Fig. 4.

Cotransfection assays using either Sp1- or Sp3-containing vectors and SLC52A3 minimal promoter-luciferase construct in Drosophila SL2 cells. SL2 cells were cotransfected with 4 μg of the minimal promoter construct in pGL3-Basic and either control plasmid pPac Sp0 or Drosophila Sp expression plasmids (pPac Sp1, pPac Sp3). At 48 h posttransfection, cells were harvested, and firefly luciferase activity was assayed. Data are reported as relative firefly luciferase activity and represent means ± SE of at least 3 independent experiments. *P < 0.01.