 Arp2 / 3 complex is a seven @-@ subunit protein complex that plays a major role in the regulation of the actin cytoskeleton . It is a major component of the actin cytoskeleton and is found in most actin cytoskeleton @-@ containing eukaryotic cells . Two of its subunits , the Actin @-@ Related Proteins ARP2 and ARP3 closely resemble the structure of monomeric actin and serve as nucleation sites for new actin filaments . The complex binds to the sides of existing ( " mother " ) filaments and initiates growth of a new ( " daughter " ) filament at a distinctive 70 degree angle from the mother . Branched actin networks are created as a result of this nucleation of new filaments . The regulation of rearrangements of the actin cytoskeleton is important for processes like cell locomotion , phagocytosis , and intracellular motility of lipid vesicles . 
