Structure and Function of ARF Proteins: Activators of Cholera Toxin and Critical Components of Intracellular Vesicular Transport Processes

During the 1980s, several cellular factors that enhanced cholera toxin-catalyzed ADP-ribosylation of Gsα or activation of adenylyl cyclase were described. Kahn and Gilman (1) reported the first purification of an ∼20-kDa membrane-associated protein that enhanced ADP-ribosylation of Gsα and named it ADP-ribosylation factor or ARF.1(1) Two soluble ARFs purified later stimulated toxin-catalyzed ADP-ribosylation of Gsα and simple guanidino compounds (e.g. arginine) as well as toxin auto-ADP-ribosylation in a GTP-dependent manner (2).