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. Regulates formation of new microtubules and centrosome integrity. Prevents the TBCD-induced microtubule destruction. Participates in association with TBCD, in the disassembly of the apical junction complexes. Antagonizes the effect of TBCD on epithelial cell detachment and tight and adherens junctions disassembly. Together with ARL2, plays a role in the nuclear translocation, retention and transcriptional activity of STAT3. Component of a regulated secretory pathway involved in Ca(2+)-dependent release of acetylcholine. Required for normal progress through the cell cycle (By similarity). Found in a complex with ARL2, ARL2BP and SLC25A6. Found in a complex with at least ARL2, PPP2CB, PPP2R1A, PPP2R2A, PPP2R5E and TBCD. Interacts with ELMOD2. The GTP-bound form interacts with ARL2BP. The GDP-bound form interacts preferentially with TBCD. Interacts with UNC119. Found in a complex with ARL2, ARL2BP and SLC25A4. The GTP-bound form interacts with PDE6D (By similarity). The complex formed with ARL2BP, ARL2 and SLC25A6 is expressed in mitochondria. Not detected in the Golgi, nucleus and on the mitotic spindle. Centrosome-associated throughout the cell cycle. Not detected to interphase microtubules. The complex formed with ARL2BP, ARL2 and SLC25A4 is expressed in mitochondria (By similarity). Expressed in brain, retina, lung, cerebellum, liver, kidney, hippocampus, spleen, cortex and heart (at protein level). Not N-myristoylated. Belongs to the small GTPase superfamily. Arf family.