Coactivation of Rac1 and Cdc42 at Lamellipodia and Membrane Ruffles Induced by Epidermal Growth FactorV⃞
AUTOR(ES)
Kurokawa, Kazuo
FONTE
The American Society for Cell Biology
RESUMO
A major function of Rho-family GTPases is to regulate the organization of the actin cytoskeleton; filopodia, lamellipodia, and stress fiber are regarded as typical phenotypes of the activated Cdc42, Rac, and Rho, respectively. Using probes based on fluorescent resonance energy transfer, we report on the spatiotemporal regulation of Rac1 and Cdc42 at lamellipodia and membrane ruffles. In epidermal growth factor (EGF)-stimulated Cos1 and A431 cells, both Rac1 and Cdc42 were activated diffusely at the plasma membrane, followed by lamellipodial protrusion and membrane ruffling. Although Rac1 activity subsided rapidly, Cdc42 activity was sustained at lamellipodia. A critical role of Cdc42 in these EGF-induced morphological changes was demonstrated as follows. First, phorbol 12-myristate 13-acetate, which activated Rac1 but not Cdc42, could not induce full-grown lamellipodia in Cos1 cells. Second, a GTPase-activating protein for Cdc42, KIAA1204/CdGAP, inhibited lamellipodial protrusion and membrane ruffling without interfering with Rac1 activation. Third, expression of the Cdc42-binding domain of N-WASP inhibited the EGF-induced morphological changes. Therefore, Rac1 and Cdc42 seem to synergistically induce lamellipodia and membrane ruffles in EGF-stimulated Cos1 cells and A431 cells.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=363057Documentos Relacionados
- Interação entre IQGAP1 e actina mediado por CDC42 e RAC1
- Raf-MEK-Erk Cascade in Anoikis Is Controlled by Rac1 and Cdc42 via Akt
- Involvement of IQGAP1, an Effector of Rac1 and Cdc42 GTPases, in Cell-Cell Dissociation during Cell Scattering
- The GTPase-activating protein n-chimaerin cooperates with Rac1 and Cdc42Hs to induce the formation of lamellipodia and filopodia.
- Activation of Rac and Cdc42 by Integrins Mediates Cell Spreading