, pleuromutilins, and amphenicols; 16S rRNAs for tetracyclines and aminoglycosides. Further work should be carried out to determine and harmonize specific breakpoints for animal mycoplasmas so that in vitro information can be used to provide advice on selection of in vivo treatments.
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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: 46] [Impact Index Per Article: 7.7] [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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29
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Albert P, Varga B, Zsibrita N, Kiss A. Circularly permuted variants of two CG-specific prokaryotic DNA methyltransferases. PLoS One 2018; 13:e0197232. [PMID: 29746549 PMCID: PMC5944983 DOI: 10.1371/journal.pone.0197232] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2018] [Accepted: 04/27/2018] [Indexed: 01/06/2023] Open
Abstract
The highly similar prokaryotic DNA (cytosine-5) methyltransferases (C5-MTases) M.MpeI and M.SssI share the specificity of eukaryotic C5-MTases (5'-CG), and can be useful research tools in the study of eukaryotic DNA methylation and epigenetic regulation. In an effort to improve the stability and solubility of complementing fragments of the two MTases, genes encoding circularly permuted (CP) variants of M.MpeI and M.SssI were created, and cloned in a plasmid vector downstream of an arabinose-inducible promoter. MTase activity of the CP variants was tested by digestion of the plasmids with methylation-sensitive restriction enzymes. Eleven of the fourteen M.MpeI permutants and six of the seven M.SssI permutants had detectable MTase activity as indicated by the full or partial protection of the plasmid carrying the cpMTase gene. Permutants cp62M.MpeI and cp58M.SssI, in which the new N-termini are located between conserved motifs II and III, had by far the highest activity. The activity of cp62M.MpeI was comparable to the activity of wild-type M.MpeI. Based on the location of the split sites, the permutants possessing MTase activity can be classified in ten types. Although most permutation sites were designed to fall outside of conserved motifs, and the MTase activity of the permutants measured in cell extracts was in most cases substantially lower than that of the wild-type enzyme, the high proportion of circular permutation topologies compatible with MTase activity is remarkable, and is a new evidence for the structural plasticity of C5-MTases. A computer search of the REBASE database identified putative C5-MTases with CP arrangement. Interestingly, all natural circularly permuted C5-MTases appear to represent only one of the ten types of permutation topology created in this work.
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Affiliation(s)
- Pál Albert
- Institute of Biochemistry, Biological Research Centre of the Hungarian Academy of Sciences, Szeged, Hungary
- Doctoral School in Biology, Faculty of Science and Informatics, University of Szeged, Szeged, Hungary
| | - Bence Varga
- Institute of Biochemistry, Biological Research Centre of the Hungarian Academy of Sciences, Szeged, Hungary
| | - Nikolett Zsibrita
- Institute of Biochemistry, Biological Research Centre of the Hungarian Academy of Sciences, Szeged, Hungary
- Doctoral School in Biology, Faculty of Science and Informatics, University of Szeged, Szeged, Hungary
| | - Antal Kiss
- Institute of Biochemistry, Biological Research Centre of the Hungarian Academy of Sciences, Szeged, Hungary
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30
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Abstract
PURPOSE OF REVIEW We wished to overview recent data on a subset of epigenetic changes elicited by intracellular bacteria in human cells. Reprogramming the gene expression pattern of various host cells may facilitate bacterial growth, survival, and spread. RECENT FINDINGS DNA-(cytosine C5)-methyltransferases of Mycoplasma hyorhinis targeting cytosine-phosphate-guanine (CpG) dinucleotides and a Mycobacterium tuberculosis methyltransferase targeting non-CpG sites methylated the host cell DNA and altered the pattern of gene expression. Gene silencing by CpG methylation and histone deacetylation, mediated by cellular enzymes, also occurred in M. tuberculosis-infected macrophages. M. tuberculosis elicited cell type-specific epigenetic changes: it caused increased DNA methylation in macrophages, but induced demethylation, deposition of euchromatic histone marks and activation of immune-related genes in dendritic cells. A secreted transposase of Acinetobacter baumannii silenced a cellular gene, whereas Mycobacterium leprae altered the epigenotype, phenotype, and fate of infected Schwann cells. The 'keystone pathogen' oral bacterium Porphyromonas gingivalis induced local DNA methylation and increased the level of histone acetylation in host cells. These epigenetic changes at the biofilm-gingiva interface may contribute to the development of periodontitis. SUMMARY Epigenetic regulators produced by intracellular bacteria alter the epigenotype and gene expression pattern of host cells and play an important role in pathogenesis.
