An auto-suppression mechanism for Tet dioxygenase protects the mouse genome from oxidative demethylation
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PROVIDER: PRJNA922892 | ENA |
REPOSITORIES: ENA
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Project description:Dynamic DNA methylation and demethylation regulate gene expression during development. While DNA methyltransferases (DNMTs) establish and maintain cytosine methylation patterns, Ten-eleven translocation (Tet) dioxygenases catalyze sequential oxidation of 5-methylcytosine (5mC) to promote demethylation. Target-specific 5mC oxidation requires precise regulation of the Tet enzymatic activity. However, the mechanism underlying their activity control remains largely unexplored. Here we show a large low-complexity domain (LCD), present within the catalytic domain of Tet3, functions to repress the dioxygenase activity. Recombinant LCD-deleted Tet3 exhibits enhanced activity to convert 5mC into oxidized species. Deletion of the Tet3 LCD in mouse oocytes renders 5mC oxidation indiscriminately across the genome, leading to most prominently the derepression of ERVK retrotransposons and upregulation of adjacent genes. The extensive 5mC oxidation is associated with impairments in oocyte development. These findings suggest an intrinsic auto-regulatory mechanism of Tet3 dioxygenase operating to ensure a tight regulation of its enzymatic activity to achieve spatiotemporal specificity of methylome reprogramming during oocyte development.
2023-06-26 | GSE222618 | GEO
Project description:Dynamic DNA methylation and demethylation regulate gene expression during development. While DNA methyltransferases (DNMTs) establish and maintain cytosine methylation patterns, Ten-eleven translocation (Tet) dioxygenases catalyze sequential oxidation of 5-methylcytosine (5mC) to promote demethylation. Target-specific 5mC oxidation requires precise regulation of the Tet enzymatic activity. However, the mechanism underlying their activity control remains largely unexplored. Here we show a large low-complexity domain (LCD), present within the catalytic domain of Tet3, functions to repress the dioxygenase activity. Recombinant LCD-deleted Tet3 exhibits enhanced activity to convert 5mC into oxidized species. Deletion of the Tet3 LCD in mouse oocytes renders 5mC oxidation indiscriminately across the genome, leading to most prominently the derepression of ERVK retrotransposons and upregulation of adjacent genes. The extensive 5mC oxidation is associated with impairments in oocyte development. These findings suggest an intrinsic auto-regulatory mechanism of Tet3 dioxygenase operating to ensure a tight regulation of its enzymatic activity to achieve spatiotemporal specificity of methylome reprogramming during oocyte development.
2023-08-24 | GSE222492 | GEO
Project description:Dynamic DNA methylation and demethylation regulate gene expression during development. While DNA methyltransferases (DNMTs) establish and maintain cytosine methylation patterns, Ten-eleven translocation (Tet) dioxygenases catalyze sequential oxidation of 5-methylcytosine (5mC) to promote demethylation. Target-specific 5mC oxidation requires precise regulation of the Tet enzymatic activity. However, the mechanism underlying their activity control remains largely unexplored. Here we show a large low-complexity domain (LCD), present within the catalytic domain of Tet3, functions to repress the dioxygenase activity. Recombinant LCD-deleted Tet3 exhibits enhanced activity to convert 5mC into oxidized species. Deletion of the Tet3 LCD in mouse oocytes renders 5mC oxidation indiscriminately across the genome, leading to most prominently the derepression of ERVK retrotransposons and upregulation of adjacent genes. The extensive 5mC oxidation is associated with impairments in oocyte development. These findings suggest an intrinsic auto-regulatory mechanism of Tet3 dioxygenase operating to ensure a tight regulation of its enzymatic activity to achieve spatiotemporal specificity of methylome reprogramming during oocyte development.
