Drosophila Asap regulates cellular protrusions via dArf6-dependent actin regulatory pathway

Membrane protrusions are fundamental to cellular functions like migration, adhesion, and communication and depend upon the dynamic reorganization of the cytoskeleton. The GAP-dependent GTP hydrolysis of Arf proteins regulates actin-dependent membrane remodeling. Here, we show that the dAsap regulates membrane protrusions in S2R+ cells by a mechanism that critically relies on its ArfGAP domain and re-localization of actin regulators, SCAR, and Ena. While our data reinforce the preference of dAsap for Arf1 GTP hydrolysis in vitro, we demonstrate that induction of membrane protrusions in S2R+ cells depends on Arf6 inactivation. This study furthers our understanding of how dAsap-dependent GTP hydrolysis maintains a balance between active and inactive states of dArf6 to regulate cell shape.