Interaction of ezrin with the novel guanine nucleotide exchange factor PLEKHG6 promotes RhoG-dependent apical cytoskeleton rearrangements in epithelial cells.
Mol Biol Cell
; 18(12): 4780-93, 2007 Dec.
Article
em En
| MEDLINE
| ID: mdl-17881735
ABSTRACT
The mechanisms underlying functional interactions between ERM (ezrin, radixin, moesin) proteins and Rho GTPases are not well understood. Here we characterized the interaction between ezrin and a novel Rho guanine nucleotide exchange factor, PLEKHG6. We show that ezrin recruits PLEKHG6 to the apical pole of epithelial cells where PLEKHG6 induces the formation of microvilli and membrane ruffles. These morphological changes are inhibited by dominant negative forms of RhoG. Indeed, we found that PLEKHG6 activates RhoG and to a much lesser extent Rac1. In addition we show that ezrin forms a complex with PLEKHG6 and RhoG. Furthermore, we detected a ternary complex between ezrin, PLEKHG6, and the RhoG effector ELMO. We demonstrate that PLEKHG6 and ezrin are both required in macropinocytosis. After down-regulation of either PLEKHG6 or ezrin expression, we observed an inhibition of dextran uptake in EGF-stimulated A431 cells. Altogether, our data indicate that ezrin allows the local activation of RhoG at the apical pole of epithelial cells by recruiting upstream and downstream regulators of RhoG and that both PLEKHG6 and ezrin are required for efficient macropinocytosis.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Citoesqueleto
/
Proteínas rho de Ligação ao GTP
/
Fatores de Troca do Nucleotídeo Guanina
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Proteínas do Citoesqueleto
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Células Epiteliais
Limite:
Animals
/
Humans
Idioma:
En
Revista:
Mol Biol Cell
Assunto da revista:
BIOLOGIA MOLECULAR
Ano de publicação:
2007
Tipo de documento:
Article
País de afiliação:
França