DNA damage and sequencing errors
Ontology highlight
ABSTRACT:
PROVIDER: PRJEB16681 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:DNA damage plays a major role in neural cell death by necrosis and/or apoptosis. However, our understanding of the molecular mechanisms of neural cell death remains still incomplete. To acquire a global understanding of the various mediators related to DNA damage-induced neural cell death pathways, we performed a whole genomic wide screen in neural stem cells by using a siRNA library. We identified 80 genes required for DNA damage-induced cell death. 14 genes (17.5%) are directly related to cell death and/or apoptosis. 66 genes have not been previously directly linked to DNA damage-induced cell death. Using an integrated approach with functional and bioinformatics analysis, we have uncovered a molecular network containing several partially overlapping and interconnected pathways and/or protein complexes that are required for DNA damage-induced neural cell death. The identification of the network of neural cell death mediators will greatly enhance our understanding of the molecular mechanisms of neural cell death and provide therapeutic targets for nervous system disorders.
2018-05-29 | GSE31666 | GEO
Project description:Senescent cells are a major cause of organismal aging and a key target for anti-aging therapies. Persistent DNA damage signaling is a primary driver of the induction and maintenance of cellular senescence. However, many DNA damaging stimuli that induce senescence, such as irradiation or transient exposure to genotoxic drugs, are transient. The mechanisms underlying persistent damage signaling in senescent cells, and why senescent cells fail to repair damaged DNA, remain unknown. Here, we were able to assess the mechanisms underlying persistence of DNA damage and senescence maintenance by designing a precisely controllable senescence system that does not require potent stressors to induce senescence. We demonstrate that sustained mTORC1 signaling in senescent cells causes gradually accumulating DNA damage and an inflammatory response that maintains cell-cycle arrest. Markedly, activation of E2F transcription, which promotes expression of DNA repair proteins, can reverse accumulated DNA damage. Thus, persistent DNA damage signaling arises in senescent cells by uncoupling of mTORC1 and E2F signaling, whereby prolonged mTORC1 activity causes gradually increasing DNA damage that cannot be sufficiently repaired without induction of protective E2F target genes.
2023-06-01 | GSE153683 | GEO
Project description:While the importance of random sequencing errors decreases at higher DNA or RNA sequencing depths, systematic sequencing errors (SSEs) dominate at high sequencing depths and can be difficult to distinguish from biological variants. These SSEs can cause base quality scores to underestimate the probability of error at certain genomic positions, resulting in false positive variant calls, particularly in mixtures such as samples with RNA editing, tumors, circulating tumor cells, bacteria, mitochondrial heteroplasmy, or pooled DNA. Most algorithms proposed for correction of SSEs require a training data set, which is typically either from a part of the data set being M-bM-^@M-^\recalibratedM-bM-^@M-^] (Genome Analysis ToolKit, or GATK) or from a separate data set with special characteristics (SysCall). Here, we combine the advantages of these approaches by adding synthetic RNA spike-in standards to human RNA, and use GATK to recalibrate base quality scores with reads mapped to the spike-in standards. Compared to conventional GATK recalibration that uses reads mapped to the genome, spike-ins improve the accuracy of Illumina base quality scores by a mean of 5 units, and by as much as 13 units M-BM- at CpG sites. In addition, since reads mapping to the genome are not used for recalibration, our method allows run-specific recalibration even for the many species without a comprehensive and accurate SNP database. We also use GATK with the spike-in standards to demonstrate that the Illumina RNA sequencing runs overestimate quality scores for AC, CC, GC, GG, and TC dinucleotides, while SOLiD has less dinucleotide SSEs but more SSEs for certain cycles. We conclude that using these DNA and RNA spike-in standards with GATK improves base quality score recalibration. Four human RNA samples with equimolar ERCC spike-in standards were sequenced on Illumina. Two human brain/liver/muscle RNA mixtures with dynamic range of ERCC spike-in standards were sequenced on SOLiD.
