Project description:DNA methylation and histone lysine tri-methylation at H3K27 (H3K27me3) are the two primary epigenetic marks for transcriptional silencing essential for cell fate determination and cell lineage commitment during development1, 2. These two marks are mutually exclusive and target distinct sets of genes in the mammalian genome3. However, whether and how H3K27me3 shapes the DNA methylome remains unknown. Here, we report that the loss of H3K27me3 modification leads to increased DNA methylation at previously marked H3K27me3 sites, revealing that H3K27me3 negatively regulates DNA methylation. Genome-wide analysis of H3 ubiquitination, essential for recruitment and activation of DNA methyltransferase DNMT14, reveals the absence of H3 ubiquitination at H3K27me3 marked nucleosomes. Moreover, loss of H3K27me3 modification induces an increase in H3K18 ubiquitination at the corresponding hypermethylated loci. Importantly, we show that H3K27me3 directly inhibits UHRF1-mediated H3 ubiquitination toward nucleosomes in a defined biochemical assay. Furthermore, UHRF1 is required for the increase in DNA methylation at previously marked H3K27me3 sites in cells with abolished H3K27me3 modification. Taken together, our findings reveal a general mechanism for H3K27me3-mediated shaping of the mammalian DNA methylome via modulation of H3 ubiquitination.
Project description:DNA methylation and histone lysine tri-methylation at H3K27 (H3K27me3) are the two primary epigenetic marks for transcriptional silencing essential for cell fate determination and cell lineage commitment during development1, 2. These two marks are mutually exclusive and target distinct sets of genes in the mammalian genome3. However, whether and how H3K27me3 shapes the DNA methylome remains unknown. Here, we report that the loss of H3K27me3 modification leads to increased DNA methylation at previously marked H3K27me3 sites, revealing that H3K27me3 negatively regulates DNA methylation. Genome-wide analysis of H3 ubiquitination, essential for recruitment and activation of DNA methyltransferase DNMT14, reveals the absence of H3 ubiquitination at H3K27me3 marked nucleosomes. Moreover, loss of H3K27me3 modification induces an increase in H3K18 ubiquitination at the corresponding hypermethylated loci. Importantly, we show that H3K27me3 directly inhibits UHRF1-mediated H3 ubiquitination toward nucleosomes in a defined biochemical assay. Furthermore, UHRF1 is required for the increase in DNA methylation at previously marked H3K27me3 sites in cells with abolished H3K27me3 modification. Taken together, our findings reveal a general mechanism for H3K27me3-mediated shaping of the mammalian DNA methylome via modulation of H3 ubiquitination.
Project description:DNA methylation and histone lysine tri-methylation at H3K27 (H3K27me3) are the two primary epigenetic marks for transcriptional silencing essential for cell fate determination and cell lineage commitment during development1, 2. These two marks are mutually exclusive and target distinct sets of genes in the mammalian genome3. However, whether and how H3K27me3 shapes the DNA methylome remains unknown. Here, we report that the loss of H3K27me3 modification leads to increased DNA methylation at previously marked H3K27me3 sites, revealing that H3K27me3 negatively regulates DNA methylation. Genome-wide analysis of H3 ubiquitination, essential for recruitment and activation of DNA methyltransferase DNMT14, reveals the absence of H3 ubiquitination at H3K27me3 marked nucleosomes. Moreover, loss of H3K27me3 modification induces an increase in H3K18 ubiquitination at the corresponding hypermethylated loci. Importantly, we show that H3K27me3 directly inhibits UHRF1-mediated H3 ubiquitination toward nucleosomes in a defined biochemical assay. Furthermore, UHRF1 is required for the increase in DNA methylation at previously marked H3K27me3 sites in cells with abolished H3K27me3 modification. Taken together, our findings reveal a general mechanism for H3K27me3-mediated shaping of the mammalian DNA methylome via modulation of H3 ubiquitination.
Project description:We reported that ethylene specifically elevated acetylation of histone H3 at K14 and the non-canonical acetylation of histone H3 at K23,but not H3K9ac.Thus, we further performed Chip-sequencing of H3K9Ac, using chromatins isolated from 3-day old etiolated ein2-5 seedlings treated with ethylene or air gas.
Project description:PRMT1 plays pivotal roles in normal and disease biology. Understanding its regulation is crucial for therapeutic targeting. We demonstrate that p300-mediated acetylation of PRMT1 at K228 triggers degradation via FBXL17-dependent ubiquitination at K145. Using mass spectrometry, cellular biochemistry, and genetic code-expansion, we reveal the crosstalk between acetylation and ubiquitination in PRMT1 homeostasis, highlighting mechanisms governing protein stability. This study results in Identification of K228 acetylation and K145 ubiquitination sites on PRMT1, FBXL17 as the E3 ligase mediating PRMT1 ubiquitination and interdependence of p300 acetylation and FBXL17 ubiquitination in PRMT1 degradation. We have used Co-IP MS to look for protein-protein interactions (e.g., PRMT1-FBXL17/p300 complexes), IP-MS to map Acetylation/ubiquitination sites (PRMT1 post-translational modifications) and genetic code-expansion (site-specific incorporation of acetyl-lysine)