Figure 3.

RPL32 Silencing Inhibits MDM2-Mediated p53 Ubiquitination and Degradation

(A and B) (A) A549 and (B) NCI-H460 cells were transfected with scramble siRNA or RPL32 siRNA and the RPL32 and p53 mRNA levels were determined with quantitative real-time PCR analysis. ***p < 0.001. (C) Immunoblot analysis of p53 and RPL32 protein levels in cells treated with cycloheximide (25 μg/mL) at the indicated time points. Densitometric analysis is also shown (n = 3; mean ± SD). (D) Immunoblot analysis of p53 protein levels in cells after treatment with MG132 (10 μM, 4 h). (E) Cell lysates of A549 and NCI-H460 cells were immunoprecipitated with anti-p53 antibody, followed by immunoblot with anti-p53, anti-MDM2, and anti-ubiquitin antibodies. The cells were treated with MG132 (10 μM) for 10 h before harvesting.