FIG 6.

c-Fos promotes KSHV lytic replication. (A) Control, wild-type, or mutated c-Fos constructs were transfected into Bac16-harboring 293T cells for 48 h, and then the cells were left uninduced or were induced with TPA and NaB for 48 h. The total RNA was extracted and reverse transcribed, and viral cDNAs were analyzed by real-time PCR in duplicate in three independent experiments. The relative viral gene expression was normalized to GAPDH, and the results are shown as a heat map. The gene names in red indicate high c-Fos binding promoters, and the clusters of gene timing are marked at the right according to the KSHV 2.0 annotation (7). IE, immediate early; DE, delayed early. N/A, not annotated. (B) Control, wild-type, or mutated c-Fos constructs were transfected as described above, and the cells were collected, extracted, and analyzed by Western blotting as indicated. (C and D) Different amounts of wild-type or mutated c-Fos constructs were transfected into Bac16-harboring 293T cells for 4 days, and then the cells were collected and analyzed as indicated (C). The medium was collected, virion DNAs were extracted, and the genomic copy number of virion DNA was detected by real-time PCR in duplicate from triple independent experiments (D). *, P < 0.01.