EZH2 is required for the expression of Ephrin-B2 in KSHV-infected endothelial cells. A, EZH2 is required for the expression of Ephrin-B2 protein in BOEC and SLK cells. Mock- and KSHV-infected BOEC cells (top panel) and SLKp cells (lower panel) were transduced with lentivirus of EZH2 shRNA or control shRNA for 4 days, and examined for the expression of EZH2 and Ephrin-B2 proteins. B, EZH2 is required for the expression of Ephrin-B2 mRNA in BOEC cells. Mock- and KSHV-infected BOEC cells described in (A) were also examined for the expression of EZH2 and Ephrin-B2 mRNAs. C, EZH2 directly binds to the Ephrin-B2 promoter. Chromatin from SLKp cells with or without transduction with lentivirus of EZH2 shRNA or control shRNA for 4 days were immunoprecipitated with an EZH2 antibody or IgG control. Immunoprecipitated DNA were extracted and examined for the presence of Ephrin-B2 promoter DNA by qPCR. RTA and LANA promoters known to have strong and weak EZH2 binding, respectively, were used as controls. Chromatin enrichment by the EZH2 antibody was calculated as the percentage of the immunoprecipitated DNA and compared to IgG precipitated DNA (“1” in the left panel). Binding of EZH2 protein to the promoters in cells with shRNA knockdown was compared to those transduced with control shRNA (“100%” in the right panel).