GSE64464
CBP occupancy in Drosophila S2 cells
CREB-binding protein (CBP, also known as nejire) is a transcriptional co-activator that is conserved in metazoans. We have generated CBP ChIP-seq data from Drosophila S2 cells and compared it to modENCODE data. This shows that CBP is bound at genomic sites with a wide range of functions. As expected, we find that CBP is bound at active promoters and enhancers. In addition, we find that the strongest CBP sites in the genome are found at Polycomb Response Elements embedded in histone H3 lysine 27 trimethylated (H3K27me3) chromatin, where they correlate with binding of the Pho repressive complex. Interestingly, we find that CBP also binds to most insulators in the genome. At a subset of these, CBP may regulate insulating activity, measured as the ability to prevent repressive H3K27 methylation from spreading into adjacent chromatin. Overall design: ChIP seq in Drosophila S2 cells using two different antibodies against CBP (nejire), one raised in rabbit against amino acids 2540-3190 (CBP rb), and one raised in guinea-pig against amino acids 1-178 (CBP gp)