Epigenetic Analysis of KSHV Latent and Lytic Genomes
Figure 5
Polycomb group proteins are involved in the maintenance of latency of KSHV.
(A) Overexpression of the wild-type HA-tagged H3K27me3 histone methyltransferases (HMTs) UTX and JMJD3 triggers the lytic reactivation of KSHV in Vero-rKSHV.219 as shown with the expression of RFP. In contrast, the H3K9me3 HMT JMJD2A and the enzymatically inactive UTXm showed little or no effect on KSHV lytic reactivation. (B) Quantification of RFP positive cells. (C and D) JSC-1 cells were treated with 5 uM DZNep for 1, 2 and 3 days and the cells were harvested for immunoblot analysis with the indicated specific antibodies against cellular proteins and histone modifications (C) or viral proteins (D). “Dpt” indicates days post-treatment. Whole cell lysate of NaB-treated JSC-1 cells was used as a control for Zta immunoblot. (E) JSC-1 cells were treated with DZNep as described in (C) and total RNAs were isolated for RT-qPCR analysis of some selected KSHV, EBV and cellular mRNAs. (F and G) BCBL-1 cells were infected by lentivirus expressing the indicated shRNAs and were then subject to immunoblotting analysis with the indicated antibodies (F) or RT-qPCR analysis was performed for the indicated viral transcripts (G).