Fig. 4.

Mapping of the minimal responsive element in ORF59 promoter. (A) Scheme showing a series of truncated promoters (D4 to D9) were cloned into a luciferase reporter plasmid, pGL3-enhancer. Serial deletions were made on the 630-bp fragment from the 5′ end, with the number indicating the nucleotide position upstream of the AUG codon. Fixed amount (1 μg) of reporter plasmids were cotransfected into DG75 (B) and 293T (C) cells with either an Rta expression plasmid pCR3.1-RTA (5 μg) or pCR3.1 (5 μg). All the cells were harvested at 24 h posttransfection, dual-luciferase assays and fold activations were performed as described in Fig. 1. The means and standard deviations from three independent transfections are shown.