Figure 1. Activation of TATA box-containing promoters by Dorsal. (A) Activation of the asph gene by Dorsal. The asph promoter contains a TATA box, an Inr, and a DPE sequence motifs. Drosophila S2R+ cells were co-transfected with a firefly luciferase reporter construct driven by the natural enhancer-promoter of asph (which includes 8 putative Dorsal binding sites) containing wt (1), mDPE (2), or mTATA box promoter (3), as well as expression vectors of either Dorsal or an empty vector, as indicated. To control for transfection efficiency variations, cells were co-transfected with a control Renilla luciferase reporter driven by the Pol III promoter and assayed for dual luciferase. The activities are reported relative to the wild-type promoter in the absence of co-transfected Dorsal expression plasmid, which was defined to be 1. n = 3 and error bars represent S.E.M. (B) Activation of the actin5C gene by Dorsal. The actin5C promoter contains both TATA box and Inr sequence motifs. Drosophila S2R+ cells were co-transfected with a Renilla luciferase reporter construct driven by the natural enhancer-promoter of actin5C (which includes 7 putative Dorsal binding sites) containing wt (1), mTATA (2), or mTATA +DPE promoter (3), as well as expression vectors of either Dorsal or an empty vector, as indicated. To control for transfection efficiency variations, cells were co-transfected with a control firefly luciferase reporter driven by the Scr (Sex combs reduced) enhancer-promoter that is not responsive to Dorsal and assayed for dual luciferase as in (A).