MRNA aging shapes the Cap2 methylome in mammalian mRNA
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ABSTRACT:
PROVIDER: PRJNA803151 | ENA |
REPOSITORIES: ENA
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Project description:The mRNA cap structure is a major site of dynamic mRNA methylation. mRNA caps exist in either the Cap1 or Cap2 form, depending on the presence of 2’-O-methylation on the first, or both the first and second transcribed nucleotide, respectively. However, the identity of Cap2-containing mRNAs and the function of Cap2 are unclear. Here we describe CLAM-Cap-Seq, a method for transcriptome-wide mapping and quantification of Cap2. We find that unlike other epitranscriptomic modifications, Cap2 can occur on all mRNAs. Cap2 is formed through a slow continuous conversion of mRNAs from Cap1 to Cap2 as mRNAs age in the cytosol. As a result, Cap2 is enriched on long-lived mRNAs. We find that large increases in the abundance of Cap1 leads to activation of RIG-I, especially in conditions where RIG-I expression is increased. The methylation of Cap1 to Cap2 markedly reduces the ability of RNAs to bind and activate RIG-I. We find that the slow Cap2 methylation rate allows Cap2 to accumulate on host mRNAs yet ensures that low Cap2 levels occur on newly expressed viral RNAs. Overall, these results reveal an immunostimulatory role for Cap1, and that Cap2 functions to reduce activation of the innate immune response.
2022-12-12 | GSE196043 | GEO
Project description:Transcriptome Mapping of Internal N7-methylguanosine Methylome in Mammalian mRNA
| PRJNA445453 | ENA
Project description:N7-methylguanosine (m7G) is a positively charged, essential modification at the 5′ cap of eukaryotic mRNA, regulating mRNA export, translation, and splicing. m7G also occurs internally within tRNA and rRNA, but its existence and distribution within eukaryotic mRNA remain to be investigated. Here, we show the presence of internal m7G sites within mammalian mRNA. We then performed transcriptome-wide profiling of internal m7G methylome using m7G-MeRIP sequencing (MeRIP-seq). To map this modification at base resolution, we developed a chemical-assisted sequencing approach that selectively converts internal m7G sites into abasic sites, inducing misincorporation at these sites during reverse transcription. This base-resolution m7G-seq enabled transcriptome-wide mapping of m7G in human tRNA and mRNA, revealing distribution features of the internal m7G methylome in human cells. We also identified METTL1 as a methyltransferase that installs a subset of m7G within mRNA and showed that internal m7G methylation could affect mRNA translation.
2019-04-26 | GSE112276 | GEO
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.
2022-06-27 | GSE159042 | GEO
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.
2022-06-27 | GSE159041 | GEO
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.
2022-06-27 | GSE159040 | GEO
Project description:Germline DNA replication timing shapes mammalian genome composition
| PRJNA432066 | ENA
Project description:The impact of healthy aging on molecular programming of immune cells is poorly understood. Here, we report comprehensive characterization of healthy aging in human classical monocytes, with a focus on epigenomic, transcriptomic, and proteomic alterations, as well as the corresponding proteomic and metabolomic data for plasma, using healthy cohorts of 20 young and 20 older males (~27 and ~64 years old on average). For each individual, we performed eRRBS-based DNA methylation profiling, which allowed us to identify a set of age-associated differentially methylated regions (DMRs) – a novel, cell-type specific signature of aging in DNA methylome. Hypermethylation events were associated with H3K27me3 in the CpG islands near promoters of lowly-expressed genes, while hypomethylated DMRs were enriched in H3K4me1 marked regions and associated with age-related increase of expression of the corresponding genes, providing a link between DNA methylation and age-associated transcriptional changes in primary human cells.
2022-02-16 | PXD021821 | Pride
Project description:H3K27me3 shapes DNA methylome by inhibiting UHRF1-mediated H3 ubiquitination
| PRJNA667466 | ENA
Project description:The goals of this study are to compare genome-wide DNA methylation levels in young and aged oocytes,and to investigate the transgenerational inheritance of methylome profiles in oocytes during natural aging. We apply a novel protocol of rapamycin to overcome the DNA methylation drift associated with oocyte aging. 8-week-old female mice were injected intraperitoneally with rapamycin or vehicle for 40 weeks. At the end of the experiment, females (48 weeks, F0) were paired with young adult (~4 mo old) males to produce F1 offspring (OF1 and ORaF1). An F2 generation (OF2 and ORaF2) resulted from mating F1 female at 44~48 weeks of age with young adult males. To generate YF1 and YF2 as normal control (offspring of young mother), we mated females (~8 weeks) with young adult males. Then we collect oocytes (F0,F1 and F2 generations)，sperm ( F1 and F2 generations) and hippocampus (F1 female offspring) from different groups to investigate the transgenerational inheritance of DNA methylome profiles associated with oocyte aging by the single cell whole-genome methylation sequencing (sc-WGBS). We found that oocytes from aged mother exhibited increased DNA methylation levels in CpG sites. Maternal aging related methylome changes can be inherited transgenerationally though oocyte to the germ line of F1 and F2 offspring. The application of rapamycin during the course of oocyte aging could reverse these DNA methylation alterations, and it can ameliorate several neurobehavioral aging trails that were in observed in aged oocyte offspring. WGBS-seq on DNA from hippocampal tissue revealed a number of differentially methylated (P<0.05) genes in OF1 and ORaF1 compared with YF1, and some of the enriched pathways were associated with aging process, such as PI3K-Akt signaling pathway (akin to transcriptional alterations above), MAPK signaling and Ras signaling pathway .
2022-12-31 | GSE164139 | GEO