Lin28A binds active promoters and recruits Tet1 to regulate gene expression
Ontology highlight
ABSTRACT:
ORGANISM(S): Mus musculus
SUBMITTER: Bing Yao
PROVIDER: E-GEOD-74254 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
Similar Datasets
Project description:The mammalian TET dioxygenases contribute to global waves of DNA demethylation in the zygote and in primordial germ cells, but their involvement during de novo DNA methylation at peri/post-implantation development is unknown. Here, we show novel physiological functions of Tet1 in the pre-primitive streak stage mouse embryo, where it is expressed not only in the primed-state epiblast, but also in the extra-embryonic ectoderm. In the epiblast, Tet1 contributes to DNA methylation patterning, which indirectly results in dominant transcriptional repression involving a Jumonji-family gene Jmjd8. In the extra-embryonic ectoderm, Tet1 suppresses expression of metabolic genes involved in oxidative phosphorylation. These lineage-specific gene repressive functions, involving distinct modes of regulation by DNA methylation, counteract precocious differentiation of the embryo prior to the onset of gastrulation. Such dysregulation in the absence of Tet1 are surprisingly tolerated in an inbred strain but results in full embryonic lethality in non-inbred mice, thus implicating a complex but essential role of Tet1 in normal gestational development.
2017-05-15 | E-MTAB-4581 | biostudies-arrayexpress
Project description:We performed a meta analysis of publicly available TET1, 5mC, 5hmC and genome wide bisulfite profiling data mostly from mouse embryonic stem cells (ESC). Genome wide chromatin immunoprecipitation combined with deep sequencing (ChIP-seq) has revealed binding of the TET1 protein at CpG-island (CGI) promoters and at bivalent promoters. We show that TET1 also coincides with DNAseI hypersensitive sites (HS). Presence of TET1 at these THREE locations suggests that it may play a dual role: an active role at CpG-islands and DNAseI hypersensitive sites and a repressive role at bivalent loci. In line with the presence of TET1, significant enrichment of 5hmC but not 5mC is detected at bivalent promoters and DNaseI HS. Surprisingly, 5hmC is not detected or present at very low levels at CGI promoters notwithstanding the presence of TET1 at these loci. Our meta analysis suggest that asymmetric methylation is present at CA- and CT-repeats in the genome of some human ESC. Examination of the distribution of 5-methylcytosine and 5-hydroxymethylcytosine in the genome of mouse embryonic stem cells.
2011-11-24 | E-GEOD-31343 | biostudies-arrayexpress
Project description:Genomic DNA was prepared, fragmented, and immunoprecipitated with antibodies specific for 5mC or 5hmC prior to standard sequencing. The neurodegenerative disease known as ataxia-telangiectasia (A-T) is caused by the absence of the ATM (A-T mutated) protein. A long-standing mystery surrounding A-T is why cerebellar Purkinje cells (PCs) appear uniquely vulnerable to ATM-deficiency. Here, we present that 5-hydroxymethylcytosine (5hmC), a newly recognized epigenetic marker found at high levels in neurons, is substantially reduced in human A-T and Atm-/- mouse cerebellar PCs. TET1, an enzyme that converts 5mC to 5hmC, responds to DNA damage. Manipulation of TET1 activity directly affects neuronal cell cycle reentry and cell death after the induction of DNA damage. Quantitative, genome-wide analysis of 5hmC of samples from human cerebellum showed that in ATM-deficiency there is a remarkable genome-wide reduction of 5hmC enrichment at both proximal and distal regulatory elements. These results reveal a role of TET1-mediated 5hmC in DNA damage response, and provide insights into the basis of a PC-specific DNA demethylation alteration in ATM-deficiency. There are two groups, A-T and Control. For each group, cerebellar DNA samples were immunoprecipitated with anti-5mC (n=1) or anti-5hmC (n=3). There were also two replicates of input control for each group.
