Distribution of macroH2A1 nucleosomes in mouse liver chromatin
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ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE18963 | GEO | 2010/11/10
SECONDARY ACCESSION(S): PRJNA121003
REPOSITORIES: GEO
Similar Datasets
Project description:We produced a genome-wide map of the distribution of macroH2A1 histone variants in mouse liver chromatin using high-throughput sequencing of DNA from macroH2A1 nucleosomes. Although macroH2A1 nucleosomes are widely distributed across the genome, their local concentration varies over a range of 100-fold or more. The transcribed regions of most active genes are depleted of macroH2A1, with many showing depletion of 3-fold or more. The inactive X chromosome appears to have relatively uniform macroH2A1 enrichment that averages approximately 3.9-fold, but most genes that are known to escape from X inactivation do not show this enrichment. We used macroH2A1 depletion to identify additional genes that escape X inactivation, but overall, our map supports the idea that relatively few genes escape in the mouse. The map also helped identify genes that appear to be direct targets of macroH2A1-mediated repression. MacroH2A1 nucleosomes were purified from female mouse liver chromatin by thiol-affinity chromatography (Mol. Cell Biol. 26, 4410 (2006)) and their distribution was compared to that of the bulk nucleosomes used as the starting material for the purification. Nucleosomal DNA from two independent preparations was pooled and mononucleosomal DNA was prepared from both macroH2A1 and starting material nucleosomes. Each preparation used 8 to 10 livers from 8 to 10 week old female mice. For the relative macroH2A1 content file (see supplementary file), we used tools in the rna-seq workflow of Partek Genomics Suite (version 6.5b, 6.09.0806, Partek Inc.) to calculate the relative macroH2A1 content of individual genes. This program counts and normalizes hits in predefined regions specified in a refFlat file. The gene list was the Mouse build 8 version of refFlat.txt obtained from the UCSC Genome site. All exon information was stripped from the refFlat.txt file, which left only the start and stop sites for the genes. Normalized RPKM (reads per kilobase per million reads) values were compared to calculate fold change and FDR-adjusted p-values for each transcript.
2010-11-10 | E-GEOD-18963 | biostudies-arrayexpress
Project description:MacroH2A1 is a histone variant that is enriched on the inactive X chromosome (Xi) in mammals and is postulated to play an important, but unknown, role in the repression of gene expression. Here we show that although macroH2A1 marks repressed autosomal chromatin, it positively regulates transcription when located in the transcribed regions of many target genes. We used chromatin immunoprecipitation coupled with tiling microarrays (ChIP-chip) to determine the genomic localization of macroH2A1 in IMR90 human primary lung fibroblasts and MCF-7 breast cancer cells. The patterns of macroH2A1 deposition are largely similar across the autosomes of both cell lines. Our studies revealed a genomic localization pattern unique among histone variants, namely the occupation by macroH2A1 of large chromatin domains (>500 kb in some cases) that contain repressive chromatin marks (e.g., histone H3 lysine 27 trimethylation). The boundaries of macroH2A1-containing domains tend to occur in promoter proximal regions. Not all promoters, however, serve as macroH2A1 boundaries; many macroH2A1-containing chromatin domains invade the transcribed regions of genes whose products play key roles in development and cell-cell signaling. Surprisingly, the expression of many of these genes is positively regulated by macroH2A1. MacroH2A1 also plays a role in augmenting signal-regulated transcription, specifically for genes responsive to serum starvation. Collectively, our results document an unexpected role for macroH2A1 in the escape from heterochromatin-associated silencing and the enhancement of autosomal gene transcription. Two macroH2A1 ChIP-chip biological replicates from IMR90 human embryonic lung fibroblasts are included.
