ADP Ribosylation Factor Interacting Protein 2 (ARFIP2)

The RAC proteins are members of the Rho subfamily of Ras-related proteins. Like all members of the Ras superfamily, RAC proteins act as molecular switches and are implicated in the regulation of a number of cellular processes, such as the organization of the actin cytoskeleton. Microinjection of activated RAC (V12Rac) results in rapid actin polymerization and membrane ruffling. The POR1 protein binds directly to RAC1, and the interaction is GTP dependent. A mutation in RAC1 shown to abolish membrane ruffling also abolishes interaction with POR1. In addition, a truncated form of the POR1 protein inhibits the ability of activated RAC1 to induce membrane ruffling. The authors suggested a role for POR1 in RAC1-mediated signaling pathways.