Figure 1

p17 promotes E3 ligase MDM2 targeting to ribosomal proteins. (A) Vero cells were infected with ARV at an MOI of 10 or transfected with pcDNA3.1-Flag-p17 or pcDNA3.1-Flag-p17(1–118) plasmids for 24 hours, followed by Western blot assays with the indicated antibodies. (B) The expression levels of Rpl26 and Rpl27 in ARV-infected and p17-transfected cells were examined in the presence or absence of MG132 (25 uM), respectively. Whole cell lysates were harvested for Western blot assays with the indicated antibodies. The experiments were repeated three times, and representative blots are shown. (C) In co-immunoprecipitation experiments, the binding of E3 ligase MDM2 to ribosomal proteins was examinedinp17-transfected Vero cells. Vero cells were transfected with pcDNA3.1-Flag-p17 plasmid and pcDNA3.1-Flag, respectively. Cell lysates were immunoprecipitated with MDM2 or Rpl26 and interacting proteins were detected with the indicated antibodies. (D) Vero cells were transfected with pcDNA3.1-Flag-p17 with or without co-transfection with MDM2 shRNA.The interaction of MDM2 with Rpl26 and Rpl27 was examined. (E) Vero cells without treatment or pretreated with MG132 followed by mock infection, ARV infection, and p17 transfection, respectively. The interaction of ubiquitin with Rpl26 and Rpl27was examined. Similar results were obtained in three independent experiments. The protein levels were normalized to those for β-actin. The levels of indicated protein in the mock control or at 0 h were considered 1-fold.The activation and inactivation folds indicated below each lane were normalized against values for the mock control or at 0 h. The uncropped blots with molecular weights are shown in Fig. S5.