Small GTP-binding protein which cycles between an inactive GDP-bound and an active GTP-bound form, and the rate of cycling is regulated by guanine nucleotide exchange factors (GEF) and GTPase-activating proteins (GAP). GTP-binding protein that does not act as an allosteric activator of the cholera toxin catalytic subunit. Recruits CYTH1, CYTH2, CYTH3 and CYTH4 to the plasma membrane in GDP-bound form (By similarity). Interacts with CYTH2. Interacts with KPNA2; the interaction is direct. Does not interacts with ARL4A (By similarity). Localization in the nucleolus is dependent by nucleotide binding. Expressed strongly in testis and liver. Expressed slightly in heart, spleen, lung and kidney. Expressed strongly in embryo at 7 dpc. Expressed slightly in embryo at 11, 15 and 17 dpc. Myristoylated. Belongs to the small GTPase superfamily. Arf family.