The ARF1 GTPase-Activating Protein: Zinc Finger Motif and Golgi Complex Localization

TLDR

GTP hydrolysis by ARF1 requires a GTPase‑activating protein (GAP). A rat liver ARF1 GAP cDNA encodes a protein with an N‑terminal zinc finger essential for activity, localizes to the Golgi, and is displaced to the cytosol by brefeldin A, indicating ARF1‑dependent recruitment.

Abstract

Hydrolysis of guanosine triphosphate (GTP) by the small guanosine triphosphatase (GTPase) adenosine diphosphate ribosylation factor-1 (ARF1) depends on a GTPase-activating protein (GAP). A complementary DNA encoding the ARF1 GAP was cloned from rat liver and predicts a protein with a zinc finger motif near the amino terminus. The GAP function required an intact zinc finger and additional amino-terminal residues. The ARF1 GAP was localized to the Golgi complex and was redistributed into a cytosolic pattern when cells were treated with brefeldin A, a drug that prevents ARF1-dependent association of coat proteins with the Golgi. Thus, the GAP is likely to be recruited to the Golgi by an ARF1-dependent mechanism.