Effect of G4-binding ligands on the activity of HCMV promoters.

(A) Schematic representation of the experimental design. HF cells were transfected via electroporation with luciferase reporter plasmid containing the viral G4-containing promoter region for 24 h. To measure the activity of promoter regions from immediate-early genes, transfected cells were infected with HCMV (Towne) at a multiplicity of infection (MOI) of 2 with treatment of DMSO (as a control) or 5 μM of NMM or TMPyP2 for 24 h. To measure the promoter activity of E and L genes, transfected cells were infected with HCMV for 8 h (for early genes) or 24 h (for late genes), and treated with DMSO or 5 μM of NMM/TMPyP2 for 24 h prior to cell harvest and luciferase assay. (B) Expression profiles for luciferase reporter in response to G4 ligands. The repression folds of luciferase activity by NMM or TMPyP4 treatment versus DMSO treatment obtained from triplicate samples are shown. The promoter regions of the UL112 and UL99 genes without any apparent G4 were used as controls. P values calculated between UL37 and IRS1/TRS1 samples, between the UL112 control gene and early genes, or between the UL99 control gene and late genes are indicated.