Plk4-induced centriole biogenesis in human cells.
We show that overexpression of Polo-like kinase 4 (Plk4) in human cells induces centrosome amplification through the simultaneous generation of multiple procentrioles adjoining each parental centriole. This provided an opportunity for dissecting centriole assembly and characterizing assembly intermediates. Critical components were identified and ordered into an assembly pathway through siRNA and localized through immunoelectron microscopy. Plk4, hSas-6, CPAP, Cep135, gamma-tubulin, and CP110 were required at different stages of procentriole formation and in association with different centriolar structures. Remarkably, hSas-6 associated only transiently with nascent procentrioles, whereas Cep135 and CPAP formed a core structure within the proximal lumen of both parental and nascent centrioles. Finally, CP110 was recruited early and then associated with the growing distal tips, indicating that centrioles elongate through insertion of alpha-/beta-tubulin underneath a CP110 cap. Collectively, these data afford a comprehensive view of the assembly pathway underlying centriole biogenesis in human cells.
Department of Cell Biology, Max-Planck Institute of Biochemistry, Am Klopferspitz 18, D-82152 Martinsried, Germany.
Julia
J
Kleylein-Sohn
Jens
J
Westendorf
Mikael
M
Le Clech
Robert
R
Habedanck
York-Dieter
YD
Stierhof
Erich A
EA
Nigg
D002453:Cell Cycle; D018797:Cell Cycle Proteins / Q000378:metabolism; D045744:Cell Line, Tumor; D002502:Centrioles / Q000378:metabolism* / Q000648:ultrastructure; D006801:Humans; D016253:Microscopy, Immunoelectron; D008954:Models, Biological; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*
D018797:Cell Cycle Proteins; C490219:PLK4 protein, human; D017346:Protein Serine-Threonine Kinases