Figure 2.

Activation of ERK by p53 in various cell types. (A) Activation of ERK by inducible expression of p53 but not by p21 in PC3 cells. Western blots were performed with the lysates from PC3 cells with the tet-regulated expression of p53, p21, or luciferase. (B) Activation of ERK by p53 but not by p21 in 293T cells. Cells were transiently transfected with pcDNA3, p53, or p21. Lysates were made from cells after 24 and 48 h of transfection and were separated by SDS/PAGE. Immunoblotting was carried out with antibodies against p53, p21, pp-ERK, and total ERK. (C) Activation of ERK by temperature-sensitive p53 mutants (REF ts-p53). REFs were grown at 37°C and shifted to 32.5°C for the indicated time periods (1–7 days). Western blots were performed with p53, p21, pp-ERK, and total ERK antibodies.