BoHV-1 infection of MDBK cells induced the activation of MAPK/Erk1/2 pathway. (a) Time course for BoHV-1 stimulation and Erk1/2 phosphorylation. Growth arrested cells were infected with BoHV-1 and processed for Western blotting at pi time indicated. Mock infected cells were used as a control. (b) Time course for BoHV-1 stimulation and Erk1/2 phosphorylation at the early time. (c) MEK specific inhibitor U0126 inhibited the virus induced Erk1/2 phosphorylation. Cells preincubated with medium in the absence of U0126 and then mock infected or infected with virus were used as the negative and positive control, respectively. Western blotting was performed with β-actin antibody to detect the protein loading. Growth arrested MDBK cells were pretreated with Ly294002 and infected with BoHV-1 at an MOI of 2 in the presence of the inhibitor, and then processed for western blotting at the time indicated with phospho-p44/42 MAPK (Erk1/2) (Thr202/Tyr204) antibody. Each experiment was repeated three times, and representative results are shown.