Dot1L recruits OGT target chromatin to regulate histones O-GlcNAcylation
Ontology highlight
ABSTRACT: OGT (O-GlcNAc transferase) is the distinctive enzyme responsible for catalyzing O-GlcNAc to the serine or threonine residues of thousands of cytoplasm and nuclear proteins that are involved in DNA damage, RNA splicing, and transcription preinitiation and initiation complex assembly. However, the molecular mechanism by OGT regulating gene transcription remains elusive. Using proximity labeling based mass spectrometry, we searched for functional partners of OGT and found that Dot1L, the conserved and unique histone methyltransferase mediated histone H3 lys79 methylation required for gene transcription, DNA damage repair, cell proliferation, and embryo development, interacts with OGT. Although this specific interaction does not regulate the enzymatic activity of Dot1L, it facilitates OGT-dependent histones O-GlcNAcylation. Moreover, OGT associates with Dot1L at transcription start sites, and depleting Dot1L decreased OGT associated with chromatin globally. Notably, downregulation of Dot1L reduces the levels of histone H2B S112 O-GlcNAcylation and histone H2B K120 ubiquitination in vivo, which are associated with gene transcription regulation. Taken together, these results reveal a Dot1L-dependent O-GlcNAcylation of chromatin.
Project description:We report that histone GlcNAcylation of H2B S112 is a vital histone modification which facilitates histone monoubiquitination (ub). In a genome-wide analysis, H2B S112 GlcNAcylation sites were observed widely distributed over entire chromosomes including transcribed gene loci, together with co-localization of H2B S112 GlcNAcylation and K120 ub. Examination of H2B S112 GlcNAc and H2B K120 ub in HeLa S3 cells
Project description:We have found that histone H2B is GlcNAcylated at residue S112 by O-GlcNAc transferase and that H2B S112 GlcNAcylation fluctuates in response to extracellular glucose level. We have also found that H2B S112 GlcAcylation promotes H2B K120 ubiquitination. To investigate whether these histone modification correlate to transcriptional activation, we performed comprehensive gene expression analysis using Affymetrix GeneChip in HeLa cell cultured with different conditions, i.e. without glucose, with glucose and with FBS.
Project description:We report that histone GlcNAcylation of H2B S112 is a vital histone modification which facilitates histone monoubiquitination (ub). In a genome-wide analysis, H2B S112 GlcNAcylation sites were observed widely distributed over entire chromosomes including transcribed gene loci, together with co-localization of H2B S112 GlcNAcylation and K120 ub.
Project description:TET2 directly interacts with OGT, which is important for the chromatin association of OGT in vivo. Although this specific interaction does not regulate the enzymatic activity of TET2, it facilitates OGT-dependent histone O-GlcNAcylation. Moreover, OGT associates with TET2 at transcription starting sites (TSS). Down-regulation of TET2 reduces the amount of H2B S112 GlcNAc marks in vivo, which are associated with gene transcription regulation. We found that OGT interacts with TET2 tightly. Using ChIP-seq with specific antibodies, we tested the co-localization of TET2 and OGT in genome level.
Project description:TET2 directly interacts with OGT, which is important for the chromatin association of OGT in vivo. Although this specific interaction does not regulate the enzymatic activity of TET2, it facilitates OGT-dependent histone O-GlcNAcylation. Moreover, OGT associates with TET2 at transcription starting sites (TSS). Down-regulation of TET2 reduces the amount of H2B S112 GlcNAc marks in vivo, which are associated with gene transcription regulation.
Project description:TET2 directly interacts with OGT, which is important for the chromatin association of OGT in vivo. Although this specific interaction does not regulate the enzymatic activity of TET2, it facilitates OGT-dependent histone O-GlcNAcylation. Moreover, OGT associates with TET2 at transcription starting sites (TSS). Down-regulation of TET2 reduces the amount of H2B S112 GlcNAc marks in vivo, which are associated with gene transcription regulation. We used microarray to test the function of TET2 on gene expression. Mouse ES cells infected with control knockdown(KD) or TET2 KD virus were treated with puromycin. ES cells were extracted for RNA and hybridization on Affymetrix microarrays.
