Effect of SREBP-1c on human CYP7A1 reporter activity. A. Human CYP7A1 reporter constructs (0.2μg) were co-transfected with pcDNA3 empty vector or SREBP-1c expression plasmids (0.1 μg) into HepG2 cells and luciferase activities were analyzed 40 hr after transfection. B. HNF4α site mutant reporter (mHNF4-ph1887/Luc) (0.2μg) was co-transfected with 0.1μg pcDNA3 or SREBP-1c expression plasmid into HepG2 cells. C. Mammalian one-hybrid assay. The Gal4/luciferase reporter, 5xUAS/TK/Luc (0.2μg) was co-transfected with Gal4 empty vector (−)(0.1μg), Gal4-HNF4α (0.1μg), PGC-1α (0.1μg) and increasing amounts of SREBP-1c expression plasmid (0.05-0.2μg) as indicated. D. Human CYP7A1 reporter construct, ph-371-Luc (0.2 μg) was co-transfected with 0.1 μg each of HNF4α and PGC-1α and/or SREBP-1c expression plasmid as indicated. Each assay was performed in triplicates and statistical analysis was performed using student’s t-test, “*”, significant, P< 0.05.