title: Abnormal centrosomal structure and duplication in Cep135-deficient vertebrate cells.
abstract: Centrosomes are key microtubule-organizing centers that contain a pair of centrioles, conserved cylindrical, microtubule-based structures. Centrosome duplication occurs once per cell cycle and relies on templated centriole assembly. In many animal cells this process starts with the formation of a radially symmetrical cartwheel structure. The centrosomal protein Cep135 localizes to this cartwheel, but its role in vertebrates is not well understood. Here we examine the involvement of Cep135 in centriole function by disrupting the Cep135 gene in the DT40 chicken B-cell line. DT40 cells that lack Cep135 are viable and show no major defects in centrosome composition or function, although we note a small decrease in centriole numbers and a concomitant increase in the frequency of monopolar spindles. Furthermore, electron microscopy reveals an atypical structure in the lumen of Cep135-deficient centrioles. Centrosome amplification after hydroxyurea treatment increases significantly in Cep135-deficient cells, suggesting an inhibitory role for the protein in centrosome reduplication during S-phase delay. We propose that Cep135 is required for the structural integrity of centrioles in proliferating vertebrate cells, a role that also limits centrosome amplification in S-phase-arrested cells.
authors.affiliation: Centre for Chromosome Biology, School of Natural Sciences, National University of Ireland Galway, Galway, Ireland.
authors.forename: Burcu
authors.initials: B
authors.lastname: Inanç
authors.forename: Monika
authors.initials: M
authors.lastname: Pütz
authors.forename: Pierce
authors.initials: P
authors.lastname: Lalor
authors.forename: Peter
authors.initials: P
authors.lastname: Dockery
authors.forename: Ryoko
authors.initials: R
authors.lastname: Kuriyama
authors.forename: Fanni
authors.initials: F
authors.lastname: Gergely
authors.forename: Ciaran G
authors.initials: CG
authors.lastname: Morrison
mesh_terms: D000818:Animals; D030161:Avian Proteins / Q000235:genetics / Q000378:metabolism*; D002352:Carrier Proteins / Q000235:genetics / Q000502:physiology*; D002453:Cell Cycle / Q000235:genetics; D002455:Cell Division; D002460:Cell Line; D049109:Cell Proliferation; D002470:Cell Survival; D002502:Centrioles / Q000235:genetics / Q000378:metabolism*; D018385:Centrosome / Q000737:chemistry / Q000378:metabolism* / Q000648:ultrastructure*; D002645:Chickens; D055879:Gene Knock-In Techniques; D055786:Gene Knockout Techniques; D018390:Gene Targeting; D008870:Microtubules / Q000235:genetics / Q000378:metabolism; D008938:Mitosis; D016196:S Phase / Q000235:genetics / Q000502:physiology
chemical_list: D030161:Avian Proteins; D002352:Carrier Proteins