MBD2 couples DNA methylation to Transposable Elements silencing during male gametogenesis
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA989636 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:DNA methylation is an essential component of transposable element (TE) silencing, yet the mechanism by which methylation causes transcriptional repression remains poorly understood. Here we study the Arabidopsis thaliana Methyl-CpG Binding Domain (MBD) proteins MBD1, MBD2, and MBD4, and show that MBD2 acts as a transposable element (TE) repressor during male gametogenesis. MBD2 bound chromatin regions containing high levels of CG methylation, and MBD2 was capable of silencing the FWA gene when tethered to its promoter. MBD2 loss caused TE activation in the vegetative cell (VC) of mature pollen without affecting DNA methylation levels, demonstrating that MBD2-mediated silencing acts strictly downstream of DNA methylation. Loss of silencing in mbd2 became more significant in the mbd5 mbd6 or adcp1 mutant backgrounds, as well as in plants with chemically induced genome-wide DNA demethylation, suggesting that MBD2 acts redundantly with other silencing pathways to safeguard TEs from activation. Overall, our study identifies MBD2 as a novel methyl reader that acts downstream of DNA methylation to silence TEs during male gametogenesis.
2024-01-12 | GSE236290 | GEO
Project description:The propagation of epigenetic marks has received a great deal of attention, yet the initiation of epigenetic silencing on a new transgene, virus, or transposable element remains incompletely characterized. The overlapping function of multiple silencing mechanisms has obscured this area of investigation. Here, we have revealed two broad mechanisms that are both able to initiate silencing independently: homology-based silencing and expression-dependent silencing. By transforming exogenous transposable elements into Arabidopsis, we circumvented homology-based silencing allowing us to isolate and investigate the molecular mechanism of expression-dependent silencing. We found that several small RNA-generating mechanisms all trigger de novo expression-dependent RNA-directed DNA methylation (RdDM) through RNA Polymerase V. In addition, the silencing of transposable elements fragments stalls at the RdDM phase, while full-length elements quickly progress through RdDM to maintenance methylation and heterochromatin formation. We found that there is a narrow window of time for the transition to a fully silenced state. Transformation into a mutant genotype followed by introgression into wild-type does not result in the same level of silencing as direct transformation into wild-type. This demonstrates that the genotype of transposable element insertion or transgene transformation is key for establishing the transgenerational extent of epigenetic silencing.
2017-08-25 | GSE86787 | GEO
Project description:We show that in vivo MBD2 is mainly recruited to CpG island promoters that are highly methylated. We also report that MBD2 binds to a subset of CpG island promoters that are characterized by the presence of active histone marks and RNA polymerase II (Pol2). At such sites, MBD2 binds downstream of the transcription start site. Active promoters bound by MBD2 show low to medium gene expression levels and H3K36me3 deposition suggesting a putative role for MBD2 in blocking polymerase II (Pol2) elongation at these promoters.
2014-07-03 | GSE54693 | GEO
Project description:The mutagenic activity of transposable elements (TEs) is suppressed by epigenetic silencing and small interfering RNAs (siRNAs), especially in gametes that would transmit transposed elements to the next generation. In pollen from the model plant Arabidopsis, we show that TEs are unexpectedly reactivated and transpose, but only in the pollen vegetative nucleus, which accompanies the sperm cells but does not provide DNA to the fertilized zygote. TE expression coincides with down-regulation of the heterochromatin remodeler DECREASE IN DNA METHYLATION 1 and of most TE siRNAs. However, 21 nucleotide siRNA from Athila retrotransposons is generated in pollen and accumulates in sperm, indicating that siRNA from TEs activated in the vegetative nucleus can target silencing in gametes. We propose a conserved role for reprogramming in germline companion cells, such as nurse cells in insects and vegetative nuclei in plants, to reveal intact TEs in the genome and regulate their activity in gametes. Mature pollen was collected from Columbia reference strain plants by vacuum filtration (Johnson-Brousseau and McCormick, 2004). DNA and RNA were isolated from a ddm1-2 plant in the Columbia reference background. Small RNAs of 19–28 nt were size selected by denaturing 15% PAGE, and cloned as in Brennecke et al. (2007). Additional details regarding the cloning of small RNAs are found in the Supplemental Data. The small RNA libraries were sequenced on Illumina 1G sequencer. The total number of sequences perfectly matching the Arabidopsis genome were as follows: WT inflorescence, 4,158,848 (2,286,133 unique); WT pollen, 1,034,665 (437,984 unique); ddm1 inflorescence, 4,098,772 (1,637,771 unique); and WT sperm, 760,651 (429,972 unique).
