DNA double-strand breaks and 3D chromatin conformation (ChIP-chip)
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
SUBMITTER: Vincent Rocher
PROVIDER: E-MTAB-8793 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
Similar Datasets
Project description:DNA Double Strand Breaks (DSBs) are harmful lesions that require rapid detection and repair in order to avoid toxic genomic rearrangements. DSBs elicit the so called DNA Damage Response (DDR), largely relying on ataxia telangiectasia mutated (ATM) and DNA Protein Kinase (DNAPK), two members of the PI3K-like kinase family, whose respective functions during the sequential steps of the DDR remains controversial. Using the DIvA cell line, expressing the AsiSI restriction enzyme, we have investigated the role of ATM and DNAPK in several aspects of the DDR upon induction of multiple clean DSBs throughout the human genome. High resolution mapping revealed that they are activated and spread in cis on a confined region surrounding all DSBs, independently of the pathway used for repair. However, a thorough analysis of repair kinetics, H2AX domain establishment and H2AX foci structure and dynamics revealed non overlapping functions for the two kinases once recruited at DSBs. Our results suggest that ATM is not solely acting on chromatin marks but also on chromatin organisation in order to ensure repair accuracy and survival.
2015-09-30 | E-MTAB-2992 | biostudies-arrayexpress
Project description:DNA Double-Strand Breaks (DSBs) are highly detrimental since they can lead to mutations and chromosomes rearrangements (amplification, deletion, translocation and chromosome loss). Here, we set to assess the tridimensional genome organization around DSBs and its role in DSB repair foci formation. We performed Hi-C experiments before and after DSB induction and upon ctrl or SCC1 depletion, 4C-seq experiments before and after DSB induction and upon cohesin (SCC1) depletion or ATM inhibition. We also performed ChIP-seq of pATM(S1981), CTCF, P-SMC3(S1083), MDC1 and a calibrated ChIP-seq of SCC1 with or without damage. ChIP-chip of SMC3 (S1083) and SMC1 (S966) were used to show the recruitment of these marks on DNA repair foci. ChIP-chip of gammaH2AX was realized upon SCC1 depletion and ChIP-seq of gammaH2AX was realized upon SCC1 or WAPL to show the role of the cohesin complex in gammaH2AX foci formation. ChIP-seq of gammaH2AX was realized upon ATM or ATR inhibition to show that ATM is the major kinase that phosphorylates H2AX at clean breaks in human cells.
2021-01-29 | E-MTAB-8851 | biostudies-arrayexpress
Project description:DNA Double Strand Breaks (DSBs) repair is essential to safeguard genome integrity but little is known about the contribution of chromosome folding into these processes. Here we unveiled basic principles of chromosome dynamics occurring post-DSB both locally and at a genome wide scale in mammalian cells. We report that topologically associating domains (TAD) that experience a DSB undergo acute ATM-dependent but DNAPK- independent changes. Within these damaged TADs, DSB-induced loop extrusion ensures local transcriptional regulation in response to DSBs. Damaged TADs further coalesce in an ATM-dependent manner, forming a new “D” compartment, where upregulated genes of the DNA damage response (DDR) physically localize suggesting a function of DSB clustering in activating the DNA damage Response. However, these alterations of chromosome folding induced by DSB also come at the expense of an increased translocations rate. Our work highlights the critical impact of chromosome conformation in the maintenance of genome integrity.
2023-11-17 | E-MTAB-10865 | biostudies-arrayexpress
Project description:DNA Double Strands Breaks (DSBs) are highly detrimental since they can lead to mutations and chromosomes rearrangements (amplification, deletion, translocation and chromosome loss). Here, we used in a standardized system, where multiples DSBs are induced at defined positions across the human genome (U2OS-DIvA cells), to describe the distribution of eighteen histone modifications before and after damage using ChIP-Seq. This provides a comprehensive picture of the chromatin landscape induced at DSBs.
2018-09-27 | E-MTAB-5817 | biostudies-arrayexpress
Project description:DNA Double Strands Breaks (DSBs) are highly detrimental since they can lead to mutations and chromosomes rearrangements (amplification, deletion, translocation and chromosome loss). Here, we set to assess the role of senataxin, a RNA:DNA helicase involved in the regulation of transcription and the maintenance of genome integrity, at sites of DNA Double Strand Breaks. We performed ChIP-Seq mapping of senataxin before and after damage, genome-wide DNA:RNA hybrids (DRIP) mapping before and after damage. We also performed RNA-Seq and RNA pol II mapping (total and phosphorylated on serine 2 of the CTD) by ChIP-Seq in undamaged cells to discriminate between damage in active versus inactive regions.
2018-02-20 | E-MTAB-6318 | biostudies-arrayexpress
Project description:Transcriptionally active loci are particularly prone to breakage and mounting evidence suggest that DNA Double-Strand Breaks arising in active genes are handled by a dedicated repair pathway, Transcription-Coupled DSB Repair (TC-DSBR), that entails R-loop accumulation and dissolution. Here, we uncovered a function for the Bloom RecQ DNA helicase (BLM) in TC-DSBR in human cells. BLM is recruited in a transcription dependent-manner at DSBs where it fosters resection, RAD51 binding and accurate Homologous Recombination repair. However, in an R-loop dissolution-deficient background, we found that BLM promotes cell death. We report that upon excessive R-loop accumulation, DNA synthesis is enhanced at DSBs, in a anner that depends on BLM and POLD3. Altogether our work unveils a role for BLM at DSBs in active chromatin, and highlights the toxic potential of RNA:DNA hybrids that accumulate at transcription-associated DSBs.
