Figure 5

MSK1-mediated histone H3 phosphorylation at Ser10 regulated LMP1-induced AP-1 activation 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 AP-1 firefly luciferase activity was measured and normalized against Renilla luciferase activity. Asterisks indicate a significant difference compared with LMP1-transfected cells untreated with H89 (*, p < 0.05; **, p < 0.005). (B) CNE1 cells were cotransfected with si-mock or si-MSK1 and pcDNA3.0-LMP1. At 48 hours after transfection, the AP-1 firefly luciferase activity was measured and normalized against Renilla luciferase activity. Asterisks indicate a significant difference between two groups (*, p< 0.05). (C) CNE1 cells were cotransfected with pcDNA6.0, pcDNA6.0-H3 or pcDNA6.0-H3S10A and pcDNA3.0-LMP1. After 24 h of transfection, cells were starved for another 24 h. The AP-1 firefly luciferase activity was measured and normalized against Renilla luciferase activity. Asterisks indicate a significant difference compared with mock control cells (*, p< 0.05).