FIG 3.

TPA-mediated stimulation of viral translation depends on catalytically active MNK. Dox-inducible cells expressing wt HA-tagged MNK1, MNK1(D191A), MNK1(ΔMAPK), or MNK2 (see the text for details) were used for mock or TPA stimulation after siCtrl (mock) or siMNK (MNK1) depletion. Dox-induced expression (exp.) of the corresponding HA-tagged MNK (lanes 4, 8, 12, and 16) was detected by HA immunoblotting. The MNK1 antibody used does not recognize MNK1(ΔMAPK) or MNK2. Viral translation was assayed at 4 h p.i. The percent reconstitution of viral translation was calculated as follows: (siMNK + Dox + TPA − siMNK + TPA) divided by (siCtrl + TPA − siMNK + TPA), representing the average of 3 experiments. The error bars represent SEM, and the asterisks indicate significance (P < 0.05 by Student's t test compared to 0% reconstitution).