Fig. 7. The Cdc42-binding domain is required for AJ localisation of the Mbt protein. Pupal eye discs (50% p.d.) from mbt^P1 animals expressing transgenic Mbt (A-C), Mbt^T525A (D-F), or Mbt^H19,22L (G-I) with Gal4:238Y were co-stained with the anti-Mbt (A,D,G) and anti-Arm (B,E,H). A merge of the staining for both is seen in C, F and I. Below each proximal to distal projection view, a proximal-to-distal cross-section is shown. The transgenic Mbt and Mbt^T525A proteins colocalise with Arm at AJs of the photoreceptor cells (A-C and D-F, respectively). In contrast to the non-mutated Mbt protein, the Mbt^T525A protein is unable to rescue the mbt^P1 AJ defects fully (compare B with E). Mutation of the Cdc42-binding site leads to cytoplasmic distribution of the Mbt^H19,22L protein (G). As revealed by anti-Arm staining, the Mbt^H19,22L protein cannot rescue the mbt^P1 AJs defects fully (H). (K-M) Expression of Mbt^H19,22L in a wild-type background. Note that the Mbt antibody recognises both the endogenous and the Mbt^H19,22L protein in this preparation. Scale bar: 10 µm.