ARAP3 is a phosphatidylinositol 3,4,5-trisphosphate-dependent GTPase-activating protein that modulates actin cytoskeleton remodeling by regulating ARF and RHO family members. It is activated by phosphatidylinositol 3,4,5-trisphosphate (PtdIns(3,4,5)P3) binding. It can also be activated by phosphatidylinositol 3,4-bisphosphate (PtdIns(3,4,5)P2) binding, albeit with lower efficiency. ARAP3 acts on ARF6, RAC1, RHOA and CDC42. ARAP3 plays a role in the internalization of anthrax toxin [taken from the Universal Protein Resource (UniProt) www.uniprot.org/uniprot/Q8WWN8].