Genome-wide analysis of 8-oxoguanine DNA glycosylase-1

We report the application of ChIP-Sequencing for profiling genome-wide distribution of 8-oxoguanine DNA glycosylase (OGG1) which is a DNA base excision repair protein, after TNF exposure of cells. By obtaining an average of over 18 million of total reads per sample and over 19.5 million of unique reads per sample from chromatin immunoprecipitated DNA, we generated genome-wide chromatin-state maps of HEK293 cells. We performed gene ontology and functional pathway analysis of genes associate with peaks, and identify regions of the genomes (e.g. promoter, introns, etc) where the peaks tend to occur. The results show that OGG1 is primarily associated with promoter regions in vicinity of transcription factor binding sites 5' of transcription start sites (TSS). This pattern of distribution occurs in spite of genome-wide oxidative modifications of guanine (primarily 8-oxoG). OGG1 increased highly significant (1e-09 to 1e-517) enrichment of 57 transcription factor binding sites including those for Sox(2, 3, 6, 10), RUNX, RUNX(1, 2), HOX(C, D), STAT(1, 3, 6), IRF(1 to 4), NF-κB. In controls, the DNA was chromatin immunoprecipitated using antibody to NF-κB/RelA. These and other data derived from further analysis, suggest that OGG1 modulates binding of transcription factors and gene expression.