Structure of DNA methyltransferases DNMT3A/DNMT3B bound to a nucleosome [seq]
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ABSTRACT:
ORGANISM(S): synthetic construct
PROVIDER: GSE152639 | GEO | 2020/06/17
REPOSITORIES: GEO
Similar Datasets
Project description:CpG methylation by the de novo DNA methyltransferases (DNMTs) 3A and 3B is essential for mammalian development and differentiation and is frequently dysregulated in cancer1. These two DNMTs preferentially bind to nucleosomes yet cannot methylate the DNA wrapped around the nucleosome core2, and favor the methylation of linker DNA at positioned nucleosomes3,4. Here we present the cryo-EM structure of a ternary complex of catalytically competent DNMT3A2, the catalytically inactive accessory subunit DNMT3B3, and a nucleosome core particle flanked by linker DNA. The catalytic-like domain of the accessory DNMT3B3 binds the acidic patch of the nucleosome core, which orients the binding of DNMT3A2 to the linker DNA. The steric constraints of this arrangement suggest that nucleosomal DNA must be moved relative to the nucleosome core for de novo methylation to occur. CpG methylation by the de novo DNA methyltransferases (DNMTs) 3A and 3B is essential for mammalian development and differentiation and is frequently dysregulated in cancer1. These two DNMTs preferentially bind to nucleosomes yet cannot methylate the DNA wrapped around the nucleosome core2, and favor the methylation of linker DNA at positioned nucleosomes3,4. Here we present the cryo-EM structure of a ternary complex of catalytically competent DNMT3A2, the catalytically inactive accessory subunit DNMT3B3, and a nucleosome core particle flanked by linker DNA. The catalytic-like domain of the accessory DNMT3B3 binds the acidic patch of the nucleosome core, which orients the binding of DNMT3A2 to the linker DNA. The steric constraints of this arrangement suggest that nucleosomal DNA must be moved relative to the nucleosome core for de novo methylation to occur.
2020-06-17 | GSE152541 | GEO
Project description:Effect of induced Methylation on Nucleosome positioning in yeast. Mnase digested DNA from a control strain, a strain expressing the 4 murine DNMTs or a strain expressing catalytically inactive murine DNMTs were extracted and sequenced on a hiseq 2000
2021-04-01 | E-MTAB-10254 | biostudies-arrayexpress
Project description:Histone modifications and DNA methylation represent two distinct modes of varying epigenetic landscapes, but whose exact interrelationship remains unclear. Previous studies have shown that histone H3 lysine 4 trimethylation (H3K4me3) inhibits the binding of de novo DNA methyltransferases (Dnmt) through the ATRX-DNMT3-DNMTL (ADD) domain, thus protecting H3K4me3 marked CpG islands (CGI) from DNA methylation. In addition to H3K4me3, we identified antagonistic relationship between H3T3 phosphorylation and the binding of the ADD domain to the unmodified H3 N-terminus. To assess the physiological relevance of these restrictions, we engineered the wild-type ADD domain of Dnmt3a (WT) to permit additional binding to either H3K4me3 (WWD) or H3T3ph (R) and stably introduced FLAG-tagged, full-length normal or mutant Dnmt3a2 into ESCs lacking all Dnmts (TKO; triple knock-out of Dnmt1, Dnmt3a, and Dnmt3b) using the PiggyBac transposon system. For each WT-, WWD-, and R-Dnmt3a2, we generated bulk and clonally-derived ESC lines. We then employed chromatin immunoprecipitation followed by high-throughput DNA sequencing (ChIP-seq) to identify the genomic distribution of full-length WT-, WWD-, R-Dnmt3a2, and the H3K4me3 distribution. In parallel, we quantitatively measured genome-wide CpG (cytosine) methylation at base-pair resolution using an enhanced form of reduced representation bisulfite sequencing (RRBS), and performed RNA-seq to assess transcription in matched ESC lines. Examination of DNA methylation levels in Dnmt TKO-ESCs expressing wild-type/mutant Dnmt3a2.
