Project description:RNA is subject to a multitude of different chemical modifications that collectively represent the epitranscriptome. Individual RNA modifications including N6-methyladenosine (m6A) on mRNA play essential roles in the posttranscriptional control of gene expression. Recent technological advances have enabled the transcriptome-wide mapping of certain RNA modifications, to reveal their broad relevance and characteristic distribution patterns. However, convenient methods that enable the simultaneous mapping of multiple different RNA marks within the same sample are generally lacking. Here we present EpiPlex RNA modification profiling, a bead-based proximity barcoding assay with sequencing readout that expands the scope of molecular recognition-based RNA modification detection to multiple targets, while providing relative quantification and enabling low RNA input. Measuring signal intensity against spike-in controls provides relative quantification, indicative of the RNA mod abundance at each locus. We report on changes in the modification status of HEK293T cells upon treatment with pharmacological inhibitors separately targeting METTL3, the dominant m6A writer enzyme, and the EIF4A3 component of the exon junction complex (EJC). The treatments resulted in decreased or increased m6A levels, respectively, without effect on inosine levels. Inhibiting the helicase activity of EIF4A3 and EIF4A3 knockdown both cause a significant increase of m6A sites near exon junctions, consistent with the previously reported role of EIF4A3 in shaping the m6A landscape. Thus, EpiPlex offers a reliable and convenient method for simultaneous mapping of multiple RNA modifications to facilitate epitranscriptome studies .
Project description:Endogenous and exogenous chemical modifications in DNA have profound influences on genome function. We have developed a novel technology, Nick-seq, for mapping variety of DNA chemical modifications across the genomes at single-nucleotide resolution, by which we achieved quantitative profiling of single-strand breaks, phosphorothioate modifications, and oxidative DNA damage sites. This method is applicable for mapping of any DNA metabolism events that are involved in or can be converted, enzymatically or chemically, to DNA strand breaks such as DNA modifications, damages, genome replication, and chromatin structures.
Project description:Endogenous and exogenous chemical modifications in DNA have profound influences on genome function. We have developed a novel technology, Nick-seq, for mapping variety of DNA chemical modifications across the genomes at single-nucleotide resolution, by which we achieved quantitative profiling of single-strand breaks, phosphorothioate modifications, and oxidative DNA damage sites. This method is applicable for mapping of any DNA metabolism events that are involved in or can be converted, enzymatically or chemically, to DNA strand breaks such as DNA modifications, damages, genome replication, and chromatin structures.
Project description:Endogenous and exogenous chemical modifications in DNA have profound influences on genome function. We have developed a novel technology, Nick-seq, for mapping variety of DNA chemical modifications across the genomes at single-nucleotide resolution, by which we achieved quantitative profiling of single-strand breaks, phosphorothioate modifications, and oxidative DNA damage sites. This method is applicable for mapping of any DNA metabolism events that are involved in or can be converted, enzymatically or chemically, to DNA strand breaks such as DNA modifications, damages, genome replication, and chromatin structures.
Project description:The expression patterns of eukaryotic genomes are controlled by their chromatin structure, consisting of nucleosome subunits in which DNA of approximately 146 bp is wrapped around a core of 8 histone molecules. Post-translational histone modifications play an essential role in modifying chromatin structure. Here we apply a combination of SAGE and chromatin immunoprecipitation (ChIP) protocols to determine the distribution of hyperacetylated histones H3 and H4 in the Saccharomyces cerevisiae genome. We call this approach genome-wide mapping technique (GMAT). Using GMAT, we find that the highest acetylation levels are detected in the 5' end of a gene's coding region, but not in the promoter. Furthermore, we show that the histone acetyltransferase, GCN5p, regulates H3 acetylation in the promoter and 5' end of the coding regions. These findings indicate that GMAT should find valuable applications in mapping target sites of chromatin-modifying enzymes. Keywords: SAGE-ChIP