Project description:To investigate the genomic effects of CuCl2 on A549 cells in vitro, we treated cells with sDMEM (DMEM + 10% FBS + 1% Pen/Strep cocktail) or sDMEM + CuCl2 for various timepoints at various concentrations (or untreated cell control) followed by kethoxal labeling of single stranded DNA (ssDNA) We then performed differential analysis of ssDNA levels following the KAS-pipe pipeline
Project description:DNA N6-methyladenine (N6-mA) is an emerging epigenetic mark in the mammalian genome. Levels of N6-mA undergo drastic fluctuation during early embryogenesis, indicative of active regulation. Here we demonstrate that the 2-oxoglurarate oxygenase ALKBH1 functions as a nuclear eraser of N6-mA in unpairing regions (e.g. SIDD, Stress Induced DNA Double Helix Destabilization regions). Enzymatic profiling studies revealed that ALKBH1 displays demethylation activity towards N6-mA on DNA substrates that share a common unpairing feature, e.g. bubbled, bulged or single-stranded DNA oligos. Furthermore, ssDNA-seq and DIP-seq analyses revealed significant genome-wide co-occurrence of base unpairing regions with N6-mA in mouse embryonic stem cells, especially during cell fate transition. Collectively, our biochemical, structural and genomic studies demonstrate that ALKBH1 is an important DNA demethylase that regulates genome N6-mA turnover in unpairing regions associated with dynamic chromatin regulation in early development. This series contains data from ssDNA-seq experiments on mouse ES cells. We used the S1 nuclease and biotin end-labeling to enrich for DNA at ssDNA regions followed by HiSeq4000 sequencing and data analysis.
Project description:To identify origins of replication in Lachancea waltii by mapping regions of ssDNA that are enriched in S phase. L. waltii cells are grown in the presence of hydroxyurea, which slows replication forks and causes the accumulation of ssDNA at the replication fork.
Project description:Meiotic DNA double stranded breaks (DSBs) initiate genetic recombination in discrete areas of the genome called recombination hotspots. Although DSBs can be directly mapped using ChIP-Seq and antibody against ssDNA-associated proteins, genome-wide mapping of recombination hotspots in mammals is still a challenge due to the low frequency of recombination, high heterogeneity of the germ cell population and the relatively low efficiency of ChIP. To overcome these limitations we have developed a novel method, single-stranded DNA (ssDNA) sequencing (SSDS), that specifically detects protein-bound single-stranded DNA at DSB ends. SSDS consists of a computational framework for the specific detection of ssDNA-derived reads in a sequencing library and a new library preparation procedure for the enrichment of fragments originating from ssDNA. When applied to mapping meiotic DSBs, the use of SSDS reduces the non-specific dsDNA background more than ten-fold. Our method can be extended to other systems where the identification of ssDNA or DSBs is desired. Development and validation of the method, SSDS, for the specific detection of ssDNA-derived and dsDNA-derived fragments in sequencing libraries and enrichment of ssDNA-derived fragments. SSDS was used to detect meiotic DSBs in 9R/13R mice.
Project description:Meiotic DNA double stranded breaks (DSBs) initiate genetic recombination in discrete areas of the genome called recombination hotspots. Although DSBs can be directly mapped using ChIP-Seq and antibody against ssDNA-associated proteins, genome-wide mapping of recombination hotspots in mammals is still a challenge due to the low frequency of recombination, high heterogeneity of the germ cell population and the relatively low efficiency of ChIP. To overcome these limitations we have developed a novel method, single-stranded DNA (ssDNA) sequencing (SSDS), that specifically detects protein-bound single-stranded DNA at DSB ends. SSDS consists of a computational framework for the specific detection of ssDNA-derived reads in a sequencing library and a new library preparation procedure for the enrichment of fragments originating from ssDNA. When applied to mapping meiotic DSBs, the use of SSDS reduces the non-specific dsDNA background more than ten-fold. Our method can be extended to other systems where the identification of ssDNA or DSBs is desired.
Project description:Genomic changes in low and highly metastatic A549 cells were analyzed by 500K SNP arrays. A large number of genomic alterations were present in A549 cells but no significant differences were observed between the low or highly metastatic A549 cell lines.
Project description:The multifunctional scaffolding protein M-NM-2-arrestin-1 plays a vital role in mediating the proliferative effects of nicotine through nAChR signaling. M-NM-2-arrestins were initially known as negative regulators of GPCR mediated signaling as they promote internalization and desensitization of GPCRs. However, new roles of M-NM-2-arrestins in receptor trafficking and signaling have been discovered in recent years. They are known to regulate signaling through a number of receptors such as Notch, endothelin A receptor, frizzled, smoothened and the nicotinic cholinergic receptors. Studies from our lab revealed that nAChR signaling induces the translocation of M-NM-2-arrestin-1 to the nucleus, in a Src dependent manner, where it directly binds to the proliferative E2Fs. Furthermore, the nuclear translocation of M-NM-2-arrestin-1 results in recruitment of p300 to E2F1 regulated proliferative promoters facilitating histone acetylation and transcription of these promoters. Given the role of M-NM-2-arrestin-1 in nicotine induced gene expression, we attempted to explore the global association of M-NM-2-arrestin-1 to the genomic regions upon nicotine stimulation by ChIP sequencing. It was found that M-NM-2-arrestin-1 is recruited on the promoters of many genes that regulate EMT as well as other regulatory pathways. In this assay, M-NM-2-arrestin-1 was found to be associated with the promoter regions of genes such as ZNF768, ZNF131, CSF3R, HMGA2, TAL1, RCC1, NKX2-4 etc in response to nicotine stimulation. Serum starved/quiescent A549 cells and Nicotine stimulated A549 cells
Project description:To study the effect of rs1663689 on lung cancer cells, we generated A549(C/C) from A549(T/T) using CRISPR/Cas9 technology and performed RNA-seq.