2010-06-20 | E-GEOD-18633 | biostudies-arrayexpress
Project description:MacroH2A1 is a histone variant that is enriched on the inactive X chromosome (Xi) in mammals and is postulated to play an important, but unknown, role in the repression of gene expression. Here we show that although macroH2A1 marks repressed autosomal chromatin, it positively regulates transcription when located in the transcribed regions of many target genes. We used chromatin immunoprecipitation coupled with tiling microarrays (ChIP-chip) to determine the genomic localization of macroH2A1 in IMR90 human primary lung fibroblasts and MCF-7 breast cancer cells. The patterns of macroH2A1 deposition are largely similar across the autosomes of both cell lines. Our studies revealed a genomic localization pattern unique among histone variants, namely the occupation by macroH2A1 of large chromatin domains (>500 kb in some cases) that contain repressive chromatin marks (e.g., histone H3 lysine 27 trimethylation). The boundaries of macroH2A1-containing domains tend to occur in promoter proximal regions. Not all promoters, however, serve as macroH2A1 boundaries; many macroH2A1-containing chromatin domains invade the transcribed regions of genes whose products play key roles in development and cell-cell signaling. Surprisingly, the expression of many of these genes is positively regulated by macroH2A1. MacroH2A1 also plays a role in augmenting signal-regulated transcription, specifically for genes responsive to serum starvation. Collectively, our results document an unexpected role for macroH2A1 in the escape from heterochromatin-associated silencing and the enhancement of autosomal gene transcription.
2009-11-13 | GSE18633 | GEO
Project description:One of the most striking epigenetic alterations that occurs at the level of the nucleosome is the complete exchange of the canonical H2A histones for the macroH2A variant. Here, we provide insight in the function of this unique histone variant in embryonic and adult stem cells. Knockdown of macroH2A1 in mouse embryonic stem (mES) cells limited their capacity to differentiate but not their self-renewal. The loss of macroH2A1 interfered with the proper activation of differentiation genes, most of which are direct target genes of macroH2A. Additionally, macroH2A1-deficient mES cells displayed incomplete inactivation of pluripotency genes and formed defective embryoid bodies. In vivo, macroH2A1-deficient teratomas contained a massive expansion of malignant, undifferentiated carcinoma tissue. In the heterogeneous culture of primary human keratinocytes, macroH2A1 levels negatively correlated with the self-renewal capacity of the pluripotent compartment. Together these results establish macroH2A1 as a critical chromatin component that regulates the delicate balance between self-renewal and differentiation of embryonic and adult stem cells. Examination of the histone variant macroH2A1 in mouse Embryonic stem cells
2012-02-20 | E-GEOD-35087 | biostudies-arrayexpress
Project description:One of the most striking epigenetic alterations that occurs at the level of the nucleosome is the complete exchange of the canonical H2A histones for the macroH2A variant. Here, we provide insight in the function of this unique histone variant in embryonic and adult stem cells. Knockdown of macroH2A1 in mouse embryonic stem (mES) cells limited their capacity to differentiate but not their self-renewal. The loss of macroH2A1 interfered with the proper activation of differentiation genes, most of which are direct target genes of macroH2A. Additionally, macroH2A1-deficient mES cells displayed incomplete inactivation of pluripotency genes and formed defective embryoid bodies. In vivo, macroH2A1-deficient teratomas contained a massive expansion of malignant, undifferentiated carcinoma tissue. In the heterogeneous culture of primary human keratinocytes, macroH2A1 levels negatively correlated with the self-renewal capacity of the pluripotent compartment. Together these results establish macroH2A1 as a critical chromatin component that regulates the delicate balance between self-renewal and differentiation of embryonic and adult stem cells.
2012-02-20 | GSE35087 | GEO
Project description:The histone variant macroH2A1 and the poly(ADP-ribose) polymerase PARP-1 both regulate gene transcription by modulating chromatin structure and function. Of the two macroH2A1 splice variants, macroH2A1.1 and macroH2A1.2, the former is often suppressed in cancer and has the unique ability to interact with poly(ADP-ribose). Using ChIP-seq in primary lung fibroblasts, we demonstrate that macroH2A1 is incorporated into either of two spatially and functionally distinct types of chromatin; the first is marked by H3 K27 trimethylation, while the second contains a set of nine histone acetylations. MacroH2A1-regulated genes are involved in cancer progression are specifically found in macroH2A1-containing acetylated chromatin. Through the recruitment of PARP-1, macroH2A1.1 promotes the acetylation of H2B K12 and K120 which plays a key role in the regulation of macroH2A1 target genes in primary cells. The macroH2A1/PARP-1 pathway regulating H2B K12 and K120 acetylation is disrupted in cancer cells, in part, explaining macroH2A1’s role in cancer suppression.
