Figure 2.

EV71 infection induces activation of AP-1 via c-Src, PDGFR, and PI3K/Akt. Cells were incubated with JEV (moi = 1) for the indicated time intervals. (A) mRNA levels for c-Jun and c-Fos were determined by RT-PCR. (B) Protein levels of c-Jun and c-Fos were determined by western blotting. (C) Cells were transfected with an AP-1 promoter luciferase construct or control vector (pGL3-Luc) together with a β-galactosidase plasmid, and then incubated with JEV (moi = 1) for the indicated time intervals. AP-1 promoter activity was normalized to that of β-galactosidase activity. (D) Cells were incubated with JEV (moi = 1) for the indicated time intervals. c-Fos and c-Jun binding activities were analyzed by chromatin immunoprecipitation (ChIP) assay. (E, F) Cells were pretreated with AG1296 (AG, 10 μM), PP1 (10 μM), or LY294002 (LY, 30 μM) for 1 h, and then incubated with JEV (moi = 1) for (E) 20 min or (F) 60 min. (E) mRNA expression for c-Jun and c-Fos were examined by RT-PCR. (F) Protein levels of c-Jun and c-Fos were determined by western blotting. (G) Cells were transfected with an AP-1 promoter luciferase construct or control vector (pGL3-Luc) together with a β-galactosidase plasmid, pretreated with AG1296 (AG, 10 μM), PP1 (10 μM), or LY294002 (LY, 30 μM) for 1 h, and then incubated with JEV (moi = 1) for 30 min. The AP-1 promoter activity was normalized to that of β-galactosidase activity. Data are expressed as mean ± S.E.M. for five independent experiments. ^#P < 0.01, as compared with the basal level (C). *P < 0.05, as compared with cells exposed to JEV alone (G).