FIG. 5.

K-RBP suppresses KSHV ORF57 promoter is dependent on the GC-rich element. (A) Schematic representation of the luciferase promoter reporters used. (B-F) 293T cells were transfected with 100ng of pGL3-basic as shown in (B), p57Pluc1 in (C), p57-3RRE in (D), p57-3RRE4 in (E), p57-3RRE2 in (F) using the indicated amounts of K-RBP plasmid pcDNAK-RBP. The luciferase activities were detected at 24 h post-transfection. For all transfections, total DNA amounts used in each transfection were normalized by the addition of control plasmid. The percentages of inhibition by K-RBP were indicated. The error bars indicate standard deviations of at least 3 independent experiments. Transfection efficiency for each experiment was normalized using a β-Gal expression plasmid as internal control. The basal levels of the promoter activity were normalized to 100%.