Figure 6

The phosphatase activity of DUSP6 is sufficient for suppressing ERK1/2 signaling, promoting apoptosis, and impairing IBV replication. Vero (A), H1299 (B), and DF-1 (C) cells were transfected with constructs encoding HA tagged DUSP6-WT and DUSP6-DN, or vector pCMV-HA, respectively. At 24 h post-transfection, cells were infected with IBV (MOI = 1) for 20 and 24 h. The expression of HA-DUSP6-WT and HA-DUSP6-DN, the levels of p-ERK1/2, ERK1/2, PARP, Bcl-2, Mcl-1, IBV N, and β-actin were checked by Western blot analysis. The experiments were repeated in triplicate and the representative data were shown. The signal of protein bands was determined by Image J software. The intensities of p-ERK1/2 or p-ERK2 were normalized to total ERK1/2 or total ERK2, the intensities of Bcl-2, Mcl-1, IBV N were normalized to β-actin, and the intensities of PARP-C were normalized to PARP-FL. The ratio of p-ERK1/2, p-ERK2, Bcl-2, Mcl-1, and IBV N in DUSP6 or DUSP6-DN transfected cells to vector transfected cells are shown as (DUSP6:pCMV). The ratio of PARP-C in DUSP6 transfected cells to DUSP6-DN transfected cells are shown as PARP-C (DUSP6:DUSP6-DN).