DREAMS Illuminates DNA & RNA Modification Landscapes with a Spotlight on TET1's New Role in m1A
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ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE274195 | GEO | 2026/06/12
REPOSITORIES: GEO
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Project description:tRNA modifications help maintain tRNA structure and facilitate stress responses. Found in all three kingdoms of life, m1A tRNA modification occurs in the T loop of many tRNAs and stabilizes tertiary tRNA structure and impacts translation. M1A in T loop is known to be reversible by three mammalian demethylase enzymes, which bypasses the need of turning over the tRNA molecule to adjust their m1A levels in cells. However, no prokaryotic tRNA demethylase enzyme has been identified. Using Streptomyces venezuelae as a model organism, we confirmed the presence and quantitative m1A tRNA signatures using mass spectrometry and high throughput tRNA sequencing. We identified two RNA demethylases that can remove m1A in tRNA and confirmed the activity of a previously annotated tRNA m1A writer. Using single gene knockouts of these erasers and the m1A writer, we subjected these strains to stress conditions and found dynamic changes to m1A levels in many tRNAs. Phenotypic characterization highlighted changes to their growth and altered antibiotic production. Our identification of the first prokaryotic tRNA demethylase enzyme paves the way for investigating new mechanisms in global translational regulation in bacteria.
2024-06-20 | GSE264330 | GEO
Project description:Surveillance of DNA methylation is critical for genome stability and epigenetic regulation in mammals. 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 maintenance and remodeling. 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, mass spectrometry 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. Our study identifies TET1 as a scaffold protein and a global regulator of histone modifications. Moreover, we show that the establishment of H3K9me3 and H4K20me3 at ERV1, ERVK and ERVL is mediated by TET1 independent of DNA demethylation. Finally, we provide evidence that repression of endogenous retroviruses depends on the interaction between TET1 and SIN3A. In summary, we found that the non-catalytic functions of TET1 are critical for regulation of gene expression and the silencing of endogenous retroviruses in mESCs.
2022-07-14 | GSE183465 | GEO
Project description:5-hydroxymethylcytosine (5hmC) is a recently discovered epigenetic modification that is lost in human cancers. Formation of 5hmC is catalysed by the Ten eleven translocation (TET) proteins that mediate the sequential oxidation of 5-methylcytosine (5mC) to 5hmC, leading to eventual DNA demethylation. Several mechanisms can lead to loss of 5hmC in cancers, including mutations in IDH or TET2 genes. However, little is known about the role of TET proteins and 5hmC in adult cells. Here, we report that TET1 downmodulation is required to permit adult cells to proliferate. TET1 is rapidly downmodulated in proliferating primary cells and in regenerating liver. TET1 silencing accelerates cell cycle progression while its constitutive expression inhibits cell growth. TET1 is a negative regulator of cell proliferation and it is regulated during development in tissue specific manner. These findings enlarge our knowledge on how one epigenetic modification such as the DNA hydroxymethylation mediated by TET1 is a key player on the control of cell proliferation. Examination of 5hmC in MEF at passage 0 and at passage 5.
2015-08-04 | E-GEOD-57250 | biostudies-arrayexpress
Project description:N1-methyladenosine (m1A) is an abundant post-transcriptional RNA modification, yet little is known about its prevalence, topology and dynamics in mRNA. Here, we show that m1A is abundant in human mRNA, with an m1A/A ratio of ~0.02%. We develop m1A-ID-Seq, based on m1A immunoprecipitation and the inherent property of m1A to stall reverse transcription, for the transcriptome-wide m1A analysis. m1A-ID-Seq identifies 901 m1A peaks (from 583 genes) in mRNA and ncRNA, and reveals a prominent feature of enrichment in the 5â-untranslated region of mRNA transcripts, distinct from that of N6-methyladenosine, the most abundant internal mammalian mRNA modification. m1A in mRNA is also reversible by ALKBH3, a known DNA/RNA demethylase. Lastly, m1A responds dynamically to stimuli and hundreds of stress-induced m1A sites are identified. Collectively, our approaches allow comprehensive analysis of m1A methylation and provide an important tool for functional studies of potential epigenetic regulation via the reversible and dynamic m1A methylation. Identification of m1A sites in human embryonic kidney cells. Comparisons of m1A profiles of wild type HEK293T with ALKBH3 knock out cell line reveals the ALKBH3 specific sites. Stress inducible m1A sites are also identified by comparing the profiles of untreated cells with stress treated cells.