2014-09-04 | E-GEOD-61028 | biostudies-arrayexpress
Project description:Pleurotus ostreatus, also known as the oyster mushroom, is an active lignin decomposer in the forests. The genomes of the monokaryotic strains PC15 and PC9 have been used to characterize the content and distribution of transposable elements. This study analyzes the impact of transposable element insertions on the global transcriptome of P. ostreatus. The transcriptome of PC15 and PC9 has been analyzed in exponential growth during submerged fermentation in malt-yeast extract-sucrose medium RNAseq of two P. ostreatus strains: PC15 and PC9
2016-05-19 | E-GEOD-81586 | biostudies-arrayexpress
Project description:We show that in vivo MBD2 is mainly recruited to CpG island promoters that are highly methylated. We also report that MBD2 binds to a subset of CpG island promoters that are characterized by the presence of active histone marks and RNA polymerase II (Pol2). At such sites, MBD2 binds downstream of the transcription start site. Active promoters bound by MBD2 show low to medium gene expression levels and H3K36me3 deposition suggesting a putative role for MBD2 in blocking polymerase II (Pol2) elongation at these promoters. To gain further insight into the function of and epigenetic regulation by MBD2 we generated a tagged version of the protein and stably expressed it in the MCF-7 cell line. We mapped genome wide binding of MBD2 by ChIP sequencing (ChIP-seq) and together with base resolution whole genome bisulfite sequencing (WGBS) we were able to determine the methylation content and the role of methylation density at MBD2 enriched regions. We further dissected MBD2 binding properties, taking advantage of a large set of ChIP-seq data including active histone marks, RNA polymerase II (POL2) and strand specific RNA-seq.
2014-07-03 | E-GEOD-54693 | biostudies-arrayexpress
Project description:The heterogeneous collection of NuRD complexes can be grouped into the MBD2 or MBD3 containing complexes MBD2-NuRD and MBD3-NuRD. MBD2 is known to bind to methylated CpG sequences in vitro in contrast to MBD3. Although functional differences have been described, a direct comparison of MBD2 and MBD3 in respect to genome-wide binding and function has been lacking. Here we show when depleting cells for MBD2, the MBD2 bound genes increase their activity, whereas MBD2 plus MBD3 bound genes reduce their activity. Most strikingly, MBD3 is enriched at active promoters, whereas MBD2 is bound at methylated promoters and enriched at exon sequences of active genes. This suggests a functional connection between MBD2 binding to chromatin and splicing.
2013-02-08 | GSE41003 | GEO
Project description:Methylated DNA binding protein 2 (MBD2) has been shown to bind specific methylated promoters and suppress transcription. Here we systematically investigate MBD2 suppression by overexpressing MBD2 in MCF-10A cells and generating gene expression profiles of overexpressing cells and normal MCF-10A cells.
2013-06-17 | GSE47873 | GEO
Project description:The heterogeneous collection of NuRD complexes can be grouped into the MBD2 or MBD3 containing complexes MBD2-NuRD and MBD3-NuRD. Although functional differences have been described, a direct comparison of MBD2 and MBD3 in respect to genome-wide binding and function has been lacking. Here we show a strong enrichment for MBD2 at methylated CpG sequences, whereas CpGs bound by MBD3 are devoid of methylation. Gene activity of MBD2 bound genes is four fold lower as compared to genes bound by MBD3. When depleting cells for MBD2, the MBD2 bound genes increase their activity, whereas MBD2 plus MBD3 bound genes reduce their activity. Most strikingly, MBD3 is enriched at active promoters, whereas MBD2 is bound at methylated promoters and enriched at exon sequences of active genes. This suggests a functional connection between MBD2 binding to chromatin and splicing.
2013-02-08 | GSE41006 | GEO
Project description:The proposed use of Foxp3+ T-regulatory (Treg) cells as potential cellular therapy in patients with autoimmune diseases, or post-hemopoietic stem cell or organ transplantation, requires a sound understanding of the transcriptional regulation of Foxp3 expression. Conserved CpG dinucleotides in the Treg-specific demethylated region (TSDR) upstream of Foxp3 are demethylated only in stable, thymic-derived Foxp3+ Tregs. Since methyl-binding domain (Mbd) proteins recruit histone-modifying and chromatin-remodeling complexes to methylated sites, we tested whether targeting of Mbd2 might promote demethylation of Foxp3 and thereby promote Treg numbers or function. Surprisingly, while ChIP analysis showed Mbd2 binding to the Foxp3-associated TSDR site in Tregs, Mbd2 targeting by homologous recombination or siRNA decreased Treg numbers and impaired Treg suppressive function in vitro and in vivo. Moreover, we found complete TSDR demethylation in WT Tregs but >75% methylation in Mbd2-/- Tregs, whereas re-introduction of Mbd2 into Mbd2-null Tregs restored TSDR demethylation, Foxp3 gene expression and Treg suppressive function. Lastly, Mbd2-/- Tregs had markedly binding of the DNA demethylase enzyme, Tet2, in the TSDR region. These data show that Mbd2 has a key role in promoting TSDR demethylation, Foxp3 expression and Treg suppressive function.
2013-09-01 | GSE48653 | GEO