ADP Ribosylation Factor Like Protein 1 (ARL1)

ARL1 belongs to the ARL family of proteins, which are structurally related to ADP-ribosylation factors (ARFs). ARFs, described as activators of cholera toxin (CT) ADP-ribosyltransferase activity, regulate intracellular vesicular membrane trafficking, and stimulate a phospholipase D (PLD) isoform. Although, ARL proteins were initially thought not to activate CT or PLD, later work showed that they are weak stimulators of PLD and CT in a phospholipid dependent manner.

By Northern blot analysis, they detected 3.2-, 1.7-, and 1.2-kb ARL1 mRNAs in all human tissues tested except brain, which had only the 3.2-kb species. Western blot analysis demonstrated highest levels of ARL1 protein in kidney, liver, heart, and lung.