Fig. 5.

MSK1 regulates LMP1-induced transcriptional activation of Fra-1 and c-Jun in CNE1 cells. (a) CNE1 cells were transfected with pcDNA3.0 or pcDNA3.0-LMP1. H89 was added to the culture medium at the concentration indicated every 12 h after transfection. The firefly luciferase activity was measured and normalized against Renilla luciferase activity respectively. Each bar represents the mean ± SD of three independent experiments. *P < 0.05; **P < 0.005, compared with LMP1-transfected CNE1 cells untreated with H89. (b) The effect of H89 on Fra-1 or c-Jun protein levels induced by LMP1 was examined by Western blotting. (c) CNE1 cells stably expressing si-mock or si-MSK1 were transfected with pcDNA3.0 or pcDNA3.0-LMP1. At 36 hours after transfection, the firefly luciferase activity was measured and normalized against Renilla luciferase activity respectively. *P < 0.01; **P < 0.005, compared with si-mock/LMP1 cells. (d) The effect of MSK1 knockdown on Fra-1 or c-Jun protein levels induced by LMP1 was examined by Western blotting. β-actin was used as loading control