ARL1 is part of the ARL (ADP-ribosylation factor-like) family of proteins, which are structurally associated to ADP-ribosylation factors (ARFs). ARFs, described as activators of cholera toxin (CT) ADP-ribosyltransferase activity, control intracellular vesicular membrane trafficking, and stimulate a phospholipase D (PLD) isoform. ARL1 is a weak stimulator of PLD and CT in a phospholipid dependent manner. ARL1 is a GTP-binding protein that has low efficiency as allosteric activator of the cholera toxin catalytic subunit, an ADP-ribosyltransferase. ARL1 is involved in the Golgi apparatus Synonyms: ARFL1