Figure 8.

UPF caspase-cleavage fragments induce apoptosis and/or NMD inhibition. (a) Measure of apoptosis as described before in HeLa cells expressing one of the UPF caspase-cleavage fragments or as a control the empty expression vector (CFP) or the full-length UPF protein UPF1 (CFP-UPF1) or UPF2 (CFP UPF2). The N-terminal caspase-cleavage fragment of UPF1, UPF2 or the C-terminal caspase-cleavage fragment of UPF1 or UPF2 are noted CFP-UPF1-Nter, CFP UPF2-Nter, CFP-UPF1-Cter or CFP UPF2-Cter, respectively. (b) Effect of the UPF caspase-cleavage fragments on NMD efficiency. HeLa cells were transfected with expression vectors encoding globin mRNA Norm or Ter, MUP mRNA as a loading control, one of the UPF caspase-cleavage fragments or as a control the empty expression vector or the expression vector encoding the full-length UPF1 or UPF2. The level of NMD efficiency was measured by RT-PCR after quantifying the level of Globin and MUP mRNA. A histogram representation of the mRNA measures is presented. The results of figure 8 are representative of two independent experiments. Error bar=S.D., student t-test: *P<0.1; **P<0.05