title: Protein phosphatase 2A-SUR-6/B55 regulates centriole duplication in C. elegans by controlling the levels of centriole assembly factors.
abstract: Centrioles play a crucial role in mitotic spindle assembly and duplicate precisely once per cell cycle. In worms, flies, and humans, centriole assembly is dependent upon a key regulatory kinase (ZYG-1/Sak/Plk4) and its downstream effectors SAS-5 and SAS-6. Here we report a role for protein phosphatase 2A (PP2A) in centriole duplication. We find that the PP2A catalytic subunit LET-92, the scaffolding subunit PAA-1, and the B55 regulatory subunit SUR-6 function together to positively regulate centriole assembly. In PP2A-SUR-6-depleted embryos, the levels of ZYG-1 and SAS-5 are reduced and the ZYG-1- and SAS-5-dependent recruitment of SAS-6 to the nascent centriole fails. We show that PP2A physically associates with SAS-5 in vivo and that inhibiting proteolysis can rescue SAS-5 levels and the centriole duplication defect of PP2A-depleted embryos. Together, our findings indicate that PP2A-SUR-6 promotes centriole assembly by protecting ZYG-1 and SAS-5 from degradation.
authors.affiliation: Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA. mhsong@mtu.edu
authors.forename: Mi Hye
authors.initials: MH
authors.lastname: Song
authors.forename: Yan
authors.initials: Y
authors.lastname: Liu
authors.forename: D Eric
authors.initials: DE
authors.lastname: Anderson
authors.forename: Wan Jin
authors.initials: WJ
authors.lastname: Jahng
authors.forename: Kevin F
authors.initials: KF
authors.lastname: O'Connell
mesh_terms: D000818:Animals; D017173:Caenorhabditis elegans / Q000166:cytology* / Q000196:embryology / Q000201:enzymology / Q000378:metabolism*; D029742:Caenorhabditis elegans Proteins / Q000235:genetics / Q000378:metabolism*; D002502:Centrioles / Q000235:genetics / Q000378:metabolism*; D020440:Gene Duplication; D054648:Protein Phosphatase 2 / Q000235:genetics / Q000378:metabolism*; D021122:Protein Subunits / Q000235:genetics / Q000378:metabolism*
chemical_list: D029742:Caenorhabditis elegans Proteins; D021122:Protein Subunits; D054648:Protein Phosphatase 2; C489811:SUR-6 protein, C elegans