2015-10-30 | E-GEOD-61133 | biostudies-arrayexpress
Project description:Lin28, a well-known RNA-binding protein, regulates diverse cellular properties. All physiological functions of Lin28A characterized so far have been attributed to its repression of let-7 miRNA biogenesis or modulation of the mRNA translational efficiency. Here we show that Lin28A directly binds to a consensus DNA sequence in vitro and in mouse embryonic stem cells in vivo. ChIP-seq and RNA-seq reveal the enrichment of Lin28A binding around transcription start sites, and a positive correlation between its genomic occupancy and expression of many associated genes. Mechanistically, Lin28A recruits 5-methylcytosine-dioxygenase Tet1 to genomic binding sites to orchestrate 5-methylcytosine and 5-hydroxymethylcytosine dynamics. Either Lin28A or Tet1 knockdown leads to dysregulated DNA methylation and expression of common target genes. These results reveal a surprising role for Lin28A in transcriptional regulation via epigenetic DNA modifications and provide a new framework for understanding mechanisms underlying versatile functions of Lin28A in mammalian systems.
2015-12-07 | GSE74254 | GEO
Project description:This SuperSeries is composed of the SubSeries listed below. The neurodegenerative disease known as ataxia-telangiectasia (A-T) is caused by the absence of the ATM (A-T mutated) protein. A long-standing mystery surrounding A-T is why cerebellar Purkinje cells (PCs) appear uniquely vulnerable to ATM-deficiency. Here, we present that 5-hydroxymethylcytosine (5hmC), a newly recognized epigenetic marker found at high levels in neurons, is substantially reduced in human A-T and Atm-/- mouse cerebellar PCs. TET1, an enzyme that converts 5mC to 5hmC, responds to DNA damage. Manipulation of TET1 activity directly affects neuronal cell cycle reentry and cell death after the induction of DNA damage. Quantitative, genome-wide analysis of 5hmC of samples from human cerebellum showed that in ATM-deficiency there is a remarkable genome-wide reduction of 5hmC enrichment at both proximal and distal regulatory elements. These results reveal a role of TET1-mediated 5hmC in DNA damage response, and provide insights into the basis of a PC-specific DNA demethylation alteration in ATM-deficiency. Refer to individual Series
2015-10-30 | E-GEOD-61169 | biostudies-arrayexpress
Project description:DNA methylation of C5-cytosine (5mC) in the mammalian genome is a key epigenetic event that is critical for various cellular processes. However, how the genome-wide 5mC pattern is dynamically regulated remains a fundamental question in epigenetic biology. The TET family of 5mC hydroxylases, which convert 5mC to 5-hydroxymethylcytosine (5hmC), have provided a new potential mechanism for the dynamic regulation of DNA methylation. The extent to which individual Tet family members contribute to the genome-wide 5mC and 5hmC patterns and associated gene network remains largely unknown. Here we report genome-wide mapping of Tet1 and 5hmC in mESCs and reveal a mechanism of action by which Tet1 controls 5hmC and 5mC levels in mESCs. In combination with microarray and mRNA-seq expression profiling, we identify a comprehensive yet intricate gene network influenced by Tet1. We propose a model whereby Tet1 controls DNA methylation both by binding to CpG-rich regions to prevent unwanted DNA methyltransferase activity, and by converting the existing 5mC to 5hmC through its enzymatic activity. This Tet1-mediated antagonism of CpG methylation imparts differential maintenance of DNA methylation status at Tet1 target loci, thereby providing a new regulatory mechanism for establishing the epigenetic landscape of mESCs, which ultimately contributes to mESC differentiation and the onset of embryonic development. To determine the genome-wide distribution of Tet1 and 5hmC in mouse ES cells, as well as identify the gene transcription changes after Tet1 depletion. GSM706669-GSM706671: We used GST pull-down followed by deep sequencing to map the DNA bound by the Tet1 CXXC domain in vitro. We made two mutants that have a single point mutation (Cys574 to Ala or Cys586 to Ala) in the core CXXC domain to ascertain the essential role of the CXXC domain in DNA binding by comparing the sequencing profile of DNA bound by wild type CXXC with the profiles of the CXXC mutants. GSM706672-GSM706673: Tet1 ChIP-seq was performed to identify the genome-wide distribution of Tet1 in mouse ES cells. GSM706674-GSM706679: We performed hydroxymethylated DNA immunoprecipitation (hMeDIP)-seq combined with a shRNA-mediated gene depletion strategy. To identify the loci specific 5hmC regulation by Tet1, we compared the 5hmC genome-wide distributions in control (Luc shRNA) and Tet1-depleted (Tet1 shRNA2863) mouse ES cells. GSM706680-GSM706682: To identify the gene regulation network by Tet1, we compared the gene expression profiles of control (scramble shRNA) and Tet1-depleted (Tet1 shRNA 2863 and Tet1 shRNA 3387) mouse ES cells determined by mRNA-seq.
