Regulates and controls rearrangements of the actin cytoskeleton. Required for tip formation, morphogenesis, cell adhesion and motility, chemotaxis and aggregates formation. May function downstream of paxB. Expressed after 4 hours of development, reaches a peak at 8 to 12 hours, and then decreases. Cells exhibit an aberrant actin cytoskeleton and numerous F-actin-enriched microspikes. Cells aggregate poorly and aggregates arrest at the mound stage. They exhibit poor adhesion, form weak cell-cell agglomerates in suspension, do not polarize in chemoattractant gradient and move very poorly.