FIGURE 5.

Overexpression of c-Jun or FosB overcomes transcriptional silencing in HeLa cells, but overexpression of FosB, not c-Jun, overcomes transcriptional silencing in U937 cells. A, HeLa cells were transiently transfected with the indicated expression plasmids together with pCAT-4952 or (B) pCAT-4952mAP-1 in the presence of PMA. C, U937 cells were transiently transfected with the indicated expression plasmids together with pCAT-4952 in the presence of PMA. CAT activities are reported as the percentage conversion of chloramphenicol normalized to the average value for untreated pCAT control. The results represent the mean ± S.E. from at least three independent transfections performed in triplicate.