title: Regulation of Cdc42-mediated morphological effects: a novel function for p53.
abstract: The tumour suppressor functions of p53 that are important for its activity depend on its role as a cell cycle arrest mediator and apoptosis inducer. Here we identify a novel function for p53 in regulating cell morphology and movement. We investigated the overall effect of p53 on morphological changes induced by RhoA, Rac1 and Cdc42 GTPases in mouse embryonic fibroblasts (MEFs). Interestingly, p53 exerted a selective effect on Cdc42-mediated cell functions. (i) Both overexpression of wild-type p53 and activation of endogenous p53 counteracted Cdc42-induced filopodia formation. Conversely, p53-deficient MEFs exhibited constitutive membrane filopodia. Mechanistic studies indicate that p53 prevents the initiating steps of filopodia formation downstream of Cdc42. (ii) Over expression of p53 modulates cell spreading of MEFs on fibronectin. (iii) During cell migration, the reorientation of the Golgi apparatus in the direction of movement is abolished by wild-type p53 expression, thus preventing cell polarity. Our data demonstrate a previously uncharacterized role for p53 in regulating Cdc42-dependent cell effects that control actin cytoskeletal dynamics and cell movement. This novel function may contribute to p53 anti-tumour activity.
authors: Centre de Recherche en Biochimie Macromoléculaire, CNRS UPR1086, IFR 24, 1919 route de Mende, F-34293 Montpellier cedex 5, France.
authors: Gilles
authors: G
authors: Gadéa
authors: Laure
authors: L
authors: Lapasset
authors: Cécile
authors: C
authors: Gauthier-Rouvière
authors: Pierre
authors: P
authors: Roux
mesh_terms: D000818:Animals; D016764:Cell Polarity; D004622:Embryo, Mammalian; D005047:Etoposide / Q000494:pharmacology; D005347:Fibroblasts / Q000166:cytology / Q000187:drug effects / Q000502:physiology / Q000648:ultrastructure; D051379:Mice; D008855:Microscopy, Electron, Scanning; D011554:Pseudopodia / Q000187:drug effects / Q000502:physiology; D011994:Recombinant Proteins / Q000378:metabolism; D015533:Transcriptional Activation; D014162:Transfection; D016159:Tumor Suppressor Protein p53 / Q000172:deficiency / Q000378:metabolism*; D020764:cdc42 GTP-Binding Protein / Q000502:physiology*
chemical_list: D011994:Recombinant Proteins; D016159:Tumor Suppressor Protein p53; D005047:Etoposide; D020764:cdc42 GTP-Binding Protein