DNA Methylation shapes histone modification landscape for transcription regulation in Arabidopsis [ChIP-Seq]
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ABSTRACT: DNA methylation and histone modifications cooperate to shape the epigenetic landscape for transcription regulation, but their orchestration is not fully understood due to the lack of met1 drm1 drm2 cmt2 cmt3 mutants (mddcc), in which total DNA methylation were eliminated. This is the first time to generate mddcc that allow us to elucidate the roles of DNA methylation in the upheaval of histone modification landscape, transposon activity and gene expression. We found that DNA methylation elimination-triggered genome-wide transcriptional reprogramming is largely orchestrated by the redistribution and conversion of histone modifications. We also distinguished the contribution of CG and non-CG methylation to the histone modification landscape. Furthermore, we reveal histone modifications can serve as an independent regulatory system despite the influence of DNA methylation. Taken together, we provide comprehensive insights into the roles of DNA methylation in shaping epigenomic landscape for genome transcription, which deep understanding of epigenomic regulation.
Project description:DNA methylation and histone modifications cooperate to shape the epigenetic landscape for transcription regulation, but their orchestration is not fully understood due to the lack of met1 drm1 drm2 cmt2 cmt3 mutants (mddcc), in which total DNA methylation were eliminated. This is the first time to generate mddcc that allow us to elucidate the roles of DNA methylation in the upheaval of histone modification landscape, transposon activity and gene expression. We found that DNA methylation elimination-triggered genome-wide transcriptional reprogramming is largely orchestrated by the redistribution and conversion of histone modifications. We also distinguished the contribution of CG and non-CG methylation to the histone modification landscape. Furthermore, we reveal histone modifications can serve as an independent regulatory system despite the influence of DNA methylation. Taken together, we provide comprehensive insights into the roles of DNA methylation in shaping epigenomic landscape for genome transcription, which deep understanding of epigenomic regulation.
Project description:DNA methylation and histone modifications cooperate to shape the epigenetic landscape for transcription regulation, but their orchestration is not fully understood due to the lack of met1 drm1 drm2 cmt2 cmt3 mutants (mddcc), in which total DNA methylation were eliminated. This is the first time to generate mddcc that allow us to elucidate the roles of DNA methylation in the upheaval of histone modification landscape, transposon activity and gene expression. We found that DNA methylation elimination-triggered genome-wide transcriptional reprogramming is largely orchestrated by the redistribution and conversion of histone modifications. We also distinguished the contribution of CG and non-CG methylation to the histone modification landscape. Furthermore, we reveal histone modifications can serve as an independent regulatory system despite the influence of DNA methylation. Taken together, we provide comprehensive insights into the roles of DNA methylation in shaping epigenomic landscape for genome transcription, which deep understanding of epigenomic regulation.
Project description:The role of on-CG methylation in seed development and dormancy remains unknown. There are four genes in charge of non-CG methylation in Arabidopsis: drm1, drm2, cmt2 and cmt3. The majority of non-CG methylation in vegetative tissues, leaf, is gone in homozygous ddcc mutant line (Hume et al., 2014). To uncover the possible role of non-CG DNA methylation in seed development and dormancy, we characterized the transcriptome of ddcc mutant in Arabidopsis post-mature green seeds using Illumina sequencing. Meanwhile, post-mature green seeds from wild type were used as control.
Project description:The role of on-CG methylation in seed development and dormancy remains unknown. There are four genes in charge of non-CG methylation in Arabidopsis: drm1, drm2, cmt2 and cmt3. The majority of non-CG methylation in vegetative tissues, leaf, is gone in homozygous ddcc mutant line (Hume et al., 2014). To uncover the possible role of non-CG DNA methylation in seed development and dormancy, we characterized the transcriptome of ddcc mutant in Arabidopsis post-mature green seeds using Illumina sequencing. Meanwhile, post-mature green seeds from wild type were used as control. Illumina sequencing of transcripts from post-mature green seeds of ddcc mutant and wild type. Two biological replicates were collected.
Project description:The role of on-CG methylation in seed development and dormancy remains unknown. There are four genes in charge of non-CG methylation in Arabidopsis: drm1, drm2, cmt2 and cmt3. The majority of non-CG methylation in vegetative tissues, leaf, is gone in homozygous ddcc mutant line (Hume et al., 2014). To uncover the possible role of non-CG DNA methylation in seed development and dormancy, we characterized the methylome of ddcc mutant in Arabidopsis dry seed using Illumina sequencing. Meanwhile, vegetative tissue, leaves from 3 week plant with ddcc mutant and from wild type, and dry seed from wild type plant were used as control. Illumina sequencing of bisulfite-converted genomic DNA from dry seed and 3-week-plant leaves of ddcc mutant and wild type.
