Evidence that direct inhibition of transcription factor binding is the prevailing mode of gene and repeat repression by DNA methylation [ChIP-Seq]
Ontology highlight
ABSTRACT: Cytosine methylation efficiently silences CpG-rich regulatory regions of genes and repeats in mammalian genomes. To what extent this entails direct inhibition of transcription factor (TF) binding versus indirect inhibition via recruitment of Methyl-CpG Binding Domain (MBD) proteins is unclear. Here we show that combinatorial genetic deletions of all four proteins with functional MBDs in mouse stem cells, derived neurons or a human cell line does not reactivate genes or repeats with methylated promoters. These do however become activated by methylation-restricted TFs if DNA methylation is removed. We identify several causal TFs in neurons, including ONECUT1, which is methylation-sensitive only at a motif variant. Rampantly upregulated retrotransposons in methylation-free neurons feature a CRE motif, which activates them in absence of DNA methylation via methylation-sensitive binding of CREB1. Our study reveals methylation-sensitive TFs in vivo and argues that direct inhibition, rather than indirect repression by the tested MBD proteins, is the prevailing mechanism of methylation-mediated repression at regulatory regions and repeats.
Project description:Cytosine methylation efficiently silences CpG-rich regulatory regions of genes and repeats in mammalian genomes. To what extent this entails direct inhibition of transcription factor (TF) binding versus indirect inhibition via recruitment of Methyl-CpG Binding Domain (MBD) proteins is unclear. Here we show that combinatorial genetic deletions of all four proteins with functional MBDs in mouse stem cells, derived neurons or a human cell line does not reactivate genes or repeats with methylated promoters. These do however become activated by methylation-restricted TFs if DNA methylation is removed. We identify several causal TFs in neurons, including ONECUT1, which is methylation-sensitive only at a motif variant. Rampantly upregulated retrotransposons in methylation-free neurons feature a CRE motif, which activates them in absence of DNA methylation via methylation-sensitive binding of CREB1. Our study reveals methylation-sensitive TFs in vivo and argues that direct inhibition, rather than indirect repression by the tested MBD proteins, is the prevailing mechanism of methylation-mediated repression at regulatory regions and repeats.
Project description:Cytosine methylation efficiently silences CpG-rich regulatory regions of genes and repeats in mammalian genomes. To what extent this entails direct inhibition of transcription factor (TF) binding versus indirect inhibition via recruitment of Methyl-CpG Binding Domain (MBD) proteins is unclear. Here we show that combinatorial genetic deletions of all four proteins with functional MBDs in mouse stem cells, derived neurons or a human cell line does not reactivate genes or repeats with methylated promoters. These do however become activated by methylation-restricted TFs if DNA methylation is removed. We identify several causal TFs in neurons, including ONECUT1, which is methylation-sensitive only at a motif variant. Rampantly upregulated retrotransposons in methylation-free neurons feature a CRE motif, which activates them in absence of DNA methylation via methylation-sensitive binding of CREB1. Our study reveals methylation-sensitive TFs in vivo and argues that direct inhibition, rather than indirect repression by the tested MBD proteins, is the prevailing mechanism of methylation-mediated repression at regulatory regions and repeats.
Project description:Cytosine methylation efficiently silences CpG-rich regulatory regions of genes and repeats in mammalian genomes. To what extent this entails direct inhibition of transcription factor (TF) binding versus indirect inhibition via recruitment of Methyl-CpG Binding Domain (MBD) proteins is unclear. Here we show that combinatorial genetic deletions of all four proteins with functional MBDs in mouse stem cells, derived neurons or a human cell line does not reactivate genes or repeats with methylated promoters. These do however become activated by methylation-restricted TFs if DNA methylation is removed. We identify several causal TFs in neurons, including ONECUT1, which is methylation-sensitive only at a motif variant. Rampantly upregulated retrotransposons in methylation-free neurons feature a CRE motif, which activates them in absence of DNA methylation via methylation-sensitive binding of CREB1. Our study reveals methylation-sensitive TFs in vivo and argues that direct inhibition, rather than indirect repression by the tested MBD proteins, is the prevailing mechanism of methylation-mediated repression at regulatory regions and repeats.
