FIGURE 3.

Proteasome-mediated degradation of MBP in mammalian cells is not affected by E1 silencing. A, HEK293 cells were transfected with cDNAs coding for MBP, ODC, and c-Myc, in addition to either non-targeting or anti-E1 siRNA. After 24 h, the cells were subjected to cycloheximide (CHX) chase followed by Western blotting analysis. The percentage of protein remaining was calculated as the ratio of protein at the time points indicated relative to the initial protein. The data are represented as the mean ± S.E. from three separate experiments. B, the knockdown of E1 in treated cells compared with control cells was confirmed by staining for the E1 protein. nonTarg, non-targeting.