2015-06-22 | E-GEOD-57576 | biostudies-arrayexpress
Project description:Histone modifications and DNA methylation represent two distinct modes of varying epigenetic landscapes, but whose exact interrelationship remains unclear. Previous studies have shown that histone H3 lysine 4 trimethylation (H3K4me3) inhibits the binding of de novo DNA methyltransferases (Dnmt) through the ATRX-DNMT3-DNMTL (ADD) domain, thus protecting H3K4me3 marked CpG islands (CGI) from DNA methylation. In addition to H3K4me3, we identified antagonistic relationship between H3T3 phosphorylation and the binding of the ADD domain to the unmodified H3 N-terminus. To assess the physiological relevance of these restrictions, we engineered the wild-type ADD domain of Dnmt3a (WT) to permit additional binding to either H3K4me3 (WWD) or H3T3ph (R) and stably introduced FLAG-tagged, full-length normal or mutant Dnmt3a2 into ESCs lacking all Dnmts (TKO; triple knock-out of Dnmt1, Dnmt3a, and Dnmt3b) using the PiggyBac transposon system. For each WT-, WWD-, and R-Dnmt3a2, we generated bulk and clonally-derived ESC lines. We then employed chromatin immunoprecipitation followed by high-throughput DNA sequencing (ChIP-seq) to identify the genomic distribution of full-length WT-, WWD-, R-Dnmt3a2, and the H3K4me3 distribution. In parallel, we quantitatively measured genome-wide CpG (cytosine) methylation at base-pair resolution using an enhanced form of reduced representation bisulfite sequencing (RRBS), and performed RNA-seq to assess transcription in matched ESC lines. Examination of mRNA profiles in Dnmt TKO-ESCs expressing wild-type/mutant Dnmt3a2.
2015-06-22 | E-GEOD-57575 | biostudies-arrayexpress
Project description:Histone modifications and DNA methylation represent two distinct modes of varying epigenetic landscapes, but whose exact interrelationship remains unclear. Previous studies have shown that histone H3 lysine 4 trimethylation (H3K4me3) inhibits the binding of de novo DNA methyltransferases (Dnmt) through the ATRX-DNMT3-DNMTL (ADD) domain, thus protecting H3K4me3 marked CpG islands (CGI) from DNA methylation. In addition to H3K4me3, we identified antagonistic relationship between H3T3 phosphorylation and the binding of the ADD domain to the unmodified H3 N-terminus. To assess the physiological relevance of these restrictions, we engineered the wild-type ADD domain of Dnmt3a (WT) to permit additional binding to either H3K4me3 (WWD) or H3T3ph (R) and stably introduced FLAG-tagged, full-length normal or mutant Dnmt3a2 into ESCs lacking all Dnmts (TKO; triple knock-out of Dnmt1, Dnmt3a, and Dnmt3b) using the PiggyBac transposon system. For each WT-, WWD-, and R-Dnmt3a2, we generated bulk and clonally-derived ESC lines. We then employed chromatin immunoprecipitation followed by high-throughput DNA sequencing (ChIP-seq) to identify the genomic distribution of full-length WT-, WWD-, R-Dnmt3a2, and the H3K4me3 distribution. In parallel, we quantitatively measured genome-wide CpG (cytosine) methylation at base-pair resolution using an enhanced form of reduced representation bisulfite sequencing (RRBS), and performed RNA-seq to assess transcription in matched ESC lines. Examination of wild-type/mutant Dnmt3a2 and matched H3K4me3 distributions in TKO-ESCs.
2015-06-22 | E-GEOD-57574 | biostudies-arrayexpress
Project description:Eukaryotic chromosomal DNA is assembled into regularly spaced nucleosomes, which play a central role in gene regulation by determining accessibility of control regions. The nucleosome contains ~147 bp of DNA wrapped ~1.7 times around a central core histone octamer. The linker histone, H1, binds both to the nucleosome, sealing the DNA coils, and to the linker DNA between nucleosomes, directing chromatin folding. Micrococcal nuclease (MNase) digests the linker to yield the chromatosome, containing H1 and ~160 bp, and then converts it to a core particle, containing ~147 bp and no H1. Sequencing of nucleosomal DNA obtained after MNase digestion (MNase-seq) generates genome-wide nucleosome maps that are important for understanding gene regulation. We present an improved MNase-seq method involving simultaneous digestion with exonuclease III, which removes linker DNA. Remarkably, we discovered two novel intermediate particles containing 154 or 161 bp, corresponding to 7 bp protruding from one or both sides of the nucleosome core. These particles are detected in yeast lacking H1 and in H1-depleted mouse chromatin. They can be reconstituted in vitro using purified core histones and DNA. We propose that these "proto-chromatosomes" are fundamental chromatin subunits, which include the H1 binding site and influence nucleosome spacing independently of H1.
2015-09-23 | GSE65889 | GEO
Project description:Multiple epigenetic pathways underlie the temporal order of DNA replication (replication timing) in the context of development and disease. DNA methylation by DNA methyltransferases (DNMTs) and downstream chromatin reorganization and transcriptional changes are thought to impact DNA replication, yet this remains to be comprehensively tested. Using cell biological and genome-wide approaches to measure replication timing, we identified a number of genomic regions undergoing subtle but reproducible replication timing changes in various DNMT-mutant mouse ES cell lines that include a line with a drug-inducible DNMT3a2 expression system. Replication timing within pericentromeric heterochromatin (PH) correlates with redistribution of H3K27me3 induced upon DNA hypomethylation: later replicating PH coincides with H3K27me3 enriched regions. In contrast, this relationship with H3K27me3 was not evident at chromosomal arm regions that undergo either early-to-late (EtoL) or late-to-early (LtoE) replication timing switching upon loss of DNMTs. Interestingly, transcriptional up- and down-regulation frequently coincide with earlier and later shifts in replication timing of chromosomal arm regions, respectively. Our study revealed previously unrecognized complex and diverse roles of DNMTs in shaping the mammalian DNA replication landscape. We investigated the effect of Dnmt3a2 expression in the transcription profile of Dnmt3a and 3b double knockout (DKO) ES cells.
