SRM: Proteins and Enzymes

The Arp2/3 protein complex has been implicated in the control of actin polymerization in cells. The human complex consists of seven subunits which include the actin related proteins Arp2 and Arp3, and five others referred to as p41-Arc, p34-Arc, p21-Arc, p20-Arc, and p16-Arc (p omplex) (1). These proteins localize in the cytoplasm of fibroblasts that lack lamellipodia, but are enriched in lamellipodia on stimulation with serum or platelet-derived growth factor. A dynamic role for this complex in the organization of the actin cytoskeleton has been suggested (2). p16-Arc has been found to be a globular alpha-helical subunit (3).