Epigenetic control of Topoisomerase 1 by macroH2A1.1
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PROVIDER: PRJNA1143591 | ENA |
REPOSITORIES: ENA
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Project description:Epigenetic control of Topoisomerase 1 by macroH2A1.1
| PRJNA1143592 | ENA
Project description:The macro domain of the histone variant macroH2A1.1 is an evolutionary conserved ADP ribose-binding module of unknown physiological function. We demonstrate that during myogenic differentiation alternative splicing switches the expression of macroH2A1 from the non-ADP ribose binding to the binding isoform. While differentiation commitment is normal in cells lacking macroH2A1.1, we observe two phenotypes: diminished cell fusion correlating with reduced expression of adhesion and migration genes and reduced mitochondrial capacity. While the integrity of the ADP ribose-binding pocket is dispensable for gene regulation and fusion, it is critical to sustain optimal mitochondrial fatty acid oxidation. Rescue experiments using a pharmacological PARP-1 inhibitor and metabolomics support the idea that loss of macroH2A1.1 leads to PARP-1 activation and accelerated NAD+ consumption. As a consequence, the level of nicotinamide mononucleotide, the key metabolite for mitochondrial NAD+ pool regeneration, is reduced and sirtuins fail to maintain mitochondrial proteins in their hypoacetylated and active form. Our results support the idea that chromatin states containing the histone variant macroH2A1.1 contribute to optimal mitochondrial oxidative capacity by channeling the consumption of NAD+ from the nucleus to mitochondria in a manner largely independent on transcriptional regulation.
2017-08-18 | GSE78256 | GEO
Project description:The histone variant macroH2A1.1 plays a role in cancer development and metastasis. To determine the underlying molecular mechanisms, we mapped the genome-wide localization of endogenous macroH2A1.1 in the human breast cancer cell line MDA-MB 231. We demonstrate that macroH2A1.1 specifically binds to active promoters and enhancers in addition to facultative heterochromatin. Selective knock-down of macroH2A1.1 deregulates expression of hundreds of highly active genes. Depending on the chromatin landscape, macroH2A1.1 acts through two distinct molecular mechanisms. The first mitigates excessive transcription by binding over domains including the promoter and the gene body. The second stimulates expression of RNA Polymerase II (Pol II) paused genes, including genes regulating mammary tumor cell migration. In contrast to the first one, macroH2A1.1 specifically associates with the TSS of Pol II paused genes. These processes occur in a predefined local 3D genome organization but do not require rewiring of enhancer-promoter contacts. We thus propose that macroH2A1.1 serves as a transcriptional modulator with a potential role in assisting the conversion of promoter-locked into a productive and elongating Pol II.
2022-03-31 | GSE140022 | GEO
Project description:The macro domain of the histone variant macroH2A1.1 is an evolutionary conserved ADP ribose-binding module of unknown physiological function. We demonstrate that during myogenic differentiation alternative splicing switches the expression of macroH2A1 from the non-ADP ribose binding to the binding isoform. While differentiation commitment is normal in cells lacking macroH2A1.1, we observe two phenotypes: diminished cell fusion correlating with reduced expression of adhesion and migration genes and reduced mitochondrial capacity. While the integrity of the ADP ribose-binding pocket is dispensable for gene regulation and fusion, it is critical to sustain optimal mitochondrial fatty acid oxidation. Rescue experiments using a pharmacological PARP-1 inhibitor and metabolomics support the idea that loss of macroH2A1.1 leads to PARP-1 activation and accelerated NAD+ consumption. As a consequence, the level of nicotinamide mononucleotide, the key metabolite for mitochondrial NAD+ pool regeneration, is reduced and sirtuins fail to maintain mitochondrial proteins in their hypoacetylated and active form. Our results support the idea that chromatin states containing the histone variant macroH2A1.1 contribute to optimal mitochondrial oxidative capacity by channeling the consumption of NAD+ from the nucleus to mitochondria in a manner largely independent on transcriptional regulation.
2017-08-18 | GSE70015 | GEO
Project description:Sirtuins are key players in the response to oxidative, metabolic and genotoxic stress, and are involved in genome stability, metabolic homeostasis and aging. Originally described as NAD+-dependent deacetylases, some sirtuins are also characterized by poorly understood mono-ADP-ribosyltransferase (MADPRT) activity. Here we report that the deacetylase SirT7 is a dual sirtuin as it also features auto-MADPRT activity. Molecular and structural evidence suggests that this novel activity occurs at a second previously undefined active site that is physically separated in another domain. Specific abrogation of this activity alters SirT7 chromatin distribution, suggesting a role for this modification in SirT7 chromatin binding specificity and localization. Our studies uncover an epigenetic pathway by which ADP-ribosyl-SirT7 is recognized by the ADP-ribose reader macroH2A1.1, a histone variant involved in chromatin organization, metabolism and differentiation. Glucose starvation (GS) boosts this interaction and promotes SirT7 re-localization intergenic regions in a macroH2A1-dependent manner, which is required for specific up- or downregulation of a subset of nearby genes upon GS in primary cells and in vivo in the livers of calorie-restricted (CR) Wt and SirT7-/- mice. The level of expression of these genes decreases with age in SirT7-deficient mice, reinforcing the link between Sirtuins, CR and aging. Our work provides a novel perspective about sirtuin duality and suggests a key role for SirT7/macroH2A1.1 axis in mammalian glucose homeostasis, calorie restriction signaling and aging.
