Arfaptin 2 （ARFIP2） is a Rac1 binding protein essential for Rac-mediated actin polymerization and the succeeding formation of membrane ruffles and lamellipodia. ARFIP2 is a putative target protein of ADP-ribosylation factor. ARFIP2 is also involved in membrane ruffling. ARFIP2 expression is increased at sites of neurodegeneration. In addition， ARFIP2 interacts with the ADP ribosylation factor ARF6， a GTPase which associates with the plasma membrane and intracellular endosome vesicles， in a GTP dependent mode. Furthermore， Arfaptin 2 controls the aggregation of mutant Huntingtin protein by weakening proteasome function.
