Fig. 3. Diagram showing a structural role for nonmuscle myosin II in maintaining cell adhesion. The extracellular domains of cadherin molecules interact with those of the neighboring cell. Bipolar filaments of myosin bind to actin, which, in turn, interacts with the catenins, which are shown interacting with the cytoplasmic portion of cadherins (green rectangles). The nature of the interaction between the catenin and associated proteins and actin is unclear at present (see text). As outlined above, NMII plays a role in both maintaining and disassembling the adhesion junction complex. (Right) A similar type of role can be visualized for NMII with regard to focal adhesions through which the cell interacts with the extracellular matrix (ECM). Among the various proteins binding to the integrins are -actinin, talin, focal adhesion kinase, vinculin and paxillin. (Bottom) NMII also serves as a scaffold for kinases and small GTP-binding molecules (as well as molecules that have yet to be identified), which regulate its activity and its interaction with actin and other molecules such as microtubules. The diagram omits numerous actin-bundling and regulatory proteins.