2014-09-15 | GSE54845 | GEO
Project description:The histone variant macroH2A1 and the poly(ADP-ribose) polymerase PARP-1 both regulate gene transcription by modulating chromatin structure and function. Of the two macroH2A1 splice variants, macroH2A1.1 and macroH2A1.2, the former is often suppressed in cancer and has the unique ability to interact with poly(ADP-ribose). Using ChIP-seq in primary lung fibroblasts, we demonstrate that macroH2A1 is incorporated into either of two spatially and functionally distinct types of chromatin; the first is marked by H3 K27 trimethylation, while the second contains a set of nine histone acetylations. MacroH2A1-regulated genes are involved in cancer progression are specifically found in macroH2A1-containing acetylated chromatin. Through the recruitment of PARP-1, macroH2A1.1 promotes the acetylation of H2B K12 and K120 which plays a key role in the regulation of macroH2A1 target genes in primary cells. The macroH2A1/PARP-1 pathway regulating H2B K12 and K120 acetylation is disrupted in cancer cells, in part, explaining macroH2A1M-bM-^@M-^Ys role in cancer suppression. Two biological replicates of the macroH2A1 ChIP and two corresponding input samples were sequenced
2014-09-15 | E-GEOD-54845 | biostudies-arrayexpress
Project description:Oncogene induced senescence (OIS) is a tumor suppressive mechanism typified by stable proliferative arrest, a persistent DNA damage response and the senescent-associated secretory phenotype (SASP). MacroH2A1, a tumor suppressive histone variant, is upregulated during OIS. Using ChIP-seq, we found that macroH2A1 undergoes dramatic relocalization during OIS. SASP genes are enriched in macroH2A1-containing chromatin and macroH2A1 is a critical component of the positive feedback loop that maintains SASP expression. Endoplasmic reticulum (ER) stress, a feature of OIS that requires macroH2A1, leads to ATM activation. ER stress triggers a negative feedback loop reducing SASP expression by causing the ATM-dependent removal of macroH2A1 from SASP genes. MacroH2A1 represents a critical control point in the regulation of SASP expression during OIS by We demonstrate that SASP gene expression is regulated by the combined actions of a positive feedback loop that requires macroH2A1 and a negative feedback loop where ER stress leads to ATM activation critical for the removal of macroH2A1 from SASP genes and consequently their repression.
2015-08-19 | GSE64601 | GEO
Project description:The histone variant macroH2A1 and the poly(ADP-ribose) polymerase PARP-1 both regulate gene transcription by modulating chromatin structure and function. Of the two macroH2A1 splice variants, macroH2A1.1 and macroH2A1.2, the former is often suppressed in cancer and has the unique ability to interact with poly(ADP-ribose). Using ChIP-seq in primary lung fibroblasts, we demonstrate that macroH2A1 is incorporated into either of two spatially and functionally distinct types of chromatin; the first is marked by H3 K27 trimethylation, while the second contains a set of nine histone acetylations. MacroH2A1-regulated genes are involved in cancer progression are specifically found in macroH2A1-containing acetylated chromatin. Through the recruitment of PARP-1, macroH2A1.1 promotes the acetylation of H2B K12 and K120 which plays a key role in the regulation of macroH2A1 target genes in primary cells. The macroH2A1/PARP-1 pathway regulating H2B K12 and K120 acetylation is disrupted in cancer cells, in part, explaining macroH2A1’s role in cancer suppression.
2014-09-15 | GSE54846 | GEO
Project description:The histone variant macroH2A1 and the poly(ADP-ribose) polymerase PARP-1 both regulate gene transcription by modulating chromatin structure and function. Of the two macroH2A1 splice variants, macroH2A1.1 and macroH2A1.2, the former is often suppressed in cancer and has the unique ability to interact with poly(ADP-ribose). Using ChIP-seq in primary lung fibroblasts, we demonstrate that macroH2A1 is incorporated into either of two spatially and functionally distinct types of chromatin; the first is marked by H3 K27 trimethylation, while the second contains a set of nine histone acetylations. MacroH2A1-regulated genes are involved in cancer progression are specifically found in macroH2A1-containing acetylated chromatin. Through the recruitment of PARP-1, macroH2A1.1 promotes the acetylation of H2B K12 and K120 which plays a key role in the regulation of macroH2A1 target genes in primary cells. The macroH2A1/PARP-1 pathway regulating H2B K12 and K120 acetylation is disrupted in cancer cells, in part, explaining macroH2A1’s role in cancer suppression. Three biological replicates of RNA-seq from cells expressing shRNA directed against macroH2A1 or luciferase as a control
2014-09-15 | E-GEOD-54846 | biostudies-arrayexpress