title: TBCD links centriologenesis, spindle microtubule dynamics, and midbody abscission in human cells.
abstract: Microtubule-organizing centers recruit alpha- and beta-tubulin polypeptides for microtubule nucleation. Tubulin synthesis is complex, requiring five specific cofactors, designated tubulin cofactors (TBCs) A-E, which contribute to various aspects of microtubule dynamics in vivo. Here, we show that tubulin cofactor D (TBCD) is concentrated at the centrosome and midbody, where it participates in centriologenesis, spindle organization, and cell abscission. TBCD exhibits a cell-cycle-specific pattern, localizing on the daughter centriole at G1 and on procentrioles by S, and disappearing from older centrioles at telophase as the protein is recruited to the midbody. Our data show that TBCD overexpression results in microtubule release from the centrosome and G1 arrest, whereas its depletion produces mitotic aberrations and incomplete microtubule retraction at the midbody during cytokinesis. TBCD is recruited to the centriole replication site at the onset of the centrosome duplication cycle. A role in centriologenesis is further supported in differentiating ciliated cells, where TBCD is organized into "centriolar rosettes". These data suggest that TBCD participates in both canonical and de novo centriolar assembly pathways.
authors.affiliation: Departamentos de Biología Molecular, Instituto de Formación e Investigación Marqués de Valdecilla Facultad de Medicina, Universidad de Cantabria, Santander, Spain.
authors.forename: Mónica López
authors.initials: ML
authors.lastname: Fanarraga
authors.forename: Javier
authors.initials: J
authors.lastname: Bellido
authors.forename: Cristina
authors.initials: C
authors.lastname: Jaén
authors.forename: Juan Carlos
authors.initials: JC
authors.lastname: Villegas
authors.forename: Juan Carlos
authors.initials: JC
authors.lastname: Zabala
mesh_terms: D000818:Animals; D002453:Cell Cycle; D002502:Centrioles; D005434:Flow Cytometry; D006367:HeLa Cells; D006801:Humans; D007150:Immunohistochemistry; D051379:Mice; D018613:Microscopy, Confocal; D008869:Microtubule-Associated Proteins / Q000502:physiology*; D034622:RNA Interference; D008941:Spindle Apparatus
chemical_list: D008869:Microtubule-Associated Proteins