title: CEP295 interacts with microtubules and is required for centriole elongation.
abstract: Centriole duplication is a tightly ordered process during which procentrioles are assembled in G1-S and elongate during S and G2. Here, we show that human CEP295 (Drosophila Ana1) is not essential for initial cartwheel assembly, but is required to build distal half centrioles during S and G2. Using super-resolution and immunogold electron microscopy, we demonstrate that CEP295 is recruited to the proximal end of procentrioles in early S phase, when it is also localized at the centriolar microtubule wall that surrounds the human SAS6 cartwheel hub. Interestingly, depletion of CEP295 not only inhibits the recruitments of POC5 and POC1B to the distal half centrioles in G2, resulting in shorter centrioles, it also blocks the post-translational modification of centriolar microtubules (e.g. acetylation and glutamylation). Importantly, our results indicate that CEP295 directly interacts with microtubules, and that excess CEP295 could induce the assembly of overly long centrioles. Furthermore, exogenous expression of the N-terminal domain of CEP295 exerts a dominant-negative effect on centriole elongation. Collectively, these findings suggest that CEP295 is essential for building the distal half centrioles and for post-translational modification of centriolar microtubules.
authors.affiliation: Institute of Biomedical Sciences, Academia Sinica, Taipei 11529, Taiwan.
authors.forename: Ching-Wen
authors.initials: CW
authors.lastname: Chang
authors.affiliation: Institute of Biomedical Sciences, Academia Sinica, Taipei 11529, Taiwan.
authors.forename: Wen-Bin
authors.initials: WB
authors.lastname: Hsu
authors.affiliation: Institute of Biomedical Sciences, Academia Sinica, Taipei 11529, Taiwan.
authors.forename: Jhih-Jie
authors.initials: JJ
authors.lastname: Tsai
authors.affiliation: Institute of Biomedical Sciences, Academia Sinica, Taipei 11529, Taiwan.
authors.forename: Chieh-Ju C
authors.initials: CJ
authors.lastname: Tang
authors.affiliation: Institute of Biomedical Sciences, Academia Sinica, Taipei 11529, Taiwan tktang@ibms.sinica.edu.tw.
authors.forename: Tang K
authors.identifier: 0000-0002-3660-0695
authors.initials: TK
authors.lastname: Tang
mesh_terms: D000818:Animals; D002352:Carrier Proteins / Q000235:genetics* / Q000378:metabolism; D002453:Cell Cycle / Q000235:genetics; D018797:Cell Cycle Proteins / Q000235:genetics* / Q000378:metabolism; D002502:Centrioles / Q000235:genetics* / Q000648:ultrastructure; D018385:Centrosome / Q000378:metabolism / Q000648:ultrastructure; D015972:Gene Expression Regulation, Neoplastic; D006367:HeLa Cells; D006801:Humans; D008854:Microscopy, Electron; D008869:Microtubule-Associated Proteins / Q000235:genetics / Q000378:metabolism; D008870:Microtubules / Q000235:genetics* / Q000648:ultrastructure; D011485:Protein Binding / Q000235:genetics; D011499:Protein Processing, Post-Translational / Q000235:genetics
chemical_list: C556019:CEP295 protein, human; D002352:Carrier Proteins; D018797:Cell Cycle Proteins; D008869:Microtubule-Associated Proteins; C000592372:POC1B protein, human; C540807:POC5 protein, human
keywords: Acetylation; Centriole assembly; Centriole duplication; Centrosome; Polyglutamylation; Procentriole formation