Enables several functions, including GTP binding activity; GTPase activating protein binding activity; and GTPase activity. Involved in several processes, including actomyosin structure organization; positive regulation of acetylcholine secretion, neurotransmission; and positive regulation of locomotion. Located in cell cortex and cleavage furrow. Expressed widely. Human ortholog(s) of this gene implicated in several diseases, including colorectal cancer; multiple sclerosis; and ovarian carcinoma. Is an ortholog of human RHOA (ras homolog family member A).