2016-02-05 | E-GEOD-73941 | biostudies-arrayexpress
Project description:5-hydroxymethylcytosine (5hmC) is a recently discovered epigenetic modification that is lost in human cancers. Formation of 5hmC is catalysed by the Ten eleven translocation (TET) proteins that mediate the sequential oxidation of 5-methylcytosine (5mC) to 5hmC, leading to eventual DNA demethylation. Several mechanisms can lead to loss of 5hmC in cancers, including mutations in IDH or TET2 genes. However, little is known about the role of TET proteins and 5hmC in adult cells. Here, we report that TET1 downmodulation is required to permit adult cells to proliferate. TET1 is rapidly downmodulated in proliferating primary cells and in regenerating liver. TET1 silencing accelerates cell cycle progression while its constitutive expression inhibits cell growth. TET1 is a negative regulator of cell proliferation and it is regulated during development in tissue specific manner. These findings enlarge our knowledge on how one epigenetic modification such as the DNA hydroxymethylation mediated by TET1 is a key player on the control of cell proliferation.
2015-08-04 | GSE57250 | GEO
Project description:TET enzymes convert 5-methylcytosine to 5-hydroxymethylcytosine and higher oxidized derivatives. TETs stably associate with and are post-translationally modified by the nutrient-sensing enzyme OGT, suggesting a connection between metabolism and the epigenome. Here, we show for the first time that modification by OGT enhances TET1 activity in vitro. We identify a a domain of TET1 domain that is responsible necessary and sufficient for binding to OGT and report a point mutation that disrupts the TET1-OGT interaction. We show that the TET1-OGTthis interaction is necessary for TET1 to rescue hematopoetic stem cell production in tet mutant zebrafish embryos, suggesting that OGT promotes TET1’s function during development. Finally, we show that disrupting the TET1-OGT interaction in mouse embryonic stem cells changes the abundance of TET-containing high molecular weight complexesTET2 and 5-methylcytosine, which is accompanied by alterations in gene expression and causes widespread gene expression changes. These results link metabolism and epigenetic control, which may be relevant to the developmental and disease processes regulated by these two enzymes.
2018-11-02 | GSE119500 | GEO
Project description:TET genes have been characterized as tumor suppressors because their expression levels are reduced in many human cancers including lymphoma, prostate, and pancreas, and TET2 gene mutations are common in hematological cancers. In contrast, TET1 was recently reported to be overexpressed in triple negative breast cancer and to act as a protooncogene in lung cancer. In our study, TET1 knock out and overexpressed H441 cells were isolated for multi-omics analyses.
2026-01-23 | PXD066092 | Pride
Project description:Epigenetic pathways that regulate DNA methylation and chromatin modifications are frequently found to be dysregulated in human cancers. The TET methylcytosine dioxygenase 1 (TET1) enzyme is an important regulator of hydroxymethylcytosine (5hmC) in embryonic stem cells, neural progenitors,adult cells and reprogrammed cells. Decreased expression of TET proteins and loss of 5hmC has been reported in many tumors, suggesting a critical role for the maintenance of this epigenetic modification in normal cellular function. However, loss of TET1 function in the etiology of cancer has not been directly investigated. Here, we show that deletion of the Tet1 gene promotes the development of B cell lymphoma. Tet1 is required for maintaining normal levels of 5hmC, preventing aberrant DNA hypermethylation and for the regulation of transcriptional programs involved in B-cell lineage specification, chromosome maintenance, and DNA repair. Progenitor B cells in the absence of Tet1 accumulate DNA damage and whole-exome sequencing of Tet1-deficient tumors revealed a high correlation of mutations with those most frequently found in Non-Hodgkin B cell lymphoma (B-NHL) patients. In addition, we show that the TET1 gene is deleted, hypermethylated and transcriptionally silenced in B-NHL patients. These findings provide the first in vivo evidence of TET1 function as a tumor suppressor of hematopoietic malignancy. We did hydroxymethylation tests for two wild type mice and two Tet1 knockout mice.
2015-04-12 | E-GEOD-65895 | biostudies-arrayexpress
Project description:RNA N1-methyladenosine methylation (m1A) modification is critical in regulating mRNA translation and thus protein synthesis, but the role of m1A modification in the occurrence, progression, and immunotherapy of head and neck squamous cell cancer (HNSCC) remains largely unknown. In Tgfbr1/Pten 2cKO mice, we found that the spontaneous neoplastic transformation of oral mucosa is accompanied by elevated levels of m1A modification. Analysis of m1A-associated genes identified TRMT61A as the key m1A writer associated with cancer progression, and poor prognosis. Mechanically, TRMT61A-induced tRNA-m1A modification promotes MYC protein synthesis and subsequent programmed death-ligand 1 (PD-L1) expression. In Tgfbr1/Pten 2cKO mice, RNA-m1A modification levels are also elevated in tumors that developed resistance to oncolytic herpes simplex virus (oHSV) treatment. Therapeutic inhibition of m1A modification sustains oncolytic virus-induced antitumor immunity and reduces tumor growth, providing a promising strategy for alleviating resistance to oHSV therapy. These findings indicate that m1A inhibition can prevent immune escape after oHSV therapy by reducing the expression of PD-L1. Our results provide a mutually reinforcing strategy for clinical combination immunotherapy.
2024-03-31 | GSE247024 | 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