FIGURE 3:

Et/Lat cannot bind to pathway ligands. (A) Immuno­precipitation assays show that Dome-FLAG can coprecipitate cotransfected GFP-tagged pathway ligands (black arrowheads). By contrast, no interaction is detected after precipitation of Et/Lat-FLAG. 1, Upd; 2, Upd2; 3, Upd3. Diffuse banding pattern of ligand-GFP fusions are believed to be affected by posttranslational glycosylation of these secreted proteins. (B) Immunoprecipitation assays show that Upd2-GFP (arrowheads) can be coprecipitated from conditioned medium by cells expressing Dome-FLAG but not by cells expressing empty vector (EV) or Et/Lat-FLAG. Addition of dsRNA targeting the UTR of the dome mRNA was used to deplete endogenous Dome from cells, ensuring that the interaction observed is via the transfected FLAG-tagged proteins.