2021-02-12 | GSE119406 | GEO
Project description:Epigenetic factors are well established players in memory formation. Specifically, DNA methylation is necessary for the formation of long-term memory in multiple brain regions including the hippocampus. Despite the demonstrated role for DNA methyltransferases (Dnmts) in memory formation whether individual Dnmts play unique or redundant functions in long-term memory formation is not well established. Furthermore, the downstream processes controlled by the Dnmts during the consolidation of memory are not investigated. In this study, we investigated the requirement for Dnmt3a1, the predominant Dnmt in the adult brain, in hippocampal long-term memory formation. Furthermore, we identified an activity-regulated Dnmt3a1-dependent genomic program. Our data showed that Dnmt3a1, similarly to its isoform Dnmt3a2, plays a critical role in memory formation. Furthermore, we uncovered Neuropilin 1 (Nrp1) as a downstream target of Dnmt3a1 during the formation of memory. Intriguingly, we found that Nrp1 expression is selectively regulated and a specific downstream effector of Dnmt3a1, but not Dnmt3a2. Taken together, our study uncovered a Dnmt3a isoform specific mechanism in memory formation and further highlighted the complex and highly regulated functions of distinct epigenetic regulators in brain function.
2024-05-06 | GSE232630 | GEO
Project description:The DNA methylation program is at the bottom layer of the epigenetic regulatory cascade of vertebrate development. While the methylation at C-5 position of the cytosine (C) residues on the vertebrate genomes is achieved through the catalytic activities of the DNA methyltransferases (DNMTs), the conversion of the methylated cytosine (5mC) could be accomplished by the combined actions of the TET enzyme and DNA repair. Interestingly, it has been found recently that the mouse and human DNMTs also possess active DNA demethylation activity in vitro in a Ca2+- and redox condition-dependent manner. We report here the study of tracking down the fate of the methyl group removed from 5mC on DNA during in vitro demethylation reaction by mouse de novo DNMTs, i.e. DNMT3A and DNMT3B. Remarkably, the methyl group becomes covalently linked to the catalytic cysteines utilized by the two de novo DNMTs in their DNA methylation reactions. Thus, the forward and reverse reactions of DNA methylations by the DNMTs may utilize the same cysteine residue(s) as the active site despite of their distinctive pathways. Secondly, we demonstrate that active DNA demethylation of a heavily methylated GFP reporter plasmid by ectopically expressed DNMT3A or DNMT3B occurs in vivo in transfected human HEK 293 cells in culture. Furthermore, the extent of DNA demethylation by the DNMTs in this cell-based system is affected by Ca2+ homeostasis as well as by mutation of their putative active cysteines. These findings substantiate the roles of the vertebrate DNMTs as double-edged swords in DNA methylation-demethylation in vitro as well as in a cellular context.
2022-02-24 | PXD003401 | Pride
Project description:The nucleosome plays a central role in genome regulation. Traditional methods for mapping nucleosomes depend on the resistance of the nucleosome core to micrococcal nuclease (MNase). However, the lengths of the protected DNA fragments are heterogeneous, limiting the accuracy of nucleosome position information. To resolve this problem, we removed residual linker DNA by simultaneous digestion of yeast chromatin with MNase and exonuclease III (ExoIII). Paired-end sequencing of mono-nucleosomes revealed not only core particles (145-147 bp), but also intermediate particles in which ~8 bp project from one side (154 bp) or both sides (161 bp) of the nucleosome core. We term these particles "pseudo-chromatosomes" because they are present in yeast lacking linker histone. They are also observed after MNase-ExoIII digestion of chromatin reconstituted using recombinant core histones. We propose that the pseudo-chromatosome provides a DNA framework to facilitate H1 binding. Comparison of budding yeast nucleosome sequences obtained using micrococcal nuclease (MNase-seq) and MNase + exonuclease III (ExoIII) (MNase-ExoIII-seq): wild type cells and hho1-null cells. Nucleosome sequences from native chromatin and H1-depleted chromatin from mouse liver. Nucleosome sequences from a plasmid reconstituted into nucleosomes using recombinant yeast histones or native chicken erythrocyte histones.
2015-09-23 | E-GEOD-65889 | biostudies-arrayexpress