2023-08-24 | GSE222500 | GEO
Project description:Dynamic DNA methylation and demethylation regulate gene expression during development. While DNA methyltransferases (DNMTs) establish and maintain cytosine methylation patterns, Ten-eleven translocation (Tet) dioxygenases catalyze sequential oxidation of 5-methylcytosine (5mC) to promote demethylation. Target-specific 5mC oxidation requires precise regulation of the Tet enzymatic activity. However, the mechanism underlying their activity control remains largely unexplored. Here we show a large low-complexity domain (LCD), present within the catalytic domain of Tet3, functions to repress the dioxygenase activity. Recombinant LCD-deleted Tet3 exhibits enhanced activity to convert 5mC into oxidized species. Deletion of the Tet3 LCD in mouse oocytes renders 5mC oxidation indiscriminately across the genome, leading to most prominently the derepression of ERVK retrotransposons and upregulation of adjacent genes. The extensive 5mC oxidation is associated with impairments in oocyte development. These findings suggest an intrinsic auto-regulatory mechanism of Tet3 dioxygenase operating to ensure a tight regulation of its enzymatic activity to achieve spatiotemporal specificity of methylome reprogramming during oocyte development.
2023-08-24 | GSE222498 | GEO
Project description:Synthetic lethality by TET-dioxygenase inhibition
| PRJNA682029 | ENA
Project description:To characterize target specificity of TETi76, we performed global gene expression analyses of K562TET2+/+ and TET2-/- control cells; TETi76 mimicked expression signatures generated by the loss of TET2 in K562. The addition of Ascorbic Acid (AA), known to enhance TET-dioxygenase activity, counteracted the changes induced by TETi76. In order to study the molecular pathway of synthetic lethality by TET-dioxygenase inhibition, natural TET2-/- mutant cell line SIGM5 was treated with TET inhibitor TETi76 and global gene expression analysis was performed by RNAseq. Result demostrate a significant upregulation of TNT-α signaling and the down regulation of Interferon-α signaling. Interestingly, we also observed significant up-modulation of oxidative stress response pathway genes consistent with the inhibition of dioxygenases. In particular, TETi76 treatment induces 8-fold increase of oxidative stress sensor NQO1 a NRF2 target gene that has been shown earlier to induce pro-apoptotic cell death in cancer cells.
2020-12-03 | GSE162487 | GEO
Project description:Mammalian genomes are subjected to epigenetic modifications, including cytosine methylation by DNA methyltransferases (Dnmt) and further oxidation by Ten-eleven-translocation (Tet) family of dioxygenases. Cytosine methylation plays key roles in multiple processes such as genomic imprinting and X-chromosome inactivation. However, the functional significance of cytosine methylation and the further oxidation has remained undetermined in mouse embryogenesis. Here we show that global inactivation of all three Tet genes in mice led to consistent defects in gastrulation. The defects include reduced specification of the axial mesoderm and paraxial mesoderm, mimicking phenotypes in embryos with gain-of-function Nodal signaling, a cardinal cue for gastrulation. Introduction of a single mutant allele of Nodal in the Tet mutant background partially restored patterning, suggesting that hyperactive Nodal signaling is a leading cause for the gastrulation failure of Tet mutants. Increased Nodal signaling is likely due to diminished expression of the Lefty1 and Lefty2 genes, inhibitors of Nodal signaling. Moreover, reduction in the Lefty gene expression can be ascribed to elevated DNA methylation as both Lefty-Nodal signaling and normal morphogenesis are largely restored in Tet-deficient embryos when the Dnmt3a and Dnmt3b genes are disrupted. Additionally, specific inactivation of Tet by point mutations abolishing the dioxygenase activity causes similar molecular and gastrulation abnormalities. Taken together, our results show that Tet-mediated DNA oxidation modulates the Lefty-Nodal signaling by promoting demethylation of the shared target genes with Dnmt3a and Dnmt3b. These findings reveal a fundamental epigenetic mechanism featuring dynamic DNA methylation and demethylation and their role in the regulation of key signaling in body plan formation during early embryogenesis. Examine RNA expression and DNA methylation differences between Tet-null and wild type samples of mouse epiblast in E6.5.
