Plk1-dependent recruitment of gamma-tubulin complexes to mitotic centrosomes involves multiple PCM components.
The nucleation of microtubules requires protein complexes containing gamma-tubulin, which are present in the cytoplasm and associate with the centrosome and with the mitotic spindle. We have previously shown that these interactions require the gamma-tubulin targeting factor GCP-WD/NEDD1, which has an essential role in spindle formation. The recruitment of additional gamma-tubulin to the centrosomes occurs during centrosome maturation at the G2/M transition and is regulated by the mitotic kinase Plk1. However, the molecular details of this important pathway are unknown and a Plk1 substrate that controls gamma-tubulin recruitment has not been identified. Here we show that Plk1 associates with GCP-WD in mitosis and Plk1 activity contributes to phosphorylation of GCP-WD. Plk1 depletion or inhibition prevents accumulation of GCP-WD at mitotic centrosomes, but GCP-WD mutants that are defective in Plk1-binding and -phosphorylation still accumulate at mitotic centrosomes and recruit gamma-tubulin. Moreover, Plk1 also controls the recruitment of other PCM proteins implicated in centrosomal gamma-tubulin attachment (Cep192/hSPD2, pericentrin, Cep215/Cdk5Rap2). Our results support a model in which Plk1-dependent recruitment of gamma-tubulin to mitotic centrosomes is regulated upstream of GCP-WD, involves multiple PCM proteins and therefore potentially multiple Plk1 substrates.
Haren
Laurence
L
Institut de Sciences et Technologies du Médicament de Toulouse, Centre National de la Recherche Scientifique/Pierre Fabre, Toulouse, France.
Stearns
Tim
T
Lüders
Jens
J
D018797:Cell Cycle Proteins / Q000378:metabolism*; D045744:Cell Line, Tumor; D002502:Centrioles / Q000378:metabolism*; D018385:Centrosome / Q000378:metabolism*; D003001:Cloning, Molecular; D006367:HeLa Cells; D006801:Humans; D008856:Microscopy, Fluorescence / Q000379:methods; D008938:Mitosis; D008954:Models, Biological; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D011518:Proto-Oncogene Proteins / Q000378:metabolism*; D012313:RNA / Q000737:chemistry; D034622:RNA Interference; D008941:Spindle Apparatus; D014404:Tubulin / Q000378:metabolism*; D000097869:Polo-Like Kinase 1
D018797:Cell Cycle Proteins; D017346:Protein Serine-Threonine Kinases; D011518:Proto-Oncogene Proteins; D012313:RNA; D014404:Tubulin; D000097869:Polo-Like Kinase 1