Coupling p53 binding and nucleosome occupancy measurements at p53 binding sites
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE22783 | GEO | 2010/08/09
SECONDARY ACCESSION(S): PRJNA129117
REPOSITORIES: GEO
Similar Datasets
Project description:We were interested to explain why p53 binds some high affinity sites in contrast to other high affinity sites that are not bound by p53. p53 binding was measured using p53 ChIP-CHIP and in parallel nucleosome occupancy was measured on these same sites Comparison between p53 binding and nucleosome occupancy at p53 predicted binding sites ChIP-CHIP of p53 from MCF7EcoR under Basal conditions and MCF7EcoR treated with NCS (Activated) and Mononucleosomal extraction from MCF7sip53, MCF7EcoR under Basal conditions and MCF7EcoR treated with NCS (Activated) Expression analysis of MCF7sip53 and MCF7EcoR treated with NCS (Activated)
2010-08-09 | E-GEOD-22783 | biostudies-arrayexpress
Project description:Coupling p53 binding and nucleosome occupancy measurements at p53 binding sites
| PRJNA129117 | ENA
Project description:We report the chromatin modification dynamics at p53 binding sites afte 6 hours of treatment of etoposide (100 micromolar final) in IMR90 human lung fibroblasts using ChIP-seq , ATAC-seq, and polyA+ RNA-seq analyses. We assessed the genomewide occupancy of histone H3, H3K4me3, H3K4me2, H3K4me1, H3K27ac, H4K16ac, RNA polymerase II, p53, and transposase-accessible chromatin (ATAC-seq) in response to etoposide treatment.
2018-06-19 | GSE115940 | GEO
Project description:CTCF binding sites serve as anchors for the 3D chromatin architecture in vertebrates. The functionality of these anchors is influenced by the residence time of CTCF on chromatin, which is determined by its binding affinity and its interactions with nucleosomes and other chromatin-associated factors. In this study, we demonstrate that CTCF occupancy is driven by CTCF motifs strategically positioned at the entry sites of well-positioned nucleosome, such that, upon binding, the N-terminus of CTCF is oriented towards the nucleosome. We refer to this nucleosome as the CTCF priming nucleosome (CpN). CTCF recognizes its binding sites as long as they are not methylated. It can then displace the CpN, provided the nucleosome is not marked by CpG methylation or repressive histone modifications. Under these permissive conditions, the N-terminus of CTCF recruits SMARCA5 to reposition the CpN downstream, thereby creating nucleosome-free regions that enhance CTCF occupancy and cohesin stalling. In contrast, when CpNs carry repressive epigenetic marks, CTCF binding is transient, without nucleosome displacement or chromatin opening. In such cases, cohesin is not effectively retained at CTCF binding sites. We propose that the epigenetic status of CpNs governs cell-specific CTCF binding patterns, ensuring the maintenance of chromatin architecture throughout the cell cycle.
2024-09-24 | GSE277826 | GEO
Project description:We accessed the cell type specificity of p53 by directly measuring DNA binding in twelve cell lines in response to ionizing radiation. We find that that vast majority of binding sites are occupied across all cells lines uniformly, in contrast to p53 regulated gene expression which shows great diversity in the same context. We further identify a subset of p53 binding sites that are more restricted, appearing in one or a few cell lines. We find that chromatin accessibility explains much of these differential binding events.
2018-06-20 | GSE100292 | GEO
Project description:We report here genome-wide analysis of the tumor suppressor p53 binding sites in normal human cells. 743 high-confidence ChIP-seq peaks representing putative genomic binding sites were identified in normal IMR90 fibroblasts using a reference chromatin sample. More than 40 % were located within 2 kb of a transcription start site (TSS), a distribution similar to that documented for individually studied functional p53 binding sites and to date not observed by previous genome-wide studies. Nearly half of the high-confidence binding sites in the IMR90 cells reside in CpG islands, in marked contrast to sites reported in cancer-derived cells. The distinct genomic features of the IMR90 binding sites do not reflect a distinct preference for specific sequences, since the de novo developed p53 motif based on our study is similar to those reported by genome-wide studies of cancer cells. More likely the different chromatin landscape in normal compared to cancer-derived cells influences p53 binding via modulating availability of the sites. We compared the IMR90 ChIP-seq peaks to the recently published IMR90 methylome1, and demonstrated that they are enriched at hypomethylated DNA. Our study represents the first genome-wide, de novo mapping of p53 binding sites in normal human cells and reveals that p53 binding sites reside in distinct genomic landscapes in normal and cancer-derived human cells. Identification of genomic p53 binding sites in normal human cells by ChIP-seq.
