FIG. 4.

Mdm2-mediated degradation is dependent on lysine residues in the C-terminal region of p53. Saos-2 cells were electroporated with plasmids encoding GFP, WT p53, or K-to-R p53 mutants, together with empty pcDNA3 vector or Mdm2 vector as indicated. (A) Twenty-four hours after transfection, whole-cell extracts were prepared and analyzed by Western blotting with anti-p53, anti-Mdm2, and anti-GFP monoclonal antibodies. (B) Transfected cells were treated with 10 μM MG132 for 4 h prior to harvest. Western blotting against p53 and Mdm2 was performed as described above.