Fig. 6.

IBV-induced autophagy requires the MAP kinase ERK but not JNK.

(a) H1299 cells were transfected with siJNK or siEGFP and infected with IBV or mock infected. Protein lysates were harvested at the indicated time points and subjected to Western blot analysis using antibodies against LC3, PARP, phosphor-JNK, total JNK, and IBV N. Beta-actin was included as the loading control. Sizes of protein ladders in kDa were indicated on the left. The LC3-II/actin ratio and percentage of PARP cleavage was determined as in Fig. 4a and normalized to the mock-infected siEGFP control. The experiment was repeated three times with similar results, and the result of one representative experiment is shown.

(b) H1299 cells were transfected with siERK or siEGFP and infected with IBV or mock infected. Protein lysates were harvested at the indicated time points and subjected to Western blot analysis using antibodies against LC3, PARP, phosphor-ERK, total ERK, and IBV N. Beta-actin was included as the loading control. Sizes of protein ladders in kDa were indicated on the left. The LC3-II/actin ratio and percentage of PARP cleavage was determined as in (a) and normalized to the mock-infected siEGFP control. The experiment was repeated three times with similar results, and the result of one representative experiment is shown.