2012-03-03 | E-GEOD-36217 | biostudies-arrayexpress
Project description:DNA replication is sensitive to damage in the template. To bypass lesions and complete replication, cells activate recombination-mediated (error-free) and translesion synthesis-mediated (error-prone) DNA damage tolerance pathways. Crucial for error-free DNA damage tolerance is template switching, which depends on the formation and resolution of damage-bypass intermediates consisting of sister chromatid junctions. Here we show that a chromatin architectural pathway involving the high mobility group box protein Hmo1 channels replication-associated lesions into the error-free DNA damage tolerance pathway mediated by Rad5 and PCNA polyubiquitylation, while preventing mutagenic bypass and toxic recombination. In the process of template switching, Hmo1 also promotes sister chromatid junction formation predominantly during replication. Its C-terminal tail, implicated in chromatin bending, facilitates the formation of catenations/hemicatenations and mediates the roles of Hmo1 in DNA damage tolerance pathway choice and sister chromatid junction formation. Together, the results suggest that replication-associated topological changes involving the molecular DNA bender, Hmo1, set the stage for dedicated repair reactions that limit errors during replication and impact on genome stability. BrdU and proteins ChIP-chip analyses analysis were carried out as described (Bermejo et al., 2009). Labelled probes were hybridized to Affymetrix S.cerevisiae Tiling 1.0 (P/N 900645) arrays and processed with TAS software.
2014-01-28 | E-GEOD-46260 | biostudies-arrayexpress
Project description:While the importance of random sequencing errors decreases at higher DNA or RNA sequencing depths, systematic sequencing errors (SSEs) dominate at high sequencing depths and can be difficult to distinguish from biological variants. These SSEs can cause base quality scores to underestimate the probability of error at certain genomic positions, resulting in false positive variant calls, particularly in mixtures such as samples with RNA editing, tumors, circulating tumor cells, bacteria, mitochondrial heteroplasmy, or pooled DNA. Most algorithms proposed for correction of SSEs require a training data set, which is typically either from a part of the data set being “recalibrated” (Genome Analysis ToolKit, or GATK) or from a separate data set with special characteristics (SysCall). Here, we combine the advantages of these approaches by adding synthetic RNA spike-in standards to human RNA, and use GATK to recalibrate base quality scores with reads mapped to the spike-in standards. Compared to conventional GATK recalibration that uses reads mapped to the genome, spike-ins improve the accuracy of Illumina base quality scores by a mean of 5 units, and by as much as 13 units at CpG sites. In addition, since reads mapping to the genome are not used for recalibration, our method allows run-specific recalibration even for the many species without a comprehensive and accurate SNP database. We also use GATK with the spike-in standards to demonstrate that the Illumina RNA sequencing runs overestimate quality scores for AC, CC, GC, GG, and TC dinucleotides, while SOLiD has less dinucleotide SSEs but more SSEs for certain cycles. We conclude that using these DNA and RNA spike-in standards with GATK improves base quality score recalibration.
2012-03-03 | GSE36217 | GEO
Project description:DNA replication is sensitive to damage in the template. To bypass lesions and complete replication, cells activate recombination-mediated (error-free) and translesion synthesis-mediated (error-prone) DNA damage tolerance pathways. Crucial for error-free DNA damage tolerance is template switching, which depends on the formation and resolution of damage-bypass intermediates consisting of sister chromatid junctions. Here we show that a chromatin architectural pathway involving the high mobility group box protein Hmo1 channels replication-associated lesions into the error-free DNA damage tolerance pathway mediated by Rad5 and PCNA polyubiquitylation, while preventing mutagenic bypass and toxic recombination. In the process of template switching, Hmo1 also promotes sister chromatid junction formation predominantly during replication. Its C-terminal tail, implicated in chromatin bending, facilitates the formation of catenations/hemicatenations and mediates the roles of Hmo1 in DNA damage tolerance pathway choice and sister chromatid junction formation. Together, the results suggest that replication-associated topological changes involving the molecular DNA bender, Hmo1, set the stage for dedicated repair reactions that limit errors during replication and impact on genome stability.
