Acts as an actin nucleation factor, remains associated with the slow-growing pointed end of the new filament. Promotes dissociation of capu from the barbed end of actin filaments. Involved in intracellular vesicle transport along actin fibers, providing a novel link between actin cytoskeleton dynamics and intracellular transport. Required for localization of determinants within the developing oocyte to the posterior pole and to the dorsal anterior corner. Links Rho family signaling and Jnk function to the actin cytoskeleton (By similarity). {By
Similarity}.