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Lei Y, Zhang X, Su J, Jeong M, Gundry MC, Huang YH, Zhou Y, Li W, Goodell MA. Targeted DNA methylation in vivo using an engineered dCas9-MQ1 fusion protein. Nat Commun 2017; 8:16026. [PMID: 28695892 PMCID: PMC5508226 DOI: 10.1038/ncomms16026] [Citation(s) in RCA: 137] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Accepted: 05/18/2017] [Indexed: 12/19/2022] Open
Abstract
Comprehensive studies have shown that DNA methylation plays vital roles in both loss of pluripotency and governance of the transcriptome during embryogenesis and subsequent developmental processes. Aberrant DNA methylation patterns have been widely observed in tumorigenesis, ageing and neurodegenerative diseases, highlighting the importance of a systematic understanding of DNA methylation and the dynamic changes of methylomes during disease onset and progression. Here we describe a facile and convenient approach for efficient targeted DNA methylation by fusing inactive Cas9 (dCas9) with an engineered prokaryotic DNA methyltransferase MQ1. Our study presents a rapid and efficient strategy to achieve locus-specific cytosine modifications in the genome without obvious impact on global methylation in 24 h. Finally, we demonstrate our tool can induce targeted CpG methylation in mice by zygote microinjection, thereby demonstrating its potential utility in early development. Understanding how DNA methylation regulates gene expression requires the capacity to deploy it to regions of interest. The authors generate a highly rapid and locus-specific CpG methylation tool by fusing dCas9 to MQ1 DNA methyltransferase and show efficacy at multiple sites in vitro and in vivo.
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Affiliation(s)
- Yong Lei
- Department of Molecular and Human Genetics, Center for Cell and Gene Therapy, Baylor College of Medicine, Houston, Texas 77030, USA.,Stem Cells and Regenerative Medicine Center, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Xiaotian Zhang
- Department of Molecular and Human Genetics, Center for Cell and Gene Therapy, Baylor College of Medicine, Houston, Texas 77030, USA.,Stem Cells and Regenerative Medicine Center, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Jianzhong Su
- Dan L. Duncan Cancer Center and Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Mira Jeong
- Department of Molecular and Human Genetics, Center for Cell and Gene Therapy, Baylor College of Medicine, Houston, Texas 77030, USA.,Stem Cells and Regenerative Medicine Center, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Michael C Gundry
- Department of Molecular and Human Genetics, Center for Cell and Gene Therapy, Baylor College of Medicine, Houston, Texas 77030, USA.,Stem Cells and Regenerative Medicine Center, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Yung-Hsin Huang
- Stem Cells and Regenerative Medicine Center, Baylor College of Medicine, Houston, Texas 77030, USA.,Department of Developmental Biology, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Yubin Zhou
- Center for Translational Cancer Research, Institute of Biosciences and Technology, Department of Medical Physiology, College of Medicine, Texas A&M University, Houston, Texas 77030, USA
| | - Wei Li
- Stem Cells and Regenerative Medicine Center, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Margaret A Goodell
- Department of Molecular and Human Genetics, Center for Cell and Gene Therapy, Baylor College of Medicine, Houston, Texas 77030, USA.,Stem Cells and Regenerative Medicine Center, Baylor College of Medicine, Houston, Texas 77030, USA.,Dan L. Duncan Cancer Center and Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas 77030, USA
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Foronjy RF, Salathe MA, Dabo AJ, Baumlin N, Cummins N, Eden E, Geraghty P. TLR9 expression is required for the development of cigarette smoke-induced emphysema in mice. Am J Physiol Lung Cell Mol Physiol 2016; 311:L154-66. [PMID: 27288485 PMCID: PMC4967186 DOI: 10.1152/ajplung.00073.2016] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Accepted: 06/04/2016] [Indexed: 11/22/2022] Open
Abstract
