The Arp2/3 (Actin-related protein 2/3) complex consists of seven subunits, all of which are actin-related proteins. The complex is involved in the control of actin polymerization and in mediating the formation of branched actin networks. p16-ARC, also known as ARPC5 (Actin-related protein 2/3 complex subunit 5) or ARC16 (Arp2/3 complex 16 kDa subunit), is a 151 amino acid subunit of the Arp2/3 complex. Thought to play a role in maintaining the integrity of Arp2/3, p16-ARC is a substrate for MAPKAPK-2 which, through phosphorylation of p16-ARC, may participate in Arp2/3 regulatory functions and remodeling of the Actin cytoskeleton. Two isoforms of p16-ARC exist due to alternative splicing events.