Homo sapiens
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA218854 | ENA |
REPOSITORIES: ENA
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Project description:Recent large-scale studies have defined genomewide, cell type-specific patterns of DNA methylation, a modification known to be important for regulating gene expression in both normal development and disease states. However, determining the functional significance of specific methylation events remains a challenging problem due to the current lack of targeted methodologies for removing these modifications. Here we describe an approach for efficient targeted demethylation of specific CpGs in human cells using fusions of engineered transcription activator-like effector (TALE) repeat arrays and the TET1 hydroxylase catalytic domain. Using these TALE-TET1 fusions, we demonstrate that modification of certain critical methylated promoter CpG positions can be associated with substantial increases in endogenous human gene expression. Our results delineate a general strategy for defining the functional significance of specific CpG methylation marks in the context of endogenous gene loci and validate new programmable DNA demethylation reagents with broad utility for research and potential therapeutic applications. Bisulfite sequencing of three different loci in three different cell lines (Klf4 in K562s, HBB in K562s and RHOXF2 in 293s and HeLas. Biological triplicates of all samples and controls (off-target and GFP controls).
2013-09-23 | E-GEOD-50761 | biostudies-arrayexpress
Project description:Recent large-scale studies have defined genomewide, cell type-specific patterns of DNA methylation, a modification known to be important for regulating gene expression in both normal development and disease states. However, determining the functional significance of specific methylation events remains a challenging problem due to the current lack of targeted methodologies for removing these modifications. Here we describe an approach for efficient targeted demethylation of specific CpGs in human cells using fusions of engineered transcription activator-like effector (TALE) repeat arrays and the TET1 hydroxylase catalytic domain. Using these TALE-TET1 fusions, we demonstrate that modification of certain critical methylated promoter CpG positions can be associated with substantial increases in endogenous human gene expression. Our results delineate a general strategy for defining the functional significance of specific CpG methylation marks in the context of endogenous gene loci and validate new programmable DNA demethylation reagents with broad utility for research and potential therapeutic applications.
2013-09-23 | GSE50761 | GEO
Project description:Surveillance of DNA methylation in mammals is critical for genome stability and epigenetic regulation. The discovery of the ten-eleven translocation (TET) proteins catalyzing the oxidation from 5-methylcytosine (5mC) to 5-hydroxymethylcytosine (5hmC), 5-formylcytosine (5fC), and 5-carboxylcytosine (5caC) revolutionized the understanding of DNA methylation dynamics. Interestingly, in recent years evidence accumulated that TET1 also harbours non-catalytic functions. However, the role and mechanism of TET1 DNA demethylation independent functions still remain poorly understood. Here, we use genome engineering and quantitative multi-omics approaches to dissect the non-catalytic role of TET1. Strikingly, we find that the majority of transcriptional regulation depends on non-catalytic functions of TET1. To gain insights into possible mechanisms by which TET1 regulates transcription independent of DNA demethylation, we asked if the loss of TET1 is accompanied by changes in the histone modificaiton landscape. To this end, we compared the relative abundances of core histone modifications between Tet1 KO, Tet1 CM and WT mESCs using quantitative LC-MS/MS analysis. Surprisingly, we observed a profound global reduction of pH4Kac and H4K20me3 as well as H3K27me3 in Tet1 KO mESC. Vice versa, the monomethylation states of the latter two residues, H3K27me1 and H4K20me1 were significantly increased in Tet1 KO. Similar to the results from the transcriptome data, most of these changes were specific to Tet1 KO cells.
2022-08-11 | PXD028566 | Pride
Project description:Mammalian DNA methylation is a critical epigenetic mechanism orchestrating gene expression networks in many biological processes. However, investigation of the functions of specific methylation events remains challenging. Here, we demonstrate that fusion of Tet1 or Dnmt3a with a catalytically inactive Cas9 (dCas9) enables targeted DNA methylation editing. Targeting of the dCas9-Tet1 or -Dnmt3a fusion protein to methylated or unmethylated promoter sequences caused activation or silencing, respectively, of an endogenous reporter. Targeted demethylation of the BDNF promoter IV or the MyoD distal enhancer by dCas9-Tet1 induced BDNF expression in post-mitotic neurons or activated MyoD facilitating reprogramming of fibroblasts into myoblasts, respectively. Targeted de novo methylation of a CTCF loop anchor site by dCas9-Dnmt3a blocked CTCF binding and interfered with DNA looping, causing altered gene expression in the neighboring loop. Finally, we show that these tools can edit DNA methylation in mice demonstrating their wide utility for functional studies of epigenetic regulation.