2014-01-28 | GSE46260 | GEO
Project description:DNA damage results in the activation of checkpoint kinases, which phosphorylate downstream effectors that inhibit the cell cycle, activate DNA repair, and cause widespread changes in transcription. However, the specific connections between the checkpoint kinases and downstream transcription factors (TFs) are not well understood. Here, we introduce a strategy for mapping regulatory networks between kinases and TFs involving integration of kinase mutant expression profiles, transcriptional regulatory interactions, and phosphoproteomics. We use this approach to investigate the role of the Saccharomyces cerevisiae checkpoint kinases (Mec1, Tel1, Chk1, Rad53, and Dun1) in the transcriptional response to DNA damage caused by methyl methanesulfonate (MMS). The result is a global kinase-TF regulatory network in which Mec1 and Tel1 signal through Rad53 to synergistically regulate the expression of more than 600 genes. This network implicates at least nine TFs, including Msn4, Gcn4, SBF (Swi4/Swi6), MBF (Swi6/Mbp1), and Fkh2/Ndd1/Mcm1, nearly all of which have sites of Rad53-dependent phosphorylation, as downstream regulators of checkpoint kinase-dependent genes. We also identify a major DNA damage-induced transcriptional network acting independently of Rad53 and other checkpoint kinases to regulate expression of genes involved in general and oxidative stress responses. Expression was profiled with and without MMS treatment in several genetic backgrounds (gene deletion strains).
2013-03-31 | E-GEOD-40351 | biostudies-arrayexpress
Project description:We have developed a generally adaptable, novel high-throughput chromosome conformation capture assay for use in trans (V3C-seq) that allows genome-wide identification of the direct associations of a lytic virus genome with discreet regions of the cellular chromosome. Upon infection, the parvovirus Minute Virus of Mice genome associated directly with sites of cellular DNA damage. These sites also exhibited damage in uninfected cells when cycling through S-phase. As infection proceeded, new sites of DNA damage were induced, and virus subsequently also associated with these.
2018-07-25 | GSE112957 | GEO
Project description:In our project we are using the Top2 inhibitor, ICRF-193, in order to induce damage in NIH3T3 MEFs. We report the high-throughput identification of genomic hotspots for damage induction by ICRF-193, using γH2AX as a marker. We find that ICRF-193 primarily induces damage in repetitive sequences, which are known to reside in regions of heterochromatin, with a very small portion of damaged sites residing in regions of active genes in euchromatin. Overall, this study provides evidence that catalytic inhibition of Top2 enzymes by ICRF-193, leads to induction of damage in the nuclear sub-compartments of heterochromatin.
2024-04-17 | GSE256090 | GEO
Project description:Ubiquitin widely modifies proteins, thereby regulating most cellular functions. The complexity of ubiquitin signalling necessitates unbiased methods enabling global detection of dynamic protein ubiquitylation. Here, we describe UBIMAX (UBiquitin target Identification by Mass spectrometry in Xenopus egg extracts), which enriches ubiquitin-conjugated proteins and quantifies regulation of protein ubiquitylation under precise and adaptable conditions. We benchmark UBIMAX by investigating DNA double-strand break-responsive ubiquitylation events, identifying previously known targets and revealing the actin-organising protein Dbn1 as a novel major target of DNA damage-induced ubiquitylation. We find that Dbn1 is targeted for proteasomal degradation by the SCFβ-Trcp1 ubiquitin ligase, in a conserved mechanism driven by ATM-mediated phosphorylation of a previously uncharacterized β-Trcp1 degron containing an SQ motif. We further show that this degron is sufficient to induce DNA-damage dependent protein degradation of a model substrate. Collectively, we demonstrate UBIMAX’s ability to identify novel targets of stimulus-regulated ubiquitylation and reveal an SCFβ-Trcp1-mediated ubiquitylation mechanism controlled directly by the apical DNA damage response kinases.
2023-12-14 | PXD042086 | Pride