Figure 10.—

Working model for Wts signaling from the BLJ. We propose that Dlg organizes two or more signaling complexes to repress invasive tumorigenesis. One complex includes Fas2 as a Dlg PDZ ligand. This complex includes an unknown activator of Wts (X) that represses EMT and proliferation, through regulation of Roe, CycE, DIAP1, and other unknown factors. DIAP1 promotes movement as part of a complex with Rac1, and by triggering Dlg cleavage (scissors, see text). The complex also includes Lgl and does not or only weakly interacts with Scrib (represented as a reduced intensity). Fas2–Dlg–Lgl also repress motility through an undefined pathway. A second complex has an unknown Dlg PDZ ligand (?). This complex is associated predominantly with Scrib, also includes Lgl, and represses EMT and proliferation. In addition to repressing DIAP1, Scrib may promote border cell movement by localizing Rac1, as in humans. Ex and Mer may also be involved in Wts signaling starting during midoogenesis (not shown, see text).