title: Phosphoregulation of MgcRacGAP in mitosis involves Aurora B and Cdk1 protein kinases and the PP2A phosphatase.
abstract: MgcRacGAP, a Rho GAP essential to cytokinesis, works both as a Rho GTPase regulator and as a scaffolding protein. MgcRacGAP interacts with MKLP1 to form the centralspindlin complex and associates with the RhoGEF Ect2. The GAP activity of MgcRacGAP is regulated by Aurora B phosphorylation. We have isolated B56epsilon, a PP2A regulatory subunit, as a new MgcRacGAP partner. We report here that (i) MgcRacGAP is phosphorylated by Aurora B and Cdk1, (ii) PP2A dephosphorylates Aurora B and Cdk1 phosphorylated sites and (iii) inhibition of PP2A abrogates MgcRacGAP/Ect2 interaction. Therefore, PP2A may regulate cytokinesis by dephosphorylating MgcRacGAP and its interacting partners.
authors.affiliation: Institut Cochin, Département de Génétique et Développement, INSERM U567/CNRS UMR8104/Université Paris Descartes, 24 rue du Faubourg Saint Jacques, 75014 Paris, France.
authors.forename: Aminata
authors.initials: A
authors.lastname: Touré
authors.forename: Rym
authors.initials: R
authors.lastname: Mzali
authors.forename: Caroline
authors.initials: C
authors.lastname: Liot
authors.forename: Laetitia
authors.initials: L
authors.lastname: Seguin
authors.forename: Laurence
authors.initials: L
authors.lastname: Morin
authors.forename: Catherine
authors.initials: C
authors.lastname: Crouin
authors.forename: Ilin
authors.initials: I
authors.lastname: Chen-Yang
authors.forename: Yeou-Guang
authors.initials: YG
authors.lastname: Tsay
authors.forename: Olivier
authors.initials: O
authors.lastname: Dorseuil
authors.forename: Gérard
authors.initials: G
authors.lastname: Gacon
authors.forename: Jacques
authors.initials: J
authors.lastname: Bertoglio
mesh_terms: D000818:Animals; D064107:Aurora Kinase B; D064127:Aurora Kinases; D016203:CDC2 Protein Kinase / Q000378:metabolism*; D019556:COS Cells; D045744:Cell Line, Tumor; D002522:Chlorocebus aethiops; D002851:Chromatography, High Pressure Liquid; D020690:GTPase-Activating Proteins / Q000502:physiology*; D006801:Humans; D008938:Mitosis / Q000502:physiology*; D010766:Phosphorylation; D054648:Protein Phosphatase 2 / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D053719:Tandem Mass Spectrometry; D020798:Two-Hybrid System Techniques
chemical_list: D020690:GTPase-Activating Proteins; C115995:mgcRacGAP; C576921:AURKB protein, human; D064107:Aurora Kinase B; D064127:Aurora Kinases; D017346:Protein Serine-Threonine Kinases; D016203:CDC2 Protein Kinase; C517189:PPP2CA protein, human; D054648:Protein Phosphatase 2