Fig. 3.

Characterization of CES1A1 guggulsterone element. (A) Stimulation of the CES1A1 and BSEP element reporters. Reporter assays were performed as described above but with element reporters. An asterisk indicates statistical significance of a treatment over solvent control, and an alpha indicates statistical significance between two columns linked by a line (P < 0.05). (B) EMSA analysis. Nuclear extracts (5 μg) from Huh7 cells treated with Z-guggulsterone (10 μM) were incubated with a biotinylated probe (0.01 pmol) for 20 min. In the competition assay, nuclear extracts were preincubated with the unlabeled probe or mutant at 50× (+) or 100× (++) excess for 20 min, and then incubated with the biotinylated probe. The protein-DNA complexes were electrophoretically resolved and detected with streptavidin-conjugated horseradish peroxidase and chemiluminescent substrate.