ARFGAP1 (ADP-ribosylation factor GTPase activating protein 1), also known as ARF1 GAP, is a 406 amino acid protein that contains one ARF-GAP domain and localizes to the cytoplasm and the golgi apparatus. Functioning as a GTPase-activating protein (GAP), ARFGAP1 interacts with ARF1 and promotes hydrolysis of ARF1-bound GTP, an event that is required for both the dissociation of coat proteins from golgi structures and for the subsequent fusion of golgi vesicles with target compartments. When overexpressed, ARFGAP1, whose activity is inhibited by phosphatidylcholine and stimulated by phosphoinosides, can induce the redistribution of the entire golgi apparatus to the endoplasmic reticulum. Multiple isoforms of ARFGAP1 exist due to alternative splicing events.