FIGURE 7.

EGR1 co-regulates CAR but not PXR. A, Yh18 (HepG2 cells stably expressing human CAR) were co-transfected with –1.8 kb promoter, phRL-SV40, and pcDNA3.1 or pcDNA3.1-EGR1 and were treated with Me₂SO (DMSO) or CITCO (250 nm) for 48 h and assayed for luciferase activity. -Fold luciferase reporter activation was calculated by taking the control activity (pcDNA3.1 with Me₂SO) as 1. B, COS-1 cells were co-transfected with –1.8 kb promoter, phRL-SV40, and various combinations of pcDNA3.1, pCR3-hCAR, pcDNA3.1-HNF4α, and pcDNA3.1-EGR1. The total amounts of plasmids transfected into cells were adjusted by adding supplementary pcDNA3.1. -Fold activation was calculated by taking the control activity (pcDNA3.1) as 1. C, instead of pCR3-hCAR, pCR3-hPXR was used for the experiments.