Noncoding RNA-mediated DNA methylation directs nucleosome positioning
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ABSTRACT:
PROVIDER: PRJNA623375 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:We explored the mechanism by which RdDM affects nucleosome positioning in Arabidopsis thaliana. We showed that POLV has a direct effect on nucleosomes through the SWI/SNF complex. We found that the AGO4-siRNA complex is involved in nucleosome positioning via IDN2. Moreover, the SWI/SNF complex is not required for DNA methylation in positioned nucleosomes. Instead, we found that DNA methylation is needed for nucleosome positioning in differentially methylated regions. Taken together, we propose a model where the RdDM pathway directs nucleosome positioning through DNA methylation to establish transcriptional gene silencing.
2023-04-06 | GSE148173 | GEO
Project description:N6-methyldeoxyadenosine directs nucleosome positioning in Tetrahymena DNA
| PRJNA413592 | ENA
Project description:The directionality of gene promoters, the proportion of protein coding over divergent noncoding transcription, is highly variable and regulated. How promoter directionality is controlled remains poorly understood. We show that chromatin remodelling complex RSC, general regulatory factors (GRFs) including transcription factors (TFs) can facilitate promoter directionality by attenuating divergent noncoding transcription. Depletion of RSC increased divergent noncoding and decreased protein coding transcription of promoters with strong directionality. Consistent with RSC’s role in regulating chromatin, RSC depletion negatively impacts nucleosome positions upstream of the nucleosome depleted region where divergent transcription initiates, suggesting that nucleosome positioning upstream in promoters physically blocks the recruitment of transcription machinery. Likewise, divergent transcription can be suppressed by targeting GRFs and TFs or the bulky dCas9 protein to transcriptional initiation sites. We propose that RSC mediated nucleosome positioning, GRFs including TFs form the physical barriers in promoters for limiting of divergent transcription, thereby controlling promoter directionality.
2021-07-27 | GSE179254 | GEO
Project description:The directionality of gene promoters, the proportion of protein coding over divergent noncoding transcription, is highly variable and regulated. How promoter directionality is controlled remains poorly understood. We show that chromatin remodelling complex RSC, general regulatory factors (GRFs) including transcription factors (TFs) can facilitate promoter directionality by attenuating divergent noncoding transcription. Depletion of RSC increased divergent noncoding and decreased protein coding transcription of promoters with strong directionality. Consistent with RSC’s role in regulating chromatin, RSC depletion negatively impacts nucleosome positions upstream of the nucleosome depleted region where divergent transcription initiates, suggesting that nucleosome positioning upstream in promoters physically blocks the recruitment of transcription machinery. Likewise, divergent transcription can be suppressed by targeting GRFs and TFs or the bulky dCas9 protein to transcriptional initiation sites. We propose that RSC mediated nucleosome positioning, GRFs including TFs form the physical barriers in promoters for limiting of divergent transcription, thereby controlling promoter directionality.
2021-07-27 | GSE179255 | GEO
Project description:N6-methyldeoxyadenosine (6mA or m6dA) was shown more than 40 years ago to exist in simple eukaryotes, yet functional studies have been limited. Recent investigations in multiple eukaryotes suggest 6mA as a potential DNA epigenetic mark that plays regulatory roles in gene regulation. Here we use Tetrahymena thermophila as a model to examine the effects of 6mA on nucleosome positioning. We have employed independent methods to identify genome-wide 6mA distribution, which revealed the enrichment after transcription start sites with a periodic pattern and a mutually exclusive relationship with the positions of nucleosomes. The exclusive distribution pattern of 6mA and nucleosome can be recapitulated by in vitro nucleosome assembly on native Tetrahymena genomic DNA, but not on DNA without 6mA. Model DNA containing artificially installed 6mA resists nucleosome assembling compared to unmodified DNA in vitro. Computational simulation revealed that 6mA increases dsDNA rigidity, which disfavors nucleosome wrapping. Knockout of a potential 6mA methyltransferase disturbs the nucleosome positioning in Tetrahymena, leading to the transcriptome-wide change of gene expression. These findings uncover a new mechanism by which DNA 6mA assists to shape the chromatin topology in order to stabilize gene expression.