The expression of Toll-like receptor (TLR)-9, a pathogen recognition receptor that recognizes unmethylated CpG sequences in microbial DNA molecules, is linked to the pathogenesis of several lung diseases. TLR9 expression and signaling was investigated in animal and cell models of chronic obstructive pulmonary disease (COPD). We observed enhanced TLR9 expression in mouse lungs following exposure to cigarette smoke. Tlr9(-/-) mice were resistant to cigarette smoke-induced loss of lung function as determined by mean linear intercept, total lung capacity, lung compliance, and tissue elastance analysis. Tlr9 expression also regulated smoke-mediated immune cell recruitment to the lung; apoptosis; expression of granulocyte-colony stimulating factor (G-CSF), the CXCL5 protein, and matrix metalloproteinase-2 (MMP-2); and protein tyrosine phosphatase 1B (PTP1B) activity in the lung. PTP1B, a phosphatase with anti-inflammatory abilities, was identified as binding to TLR9. In vivo delivery of a TLR9 agonist enhanced TLR9 binding to PTP1B, which inactivated PTP1B. Ptp1b(-/-) mice had elevated lung concentrations of G-CSF, CXCL5, and MMP-2, and tissue expression of type-1 interferon following TLR9 agonist administration, compared with wild-type mice. TLR9 responses were further determined in fully differentiated normal human bronchial epithelial (NHBE) cells isolated from nonsmoker, smoker, and COPD donors, and then cultured at air liquid interface. NHBE cells from smokers and patients with COPD expressed more TLR9 and secreted greater levels of G-CSF, IL-6, CXCL5, IL-1β, and MMP-2 upon TLR9 ligand stimulation compared with cells from nonsmoker donors. Although TLR9 combats infection, our results indicate that TLR9 induction can affect lung function by inactivating PTP1B and upregulating expression of proinflammatory cytokines.
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Affiliation(s)
- Robert F Foronjy
- Division of Pulmonary & Critical Care Medicine, Department of Medicine, State University of New York Downstate Medical Center, Brooklyn, New York; Department of Cell Biology, State University of New York Downstate Medical Center, Brooklyn, New York
| | - Matthias A Salathe
- Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, University of Miami, Miami, Florida; and
| | - Abdoulaye J Dabo
- Division of Pulmonary & Critical Care Medicine, Department of Medicine, State University of New York Downstate Medical Center, Brooklyn, New York; Department of Cell Biology, State University of New York Downstate Medical Center, Brooklyn, New York
| | - Nathalie Baumlin
- Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, University of Miami, Miami, Florida; and
| | - Neville Cummins
- Division of Pulmonary and Critical Care Medicine, Mount Sinai Roosevelt, Mount Sinai Health System, New York, New York
| | - Edward Eden
- Division of Pulmonary and Critical Care Medicine, Mount Sinai Roosevelt, Mount Sinai Health System, New York, New York
| | - Patrick Geraghty
- Division of Pulmonary & Critical Care Medicine, Department of Medicine, State University of New York Downstate Medical Center, Brooklyn, New York; Department of Cell Biology, State University of New York Downstate Medical Center, Brooklyn, New York;
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Lukashevich OV, Cherepanova NA, Jurkovska RZ, Jeltsch A, Gromova ES. Conserved motif VIII of murine DNA methyltransferase Dnmt3a is essential for methylation activity. BMC BIOCHEMISTRY 2016; 17:7. [PMID: 27001594 PMCID: PMC4802922 DOI: 10.1186/s12858-016-0064-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/24/2015] [Accepted: 03/02/2016] [Indexed: 11/10/2022]
Abstract
BACKGROUND Dnmt3a is a DNA methyltransferase that establishes de novo DNA methylation in mammals. The structure of the Dnmt3a C-terminal domain is similar to the bacterial M. HhaI enzyme, a well-studied prokaryotic DNA methyltransferase. No X-ray structure is available for the complex of Dnmt3a with DNA and the mechanistic details of DNA recognition and catalysis by mammalian Dnmts are not completely understood. RESULTS Mutant variants of the catalytic domain of the murine Dnmt3a carrying substitutions of highly conserved N167, R200, and R202 have been generated by site directed mutagenesis and purified. Their methylation activity, DNA binding affinity, ability to flip the target cytosine out of the DNA double helix and covalent complex formation with DNA have been examined. Substitutions of N167 lead to reduced catalytic activity and reduced base flipping. Catalytic activity, base flipping, and covalent conjugate formation were almost completely abolished for the mutant enzymes with substitutions of R200 or R202. CONCLUSIONS We conclude that R202 plays a similar role in catalysis in Dnmt3a-CD as R232 in M.SssI and R165 in M.HhaI, which could be positioning of the cytosine for nucleophilic attack by a conserved Cys. R200 of Dnmt3a-CD is important in both catalysis and cytosine flipping. Both conserved R200 and R202 are involved in creating and stabilizing of the transient covalent intermediate of the methylation reaction. N167 might contribute to the positioning of the residues from the motif VI, but does not play a direct role in catalysis.
