LANA is required for the recruitment of Polycomb proteins to lytic promoters during de novo infection.

(A) Schematic of the KSHV latency locus encoding latent genes. (B) ChIP assays testing the recruitment of PRC2 factor EZH2 and PRC1 factor RING1B onto viral lytic promoters in SLK cells 72 hours after infection with WT or the indicated KSHV mutants. (C and D) ChIP assays for the repressive (H3K27me3) and activating (H3K4me3) histone marks on viral and cellular promoters at 72 hpi. The LANA and actin (ACT) promoters devoid of H3K27me3 and the PRC2-regulated MYT1 promoter served as controls. (E) Immunoblots showing LANA protein levels in mock and KSHV-infected SLK cells at 72 hpi. *Non-specific. (F) ChIP assays for EZH2 and RING1B associations with viral promoters at 72 hpi.