Contribution of the two TBE sites within the <i>ABCD2</i> promoter to <i>β</i>-catenin/TCF-4 mediated transcriptional activation.

<p>(A) HepG2 cells were cotransfected with the indicated expression plasmids along with either wild-type (WT) 800-Luc reporter plasmid containing wild-type (WT) sequences or double mutant (Dm) 800-Luc reporter plasmid containing mutations in the two TBE sites of the <i>ABCD2</i> promoter. Mutated sequences are underlined (lower panel). At 36 h after transfection, cells were harvested, and luciferase activities were determined. The amount of DNA in each transfection was kept constant by adding an appropriate amount of pcDNA3 empty vector. Data represent the mean (± SEM) of triplicate experiments. (B) A ChIP assay was performed by immunoprecipitation of DNA/protein complexes from HepG2 cells with an anti-<i>β</i>-catenin antibody. The immunoprecipitated DNA was amplified with primers specific for the <i>ABCD2</i> promoter. Purified rabbit IgG (IgG) was used as a negative control. Input DNA (before immunoprecipitation) was amplified as a positive control for the PCR. The amplified DNA was analyzed by agarose gel electrophoresis.