Inducible recruitment of Cdc42 or WASP to a cell-surface receptor triggers actin polymerization and filopodium formation

Castellano, F., Montcourrier, P., Guillemot, J.-C., Gouin, E., Machesky, L. , Cossart, P. and Chavrier, P. (1999) Inducible recruitment of Cdc42 or WASP to a cell-surface receptor triggers actin polymerization and filopodium formation. Current Biology, 9(7), pp. 351-361. (doi: 10.1016/S0960-9822(99)80161-4) (PMID:10209117)

Abstract

Background: Cdc42, a GTP-binding protein of the Rho family, controls actin cytoskeletal organization and helps to generate actin-based protruding structures, such as filopodia. In vitro, Cdc42 regulates actin polymerization by facilitating the creation of free barbed ends – the more rapidly growing ends of actin filaments – and subsequent elongation at these ends. The Wiskott– Aldrich syndrome protein, WASP, which has a pleckstrin-homology domain and a Cdc42/Rac-binding motif, has been implicated in cell signaling and cytoskeleton reorganization. We have investigated the consequences of local recruitment of activated Cdc42 or WASP to the plasma membrane. Results: We used an activated Cdc42 protein that could be recruited to an engineered membrane receptor by adding rapamycin as a bridge, and added antibody-coupled beads to aggregate these receptors. Inducible recruitment of Cdc42 to clusters of receptors stimulated actin polymerization, resulting in the formation of membrane protrusions. Cdc42-induced protrusions were enriched in the vasodilator-stimulated phosphoprotein VASP and the focal-adhesion-associated proteins zyxin and ezrin. The Cdc42 effector WASP could also induce the formation of protrusions, albeit of different morphology. Conclusions: This is the first demonstration that the local recruitment of activated Cdc42 or its downstream effector, WASP, to a membrane receptor in whole cells is sufficient to trigger actin polymerization that results in the formation of membrane protrusions. Our data suggest that Cdc42-induced actin-based protrusions result from the local and serial recruitment of cytoskeletal proteins including zyxin, VASP, and ezrin.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Machesky, Professor Laura
• Authors: Castellano, F., Montcourrier, P., Guillemot, J.-C., Gouin, E., Machesky, L., Cossart, P., and Chavrier, P.
• College/School: College of Medical Veterinary and Life Sciences > School of Cancer Sciences
• Journal Name: Current Biology
• Publisher: Cell Press
• ISSN: 0960-9822
• ISSN (Online): 1879-0445
• Published Online: 27 January 2000