Nuclear protein binding to proximal MITF binding elements in the human TYR promoter. Nuclear protein binding to M-box and E-box binding elements was studied by using double-stranded DNA probes and nuclear extracts from ARPE-19 cells cultured for 14 days. To access the data, click or select the words “Appendix 8.” This will initiate the download of a compressed (pdf) archive that contains the file. Top panel, labeled M-box probe was competed with a sixfold excess of unlabelled probes for unrelated GAL4 (lane 2), wild-type M-box (lane 3), mutated M-box (lane 4) or wild-type OTX2 site 3 (lane 5). Bottom panel, labeled E-box probe was competed with a sixfold excess of unlabeled probes for unrelated GAL4 (lane 2), wild-type E-box (lane 3), mutated E-box (lane 4) or wild-type OTX2 site 3 (lane 5). Specific DNA–protein complexes are indicated with symbols A, A1 or A2 while non-specific complexes are indicated with B. Binding reactions in the absence of competitor are on lanes 1.