Filament-forming cytoskeletal GTPase. Required for normal organization of the actin cytoskeleton. Required for normal progress through mitosis. Involved in cytokinesis (By similarity). Plays a role in ciliogenesis and collective cell movements including convergent extension during gastrulation. Controls cell elongation but not polarization during convergent extension. {ECO:0000250; ECO:0000269|PubMed:20671153}.