FIG. 1.

RTA activates the K14-ORF74 promoter though an ISRE-like element. A. Schematic representation of K14-ORF74 promoter region and reporter constructs. RNA start sites for K14-ORF74 and for LANA are shown and are based on the report of Jeong et al. (26). The K14 ISRE and its sequence, its mutations, the reporter constructs, and BC-1 genomic coordinates are shown. The mutated nucleotides are underlined. A previously identified K14 RRE and a putative RRE are also shown. B. K14-ORF74 promoter reporter constructs are inducible in HHV-8-positive cells. DG 75 is HHV-8 negative, while BC3 is an HHV-8-positive cell line. The reporter constructs were transfected into cells by electroporation. The fold activation after TPA treatment (24 to 36 h posttreatments) is shown. C. RTA activates K14-ORF74 reporter constructs. 293T cells were transfected with reporter construct, K14A-luc, or K14B-luc, along with CMV-β-Gal and various amounts of RTA expression plasmids (10, 25, and 50 ng). The reporter activity is expressed relative to the vector control. D. RTA activates K14 ISRE. K14 ISRE-luc or mK14ISRE-luc was transfected with the RTA expression plasmid (0.1 and 0.3 μg). The reporter activity is expressed relative to vector control. In these assays, luciferase activity was normalized by β-galactosidase activity. Standard deviations are shown.