Figure 1
IER3 is a novel target gene of TAp73β.
(A) Promoter activation of IER3 by p53 family proteins was determined by luciferase reporter assay after transfection with increasing amounts of plasmids (50, 100, or 200 ng) encoding HA-tagged TAp73β, Flag-tagged TAp63 and HA-tagged p53 in HeLa, KB, Caski, SiHa and 293T cells. The luciferase activity was analyzed 24 h after transfection. Overexpression of TAp73β, TAp63, p53 was confirmed by immunoblot analysis using anti-HA or anti-Flag antibodies. The full-blots membrane was cut into pieces according to estimated molecular weight of proteins of interest and probed with indicated antibodies. All cropped bolts have been run under the same experimental condition. (B) Reduced transcriptional activity of IER3 in TAp73β knockdown (100 and 200 nM) HeLa cells is presented. Efficient silencing of TAp73β using its specific siRNA (100 or 200 nM) was confirmed by western blot analysis. GAPDH was used as a loading control. (C) The indicated truncated and deletion mutants of the IER3 promoter constructs were cotransfected with HA-TAp73β expression plasmid (200 ng) in HeLa cells. Cells were harvested for luciferase assays 24 h after transfection. All of results are expressed as the mean ± SEM of three independent experiments performed in triplicate. Different letters denote statistically significant values (p < 0.05).
