Figure 5.

Effect of TPT and MXT on the proportion of p53-Ser15^P versus total p53. A549 cells were untreated or treated with 0.15 μM TPT or 0.2 μM MXT for 5 h. Expression of cellular p53 and p53-Ser15^P was detected with Ab that reacts with p53 regardless of its status of Ser15 phosphorylation (total p53) and with the phospho-specific Ser15^P Ab, respectively, tagged with fluorochromes having different fluorescence emission (488 and 633 nm), as described in Materials and Methods. Cellular DNA was stained with DAPI. The data are presented as a the mean (±SD) ratio of the increase (Δ) of p53-Ser15^P to the increase of p53 IF in treated cells over their constitutive levels in untreated cells, estimated by gating analysis for G₁, S and G₂M cells.