Figure 7.

Coordinate regulation of p53 and p53CP in response to cell cycle blockers. Mouse H-Tx cells (A) and human PC-3 cells (B) were subjected to treatment with cell cycle blockers for 24 hr. The concentrations used were dimethyl sulfoxide (for control, 0.1%), aphidicolin (10 μg/ml), thymidine (2.5 mM), nocodazole (4 μg/ml), and lovastatin (1 μg/ml). Nuclear extracts were prepared after treatment and subjected (2 μg) to gel retardation assay. To measure p53CP binding activity, T3SF was used with a poly(dI/dC) concentration of 50 μg/ml (A, lanes 1–6 and B). To determine p53 binding, p53CON oligo was used with a poly(dI/dC) concentration of 10 μg/ml in the presence of p53Ab (A, lanes 7–12). The p53CP and p53-Ab complexed with oligonucleotides are indicated.