<p>A: Coomassie stained and anti-TFAP2 immunostained blot. TFAP2 enrichment with the SELEX-derived binding site can be visualized by Western blot, but not within the context of other protein bands in Coomassie staining. B: SNP pull-down for TFAP2. The transcription factor binds to its SELEX sequence (C variant), but a single nucleotide exchange abrogates binding (A variant). Performing proteome-wide detection for differentially binding transcription factors, only TFAP2 is enriched at the wild-type sequence observed in the individual mass spectrum of the TFAP2 peptide LSLLSSTSK<sup>2+</sup> and by comparison of all SILAC ratios of proteins detected in the experiment. C: SNP pull-down for rs509813. Applying PWAS, we identify SP1 together with SP3, which both bind to the same DNA motif. ZNF148, was also detected as a significant interaction partner in our proteome-wide screen, although not bioinformatically predicted.</p
