Identification of a mitotic Rac-GEF, Trio, that counteracts MgcRacGAP function during cytokinesis.
Bottom Line: Moreover, Trio depletion specifically rescues the cytokinesis failure induced by MgcRacGAP depletion.Of importance, we demonstrate that this rescue is mediated by the Trio-Rac1 pathway, using GEF-dead mutants of Trio and a specific inhibitor of Rac1 activation by Trio.Overall this work identifies for the first time a GEF controlling Rac1 activation in dividing cells that counteracts MgcRacGAP function in cytokinesis.
Affiliation: Signaling and Cytoskeleton Dynamics Group, University of Montpellier, 34293 Montpellier, France.Show MeSH
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Mentions: To confirm that Trio depletion could rescue the cytokinesis failure induced by MgcRacGAP depletion, we used two independent siRNAs to deplete Trio in combination with MgcRacGAP siRNA in HeLa cells. Protein depletion was controlled by Western blot analysis and immunofluorescence staining (Figure 2A and Supplemental Figure S2C). Of importance, both Trio siRNAs efficiently rescued the number of multinucleated cells induced by MgcRacGAP depletion, demonstrating that the observed phenotype was indeed specific to Trio depletion (Figure 2B).
Affiliation: Signaling and Cytoskeleton Dynamics Group, University of Montpellier, 34293 Montpellier, France.