Project description:The data set contains MS/MS data on teeth extracts for Ancient DNA teeth samples ran in both positive and Negative ionization modes
Project description:Development of high resolution/accurate mass liquid chromatography-coupled tandem mass spectrometry (LC-MS/MS) methodology enables the characterization of covalently modified DNA induced by interaction with genotoxic agents in complex biological samples. Constant neutral loss monitoring of 2´-deoxyribose or the nucleobases using data-dependent acquisition represents a powerful approach for the unbiased detection of DNA modifications (adducts). The lack of available bioinformatics tools necessitates manual processing of acquired spectral data and hampers high throughput application of these techniques. To address this limitation, we present an automated workflow for the detection and curation of putative DNA adducts by using diagnostic fragmentation filtering of LC-MS/MS experiments within the open-source software MZmine. The workflow utilizes a new feature detection algorithm, DFBuilder, which employs diagnostic fragmentation filtering using a user-defined list of fragmentation patterns to reproducibly generate feature lists for precursor ions of interest. The DFBuilder feature detection approach readily fits into a complete small molecule discovery workflow and drastically reduces the processing time associated with analyzing DNA adductomics results. We validate our workflow using a mixture of authentic DNA adduct standards and demonstrate the effectiveness of our approach by reproducing and expanding the results of a previously published study of colibactin-induced DNA adducts. The reported workflow serves as a technique to assess the diagnostic potential of novel fragmentation pattern combinations for the unbiased detection of chemical classes of interest.
Project description:Crosslinking-MS analysis of sulfo-SDA crosslinked fission yeast condensin-DNA samples in the initial binding state (absence of nucleotide) and in the DNA gripping state (in the presence of ADP•BeF3)
Project description:Targetted metabolomics in U2OS PRDX1 WT and PRDX1-/- While cellular metabolism impacts the DNA damage response, a systematic understanding of the metabolic requirements that are crucial for DNA damage repair has yet to be achieved. Here, we investigate the metabolic enzymes and processes that are essential when cells are exposed to DNA damage. By integrating functional genomics with chromatin proteomics and metabolomics, we provide a detailed description of the interplay between cellular metabolism and the DNA damage response. Subsequent analysis identified Peroxiredoxin 1, PRDX1, as fundamental for DNA damage repair. During the DNA damage response, PRDX1 translocates to the nucleus where it is required to reduce DNA damage-induced nuclear reactive oxygen species levels. Moreover, PRDX1 controls aspartate availability, which is required for the DNA damage repair-induced upregulation of de novo nucleotide synthesis. Loss of PRDX1 leads to an impairment in the clearance of γΗ2ΑΧ nuclear foci, accumulation of replicative stress and cell proliferation defects, thus revealing a crucial role for PRDX1 as a DNA damage surveillance factor.
Project description:In this work, we performed DNA affinity purification of proteins that bind to biotinylated DNA probe, denoted as difL and difR. The enriched proteins were subjected to SDS-PAGE, in-gel tryptic digestion, followed by LC-MSMS.
Project description:Non-canonical DNA structures such as G-quadruplex (G4) and i-motif (iM) are formed at the guanine- and cytosine-rich sequences, respectively, and prohibit DNA replication and transcription. The formation and resolution of these non-canonical structures are therefore required to be dynamically regulated by either physiological conditions or factors able to bind the G4 and iM structures. Although many G4 binding proteins responsible for tuning of the G4 structure have been discovered, understanding of structural regulation of the iM structure by iM binding proteins is far less behind. Here, we developed a protein-labeling DNA probe bearing an alkyne moiety through a reactive tosylate linker for proximity labeling of nucleic acid-binding proteins and searched for iM binding proteins. The proteome analyses of the captured proteins suggested new candidates that potentially bind the iM structure, in addition to the known iM binders.