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:Low Input DNA Double Strand Break Mapping
Project description:In the bacterium Escherichia coli, RecG directs DNA synthesis during the repair of DNA double-strand breaks by homologous recombination. Examination of RecA binding during double-strand break repair in Escherichia coli in the presence and absence of RecG protein
Project description:Comparative proteomic analysis identified a total of 452 differentially abundant proteins (DAPs) in the fluorescence-activated cell sorting (FACS) isolated spermatocytes from 12-month-old yak and cattleyak. 291 proteins were only identified in yak spermatocytes. Gene Ontology analysis revealed that the downregulated DAPs were mostly enriched in the cellular response to DNA damage stimulus and double-strand break (DSB) repair via break-induced replication, while the proteins specific for yak were related to cell division and cycle, spermatogenesis, and negative regulation of the extrinsic apoptotic signaling pathway.
Project description:Small RNAs have been implicated in numerous cellular processes, including effects on chromatin structure and the repression of transposons. We describe the generation of a small RNA response at DNA ends in Drosophila that is analogous to the recently reported DSB-induced RNAs (diRNAs) or Dicer and Drosha dependent small RNAs (ddRNAs) in Arabidopsis and vertebrates. Active transcription in the vicinity of the break amplifies this small RNA response, demonstrating that the normal mRNA contributes to the endo-siRNA precursor. The double-stranded RNA precursor forms with an antisense transcript that initiates at the DNA break. Breaks are thus sites of transcription initiation, a novel aspect of the cellular DSB response. This response is specific to a double-strand break since nicked DNA structures do not trigger small RNA production. The small RNAs are generated independently of the exact end structure (blunt, 3'- or 5'-overhang), can repress homologous sequences in trans and may therefore - in addition to putative roles in repair - exert a quality control function by clearing potentially truncated messages from genes in the vicinity of the break.
Project description:The effect of an induced site-specific DNA double-strand break on DNA abundance across the chromosome of E. coli cells expressing or not RecD protein, was investigated by marker frequency analysis.
Project description:Recent observations show that the single-cell response of p53 to ionizing radiation (IR) is “digital” in that it is the number of oscillations rather than the amplitude of p53 that shows dependence on the radiation dose. We present a model of this phenomenon. In our model, double-strand break (DSB) sites induced by IR interact with a limiting pool of DNA repair proteins, forming DSB–protein complexes at DNA damage foci. The persisting complexes are sensed by ataxia telangiectasia mutated (ATM), a protein kinase that activates p53 once it is phosphorylated by DNA damage. The ATM-sensing module switches on or off the downstream p53 oscillator, consisting of a feedback loop formed by p53 and its negative regulator, Mdm2. In agreement with experiments, our simulations show that by assuming stochasticity in the initial number of DSBs and the DNA repair process, p53 and Mdm2 exhibit a coordinated oscillatory dynamics upon IR stimulation in single cells, with a stochastic number of oscillations whose mean increases with IR dose. The damped oscillations previously observed in cell populations can be explained as the aggregate behavior of single cell
Project description:Here we developed BreakTag, a versatile, highly parallel and scissile-aware methodology for the profiling of Cas9-induced DNA double strand break (DSBs), to identify molecular determinants influencing Cas9 incisions
Project description:Here we developed BreakTag, a versatile, highly parallel and scissile-aware methodology for the profiling of Cas9-induced DNA double strand break (DSBs), to identify molecular determinants influencing Cas9 incisions
Project description:Here we developed BreakTag, a versatile, highly parallel and scissile-aware methodology for the profiling of Cas9-induced DNA double strand break (DSBs), to identify molecular determinants influencing Cas9 incisions
