ZNF148 and E4F1 require their DNA binding domains to bind in vitro to WT and −57A > C TERT promoter, respectively. (A) Schematic representation of ZNF148 and E4F1 WT and DNA binding mutant constructs. (B) Sequence-specific pull-down of recombinant GFP-tagged WT or binding mutant of ZNF148 with HeLa nuclear extracts with the nine probes shown in Figure 1A (left) alongside rs36115365 major SNP-G and minor SNP-C, rs509813 major SNP and minor SNP, and CDKN1A promoter (containing ZNF148 binding site) (right). (C) Sequence-specific pull-down of recombinant GFP-tagged WT or binding mutant of E4F1 with HeLa nuclear extracts with the nine probes shown in Figure 1A. (D) Binding motif of ZNF148 and E4F1 aligned to the TERT promoter sequence based on the consensus motif derived from the MethMotif database (Xuan Lin et al. 2018).
