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Protein phosphatase 2A-SUR-6/B55 regulates centriole duplication in C. elegans by controlling the levels of centriole assembly factors.

Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
Developmental Cell (Impact Factor: 10.37). 04/2011; 20(4):563-71. DOI: 10.1016/j.devcel.2011.03.007
Source: PubMed

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.

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