EMSA using Wt oligonucleotide probes with site III (−643/−638 bp) and site IV (−601/−595 bp) in MYL9 promoter and nuclear extract from PMA-treated human erythroleukemia (HEL) cells. (A) Top panel shows Wt probe (−652/−632) and Mt probe with site III mutated. Bottom panel shows EMSA using Wt and Mt probes: lane 1, no extract; lane 2, protein binding to Wt probe; lane 3, loss of binding with excess unlabeled Wt probe; lane 4, protein binding to Wt probe; lane 5, no loss of binding on competition with unlabeled mutant probe; lane 6, loss of binding with anti-RUNX1 antibody. (B) Top panel shows Wt probe (−601/−595) and Mt probe with mutated site IV. Bottom panel shows EMSA using Wt and Mt probes. Lane 1, protein binding to Wt probe; lane 2, no loss of binding by competition with unlabeled mutant probe; lane 3, loss of binding with excess unlabeled Wt probe; lane 4, protein binding to Wt probe; lane 5, loss of binding with anti-RUNX1 antibody.