Project description:DNA methylation occurs in both CG and non-CG sequence contexts. Non-CG methylation is abundant in plants, and is mediated by CHROMOMETHYLASE (CMT) and DOMAINS REARRANGED METHYLTRANSFERASE (DRM) proteins; however its roles remain poorly understood. Here we characterize the roles of non-CG methylation in Arabidopsis thaliana. We show that a poorly characterized methyltransferase, CMT2, is a functional methyltransferase in vitro and in vivo. CMT2 specifically binds histone H3 lysine 9 (H3K9) dimethylation and methylates non-CG cytosines at sites that are also regulated by H3K9 dimethylation. By generating different combinations of non-CG methylation mutants, we reveal the contributions and redundancies between each methyltransferase in DNA methylation patterning and in regulating transposable elements (TEs) and protein-coding genes. We also demonstrate extensive dependencies of small RNA accumulation and H3K9 methylation patterning on non-CG methylation, suggesting self-reinforcing mechanisms between these epigenetic factors. The results suggest that non-CG methylation patterns are critical in shaping the histone modification and small non-coding RNA landscapes. Eighteen mRNA-seq samples, five smRNA-seq samples, five bisulfite-seq samples, twenty ChIP-seq samples. Bisulfite-seq data for cmt2-7 single mutants, cmt3 single mutants, drm1/2 double mutants, drm1/2 cmt3 triple mutants are deposited in GSE39901. Processed wiggle format files for all datasets can be downloaded at http://genomes.mcdb.ucla.edu/AthBSseq/
Project description:The role of non-CG methylation in seed development and dormancy remains unknown. There are four genes in charge of non-CG methylation in Arabidopsis: drm1, drm2, cmt2 and cmt3. The majority of non-CG methylation in vegetative tissues, leaf, is gone in homozygous ddcc mutant line (Hume et al., 2014). To uncover the possible role of non-CG DNA methylation in seed development and dormancy, we characterized the methylome of ddcc mutant in Arabidopsis postmature-green-stage seed and dry seed using Illumina sequencing. Meanwhile, vegetative tissue, leaves from 3 week plant with ddcc mutant and from wild-type, and postmature-green-stage seed and dry seed from wild-type plant were used as control.
Project description:RELATIVE OF EARLY FLOWERING 6 (REF6/JMJ12), a Jumonji C (JmjC)-domain-containing histone demethylase, directly recognizes the CTCTGYTY motif by its zinc-finger domains to demethylate H3K27me3 at specific loci in Arabidopsis genome. Here we show that the recognition of CTCTGYTY motif by REF6 is prevented by DNA methylation. REF6 prefers to bind DNA hypo-methylated regions in vivo. DNA cytosine-methylation decreases REF6 binding affinity in vitro, and the crystal structure of ZnF-clusters showed that REF6 prefers unmethylated DNA sequences. Furthermore, REF6 displayed ectopic binding on multiple new target loci in drm1 drm2 cmt2 cmt3 (ddcc) quadruple mutants, where non-CG methylation was largely diminished. Collectively, this study reveals a novel targeting crosstalk between an H3K27me3 demethylase and DNA methylation.
Project description:RNA silencing is a mechanism for regulating gene expression at the transcriptional and post-transcriptional levels. Its functions include regulating endogenous gene expression and protecting the cell against viruses and invading transposable elements (TEs). A key component of the mechanism is small RNAs (sRNAs) of 21-24 nucleotides (nt) in length, which direct the silencing machinery in a sequence specific manner to target nucleic acids. sRNAs of 24 nt are involved in methylation of cytosine residues of target loci in three sequence contexts (CG, CHG and CHH), referred to as RNA-directed DNA methylation (RdDM). We previously demonstrated that 24 nt sRNAs are mobile from shoot to root in Arabidopsis thaliana. In this study we demonstrated that methylation of thousands of loci in root tissues is dependent upon mobile sRNAs from the shoot. Furthermore, we found that mobile sRNA-dependent DNA methylation occurs predominantly in non-CG contexts. These findings were made using base-resolution next generation sequencing approaches and genome wide analyses. Specific classes of short TEs are the predominant targets of mobile sRNA-dependent DNA methylation; classes typically found in gene-rich euchromatic regions. Mobile sRNA-regulated genes were also identified. Mechanistically, we demonstrate that mobile sRNA-dependent non-CG methylation is largely independent of the CMT2/3 RdDM pathway but dependent upon the DRM1/DRM2 RdDM pathway. This is in contrast to non-mobile sRNA-dependent DNA methylation, which predominantly depends upon the CMT2/3 RdDM pathway. These data are complementary to the small RNA sequencing data from Arabidopsis root grafts described in Molnar et al (Science, 2010 May 14;328(5980):872-5).
Project description:DNA methylation occurs in both CG and non-CG sequence contexts. Non-CG methylation is abundant in plants, and is mediated by CHROMOMETHYLASE (CMT) and DOMAINS REARRANGED METHYLTRANSFERASE (DRM) proteins; however its roles remain poorly understood. Here we characterize the roles of non-CG methylation in Arabidopsis thaliana. We show that a poorly characterized methyltransferase, CMT2, is a functional methyltransferase in vitro and in vivo. CMT2 specifically binds histone H3 lysine 9 (H3K9) dimethylation and methylates non-CG cytosines at sites that are also regulated by H3K9 dimethylation. By generating different combinations of non-CG methylation mutants, we reveal the contributions and redundancies between each methyltransferase in DNA methylation patterning and in regulating transposable elements (TEs) and protein-coding genes. We also demonstrate extensive dependencies of small RNA accumulation and H3K9 methylation patterning on non-CG methylation, suggesting self-reinforcing mechanisms between these epigenetic factors. The results suggest that non-CG methylation patterns are critical in shaping the histone modification and small non-coding RNA landscapes.