2022-04-13 | E-MTAB-11592 | biostudies-arrayexpress
Project description:Translocations, that occur when two DNA Double Strand breaks (DSBs) are abnormally rejoined, represent highly deleterious genome rearrangements favoring cancer apparition and progression. However, the mechanisms that drive their formation are yet poorly deciphered. One prerequisite for translocation is the juxtaposition of two distant DSBs, an event that would be favored if DSB cluster, i.e. are brought together in close spatial proximity within the nucleus. Whether DSB cluster in higher eukaryotes has been subjected to a strong controversy over the past decade, due to conflicting results obtained using microscopy based methods1-9. Here we used for the first time a high throughput chromosome conformation capture assay (Capture Hi-C10) to investigate DSB clustering. We unambiguously found that DSBs do cluster in human nuclei but only when induced in transcriptionally active genes. Clustering of damaged genes mainly occur during the G1 cell cycle phase and coincide with delayed repair. Moreover DSB clustering depends on the MRN complex, as well as the Formin 2 (FMN2) nuclear actin organizer and the LINC (LInker of Nuclear and Cytoplasmic skeleton) complex, suggesting that active mechanisms promote DSB clustering. This work reveals that when damaged, active genes exhibit a very peculiar behavior compared to the rest of the genome, being mostly left unrepaired and clustered in G1 while being repaired by homologous recombination in post-replicative cells.
2017-04-19 | E-MTAB-4846 | biostudies-arrayexpress
Project description:Chromatin undergoes major remodeling around DNA double strand breaks (DSB) to promote repair and DNA damage response (DDR) activation. We recently reported a high resolution map of gammaH2AX around multiple breaks on the human genome, using a new cell-based DSB inducible system. In an attempt to further characterize the chromatin landscape induced around DSBs, we now report the profile of SMC3, a subunit from the cohesin complex, previously characterized as required for repair by homologous recombination. We found that the recruitment of cohesin is moderate and restricted to the immediate vicinity of DSBs. In addition, we show that the cohesin complex, which was also recently proposed to be a key player in chromosome organisation and chromatin looping, controls gammaH2AX distribution within domains. Indeed, as we reported for transcription, cohesin binding antagonizes gammaH2AX spreading. Remarkably, depletion of cohesin leads to an increase of gammaH2AX at cohesin-bound genes (revelead by gammaH2AX mapping in upon SCC1 siRNA), associated with a decrease in their expression level after DSB induction. Thus our study identifies a novel role for the cohesin complex in protecting the genes located in gammaH2AX domains from both gammaH2AX spreading and transcriptional shut-down after DSB induction.
2012-01-01 | E-TABM-1164 | biostudies-arrayexpress
Project description:iMUT-seq profiles double-strand break (DSB) induced mutations at extremely high sensitive with single nucleotide resolution, allowing for the quantification of all mutation types, including chromosomal rearrangements, around endogenous DSBs. AID-DIvA cells are treated with or without 4-hydroxytamoxifen to induce DSBs, then with IAA to induce degradation of the DSB inducing AsiSI enzyme and are then incubated to allow the breaks to be repaired. The DSB loci are then PCR amplified from the genomic DNA and subjected to NGS to provide high depth mutation profiling. All samples are either untreated (m/0) or treated (p/4)with OHT and have three independent biological replicates, with the exception of ATRi which has 2 replicates and controlsi which has 6 replicates. This is because the siRNA were divided into two batches to create replicates 1-3 and 4-6 and each batch contained a controlsi sample for reference causing it to be in all 6 replicates.
2022-11-25 | E-MTAB-11259 | biostudies-arrayexpress
Project description:Chromatin acts as a key regulator of DNA related processes such as DNA damage repair. While ChIP-chip is a powerful technique to provide high-resolution maps of protein-genome interactions, its use to study DNA Double Strand Break (DSB) repair has been hindered by the limitations of the available damage induction methods. We have developed a human cell line that permits induction of multiple DSBs randomly distributed and unambiguously positioned within the genome. Using this system, we have generated the first genome-wide mapping of gammaH2AX around DSBs. We found that all DSBs trigger large gammaH2AX domains, which extend from the DSB in a bidirectional, discontinuous and not necessarily symmetrical manner. Strikingly we uncovered that, within domains, gammaH2AX distribution is highly influenced by gene transcription since parallel mapping of RNA Polymerase II and strand specific expression revealed that ?H2AX does not propagate on active genes. In addition, we demonstrate that transcription is accurately maintained within gammaH2AX domains, indicating that mechanisms may exist to protect genes transcription from gammaH2AX spreading and from the chromatin rearrangements induced by DSBs.
2010-04-20 | E-MEXP-1769 | biostudies-arrayexpress