Background information
The ADP-ribosylation factor (ARF) protein family are structurally and functionally conserved members of the Ras superfamily of regulatory GTP-binding proteins (1–3). ARFs influence vesicle trafficking and signal transduction in eukaryotic cells (1–3). ARF-dependent regulatory mechanisms include the coordination of spectrin interactions with golgi membranes and the association of actin to the golgi via rho family-dependent G-protein localization (Rac, CDC42) and WASP/Arp2/3 complexes (3–7). Additionally, ARFs play a central role in maintenance of organelle integrity, assembly of coat proteins, and activation of phospholipase D (5–7). The ARF proteins are categorized as class I (ARF1, ARF2,and ARF3), class II (ARF4 and ARF5) and class III (ARF6); members of each class share a common gene organization (8,9). The human ARF6 gene maps to chromosome 7q22.1, contains five exons and four introns, and encodes a 175 amino acid protein (8,9).