Bipartite Recognition of DNA by TCF/Pangolin Is Remarkably Flexible and Contributes to Transcriptional Responsiveness and Tissue Specificity of Wingless Signaling
Figure 6
TCF/Pan-bound chromatin is enriched for HMG-Helper site pairs.
(A) Distribution of HMG-Helper pairs in genomic sequences bound by TCF/Pan (blue bars) versus random DNA (yellow bars). TCF/Pan-bound sequences were obtained from a ChIP-seq data set from germband extended Drosophila embryos [28]. Equivalent amounts of random DNA from intergenic, intronic and 5′/3′UTR regions were analyzed, with the average of ten such runs displayed. Nearly all the HMG-Helper site configurations were enriched in TCF/Pan bound regions, with the highest degree of enrichment in FF0-2 and AK0-6. Due to the semi-palindromic nature of the Helper site, many sites with nucleotide mismatches were called as both AK/RW or FF/KK. The overlap is indicated in the Venn diagram to the right of each pair of graphs. (B) AK and FF motifs are highly enriched in peaks which are uniquely bound by TCF/Pan (see text for further explanation). Enrichment is less dramatic in TCF/Pan peaks that are shared by Pannier or pMAD.