2018-10-17 | GSE104699 | GEO
Project description:RSC mediated nucleosome positioning and GRFs form barriers in promoters to limit divergent noncoding transcription
| PRJNA743010 | ENA
Project description:Nucleosomes compact and regulate access to DNA in the nucleus, and are composed of approximately 147 bases of DNA wrapped around a histone octamer1, 2. Here we report a genome-wide nucleosome positioning analysis of Arabidopsis thaliana utilizing massively parallel sequencing of mononucleosomes. By combining this data with profiles of DNA methylation at single base resolution, we identified ten base periodicities in the DNA methylation status of nucleosome-bound DNA and found that nucleosomal DNA was more highly methylated than flanking DNA. These results suggest that nucleosome positioning strongly influences DNA methylation patterning throughout the genome and that DNA methyltransferases preferentially target nucleosome-bound DNA. We also observed similar trends in human nucleosomal DNA suggesting that the relationships between nucleosomes and DNA methyltransferases are conserved. Finally, as has been observed in animals, nucleosomes were highly enriched on exons, and preferentially positioned at intron-exon and exon-intron boundaries. RNA Pol II was also enriched on exons relative to introns, consistent with the hypothesis that nucleosome positioning regulates Pol II processivity. We also found that DNA methylation enriched on exons, consistent with the targeting of DNA methylation to nucleosomes.
2010-05-29 | GSE21818 | GEO
Project description:Nucleosome positioning for 4 yeast species
| PRJNA130921 | ENA
Project description:Nucleosomes compact and regulate access to DNA in the nucleus, and are composed of approximately 147 bases of DNA wrapped around a histone octamer1, 2. Here we report a genome-wide nucleosome positioning analysis of Arabidopsis thaliana utilizing massively parallel sequencing of mononucleosomes. By combining this data with profiles of DNA methylation at single base resolution, we identified ten base periodicities in the DNA methylation status of nucleosome-bound DNA and found that nucleosomal DNA was more highly methylated than flanking DNA. These results suggest that nucleosome positioning strongly influences DNA methylation patterning throughout the genome and that DNA methyltransferases preferentially target nucleosome-bound DNA. We also observed similar trends in human nucleosomal DNA suggesting that the relationships between nucleosomes and DNA methyltransferases are conserved. Finally, as has been observed in animals, nucleosomes were highly enriched on exons, and preferentially positioned at intron-exon and exon-intron boundaries. RNA Pol II was also enriched on exons relative to introns, consistent with the hypothesis that nucleosome positioning regulates Pol II processivity. We also found that DNA methylation enriched on exons, consistent with the targeting of DNA methylation to nucleosomes. Genomic DNA associated with RNAP II was isolated by ChIP using an anti-PolII antibody.
2010-05-28 | E-GEOD-21818 | biostudies-arrayexpress
Project description:DNA methylation and nucleosome positioning work together to generate chromatin structures that regulate gene expression. Nucleosomes are typically mapped using nuclease digestion requiring significant amounts of material and varying enzyme concentrations. We have developed a method (NOMe-seq) that uses a GpC methyltransferase (M.CviPI) and next generation sequencing to generate a high resolution footprint of nucleosome positioning genome-wide using less than 1 million cells while retaining endogenous DNA methylation information from the same DNA strand. Using a novel bioinformatics pipeline we show a striking anti-correlation between nucleosome occupancy and DNA methylation at CTCF regions, that is not present at promoters. We further show that the extent of nucleosome depletion at promoters is directly correlated to expression level and can accommodate multiple nucleosomes and provide genome-wide evidence that expressed non-CpG island promoters are nucleosome depleted. Importantly, NOMe-seq obtains DNA methylation and nucleosome positioning information from the same DNA molecule, giving the first genome-wide DNA methylation and nucleosome positioning correlation at the single molecule and thus, single cell level that can be used to monitor disease progression and response to therapy.
2012-09-12 | GSE40770 | GEO