Fig. 6. Drosophila Nab physically interacts with Rn and Sqz via their conserved C-terminal domains. (A) Results of the GST-Nab pull-down assays. GST-Nab pulls down intact [³⁵S]Rn and [³⁵S]Sqz proteins, indicating direct binding. Binding was greatly reduced when the Rn protein lacked its C-terminal domain ([³⁵S]Rn⁸⁵⁴). Each experiment was repeated three times with identical results. (B) Comparison of Rn and Sqz proteins showing the two conserved domains: the zinc-finger domain (black box) with 90% homology, and the C-terminal domain (gray box). (C) Amino acid alignment of the conserved C-terminal domains of Rn and Sqz. ^*, identical; (:) conserved substitution; (.) semi-conserved substitution. (D) Clones of rn⁸⁵⁴ misexpression (green, Act5C>Gal4>UASGFP UASrn⁸⁵⁴). wg expression (red) is activated throughout in the wing pouch (arrows). (E) Clones of rn misexpression (green, Act5C>Gal4>UASGFP UASrn) only activate wg expression (red) in the wing hinge (arrows) where Nab is not expressed, but not in the wing pouch (arrowheads).