FIGURE 2.

E2F1-mediated GRP78/BIP inhibition requires the DNA binding and transactivation domain. Hep3B cells were co-transfected with 0.5 μg of GRP78/BIP reporter plasmid using the proximal core promoter region between -371 and +2 and 1 μg of expression plasmid encoding E2F1, DNA binding-defective mutant E132, E(-TA), lacking the transactivation domain, or pcDNA3.1 as mock control. Luciferase activity (RLU) was measured 36 h after transfection. Error bars, S.D. E2F1 and GRP78/BIP protein expression was verified by Western blotting. The blots were reprobed for α-actin as a loading control.