Project description:The repressive capacity of cytosine DNA methylation is mediated by recruitment of silencing complexes by methyl-CpG binding domain (MBD) proteins. Unexpectedly, we discovered that a family of arthropod Copia retrotransposons have incorporated a host-derived MBD domain. We functionally demonstrate how retrotransposon encoded MBDs preferentially bind to CpG-dense methylated regions, which correspond to transposable element regions of the host genome, in the myriapod Strigamia maritima. Consistently, young MBD-encoding Copia retrotransposons (CopiaMBD) accumulate in regions with higher CpG-densities than other LTR-retrotransposons also present in the genome. This would suggest that retrotransposons use MBDs to integrate into heterochromatic regions in Strigamia, avoiding potentially harmful insertions into host genes. In contrast, CopiaMBD insertions in the spider Stegodyphus dumicola genome disproportionately accumulate in methylated gene bodies when compared to other spider LTR-retrotransposons. Given that transposons are not actively targeted by DNA methylation in the spider genome, this distribution bias would also support a role for MBDs in the integration process. Together, these data demonstrate that retrotransposons can co-opt host-derived epigenome readers, potentially harnessing the host epigenome landscape to advantageously tune the retrotransposition process.
Project description:We report the application of methyl-binding protein sequencing (MBD-seq) to global identify aberrant methylation between cisplatin sensitive and resistant ovarian cancer cell lines Detection of aberrant methylation states between cisplatin sensitive and resistant cell lines
Project description:We report the application of methyl-binding protein sequencing (MBD-seq) to global identify aberrant methylation between cisplatin sensitive and resistant ovarian cancer cell lines
Project description:In order to gain insight into DNA methylation readout, we have established a controlled strategy for profiling genomic targeting of chromatin-interacting factors in vivo. With this approach we determined binding preferences for the methyl-CpG binding domain (MBD) family of proteins, including disease relevant mutants, deletions and isoforms. In vivo binding of MBD proteins occurs as a linear function of local methylation density, and is dependent on functional MBD domain M-bM-^@M-^S methyl-CpG interactions. This directs specificity of MBD proteins to methylated, CpG dense and inactive regulatory regions. In contrast, binding to unmethylated sites is MBD protein specific and mediated via alternative domains or protein-protein interactions. The latter is observed for NuRD complex-mediated MBD2 tethering to a subset of unmethylated, tissue-specific regulatory regions, similar to MBD3. These functional binding maps reveal methylation-dependent and -independent binding modes determined by distinct protein domains and revise current models of DNA methylation readout through MBD proteins. Comparative binding analysis for the MBD family of proteins utilizing recombinase-assisted mapping of biotin-tagged proteins (RAMBiO). This set contains maps for 29 samples including wild type MBD proteins, mutants and domain variants in mouse ES cells, derived neurons (NP and TN) and Dnmt1/3a/3b triple-KO ES cells (TKO).
Project description:We assayed 114 human transcription factors (TFs) for DNA binding using methylation-sensitive selective microfluidics-based ligand enrichment followed by sequencing (meSMiLE-seq). Across 23 experiments, we identified DNA binding sites for 48 TFs. Among these, 13 showed aversion towards methylated DNA, while 11 exhibited either a preference for methylated DNA or an alternative binding site including the modification. The DNA binding for the remaining TFs was unaffected by DNA methylation under the conditions of the assay.
Project description:In order to gain insight into DNA methylation readout, we have established a controlled strategy for profiling genomic targeting of chromatin-interacting factors in vivo. With this approach we determined binding preferences for the methyl-CpG binding domain (MBD) family of proteins, including disease relevant mutants, deletions and isoforms. In vivo binding of MBD proteins occurs as a linear function of local methylation density, and is dependent on functional MBD domain – methyl-CpG interactions. This directs specificity of MBD proteins to methylated, CpG dense and inactive regulatory regions. In contrast, binding to unmethylated sites is MBD protein specific and mediated via alternative domains or protein-protein interactions. The latter is observed for NuRD complex-mediated MBD2 tethering to a subset of unmethylated, tissue-specific regulatory regions, similar to MBD3. These functional binding maps reveal methylation-dependent and -independent binding modes determined by distinct protein domains and revise current models of DNA methylation readout through MBD proteins.
Project description:Homeotherms maintain a stable internal body temperature despite changing environments. During energy deficiency, some species can cease to defend their body temperature and enter a hypothermic and hypometabolic state known as torpor. Despite recent advances in our understanding of thermoregulation, the precise neurons that coordinate these profound thermoregulatory and metabolic changes remain largely unknown. Here, we demonstrate that estrogen-sensitive neurons in the medial preoptic area (MPA) are key drivers of hypothermia and hypometabolism in mice. We find that selectively activating estrogen-sensitive MPA neurons was sufficient to drive a coordinated depression of metabolic rate and body temperature similar to torpor, as measured by body temperature, physical activity, indirect calorimetry, heart rate, and brain activity. Inducing torpor with a prolonged fast revealed larger and more variable calcium transients from estrogen-sensitive MPA neurons during bouts of hypothermia. Finally, selective ablation of estrogen-sensitive MPA neurons demonstrated that these neurons are required for the full expression of fasting-induced torpor. Together, these findings suggest a role for estrogen-sensitive MPA neurons in directing the thermoregulatory and metabolic responses to energy deficiency.