title: PP2A phosphatase acts upon SAS-5 to ensure centriole formation in C. elegans embryos.
abstract: Centrosome duplication occurs once per cell cycle and ensures that the two resulting centrosomes assemble a bipolar mitotic spindle. Centriole formation is fundamental for centrosome duplication. In Caenorhabditis elegans, the evolutionarily conserved proteins SPD-2, ZYG-1, SAS-6, SAS-5, and SAS-4 are essential for centriole formation, but how they function is not fully understood. Here, we demonstrate that Protein Phosphatase 2A (PP2A) is also critical for centriole formation in C. elegans embryos. We find that PP2A subunits genetically and physically interact with the SAS-5/SAS-6 complex. Furthermore, we show that PP2A-mediated dephosphorylation promotes centriolar targeting of SAS-5 and ensures SAS-6 delivery to the site of centriole assembly. We find that PP2A is similarly needed for the presence of HsSAS-6 at centrioles and for centriole formation in human cells. These findings lead us to propose that PP2A-mediated loading of SAS-6 proteins is critical at the onset of centriole formation.
authors.affiliation: Swiss Institute for Experimental Cancer Research (ISREC), School of Life Sciences, Swiss Federal Institute of Technology (EPFL), CH-1015 Lausanne, Switzerland.
authors.forename: Daiju
authors.initials: D
authors.lastname: Kitagawa
authors.forename: Isabelle
authors.initials: I
authors.lastname: Flückiger
authors.forename: Jolanta
authors.initials: J
authors.lastname: Polanowska
authors.forename: Debora
authors.initials: D
authors.lastname: Keller
authors.forename: Jérôme
authors.initials: J
authors.lastname: Reboul
authors.forename: Pierre
authors.initials: P
authors.lastname: Gönczy
mesh_terms: D000818:Animals; D017173:Caenorhabditis elegans / Q000166:cytology / Q000196:embryology* / Q000378:metabolism*; D029742:Caenorhabditis elegans Proteins / Q000378:metabolism*; D018797:Cell Cycle Proteins / Q000378:metabolism*; D002502:Centrioles / Q000378:metabolism*; D054648:Protein Phosphatase 2 / Q000378:metabolism*
chemical_list: D029742:Caenorhabditis elegans Proteins; D018797:Cell Cycle Proteins; C488496:SAS-5 protein, C elegans; D054648:Protein Phosphatase 2