Fig. 2. Physical coupling of adhesion molecules to the actin polymerization machinery. Left, the Arp2/3 complex is directly recruited to sites of integrin engagement through an interaction with the linker region of vinculin, an integrin-associated protein. Right, the Arp2/3 complex is recruited to sites of cell-cell adhesion through an interaction with E-cadherin. Recruitment of the Arp2/3 complex to E-cadherin is thought to localize actin polymerization to sites of cadherin-engagement.