2016-10-27 | E-GEOD-76261 | biostudies-arrayexpress
Project description:DNA methylation at 5-position of cytosine (5mC) is one of the best studied epigenetic modifications that plays important roles in diverse biological processes. Iterative oxidation of 5mC by the Ten-eleven translocation (Tet) family of proteins generates 5-hydroxymethylcytosine (5hmC), 5-formylcytosine (5fC), and 5-carboxylcytosine (5caC), which can be further processed by DNA repair proteins leading to DNA demethylation. Functional characterization of the Tet proteins has been complicated by the redundancy between the three Tet proteins. Using the CRISPR/Cas9 technology, we have generated mouse embryonic stem cells (ESCs) deficient for all three Tet proteins (TKO). Whole genome bisulphite sequencing (WGBS) analysis revealed that Tet-mediated DNA demethylation mainly occurs distal enhancers as well as promoters that significantly overlap with 5hmC, 5fC and 5caC. Characterization of the Tet TKO ESCs revealed a function for Tet proteins in cell fate restriction as Tet TKO ESCs tend to adopt both primed pluripotent stem cell-like state and 2-cell embryo-like state. In addition, Tet TKO ESCs exhibit elongated telomeres. Thus, our study reveals a role of Tet proteins not only in DNA demethylation, but also in cell fate restriction and telomere maintenance. 2 samples for WGBS and 2 samples for RNA-seq
2014-09-22 | E-GEOD-56986 | biostudies-arrayexpress
Project description:DNA methylation is a heritable epigenetic modification involved in gene silencing, imprinting, and the suppression of retrotransposons. Global DNA demethylation occurs in the early embryo and the germline and may be mediated by Tet (ten-eleven-translocation) enzymes, which convert 5-methylcytosine (mC) to 5-hydroxymethylcytosine (hmC). Tet enzymes have been extensively studied in mouse embryonic stem (ES) cells, which are generally cultured in the absence of Vitamin C, a potential co-factor for Fe(II) 2-oxoglutarate dioxygenase enzymes like Tets. Here we report that addition of Vitamin C to ES cells promotes Tet activity leading to a rapid and global increase in hmC. This is followed by DNA demethylation of numerous gene promoters and up-regulation of demethylated germline genes. Tet1 binding is enriched near the transcription start site (TSS) of genes affected by Vitamin C treatment. Importantly, Vitamin C, but not other antioxidants, enhances the activity of recombinant human Tet1 in a biochemical assay and the Vitamin C-induced changes in hmC and mC are entirely suppressed in Tet1/2 double knockout (Tet DKO) ES cells. Vitamin C has the strongest effects on regions that gain methylation in cultured ES cells compared to blastocysts and in vivo are methylated only after implantation. In contrast, imprinted regions and intracisternal A-particle (IAP) elements, which are resistant to demethylation in the early embryo, are resistant to Vitamin C-induced DNA demethylation. Collectively, this study establishes that Vitamin C is a direct regulator of Tet activity and DNA methylation fidelity in ES cells. Oct4-GiP mouse embryonic stem (ES) cells were cultured in the presence or absence of Vitamin C (L-ascorbic acid 2-phosphate, 200 M-NM-<g/ml) for 72 hours. RNA was harvested from biological triplicates for each condition and hybridized to Affymetrix microarrays. Cells were maintained in N2B27 medium supplemented with LIF (1000 U/ml), MEK inhibitor PD0325901 (1 M-NM-<M), and GSK3M-NM-2 inhibitor CHIR99021 (3 M-NM-<M).
2013-06-30 | E-GEOD-46319 | biostudies-arrayexpress
Project description:DNA methylation at 5-position of cytosine (5mC) is one of the best studied epigenetic modifications that plays important roles in diverse biological processes. Iterative oxidation of 5mC by the Ten-eleven translocation (Tet) family of proteins generates 5-hydroxymethylcytosine (5hmC), 5-formylcytosine (5fC), and 5-carboxylcytosine (5caC), which can be further processed by DNA repair proteins leading to DNA demethylation. Functional characterization of the Tet proteins has been complicated by the redundancy between the three Tet proteins. Using the CRISPR/Cas9 technology, we have generated mouse embryonic stem cells (ESCs) deficient for all three Tet proteins (TKO). Whole genome bisulphite sequencing (WGBS) analysis revealed that Tet-mediated DNA demethylation mainly occurs distal enhancers as well as promoters that significantly overlap with 5hmC, 5fC and 5caC. Characterization of the Tet TKO ESCs revealed a function for Tet proteins in cell fate restriction as Tet TKO ESCs tend to adopt both primed pluripotent stem cell-like state and 2-cell embryo-like state. In addition, Tet TKO ESCs exhibit elongated telomeres. Thus, our study reveals a role of Tet proteins not only in DNA demethylation, but also in cell fate restriction and telomere maintenance.
2014-09-22 | GSE56986 | GEO