2011-04-21 | E-GEOD-28532 | biostudies-arrayexpress
Project description:Through the analysis of mouse liver tumours promoted by distinct routes (DEN exposure alone, DEN exposure plus non-genotoxic insult with phenobarbital and non-alcoholic fatty liver disease); we report that the cancer associated hyper-methylated CGI events in mice are also predicated by silent promoters that are enriched for both the DNA modification 5-hydroxymethylcytosine (5hmC) and the histone modification H3K27me3 in normal liver. During cancer progression these CGIs undergo hypo-hydroxymethylation, prior to subsequent hyper-methylation; whilst retaining H3K27me3. A similar loss of promoter-core 5hmC is observed in Tet1 deficient mouse livers indicating that reduced Tet1 binding at CGIs may be responsible for the epigenetic dysregulation observed during hepatocarcinogenesis. Consistent with this reduced Tet1 protein levels are observed in mouse liver tumour lesions. As in human, DNA methylation changes at CGIs do not appear to be direct drivers of hepatocellular carcinoma progression in mice. Instead dynamic changes in H3K27me3 promoter deposition are strongly associated with tumour-specific activation and repression of transcription. Our data suggests that loss of promoter associated 5hmC in diverse liver tumours licences DNA methylation reprogramming at silent CGIs during cancer progression. We carry out 5-hydroxymethylation DNA immunoprecipitation (hmeDIP) prior to sequencing Ion Proton P1 to report on the genome-wide 5hmC patterns. Heterozygote pairs of Tet1 B6;129S4-Tet1tm1.1Jae/J mice were bought from The Jackson Laboratory (Maine USA). Heterozygotes were interbred to produce homozygous knock out males with colony mate wild type controls. Genome-wide 5hmC patterns were generated by hydroxymethyl-DNA immuoprecipitation (hmeDIP) followed by genome wide sequencing on the Ion Proton P1 sequencer.
2016-05-17 | E-GEOD-77730 | biostudies-arrayexpress
Project description:The TET family of FE(II) and 2-oxoglutarate-dependent enzymes (Tet1/2/3) promote DNA demethylation by converting 5-methylcytosine to 5-hydroxymethylcytosine (5hmC), which they further oxidize into 5-formylcytosine and 5-carboxylcytosine. Tet1 is robustly expressed in mouse embryonic stem cells (mESCs) and has been implicated in mESC maintenance. Here we demonstrate that, unlike genetic deletion, RNAi-mediated depletion of Tet1 in mESCs led to a significant reduction in 5hmC and loss of mESC identity. The differentiation phenotype due to Tet1 depletion positively correlated with the extent of 5hmC loss. Meta-analyses of genomic datasets suggested interaction between Tet1 and leukemia inhibitory factor (LIF) signaling. LIF signaling is known to promote self-renewal and pluripo-tency in mESCs partly by opposing MAPK/ERK mediated differentiation. Withdrawal of LIF leads to differentiation of mESCs. We discovered that Tet1 depletion impaired LIF-dependent Stat3-mediated gene activation by affecting Stat3's ability to bind to its target sites on chromatin. Nanog overexpression or inhibition of MAPK/ERK signaling, both known to maintain mESCs in the absence of LIF, rescued Tet1 depletion, further supporting the dependence of LIF/Stat3 signaling on Tet1. These data support the conclusion that analysis of mESCs in the hours/days immediately following efficient Tet1 depletion reveals Tet1’s normal physiological role in maintaining the pluripotent state that may be subject to homeostatic compensation in genetic models. Genome-wide mapping of 5hmC and microarray gene expression profiling in E14Tg2a mESCs after transfection with indicated siRNAs: Tet1 siRNA #1 (Invitrogen, MSS284895), Tet1 siRNA #2 (Invitrogen, MSS284897), and Control siRNA duplex targeting firefly luciferase.