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Affiliation(s)
- Olga V Lukashevich
- Department of Chemistry, Moscow State University, 119991, Moscow, Russia
| | | | - Renata Z Jurkovska
- BioMedX Innovation Center, Im Neuenheimer Feld 583, 69120, Heidelberg, Germany
| | - Albert Jeltsch
- Institute of Biochemistry, Faculty of Chemistry, University Stuttgart, Pfaffenwaldring 55, 70569, Stuttgart, Germany
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Blow MJ, Clark TA, Daum CG, Deutschbauer AM, Fomenkov A, Fries R, Froula J, Kang DD, Malmstrom RR, Morgan RD, Posfai J, Singh K, Visel A, Wetmore K, Zhao Z, Rubin EM, Korlach J, Pennacchio LA, Roberts RJ. The Epigenomic Landscape of Prokaryotes. PLoS Genet 2016; 12:e1005854. [PMID: 26870957 PMCID: PMC4752239 DOI: 10.1371/journal.pgen.1005854] [Citation(s) in RCA: 220] [Impact Index Per Article: 27.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Accepted: 01/19/2016] [Indexed: 11/18/2022] Open
Abstract
DNA methylation acts in concert with restriction enzymes to protect the integrity of prokaryotic genomes. Studies in a limited number of organisms suggest that methylation also contributes to prokaryotic genome regulation, but the prevalence and properties of such non-restriction-associated methylation systems remain poorly understood. Here, we used single molecule, real-time sequencing to map DNA modifications including m6A, m4C, and m5C across the genomes of 230 diverse bacterial and archaeal species. We observed DNA methylation in nearly all (93%) organisms examined, and identified a total of 834 distinct reproducibly methylated motifs. This data enabled annotation of the DNA binding specificities of 620 DNA Methyltransferases (MTases), doubling known specificities for previously hard to study Type I, IIG and III MTases, and revealing their extraordinary diversity. Strikingly, 48% of organisms harbor active Type II MTases with no apparent cognate restriction enzyme. These active ‘orphan’ MTases are present in diverse bacterial and archaeal phyla and show motif specificities and methylation patterns consistent with functions in gene regulation and DNA replication. Our results reveal the pervasive presence of DNA methylation throughout the prokaryotic kingdoms, as well as the diversity of sequence specificities and potential functions of DNA methylation systems. DNA methylation is a chemical modification of DNA present in many prokaryotic genomes. The best-known role of DNA methylation is as a component of restriction-modification systems. In these systems, restriction enzymes target foreign DNA for cleavage, while DNA methylation protects the host genome from destruction. Studies in a handful of organisms show that DNA methylation may also act independently of restriction systems and function in genome regulation. However, a lack of technologies has limited the study of DNA methylation to a small number of organisms, and the broader patterns and functions of DNA methylation remain unknown. Here we use SMRT-sequencing to determine the genome wide DNA methylation patterns of more than 200 diverse bacteria and archaea. We show that DNA methylation is pervasive and present in more than 90% of studied organisms. Analysis of this data enabled annotation of the specific DNA binding sites of more than 600 restriction systems, revealing their extraordinary diversity. Strikingly, we observed widespread DNA methylation in the absence of restriction systems. Analyses of these patterns reveal that they are conserved through evolution, and likely function in genome regulation. Thus DNA methylation may play a far wider function in prokaryotic genome biology than was previously supposed.
