Enables GTPase activator activity. Involved in several processes, including negative regulation of blood vessel remodeling; negative regulation of cellular extravasation; and regulation of vascular permeability. Acts upstream of or within several processes, including neuromuscular process controlling balance; regulation of vesicle-mediated transport; and response to lipopolysaccharide. Located in cytosol; glutamatergic synapse; and plasma membrane. Is active in Schaffer collateral - CA1 synapse. Is expressed in several structures, including alimentary system; mesothelium; metanephros; nervous system; and sensory organ. Orthologous to human ABR (ABR activator of RhoGEF and GTPase). [provided by Alliance of Genome Resources, Apr 2022]