2019-08-07 | GSE128487 | GEO
Project description:Eukaryotic topoisomerase I and II relax DNA and are key components in the processes of DNA replication, transcription and genome stability. It is not clear, however, how their activity controls epigenetic states across an entire eukaryotic genome. Using the fission yeast model Schizosaccharomyces pombe, we investigate genome-wide how topoisomerases affect chromatin formation through nucleosome occupancy and regulate transcription. We show that topoisomerase activity is required for nucleosome turnover at promoter regions, affecting epigenetic gene regulatory states, and for effective termination of transcription.
2010-07-02 | E-MEXP-1850 | biostudies-arrayexpress
Project description:Sirtuins are key players in the response to oxidative, metabolic and genotoxic stress, and are involved in genome stability, metabolic homeostasis and aging. Originally described as NAD+-dependent deacetylases, some sirtuins are also characterized by poorly understood mono-ADP-ribosyltransferase (MADPRT) activity. Here we report that the deacetylase SirT7 is a dual sirtuin as it also features auto-MADPRT activity. Molecular and structural evidence suggests that this novel activity occurs at a second previously undefined active site that is physically separated in another domain. Specific abrogation of this activity alters SirT7 chromatin distribution, suggesting a role for this modification in SirT7 chromatin binding specificity and localization. Our studies uncover an epigenetic pathway by which ADP-ribosyl-SirT7 is recognized by the ADP-ribose reader macroH2A1.1, a histone variant involved in chromatin organization, metabolism and differentiation. Glucose starvation (GS) boosts this interaction and promotes SirT7 re-localization intergenic regions in a macroH2A1-dependent manner, which is required for specific up- or downregulation of a subset of nearby genes upon GS in primary cells and in vivo in the livers of calorie-restricted (CR) Wt and SirT7-/- mice. The level of expression of these genes decreases with age in SirT7-deficient mice, reinforcing the link between Sirtuins, CR and aging. Our work provides a novel perspective about sirtuin duality and suggests a key role for SirT7/macroH2A1.1 axis in mammalian glucose homeostasis, calorie restriction signaling and aging.
2019-08-07 | GSE128893 | GEO
Project description:Here we used RNA-Seq to gain deep mechanistic insight into the effects of macroH2A1 splicing isoforms macroH2A1.1 and macroH2A1.2 on Human Umbelical Vein Endothelial Cells (HUVEC) undergoing cell reprogramming. The process was triggered using an episome construct carrying the reprogramming factors Oct4, Sox2, Klf4, L-Myc and Lin28. RNA-seq analysis was performed on the fourth day of the reprogramming process, to investigate the role. Heatmap anlysis of top 44 differently expressed genes (DEG) revealed that macroH2A1.1, but not macroH2A1.2,increased the expression of genes involved in DNA repair response (DDR) and cell reprogramming in HUVEC. Genes exhibiting absolute fold-change values >2 and p-values <0.05 were considered differentially expressed between contrasts. Statistical differences in gene expression were assessed by the ANOVA test. Correction for multiple test was achieved by the Benjamini-Hochberg procedure. The significance threshold was set to 0.05. Ingenuity pathway analysis (IPA) identified differences in evaluating top 44 DEG involved in DDR and top 12 DEG involved in cell reprogramming showed that macroH2A1.1 verexpression enhances several pathways involved in DNa repair and acquisition of cell pluripotency.
2021-01-08 | GSE164396 | GEO
Project description:Both transcription and replication can take place simultaneously on the same DNA template, potentially leading to transcription-replication conflicts (TRCs) and topological problems. Here we asked which topoisomerase(s) is/are the best candidate(s) for sensing TRC. Genome-wide topoisomerase binding sites were mapped in parallel for all the nuclear topoisomerases (TOP1, TOP2A, TOP2B, TOP3A and TOP3B). To increase the signal to noise ratio (SNR), we used ectopic expression of those topoisomerases in H293 cells followed by a modified CUT&Tag method. Although each topoisomerase showed distinct binding patterns, all topoisomerase binding signals positively correlated with gene transcription. TOP3A binding signals were suppressed by DNA replication inhibition. This was also observed but to a lesser extent for TOP2A and TOP2B. Hence, we propose the involvement of TOP3A in sensing both head-on TRCs (HO-TRCs) and codirectional TRCs (CD-TRCs). In which case, the TOP3A signals appear concentrated within the promoters and first 20 kb regions of the 5’ -end of genes, suggesting the prevalence of TRCs and the recruitment of TOP3A in the 5’-regions of transcribed and replicated genes.
2024-07-31 | GSE269841 | GEO
Project description:SirT7 auto-ADPribosylation regulates glucose starvation response through macroH2A1.1
| PRJNA529221 | ENA