2016-09-23 | GSE83890 | GEO
Project description:DNA demethylating agents are epigenetic drugs for the therapy of myeloid leukemias. They not only induce DNA demethylation but also have significant cytostatic and cytotoxic effects, however, the relationships between these characteristics have not been established yet due to the lack of method to induce only DNA demethylation. Here we show that a fusion protein comprising the methyl-CpG binding domain (MBD) and the catalytic domain of Ten-eleven translocation protein 1 (TET1-CD) globally demethylates and upregulates a number of methylated genes. Gene expression microarray analyses using human embryonic kidney cell line 293T indicate that cells expressing wild-type (wt) TET1 catalytic domain with MBD (MBD-TET1-CDwt) upregulated more genes than ones expressing TET1-CDwt without MBD or catalytically inactive TET1-CD mutant (mut) with MBD (MBD-TET1-CDmut) and their upregulated genes frequently contained CpG islands (CGIs) within ± 1,000 bp of the transcription start site (TSS). Interestingly, 88% of genes upregulated 5-fold or more by MBD-TET1-CDwt were also reactivated after treatment with DNA demethylating agent, 5-azacytidine, suggesting that gene reactivation by both methods is primarily based on DNA demethylation.
2017-02-09 | GSE74744 | GEO
Project description:Ten-eleven translocation (TET) proteins oxidize 5-methylcytosine (5mC) to 5-hydroxymethylcytosine (5hmC), 5-formylcytsosine (5fC), and 5-carboxylcytosine (5caC). 5fC/5caC can be excised and repaired by the base excision repair (BER) pathway, implicating 5mC oxidation in active DNA demethylation. Genome-wide DNA methylation is erased in the transition from metastable states to ground state of embryonic stem cells (ESCs) and in migrating primordial germ cells (PGCs), while some resistant regions become demethylated only in gonadal PGCs. Understanding the mechanisms underlying global hypomethylation in naïve ESCs and developing PGCs will be useful for realizing cellular pluripotency and totipotency. In this study, we found that PRDM14, the PR-domain-containing transcriptional regulator, accelerates the TET-BER cycle, resulting in the promotion of active DNA demethylation in ESCs. Induction of PRDM14 expression rapidly removed the 5mC associated with transient elevation of 5hmC at pluripotency-associated genes, germline-specific genes, and imprinted loci but not across the entire genome, which resemble second wave of DNA demethylation in gonadal PGCs. PRDM14 physically interacts with TET1/TET2 and enhances the recruitment of TET1/TET2 at target loci. Knockdown of Tet1/Tet2 impaired transcriptional regulation and DNA demethylation by PRDM14. The repression of the BER pathway by administration of pharmacological inhibitors against APE1 and PARP1 and the knockdown of thymine DNA glycosylase (TDG) also impaired DNA demethylation by PRDM14. Furthermore, DNA demethylation induced by PRDM14 normally takes place in the presence of aphidicolin, which is an inhibitor of G1/S progression. Together, our analysis provides mechanistic insight into DNA demethylation in naive pluripotent stem cells and developing PGCs. To investigate the function of TET1/TET2 in transcriptional regulation by PRDM14 in ESCs, we exploited microarray analysis using total mRNA derived from Scramble, Scramble + PRDM14, Tet1/Tet2 KD, Tet1/Tet2 KD + PRDM14 mouse ESC.
