Figure 6.

Sp1 and AP2 function cooperatively to regulate hTAF_II55 promoter activity. Wild-type (WT) hTAF_II55 promoter construct, pGL2-TAF55(–71/+36), and its derivatives pGL2-TAF55(–71/+36)Sp1*-60/AP2* and pGL2-TAF55(–71/+36)Sp1*-40/Sp1*-20, which contain mutations either at –50 and –60 or at –40 and –20 Sp1-binding sites, were cotransfected with Sp1 and AP2 insect expression plasmids, alone or in combination, into Drosophila SL2 cells. Reporter gene activities were normalized to that of the same reporter construct cotransfected with the cloning vector pPacO. Reporter plasmids used in the assay are depicted at the bottom, with brackets representing intact Sp1-binding sites and an ‘X’ denoting mutatations introduced at the core sequence.