FIG. 5.

Interaction between RHD and CTD. (A) Dorsal CTD can activate transcription. Top, schematic diagram of the G5 luciferase reporter. The firefly luciferase gene is under the control of five copies of a module containing Gal4 binding sites. These are inserted immediately upstream of the herpes simplex virus thymidine kinase (HSV TK) core promoter. Bottom, S2 cells were transfected with 5 μg of the G5 luciferase reporter and 0.1 μg of a plasmid containing the Renilla luciferase gene under the control of the herpes simplex virus thymidine kinase promoter, together with 0 ng, 150 ng, 500 ng, or 2 μg of pPac-Gal4 or pPac-Gal4-CTD. (B) The RHD binds the CTD. Left, purified GST-CTD. Right, in vitro-translated and ³⁵S-labeled Dorsal380 or the indicated Dorsal380 mutants were incubated with either GST or GST-Dorsal-CTD immobilized on glutathione beads and washed extensively. The eluted proteins were resolved by SDS-PAGE and imaged by autoradiography. One-fifth of the input protein amount is shown for comparison. Quantification of the interaction is shown below the lanes, with wild-type binding arbitrarily set to 1.