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Affiliation(s)
- Matthew J. Blow
- Genomics Division, Lawrence Berkeley National Laboratory, Berkeley, California, United States of America
- U.S. Department of Energy Joint Genome Institute, Walnut Creek, California, United States of America
- * E-mail: (MJB); (RJR)
| | - Tyson A. Clark
- Pacific Biosciences, Menlo Park, California, United States of America
| | - Chris G. Daum
- Genomics Division, Lawrence Berkeley National Laboratory, Berkeley, California, United States of America
- U.S. Department of Energy Joint Genome Institute, Walnut Creek, California, United States of America
| | - Adam M. Deutschbauer
- Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, California, United States of America
| | - Alexey Fomenkov
- New England Biolabs, Ipswich, Massachusetts, United States of America
| | - Roxanne Fries
- Genomics Division, Lawrence Berkeley National Laboratory, Berkeley, California, United States of America
- U.S. Department of Energy Joint Genome Institute, Walnut Creek, California, United States of America
| | - Jeff Froula
- Genomics Division, Lawrence Berkeley National Laboratory, Berkeley, California, United States of America
- U.S. Department of Energy Joint Genome Institute, Walnut Creek, California, United States of America
| | - Dongwan D. Kang
- Genomics Division, Lawrence Berkeley National Laboratory, Berkeley, California, United States of America
- U.S. Department of Energy Joint Genome Institute, Walnut Creek, California, United States of America
| | - Rex R. Malmstrom
- Genomics Division, Lawrence Berkeley National Laboratory, Berkeley, California, United States of America
- U.S. Department of Energy Joint Genome Institute, Walnut Creek, California, United States of America
| | - Richard D. Morgan
- New England Biolabs, Ipswich, Massachusetts, United States of America
| | - Janos Posfai
- New England Biolabs, Ipswich, Massachusetts, United States of America
| | - Kanwar Singh
- Genomics Division, Lawrence Berkeley National Laboratory, Berkeley, California, United States of America
- U.S. Department of Energy Joint Genome Institute, Walnut Creek, California, United States of America
| | - Axel Visel
- Genomics Division, Lawrence Berkeley National Laboratory, Berkeley, California, United States of America
- U.S. Department of Energy Joint Genome Institute, Walnut Creek, California, United States of America
| | - Kelly Wetmore
- Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, California, United States of America
| | - Zhiying Zhao
- Genomics Division, Lawrence Berkeley National Laboratory, Berkeley, California, United States of America
- U.S. Department of Energy Joint Genome Institute, Walnut Creek, California, United States of America
| | - Edward M. Rubin
- Genomics Division, Lawrence Berkeley National Laboratory, Berkeley, California, United States of America
- U.S. Department of Energy Joint Genome Institute, Walnut Creek, California, United States of America
| | - Jonas Korlach
- Pacific Biosciences, Menlo Park, California, United States of America
| | - Len A. Pennacchio
- Genomics Division, Lawrence Berkeley National Laboratory, Berkeley, California, United States of America
- U.S. Department of Energy Joint Genome Institute, Walnut Creek, California, United States of America
| | - Richard J. Roberts
- New England Biolabs, Ipswich, Massachusetts, United States of America
- * E-mail: (MJB); (RJR)
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Niller HH, Minarovits J. Patho-epigenetics of Infectious Diseases Caused by Intracellular Bacteria. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 879:107-130. [PMID: 26659266 DOI: 10.1007/978-3-319-24738-0_6] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
In multicellular eukaryotes including plants, animals and humans, epigenetic reprogramming may play a role in the pathogenesis of a wide variety of diseases. Recent studies revealed that in addition to viruses, pathogenic bacteria are also capable to dysregulate the epigenetic machinery of their target cells. In this chapter we focus on epigenetic alterations induced by bacteria infecting humans. Most of them are obligate or facultative intracellular bacteria that produce either bacterial toxins and surface proteins targeting the host cell membrane, or synthesise effector proteins entering the host cell nucleus. These bacterial products typically elicit histone modifications, i.e. alter the "histone code". Bacterial pathogens are capable to induce alterations of host cell DNA methylation patterns, too. Such changes in the host cell epigenotype and gene expression pattern may hinder the antibacterial immune response and create favourable conditions for bacterial colonization, growth, or spread. Epigenetic dysregulation mediated by bacterial products may also facilitate the production of inflammatory cytokines and other inflammatory mediators affecting the epigenotype of their target cells. Such indirect epigenetic changes as well as direct interference with the epigenetic machinery of the host cells may contribute to the initiation and progression of malignant tumors associated with distinct bacterial infections.
