Ontology highlight
ABSTRACT:
PROVIDER: PRJNA869698 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:Aflatoxin B1 (AFB1), a potent carcinogenic mycotoxin, is known to contribute to liver cancer development. Within the cell, bioactivated AFB1 intercalates into the DNA double helix, forming bulky DNA adducts that lead to mutagenesis if left unrepaired. Here, we adapted the tXR-seq method to map the nucleotide excision repair of AFB1-induced DNA lesions at genome-wide level. Our research uncovered that transcription-coupled repair plays a major role in repairing the AFB1-induced DNA lesions. We identified a distinctive length distribution pattern for the excision products released during repair, suggesting a unique dual incision mechanism for AFB1-induced DNA lesions. Notably, we revealed that repair activity is more pronounced on chromosomes closer to the nuclear center and A compartments undergo faster repair compared with B compartments. Additionally, we observed higher repair activity within regions encompassing TAD boundaries and loop anchors. This study provides insights into the interplay between repair, transcription, and 3D genome organization, shedding light on the mechanisms behind AFB1-associated liver cancer development.
2023-10-19 | GSE243425 | GEO
Project description:Drosophila Melanogaster has been extensively used as a model system to study ionizing radiation and chemical induced mutagenesis, double strand break repair and recombination. However, there are only limited studies on nucleotide excision repair in this important model organism. In this study, we immunopreciptated DNA-directed RNA polymerase II (RPII215) complex from untreated and UV iradiated drosophila S2 cells and identified the protein that interact with it by mass spectrometry.
2022-04-04 | PXD028924 | Pride
Project description:We have adapted the eXcision Repair-sequencing (XR-seq) method to generate single-nucleotide resolution dynamic repair maps of UV-induced cyclobutane pyrimidine dimers (CPDs) and (6-4) pyrimidine-pyrimidone photoproducts [(6-4)PPs] in the Saccharomyces cerevisiae genome. We find that these photoproducts are removed from the genome primarily by incisions 13-18 nucleotides 5’ and 6-7 nucleotides 3’ to the UV damage that generate 21-27 nt-long excision products. Analyses of the excision repair kinetics both in single genes and at the genome-wide level reveal strong transcription-coupled repair of the transcribed strand (TS) at early time points followed by predominantly non-transcribed strand (NTS) repair at later stages. We have also characterized the excision repair level as a function of transcription level. The availability of high-resolution and dynamic repair maps should aid in future repair and mutagenesis studies in this model organism.
2018-04-12 | GSE110621 | GEO
Project description:UVA light mutagenesis in xeroderma pigmentosum variant human cells
| PRJNA556825 | ENA
Project description:DNA base damage is an important contributor to genome instability, but how the formation and repair of these lesions is affected by the genomic landscape is unknown. Here we describe genome-wide maps of DNA base damage, repair, and mutagenesis at single nucleotide resolution in yeast treated with the alkylating agent methyl methanesulfonate (MMS). Analysis of these maps revealed that base excision repair (BER) of alkylation damage is significantly modulated by chromatin, with faster repair in nucleosome free regions, and slower repair and higher mutation density within strongly positioned nucleosomes. Both the translational and rotational settings of lesions within nucleosomes significantly influence BER efficiency; moreover, this effect is asymmetric relative to the nucleosome dyad and is regulated by histone modifications. Our data also indicate that MMS-induced A mutations are significantly enriched on the non-transcribed strand (NTS) of yeast genes, particularly in BER-deficient strains, due to higher damage formation on the NTS and transcription-coupled repair of the transcribed strand (TS). These findings reveal the influence of chromatin on repair and mutagenesis of base lesions on a genome-wide scale, and suggest a novel mechanism for transcription-associated mutation asymmetry, which is frequently observed in human cancers.
