title: Binding to Cep164, but not EB1, is essential for centriolar localization of TTBK2 and its function in ciliogenesis.
abstract: Primary cilia are formed by extending the microtubule-based axoneme from the mother centriole-derived basal body. Recruitment of Tau tubulin kinase-2 (TTBK2) to the mother centriole and subsequent removal of CP110 and its interactor Cep97 are crucial for the initiation of ciliogenesis. We analyzed the roles of two TTBK2-binding proteins, EB1 and Cep164, in centriolar localization of TTBK2. TTBK2 bound EB1 and Cep164 through its SxIP motifs and a proline-rich motif, respectively. Using TTBK2 variants that contained mutations in the SxIP or proline-rich motifs, we obtained evidence that Cep164, but not EB1, is essential for centriolar localization of TTBK2. Depletion of TTBK2 inhibited CP110 removal and ciliogenesis, whereas expression of wild-type TTBK2, but not non-Cep164-binding mutants, rescued CP110 removal and ciliogenesis in TTBK2-depleted cells. Therefore, Cep164 binding is essential for the function of TTBK2 in promoting CP110 removal and ciliogenesis. We also provide evidence that TTBK2 has the potential to effectively phosphorylate Cep164 and Cep97 and inhibits the interaction between Cep164 and its binding partner Dishevelled-3 (an important regulator of ciliogenesis) in a kinase activity-dependent manner.
authors.affiliation: Department of Biomolecular Sciences, Graduate School of Life Sciences, Tohoku University, Sendai, Miyagi, 980-8578, Japan.
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Oda
authors.forename: Shuhei
authors.initials: S
authors.lastname: Chiba
authors.forename: Tomoaki
authors.initials: T
authors.lastname: Nagai
authors.forename: Kensaku
authors.initials: K
authors.lastname: Mizuno
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000378:metabolism; D000818:Animals; D002454:Cell Differentiation; D002460:Cell Line; D002502:Centrioles / Q000378:metabolism*; D002923:Cilia / Q000378:metabolism*; D000072261:Dishevelled Proteins; D006801:Humans; D007685:Kidney Tubules, Collecting / Q000166:cytology / Q000378:metabolism; D051379:Mice; D008868:Microtubule Proteins / Q000378:metabolism*; D008869:Microtubule-Associated Proteins / Q000378:metabolism*; D009154:Mutation; D010750:Phosphoproteins / Q000378:metabolism; D010766:Phosphorylation; D054730:Protein Interaction Domains and Motifs; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*
chemical_list: D048868:Adaptor Proteins, Signal Transducing; C524694:CEP164 protein, human; C000606584:DVL3 protein, human; D000072261:Dishevelled Proteins; C000606585:Dvl3 protein, mouse; C500985:MAPRE1 protein, human; D008868:Microtubule Proteins; D008869:Microtubule-Associated Proteins; D010750:Phosphoproteins; C095903:tau-tubulin kinase; D017346:Protein Serine-Threonine Kinases