p53 expression and function for the TP53 PAS variant in p53-null cells. (A) Schematic representation of the TP53 constructs. Each carries a WT 5′UTR, WT CDS, a WT or mutant 3′UTR, and a 2.5-kb native genomic sequence downstream of the TP53 PAS. (B) Western blot of p53 expression in p53-null H1299 cells transfected with p53 constructs. β-actin was used as a control. OE, overexposure. (C) Northern blot of p53 mRNAs in H1299 cells carrying exogenous p53 genes. A housekeeping RNA (H1RNA, the RNA subunit of human ribonuclease P) was used as a control. (D) Apoptosis of cells with p53 constructs; representative TUNEL images (left) and percentage of TUNEL-positive cells (right). *P ≤ .05.