Project description:TET2 directly interacts with OGT, which is important for the chromatin association of OGT in vivo. Although this specific interaction does not regulate the enzymatic activity of TET2, it facilitates OGT-dependent histone O-GlcNAcylation. Moreover, OGT associates with TET2 at transcription starting sites (TSS). Down-regulation of TET2 reduces the amount of H2B S112 GlcNAc marks in vivo, which are associated with gene transcription regulation. We used microarray to test the function of TET2 on gene expression.
Project description:We have found that histone H2B is GlcNAcylated at residue S112 by O-GlcNAc transferase and that H2B S112 GlcNAcylation fluctuates in response to extracellular glucose level. We have also found that H2B S112 GlcAcylation promotes H2B K120 ubiquitination. To investigate whether these histone modification correlate to transcriptional activation, we performed comprehensive gene expression analysis using Affymetrix GeneChip in HeLa cell cultured with different conditions, i.e. without glucose, with glucose and with FBS. HeLa cells were cultured in DMEM with the following three conditions, 1) DMEM without glucose for 24 hours, 2) DMEM without glucose for 24 hours and followed by treatment with 4.5 g/L glucose for another 24 hours, 3) normal culture condition (DMEM with FBS). Total RNA was purified from these cells and each RNA was linearly amplified and hybridized to Affymetrix GeneChip.
Project description:TET proteins convert 5-methylcytosine to 5-hydroxymethylcytosine, an emerging dynamic epigenetic state of DNA that can influence transcription. Evidence has linked TET1 function to epigenetic repression complexes, yet mechanistic information, especially for the TET2 and TET3 proteins, remains limited. Here, we show a direct interaction of TET2 and TET3 with O-GlcNAc transferase (OGT). OGT does not appear to influence hmC activity, rather TET2 and TET3 promote OGT activity. TET2/3-OGT co-localize on chromatin at active promoters enriched for H3K4me3 and reduction of either TET2/3 or OGT activity results in a direct decrease in H3K4me3 and concomitant decreased transcription. Further, we show that Host Cell Factor 1 (HCF1), a component of the H3K4 methyltransferase SET1/COMPASS complex, is a specific GlcNAcylation target of TET2/3-OGT, and modification of HCF1 is important for the integrity of SET1/COMPASS. Additionally, we find both TET proteins and OGT activity promote binding of the SET1/COMPASS H3K4 methyltransferase, SETD1A, to chromatin. Finally, studies in Tet2 knockout mouse bone marrow tissue extend and support the data as decreases are observed of global GlcNAcylation and also of H3K4me3, notably at several key regulators of haematopoiesis. Together, our results unveil a step-wise model, involving TET-OGT interactions, promotion of GlcNAcylation, and influence on H3K4me3 via SET1/COMPASS, highlighting a novel means by which TETs may induce transcriptional activation. ChIP-Seq experiments were performed on Illumina HiScanSQ sequencer in wild-type HEK293T cells for H3K4me3 histone marks, O-GlcNAc and HCF1, for HT-TET2, HT-TET3 and HT-OGT in HEK293T cells overexpressing those three fusion proteins and in TET2 Kd HEK293T cells for H3K4me3 histone marks. ChIP-Seqs were also performed in mouse bone marrow tissues for H3K4me3 histone marks, O-GlcNAc, endogenous Tet2 and in Tet2 Ko bone marrow tissues for H3K4me3 histone marks.
Project description:O-GlcNAcylation is the modification of serine and threonine residues with beta-N-acetylglucosamine (O-GlcNAc) on intracellular proteins. To investigate the role of protein O-GlcNAcylation on intestinal homeostasis, we generated intestinal epithelial cell (IEC)-specific O-GlcNAc transferase (OGT) knockout in mice. The KO mice developed spontanous intestinal inflammation. To determine the underlying molecular mechanisms, we performed RNA sequencing of ileum and colon epithelial cells of wildtype and IEC-OGT KO mice.