ARF1 (ADP-ribosylation factor 1) is a protein in the ARF gene family that is responsible for vesicular trafficking within the cell through its activation of phospholipase D. It is found in the cells golgi apparatus and its main function is intra-Golgi transport within the cell. Arf1 is a GTP-binding protein and is known to activate ArfGEF (guanine nucleotide exchange factor) which is a cholera toxin catalytic subunit.