2012-01-06 | E-GEOD-34887 | biostudies-arrayexpress
Project description:Neural progenitor cells (NPCs) undergo rapid proliferation during neurulation in early development. This rapid growth generates a high demand for mRNA translation in a timing-dependent manner, but its underlying mechanism and functional importance remain poorly understood. Lin28 is an RNA-binding protein with two paralogs, Lin28a and Lin28b, in mammals. Lin28b deletion exhibited no developmental defects in mice, while we previously reported that Lin28a deletion led to microcephaly. Here we found that Lin28a/b double knockout (dKO) mice displayed neural tube defects (NTDs) coupled with reduced proliferation and precocious differentiation of NPCs. We used ribosomal protein 24 hypomorphic mice (Rpl24Bst/+) as a genetic tool to dampen global protein synthesis. In support of the importance of Lin28-mediated translation promotion, Lin28a-/-;Rpl24Bst/+ compound mutants exhibited NTDs resembling those seen in Lin28a/b dKO mice. Furthermore, increased NPC numbers and brain sizes in Lin28a-overexpressing mice were rescued by Rpl24Bst/+ heterozygosity. Mechanistically, RNA-sequencing of polysome sucrose gradient fractions revealed a reduced translation of genes involved in the regulation of cell cycle, ribosome biogenesis, and translation in mutants. Lin28a localizes in the nucleoli of NPCs, and ribosome biogenesis was reduced in dKO and increased in Lin28a-overexpressing NPCs. Together, these results suggest that Lin28-mediated promotion of protein synthesis is essential for NPC maintenance and early brain development.
2019-05-22 | GSE131536 | GEO
Project description:The heterochronic genes Lin28a/b and let-7 are well-established regulators of invertebrate development, however their functions in patterning the mammalian body plan remain unexplored. In this study, we discovered a novel function of Lin28/let-7 in controlling caudal vertebrae number during body axis formation. We found that FoxD1-driven overexpression of Lin28a or LIN28B led to a striking increase in caudal vertebrae number, whereas loss of Lin28a stunted tail formation. Accordingly, perturbation of the let-7 microRNA family led to the opposite phenotypes. We further show that overexpressing Lin28a in embryos resulted in increased tail bud cell proliferation, whereas Lin28a KO decreased cellular proliferation. This was accompanied by a transcriptional shift, including down-regulation of the neural marker Sox2, and resulted in a pro-mesodermal phenotype with decreased proportions of neural tissue relative to mesoderm in Lin28a-overexpressing embryos. Strikingly, Lin28a KO and let-7 over-expression demonstrated opposite effects, suggesting that the Lin28/let-7 pathway acts upstream of the signaling pathways controlling the self-renewal and cell fate commitment of neuro-mesodermal progenitors. We propose that Lin28a/b activity controls the pool of caudal progenitors during tail development, promotes their self-renewal potential, is involved in controlling the balance of neural versus mesodermal cell fate decisions, and that progressive down-regulation of Lin28a allows for species-specific vertebral formula to be achieved. These findings suggest that Lin28/let-7 play a role in the regulation of tail length through heterochrony of the body plan.
2019-05-01 | GSE123193 | GEO