2017-08-10 | GSE98031 | GEO
Project description:Embryonic stem cells can self-renew and differentiate, holding great promise for regenerative medicine. They also employ multiple mechanisms to preserve the integrity of their genomes. Nucleotide excision repair, a versatile repair mechanism, removes bulky DNA adducts from the genome. However, the dynamics of the capacity of nucleotide excision repair during stem cell differentiation remain unclear. Here, using immunoslot blot assay, we measured repair rates of UV-induced DNA damage during differentiation of human embryonic carcinoma (NTERA-2) cells into neurons and muscle cells. Our results revealed that the capacity of nucleotide excision repair increases as cell differentiation progresses. We also found that inhibition of the apoptotic signaling pathway has no effect on nucleotide excision repair capacity. Furthermore, RNA-seq-based transcriptomic analysis indicated that expression levels of four core repair factors, xeroderma pigmentosum (XP) complementation group A (XPA), XPC, XPG, and XPF-ERCC1, are progressively up-regulated during differentiation, but not those of replication protein A (RPA) and transcription factor IIH (TFIIH). Together, our findings reveal that increase of nucleotide excision repair capacity accompanies cell differentiation, supported by the up-regulated transcription of genes encoding DNA repair enzymes during differentiation of two distinct cell lineages.
2019-03-07 | GSE125370 | GEO
Project description:Platinum chemotherapies induce damages in DNA that distort the helical structure. In human cells, these adducts are removed primarily by the Nucleotide Excision Repair pathway. In this study, we mapped both cisplatin and oxaliplatin induced damages and their repair at single nucleotide resolution across the human genome.
2016-09-16 | GSE82213 | GEO
Project description:We developed a method for genome-wide mapping of DNA excision repair named XR-seq (eXcision Repair-seq). Human nucleotide excision repair generates two incisions surrounding the site of damage, creating a ~30-mer. In XR-seq, this fragment is isolated and subjected to high-throughput sequencing. We used XR-seq to produce stranded, nucleotide-resolution maps of repair of two UV-induced DNA damages in human cells, cyclobutane pyrimidine dimers (CPDs) and (6-4) pyrimidine-pyrimidone photoproducts ((6-4)PPs). In wild-type cells, CPD repair was highly associated with transcription, specifically with the template strand. Experiments in cells defective in either transcription-coupled excision repair or general excision repair isolated the contribution of each pathway to the overall repair pattern, and showed that transcription-coupled repair of both photoproducts occurs exclusively on the template strand. XR-seq maps capture transcription-coupled repair at sites of divergent gene promoters and bi-directional eRNA production at enhancers. XR-seq data also uncovered the repair characteristics and novel sequence preferences of CPDs and (6-4)PPs. XR-seq and the resulting repair maps will facilitate studies of the effects of genomic location, chromatin context, transcription, and replication on DNA repair in human cells. We have performed XR-seq for two types of UV-induced damages (CPD and (6-4)PP) in three different cell lines: NHF1, XP-C (XP4PA-SV-EB, GM15983)), and CS-B (CS1ANps3g2, GM16095). Two biological replicates were performed for each experiment, in which independent cell populations were UV treated and subjected to XR-seq.
2015-04-19 | E-GEOD-67941 | biostudies-arrayexpress
Project description:UV-induced DNA lesions are an important contributor to mutagenesis and cancer, but it is not fully understood how the chromosomal landscape influences UV lesion formation and repair. We have used a novel high-throughput sequencing method to precisely map UV-induced cyclobutane pyrimidine dimers (CPDs) at nucleotide resolution throughout the yeast genome. Analysis of CPD formation reveals that nucleosomal DNA having an inward rotational setting is protected from CPD lesions. In strongly positioned nucleosomes, this nucleosome 'photofootprint' overrides intrinsic dipyrimidine sequence preferences for CPD formation. CPD formation is also inhibited by DNA-bound transcription factors, in effect protecting important DNA elements from UV damage. Analysis of CPD repair revealed a clear signature of efficient transcription-coupled nucleotide excision repair. Repair was less efficient at translational positions near a nucleosome dyad and at heterochromatic regions in the yeast genome. These findings define the roles of nucleosomes and transcription factors in UV damage formation and repair. UV mapping data was analyzed for yeast cells irradiated with 125J/m2 and allowed to repair for 0hr (2 samples), 20 minutes, 1 hour, or 2 hours. Data is also included for naked DNA irradiated with UV 60 or 90 J/m2
2016-08-19 | E-GEOD-79977 | biostudies-arrayexpress