Figure 4.

AG1024 diminished JAK1 protein levels mainly through proteolysis. (A) Proteasome inhibitor MG132 significantly restored AG1024 diminished JAK1 protein level. (B) The effect of AG1024 treatment on the JAK1 transcriptional activity as determined by RT-PCR. ST cells were treated with AG1024, MG132, or ouabain as indicated and harvested at 6 h.p.i. of TGEV (MOI:7). The resulting lysates were subjected to western analyses (A) or semi-quantitative RT-PCR (B), respectively. *, p < 0.05; **, p < 0.01. Results shown are averages ± SD from three independent experiments.