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Affiliation(s)
- Hans Helmut Niller
- Institute of Medical Microbiology and Hygiene, University of Regensburg, Regensburg, Germany
| | - Janos Minarovits
- Department of Oral Biology and Experimental Dental Research, Faculty of Dentistry, University of Szeged, Tisza Lajos krt. 64, H-6720, Szeged, Hungary.
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Chernov AV, Reyes L, Peterson S, Strongin AY. Depletion of CG-Specific Methylation in Mycoplasma hyorhinis Genomic DNA after Host Cell Invasion. PLoS One 2015; 10:e0142529. [PMID: 26544880 PMCID: PMC4636357 DOI: 10.1371/journal.pone.0142529] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2015] [Accepted: 10/22/2015] [Indexed: 11/18/2022] Open
Abstract
Adaptation to the environment requires pathogenic bacteria to alter their gene expression in order to increase long-term survival in the host. Here, we present the first experimental evidence that bacterial DNA methylation affects the intracellular survival of pathogenic Mycoplasma hyorhinis. Using bisulfite sequencing, we identified that the M. hyorhinis DNA methylation landscape was distinct in free-living M. hyorhinis relative to the internalized bacteria surviving in the infected human cells. We determined that genomic GATC sites were consistently highly methylated in the bacterial chromosome suggesting that the bacterial GATC-specific 5-methylcytosine DNA methyltransferase was fully functional both pre- and post-infection. In contrast, only the low CG methylation pattern was observed in the mycoplasma genome in the infective bacteria that invaded and then survived in the host cells. In turn, two distinct populations, with either high or low CG methylation, were detected in the M. hyorhinis cultures continually grown in the rich medium independently of host cells. We also identified that M. hyorhinis efficiently evaded endosomal degradation and uses exocytosis to exit infected human cells enabling re-infection of additional cells. The well-orchestrated changes in the chromosome methylation landscape play a major regulatory role in the mycoplasma life cycle.
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Affiliation(s)
- Andrei V. Chernov
- Infectious & Inflammatory Disease Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California, United States of America
- * E-mail: (AC); (AS)
| | - Leticia Reyes
- Department of Infectious Disease & Pathology, College of Veterinary Medicine, University of Florida, Gainesville, Florida, United States of America
| | - Scott Peterson
- Infectious & Inflammatory Disease Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California, United States of America
| | - Alex Y. Strongin
- Infectious & Inflammatory Disease Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California, United States of America
- * E-mail: (AC); (AS)
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Carvalho ATP, Gouveia L, Kanna CR, Wärmländer SKTS, Platts JA, Kamerlin SCL. Understanding the structural and dynamic consequences of DNA epigenetic modifications: computational insights into cytosine methylation and hydroxymethylation. Epigenetics 2015; 9:1604-12. [PMID: 25625845 PMCID: PMC4622728 DOI: 10.4161/15592294.2014.988043] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
We report a series of molecular dynamics (MD) simulations of up to a microsecond combined simulation time designed to probe epigenetically modified DNA sequences. More specifically, by monitoring the effects of methylation and hydroxymethylation of cytosine in different DNA sequences, we show, for the first time, that DNA epigenetic modifications change the molecule's dynamical landscape, increasing the propensity of DNA toward different values of twist and/or roll/tilt angles (in relation to the unmodified DNA) at the modification sites. Moreover, both the extent and position of different modifications have significant effects on the amount of structural variation observed. We propose that these conformational differences, which are dependent on the sequence environment, can provide specificity for protein binding.