2013-12-31 | E-GEOD-52598 | biostudies-arrayexpress
Project description:Synthetic DNA-binding proteins have found broad application in gene therapies and as tools for interrogating biology. Engineered proteins based on the CRISPR/Cas9 and TALE systems have been used to alter genomic DNA sequences, control transcription of endogenous genes, and modify epigenetic states. Although the activity of these proteins at their intended genomic target sites have been assessed, the genome-wide effects of their action have not been extensively characterized. Additionally, the role of chromatin structure in determining the binding of CRISPR/Cas9 and TALE proteins to their target sites and the regulation of nearby genes is poorly understood. Characterization of the activity these proteins using modern high-throughput genomic methods would provide valuable insight into the specificity and off-target effects of CRISPR- and TALE-based genome engineering tools. We have analyzed the genome-wide effects of TALE- and CRISPR-based transcriptional activators targeted to the promoters of two different endogenous human genes in HEK293T cells using a variety of high-throughput DNA sequencing methods. In particular, we assayed the DNA-binding specificity of these proteins and their effects on the epigenome. DNA-binding specificity was evaluated by ChIP-seq and RNA-seq was used to measure the specificity of these activators in perturbing the transcriptome. Additionally, DNase-seq was used to identify the chromatin state at target sites of the synthetic transcriptional activators and the genome-wide chromatin remodeling that occurs as a result of their action. Our results show that these genome engineering technologies are highly specific in both binding to their promoter target sites and inducing expression of downstream genes when multiple activators bind to a single promoter. Moreover, we show that these synthetic activators are able to induce the expression of silent genes in heterochromatic regions of the genome by opening regions of closed chromatin and decreasing DNA methylation. Interestingly, the transcriptional activation domain was not necessary for DNA-binding or chromatin remodeling in these regions, but was critical to inducing gene expression. This study shows that these CRISPR- and TALE-based transcriptional activators are exceptionally specific. Although we detected limited binding of off-target sites in the genome and changes to genome structure, these off-target event did not lead to any detectable changes in gene regulation. Collectively, these results underscore the potential for these technologies to make precise changes to gene expression for gene and cell therapies or fundamental studies of gene function. HEK293T cells were transfected in triplicate with plasmids expressing synthetic transcription factors. The synthetic TFs were either (a) dCas9-VP64 fusion protein and a targeting guide RNA (gRNA), or (b) a TALE-VP64 fusion protein engineered to bind to a specific target site in the genome. As a control, cells were transfected with plasmids expressing GFP. After transfection, RNA-seq was used to identify both on-target and off-target binding sites for the synthetic TFs. The data in this submission were generated using the TALE transfection experiments.
2015-05-27 | E-GEOD-68341 | biostudies-arrayexpress
Project description:In this study, we characterize the fusion protein produced by the EPC1-PHF1 translocation in Low Grade Endometrial Stromal Sarcoma (LG-ESS) and Ossifying FibroMyxoid Tumors (OFMT). We express the fusion protein and necessary controls in K562 Cells. The fusion protein assembles a mega-complex harboring both NuA4/TIP60 and PRC2 subunits and enzymatic activities and leads to mislocalization of chromatin marks in the genome, linked to aberrant gene expression.
2020-12-03 | GSE162543 | GEO
Project description:Targeted DNA demethylation of the Arabidopsis genome using the Human TET1 catalytic domain.
| PRJNA429659 | ENA
Project description:Precise regulation of DNA methylation in mammals is critical for genome stability and epigenetic regulation. The discovery of the ten-eleven translocation (TET) proteins catalyzing the oxidation from 5-methylcytosine (5mC) to 5-hydroxymethylcytosine (5hmC), 5-formylcytosine (5fC), and 5-carboxylcytosine (5caC) revolutionized the perspective on the complexity and regulation of DNA modifications. Despite accumulating knowledge about the role of TET1, it remains unclear to what extent these can be attributed to its catalytic activity. Here, we use genome engineering and quantitative multi-omics approaches to dissect the role and mechanism of TET1 in mESCs. Our study identifies TET1 as an essential interaction hub for multiple chromatin modifying complexes and as a global regulator of histone modifications. Strikingly, we find that the majority of transcriptional regulation depends on non-catalytic functions of TET1. Moreover, we show that the establishment of H3K9me3 and H4K20me3 at ERV1, ERVK, and ERVL is mediated by TET1 independent of DNA demethylation. We provide evidence that repression of endogenous retroviruses depends on the interaction between TET1 and SIN3A. In summary, we demonstrate that the non-catalytic functions of TET1 are critical for regulation of gene expression and the silencing of endogenous retroviruses in mESCs.
2022-08-31 | PXD028850 | Pride