Figure 4

USF2 inhibits induction of the RIIβ promoter by C/EBP. The RIIβ promoter construct (-395 to -123) in the CAT reporter vector was co-transfected with 500 ng of expression vectors for USF1 (1), USF2a (2A) or C/EBPβ Lap (horisontally striped bars) or Lip (hached bars) isoforms or combinations of these factors. Empty expression vector was added to ensure a total of 2 μg of DNA transfected in each well. Data represent reporter activities (CAT/Luc) relative to transfection with the RIIβ promoter construct under unstimulated conditions, and were normalized for expression of luciferase from a cotransfected control vector (pGL3Control). Three separate transfections were performed in triplicate.