Enables GTPase activator activity. Acts upstream of or within several processes, including Ral protein signal transduction; activation of GTPase activity; and regulation of exocyst localization. Predicted to be located in cytosol and plasma membrane. Predicted to be active in cytoplasm. Is expressed in cochlea; diencephalon lateral wall ventricular layer; midbrain ventricular layer; olfactory cortex mantle layer; and olfactory epithelium. Orthologous to human RALGAPA2 (Ral GTPase activating protein catalytic subunit alpha 2). [provided by Alliance of Genome Resources, Apr 2022]