Enables small GTPase binding activity. Involved in several processes, including negative regulation of cell-substrate adhesion; regulation of GTPase activity; and regulation of ruffle assembly. Located in early endosome membrane; nucleus; and plasma membrane. Is expressed in several structures, including alimentary system; brain; genitourinary system; immune system; and respiratory system. Orthologous to human RCC2 (regulator of chromosome condensation 2). [provided by Alliance of Genome Resources, Apr 2022]