Figure 3.

Mapping the Dorsal interaction regions in Tube and Pelle. (A) Tube interacts with Dorsal via its C-terminal repeats. The pJG plasmids expressing full length Tube (Tube1–462) and different Tube deletions were transformed into EGY48 yeast cells containing the LexA-DL-RHR and LacZ reporter plasmid, and β-galactosidase activity was determined. The N-terminal “death domain” and C-terminal five repeats are indicated by boxes. (B) Both the N-terminal “death domain” and C-terminal kinase domain of Pelle are required for interaction with Dorsal. pJG plasmids expressing full length Pelle, Pelle1–209 and Pelle210–501, were transformed into yeast containing lexA-DL-RHR and the LacZ reporter plasmid. A novel protein y5-5 was used as negative control. (C) The Dorsal RHR domain 1 is required for Tube and Pelle binding. The positions of RHR domain 1 (amino acids 47–216) and domain 2 (amino acids 225–327) are indicated. The LexA fusion of Dorsal RHR, two of its derivatives containing only one domain, and a mutant construct DS234P were tested for their interactions with Cactus, Tube, and Pelle. The arrow indicates the position of serine-234.