FIG 4.

c-Fos shRNAs decrease late KSHV lytic gene expression. (A to E) Stable c-Fos shRNAs were transduced into BCBL1 cells, and the cells were selected with 2 μg/ml puromycin for 2 weeks. After c-Fos mRNA expression was validated by real-time PCR (A), the cells were induced with 20 ng/ml TPA or 1 mM NaB. At different time points, the cells were collected and total RNAs were extracted, reverse transcribed, and subjected to real-time PCR for ORF45 (B), ORF64 (C), and ORF50 (D) expression. Whole-cell extracts were subjected to Western blotting as indicated (E). (F) Transient c-Fos shRNAs were transduced into iSLK.219 cells with double retrovirus infection, and then the cells were induced with 1 μg/ml doxycycline and 1 mM NaB. The cells were collected at different time points, lysed, and analyzed by Western blotting as indicated. NS, nonspecific shRNA control.