FIG. 2.

Sequences required for E2F3b promoter activity. (A) Schematic depiction of E2F3b promoter constructs. Luciferase reporter constructs containing the indicated 5′-flanking sequence were used for assays of promoter activity. (B) REF52 cells were transfected with 4 μg of the indicated E2F3b-luciferase plasmids together with 2 μg of CMV–β-galactosidase. Transfected cells were treated as described in Materials and Methods and harvested at the indicated time points. Luciferase activity was normalized to the β-galactosidase activity. Symbols: □, E2F3b (−1018); ■, E2F3b (−733); ○, E2F3b (−350).