Figure 6. Np17 induces proteasome-dependent degradation of p53 by recruiting MDM2. (A–C) Western blot showed that Np17 expression inhibited doxorubicin-induced p53 activation but did not affect MDM2. The topoisomerase II inhibitor doxorubicin (2.5 μg/mL) to induce p53 for the indicated times. (D, E) Proteasome inhibitor MG132 attenuated Np17-mediated P53 degradation. (F) EGFP-Np17 protein (Green) is co-localized with MDM2 (Red) in the cell nucleus of HEK293 cells. (G) Cell lysates were immunoprecipitated (IP) with Flag antibody or control IgG, and the immunoprecipitates were analyzed by Western blot analysis with MDM2 antibody.