2011-12-08 | E-GEOD-31558 | biostudies-arrayexpress
Project description:We mapped the genomic binding sites of the tumor suppressor protein p53 in the human colorectal cancer cell line HCT116 and report here that the binding patterns of endogenous wild type p53 differed significantly between the genomes of the cancer cell line HCT116 and the normal human IMR90 fibroblasts (GSE31558) under the same experimental conditions (6 hr treatment with 5-fluorouracil). p53 binding differences affect promoter regions, CpG islands and major families of human repeat elements such as LTR, LINE and SINE. While p53 genomic binding sites residing in repeats have been reported before, we show here that the fraction of the p53 genomic binding sites residing in different repeat families differs between the normal and cancer human cell lines. We confirm that the p53 genomic binding sites in HCT116 cells are excluded from CpG islands, an observation we made previously based on analysis of data reported by others. While the p53 ability to elicit stress-specific and cell-type-specific responses is well documented, how this specificity is established, at the level of binding to the genome and/or during post-binding events, represents an open question. Our data indicate that p53 binding to the human genome is cell line-specific and highly selective. The differences in the p53 genome-wide binding patterns between the cancer cell line HCT116 and the normal cell line IMR90, namely exclusion from CpG islands and enrichment at repeats in HCT116, likely reflect cancer-associated epigenetic changes in the chromatin. Identification of genomic p53 binding sites in HCT116 cells by ChIP-seq.
2014-11-21 | E-GEOD-58714 | biostudies-arrayexpress
Project description:Telomeres and tumor suppressor protein TP53 (p53) function in genome protection, but a direct role of p53 at telomeres has not yet been described. Here, we have identified non-canonical p53 binding sites within the human subtelomeres that suppress the accumulation of DNA damage at telomeric repeat DNA. These non-canonical subtelomeric p53 binding sites conferred transcription enhancer-like functions that include an increase in local histone H3K9 and H3K27 acetylation and stimulation of subtelomeric transcripts, including telomere-repeat containing RNA (TERRA). p53 suppressed formation of telomere-associated γH2AX and prevented telomere DNA degradation in response to DNA damage stress. Our findings indicate that p53 provides a direct chromatin-associated protection to human telomeres, as well as other fragile genomic sites. We propose that p53-associated chromatin modifications enhance local DNA repair or protection to provide a previously unrecognized tumor suppressor function of p53. p53 binding was analyzed by ChIP-Seq in HCT116 cells treated with camptothecin or untreated control.
2016-01-07 | E-GEOD-75528 | biostudies-arrayexpress
Project description:We report that p53 knockdown changed AR-DNA binding across the genome. We found fewer AR-binding sites in the absence of p53. Examination of AR-DNA binding after p53 knockdown in LNCaP cells
2012-07-31 | E-GEOD-31294 | biostudies-arrayexpress
Project description:We report here genome-wide analysis of the tumor suppressor p53 binding sites in normal human cells. 743 high-confidence ChIP-seq peaks representing putative genomic binding sites were identified in normal IMR90 fibroblasts using a reference chromatin sample. More than 40 % were located within 2 kb of a transcription start site (TSS), a distribution similar to that documented for individually studied functional p53 binding sites and to date not observed by previous genome-wide studies. Nearly half of the high-confidence binding sites in the IMR90 cells reside in CpG islands, in marked contrast to sites reported in cancer-derived cells. The distinct genomic features of the IMR90 binding sites do not reflect a distinct preference for specific sequences, since the de novo developed p53 motif based on our study is similar to those reported by genome-wide studies of cancer cells. More likely the different chromatin landscape in normal compared to cancer-derived cells influences p53 binding via modulating availability of the sites. We compared the IMR90 ChIP-seq peaks to the recently published IMR90 methylome1, and demonstrated that they are enriched at hypomethylated DNA. Our study represents the first genome-wide, de novo mapping of p53 binding sites in normal human cells and reveals that p53 binding sites reside in distinct genomic landscapes in normal and cancer-derived human cells.
2011-12-08 | GSE31558 | GEO