Fig. 7. Transfection of JunD-encoding plasmid in transient transfection assays increases the luciferase activity driven by the 5'-regulatory region of the 202 gene. A, schematic of the location of AP-1-like sites within the HindIII and PstI fragment (~0.8 kb) from the 5'-regulatory region of the 202 gene, which is linked to the luciferase reporter gene. The location of the "GA-box," which contains the IFN-responsive elements, is also shown. The upstream and downstream ends of the transcription initiation region in the 202 gene are indicated by t-> and ->t. B, subconfluent cultures of murine AKR-2B cells were transfected with the reporter plasmids pGL3–202luc (5 µg) and pRL-TK (0.5 µg) along with the JunD expression plasmid (0–4 µg) or vector alone (in the same amounts) using the calcium phosphate transfection system as described in "Materials and Methods." Cells were harvested 42–48 h after transfections, and the firefly luciferase and Renilla luciferase activities were determined using the Dual-Luciferase Reporter Assay kit (Promega). The firefly luciferase activity was normalized to the Renilla luciferase activity to control for variations in transfection efficiencies. The luciferase activity in control vector-transfected cells is shown as 1. SD and the results from a representative experiment are shown.