ADP-ribosylation factor 5 is a protein that in humans is encoded by the ARF5 gene. ADP-ribosylation factor 5 (ARF5) is a member of the human ARF gene family. These genes encode small guanine nucleotide-binding proteins that stimulate the ADP-ribosyltransferase activity of cholera toxin and play a role in vesicular trafficking and as activators of phospholipase D. The gene products include 6 ARF proteins and 11 ARF-like proteins and constitute 1 family of the RAS superfamily. The ARF proteins are categorized as class I (ARF1, ARF2, and ARF3), class II (ARF4 and ARF5) and class III (ARF6). The members of each class share a common gene organization. The ARF5 gene spans approximately 3.2kb of genomic DNA and contains six exons and five introns.