title: The PH-PxxP domain of RalGPS2 promotes PC12 cells differentiation acting as a dominant negative for RalA GTPase activation.
abstract: RalGPS2 is a guanine nucleotide exchange factor for RalA GTPase characterized by a C-terminal Pleckstrin Homology (PH) domain; this GEF is endogenously expressed in PC12 cells and in rat brain but its role in PC12 cells and in cell differentiation is actually unknown. Here we have shown that transient expression of RalGPS2-PH-PxxP domain in PC12 and PC12-TrkA cells induces high level of neurite outgrowth; this differentiation is comparable with that of PC12 cells treated with RalGPS2 siRNA. Stable PC12 cell lines expressing the PH-PxxP domain of RalGPS2 have been generated; in these cell lines the PH-PxxP domain acts as a dominant negative for RalA activation, promotes cells differentiation and re-directs NGF signals towards MAPKs. Furthermore it has been also demonstrated that the PH-PxxP domain of RalGPS2 induces microspikes formation a typical feature of cells in which the Cdc42 GTPase is constitutively activated.
authors.affiliation: Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza della Scienza 2, Milan, Italy.
authors.forename: Michela
authors.initials: M
authors.lastname: Ceriani
authors.forename: Loredana
authors.initials: L
authors.lastname: Amigoni
authors.forename: Cristina
authors.initials: C
authors.lastname: Scandiuzzi
authors.forename: Giovanna
authors.initials: G
authors.lastname: Berruti
authors.forename: Enzo
authors.initials: E
authors.lastname: Martegani
mesh_terms: D000199:Actins / Q000378:metabolism; D000818:Animals; D015153:Blotting, Western; D001921:Brain / Q000378:metabolism; D002454:Cell Differentiation / Q000502:physiology*; D004789:Enzyme Activation; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D020662:Guanine Nucleotide Exchange Factors / Q000235:genetics* / Q000378:metabolism*; D020935:MAP Kinase Signaling System; D020932:Nerve Growth Factor / Q000378:metabolism; D016501:Neurites / Q000502:physiology*; D016716:PC12 Cells; D034741:RNA, Small Interfering; D051381:Rats; D020917:Receptor, trkA / Q000378:metabolism; D014162:Transfection; D020725:ral GTP-Binding Proteins / Q000378:metabolism*
chemical_list: D000199:Actins; D020662:Guanine Nucleotide Exchange Factors; D034741:RNA, Small Interfering; C549771:RalGPS2 protein, rat; D020932:Nerve Growth Factor; D020917:Receptor, trkA; D048049:Extracellular Signal-Regulated MAP Kinases; C492197:Rala protein, rat; D020725:ral GTP-Binding Proteins