title: Centriolar SAS-7 acts upstream of SPD-2 to regulate centriole assembly and pericentriolar material formation.
abstract: The centriole/basal body is a eukaryotic organelle that plays essential roles in cell division and signaling. Among five known core centriole proteins, SPD-2/Cep192 is the first recruited to the site of daughter centriole formation and regulates the centriolar localization of the other components inC. elegansand in humans. However, the molecular basis for SPD-2 centriolar localization remains unknown. Here, we describe a new centriole component, the coiled-coil protein SAS-7, as a regulator of centriole duplication, assembly and elongation. Intriguingly, our genetic data suggest that SAS-7 is required for daughter centrioles to become competent for duplication, and for mother centrioles to maintain this competence. We also show that SAS-7 binds SPD-2 and regulates SPD-2 centriolar recruitment, while SAS-7 centriolar localization is SPD-2-independent. Furthermore, pericentriolar material (PCM) formation is abnormal insas-7mutants, and the PCM-dependent induction of cell polarity that defines the anterior-posterior body axis frequently fails. We conclude that SAS-7 functions at the earliest step in centriole duplication yet identified and plays important roles in the orchestration of centriole and PCM assembly.
authors.affiliation: Institute of Molecular Biology, University of Oregon, Eugene, United States.
authors.forename: Kenji
authors.identifier: 0000-0002-5830-9639
authors.initials: K
authors.lastname: Sugioka
authors.affiliation: Department of Zoology, Ohio Wesleyan University, Delaware, United States.
authors.forename: Danielle R
authors.initials: DR
authors.lastname: Hamill
authors.affiliation: Institute of Molecular Biology, University of Oregon, Eugene, United States.
authors.forename: Joshua B
authors.initials: JB
authors.lastname: Lowry
authors.affiliation: Department of Zoology, Ohio Wesleyan University, Delaware, United States.
authors.forename: Marie E
authors.initials: ME
authors.lastname: McNeely
authors.affiliation: Department of Zoology, Ohio Wesleyan University, Delaware, United States.
authors.forename: Molly
authors.initials: M
authors.lastname: Enrick
authors.affiliation: Department of Zoology, Ohio Wesleyan University, Delaware, United States.
authors.forename: Alyssa C
authors.initials: AC
authors.lastname: Richter
authors.affiliation: Department of Zoology, Ohio Wesleyan University, Delaware, United States.
authors.forename: Lauren E
authors.initials: LE
authors.lastname: Kiebler
authors.affiliation: Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, United States.|Molecular and Cellular Biology Program, University of Washington, Seattle, United States.|Department of Biology, University of Washington, Seattle, United States.
authors.forename: James R
authors.initials: JR
authors.lastname: Priess
authors.affiliation: Institute of Molecular Biology, University of Oregon, Eugene, United States.
authors.forename: Bruce
authors.identifier: 0000-0002-6479-8707
authors.initials: B
authors.lastname: Bowerman
mesh_terms: D000818:Animals; D017173:Caenorhabditis elegans / Q000235:genetics / Q000502:physiology*; D029742:Caenorhabditis elegans Proteins / Q000378:metabolism*; D018797:Cell Cycle Proteins / Q000378:metabolism*; D002502:Centrioles / Q000378:metabolism*; D006801:Humans; D001678:Organelle Biogenesis
chemical_list: D029742:Caenorhabditis elegans Proteins; D018797:Cell Cycle Proteins; C497201:SAS-6 protein, C elegans; C486131:SPD-2 protein, C elegans
keywords: C. elegans; cell biology; cell division; centriole; centrosome