Molecular characterization of centriole assembly in ciliated epithelial cells.
Ciliated epithelial cells have the unique ability to generate hundreds of centrioles during differentiation. We used centrosomal proteins as molecular markers in cultured mouse tracheal epithelial cells to understand this process. Most centrosomal proteins were up-regulated early in ciliogenesis, initially appearing in cytoplasmic foci and then incorporated into centrioles. Three candidate proteins were further characterized. The centrosomal component SAS-6 localized to basal bodies and the proximal region of the ciliary axoneme, and depletion of SAS-6 prevented centriole assembly. The intraflagellar transport component polaris localized to nascent centrioles before incorporation into cilia, and depletion of polaris blocked axoneme formation. The centriolar satellite component PCM-1 colocalized with centrosomal components in cytoplasmic granules surrounding nascent centrioles. Interfering with PCM-1 reduced the amount of centrosomal proteins at basal bodies but did not prevent centriole assembly. This system will help determine the mechanism of centriole formation in mammalian cells and how the limitation on centriole duplication is overcome in ciliated epithelial cells.
Vladar
Eszter K
EK
Department of Genetics, Stanford University School of Medicine, Stanford University, Stanford, CA 94305, USA.
Stearns
Tim
T
D000818:Animals; D018797:Cell Cycle Proteins / Q000378:metabolism*; D002460:Cell Line; D002478:Cells, Cultured; D002502:Centrioles / Q000378:metabolism* / Q000648:ultrastructure / Q000821:virology; D002923:Cilia / Q000378:metabolism* / Q000502:physiology / Q000648:ultrastructure / Q000821:virology; D003433:Crosses, Genetic; D004847:Epithelial Cells / Q000378:metabolism* / Q000648:ultrastructure / Q000821:virology; D019084:Fluorescent Antibody Technique, Indirect; D049452:Green Fluorescent Proteins / Q000378:metabolism; D006801:Humans; D016086:Lentivirus / Q000235:genetics; D016180:Lentivirus Infections / Q000821:virology; D051379:Mice; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D008954:Models, Biological; D041681:NIH 3T3 Cells; D014132:Trachea / Q000166:cytology; D014161:Transduction, Genetic; D025521:Tumor Suppressor Proteins / Q000378:metabolism
D018797:Cell Cycle Proteins; C490114:Pcm1 protein, mouse; C522418:SAS-6 protein, mouse; C490898:Tg737Rpw protein, mouse; D025521:Tumor Suppressor Proteins; D049452:Green Fluorescent Proteins