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Key Words
- AFM, Atomic Force Microscopy
- DDD, Dickerson-Drew Dodecamer
- DFT, Density Functional Theory
- DNA methylation
- DNA, Deoxyribonucleic Acid
- DNMT, DNA Methyltransferase
- LINEs, Long Interspred Transposable Elements
- MD, Molecular Dynamics
- MM, Molecular Mechanics
- MeCP, Methylated CpG-binding proteins
- PBC, Periodic Boundary Conditions
- QM, Quantum Mechanics
- RDF, Radial Distribution Functions
- RESP, Restrained Electrostatic Potentials Model
- SINEs, Short Interspred Transposable Elements
- SPME, Smooth Particle-Mesh Ewald
- TET, Translocation Proteins
- WT, Wild Type
- epigenetics
- indirect readout
- molecular dynamics
- recognition
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Affiliation(s)
- Alexandra T P Carvalho
- a Science for Life Laboratory; Department of Cell and Molecular Biology ; Uppsala University ; Uppsala , Sweden
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Egg-specific expression of protein with DNA methyltransferase activity in the biocarcinogenic liver fluke Clonorchis sinensis. Parasitology 2015; 142:1228-38. [PMID: 26036304 DOI: 10.1017/s0031182015000566] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Despite recent reports regarding the biology of cytosine methylation in Schistosoma mansoni, the impact of the regulatory machinery remains unclear in diverse platyhelminthes. This ambiguity is reinforced by discoveries of DNA methyltransferase 2 (DNMT2)-only organisms and the substrate specificity of DNMT2 preferential to RNA molecules. Here, we characterized a novel DNA methyltransferase, named CsDNMT2, in a liver fluke Clonorchis sinensis. The protein exhibited structural properties conserved in other members of the DNMT2 family. The native and recombinant CsDNMT2 exhibited considerable enzymatic activity on DNA. The spatiotemporal expression of CsDNMT2 mirrored that of 5-methylcytosine (5 mC), both of which were elevated in the C. sinensis eggs. However, CsDNMT2 and 5 mC were marginally detected in other histological regions of C. sinensis adults including ovaries and seminal receptacle. The methylation site seemed not related to genomic loci occupied by progenies of an active long-terminal-repeat retrotransposon. Taken together, our data strongly suggest that C. sinensis has preserved the functional DNA methylation machinery and that DNMT2 acts as a genuine alternative to DNMT1/DNMT3 to methylate DNA in the DNMT2-only organism. The epigenetic regulation would target functional genes primarily involved in the formation and/or maturation of eggs, rather than retrotransposons.
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Chernov AV, Reyes L, Xu Z, Gonzalez B, Golovko G, Peterson S, Perucho M, Fofanov Y, Strongin AY. Mycoplasma CG- and GATC-specific DNA methyltransferases selectively and efficiently methylate the host genome and alter the epigenetic landscape in human cells. Epigenetics 2015; 10:303-18. [PMID: 25695131 DOI: 10.1080/15592294.2015.1020000] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
Abstract
Aberrant DNA methylation is frequently observed in disease, including many cancer types, yet the underlying mechanisms remain unclear. Because germline and somatic mutations in the genes that are responsible for DNA methylation are infrequent in malignancies, additional mechanisms must be considered. Mycoplasmas spp., including Mycoplasma hyorhinis, efficiently colonize human cells and may serve as a vehicle for delivery of enzymatically active microbial proteins into the intracellular milieu. Here, we performed, for the first time, genome-wide and individual gene mapping of methylation marks generated by the M. hyorhinis CG- and GATC-specific DNA cytosine methyltransferases (MTases) in human cells. Our results demonstrated that, upon expression in human cells, MTases readily translocated to the cell nucleus. In the nucleus, MTases selectively and efficiently methylated the host genome at the DNA sequence sites free from pre-existing endogenous methylation, including those in a variety of cancer-associated genes. We also established that mycoplasma is widespread in colorectal cancers, suggesting that either the infection contributed to malignancy onset or, alternatively, that tumors provide a favorable environment for mycoplasma growth. In the human genome, ∼ 11% of GATC sites overlap with CGs (e.g., CGAT(m)CG); therefore, the methylated status of these sites can be perpetuated by human DNMT1. Based on these results, we now suggest that the GATC-specific methylation represents a novel type of infection-specific epigenetic mark that originates in human cells with a previous exposure to infection. Overall, our findings unveil an entirely new panorama of interactions between the human microbiome and epigenome with a potential impact in disease etiology.
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Affiliation(s)
- Andrei V Chernov
- a Infectious & Inflammatory Disease Center ; Sanford-Burnham Medical Research Institute ; La Jolla , CA USA
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Lerner U, Amram E, Ayling RD, Mikula I, Gerchman I, Harrus S, Teff D, Yogev D, Lysnyansky I. Acquired resistance to the 16-membered macrolides tylosin and tilmicosin by Mycoplasma bovis. Vet Microbiol 2014; 168:365-71. [DOI: 10.1016/j.vetmic.2013.11.033] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2013] [Revised: 11/28/2013] [Accepted: 11/30/2013] [Indexed: 10/25/2022]
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