Cytoskeleton cross-talk during cell motility

Cell crawling entails the co-ordinated creation and turnover of substrate c ontact sites that interface with the actin cytoskeleton. The initiation and maturation of contact sites involves signalling via the Rho family of smal l G proteins, whereas their turnover is under the additional influence of t he microtubule cytoskeleton. By exerting relaxing effects on substrate cont act assemblies in a site- and dose-specific manner, microtubules can promot e both protrusion at the front and retraction at the rear, and thereby cont rol cell polarity, (C) 1999 Federation of European Biochemical Societies.