Enhancement of p53 protein levels by wildtype HIPK2. HeLa cells were transiently transfected with the indicated HIPK2 expression constructs. Cellular extracts were analyzed for p53 expression by Western blotting. The signals corresponding to p53 or phosphorylated p53 (Phospho-p53) are indicated by an arrow. Equal loading was confirmed by reprobing the blots with an anti-β-actin antibody as shown below. (A) Cells were left untreated after transfection. (B) 24 h after transfection, doxorubicin was added to a final concentration of 0.1 μg/ml for 3 and 6 h as indicated. (C) 24 h after transfection doxorubicin was added to a final concentration of 0.1 μg/ml for 6 h and anti-phospho-p53 (Ser 15)-antibody was used for detection of phosphorylated serine 15 in p53. wt, wildtype; vec, vector.