FIG. 2.

Effects of hUPF1 depletion on siRNA-induced mRNA decay. (A) Northern blotting (lanes 1 to 3) shows that hUPF1 is required for silencing of the off-targets (RPA2) but not on-targets (MAPK14). HeLa cells were transfected with siUPF1-1 (lane 3) or siGFP (lanes 1 and 2). After 30 h, the cells were transfected with siMAPK14 (lanes 2 and 3) or siGFP (lane 1) and incubated for 40 h before harvest. RT-PCR (lanes 4 to 6) confirms the knockdown of hUPF1. (B) Northern blot analysis and RT-PCR of mRNA. The experiment was done under the same conditions as that for Fig. 1A.