Fig. 5

Identification of NRF1 binding sites in the E2F1 promoter. a Schematic presentation of putative NRF1 binding sites on the E2F1 promoter. b, c Anti-NRF1 antibody was used for the ChIP assay. Quantification of immunoprecipitated DNA fragments was performed by PCR. d The E2F1 constructs (− 333/− 17) or (− 1291/− 869) were cotransfected with pcDNA3-NRF1 or NRF1DN in HepG2 cells. e, f Various E2F1 (− 333/− 17) and (− 1291/− 869) constructs harbouring point mutations (mut1 to mut3) were generated and cotransfected with pcDNA3-NRF1 or NRF1DN. The pRL-TK vector was also cotransfected to normalize transfection efficiencies. The luciferase activity was determined by a dual luciferase assay. The results are presented as a luciferase/Renilla ratio. The data represent means ± SD. *P < 0.05, **P < 0.01 and ****P < 0.0001 compared with the control