Fig. 8.

Model describing interactions between Slpr, Rac and Msn. The SKLC region of Slpr supports signaling functions whereas the C-terminal half is responsible for subcellular localization. The PVP motif in the LZ–CRIB linker region of Slpr is involved in SH3-mediated inhibition, which is relieved by interaction of the LZ–CRIB region with active Rac and the CNH domain of Msn to activate JNK signaling, gene expression and dorsal closure. Active Rac also participates in additional JNK-independent functions with other effectors to facilitate dorsal closure.