GCP-WD is a gamma-tubulin targeting factor required for centrosomal and chromatin-mediated microtubule nucleation.
The gamma-tubulin ring complex (gammaTuRC) is a large multi-protein complex that is required for microtubule nucleation from the centrosome. Here, we show that the GCP-WD protein (originally named NEDD1) is the orthologue of the Drosophila Dgrip71WD protein, and is a subunit of the human gammaTuRC. GCP-WD has the properties of an attachment factor for the gammaTuRC: depletion or inhibition of GCP-WD results in loss of the gammaTuRC from the centrosome, abolishing centrosomal microtubule nucleation, although the gammaTuRC is intact and able to bind to microtubules. GCP-WD depletion also blocks mitotic chromatin-mediated microtubule nucleation, resulting in failure of spindle assembly. Mitotic phosphorylation of GCP-WD is required for association of gamma-tubulin with the spindle, separately from association with the centrosome. Our results indicate that GCP-WD broadly mediates targeting of the gammaTuRC to sites of microtubule nucleation and to the mitotic spindle, which is essential for spindle formation.
Lüders
Jens
J
Department of Biological Sciences, Stanford University, Stanford, CA 94305, USA.
Patel
Urvashi K
UK
Stearns
Tim
T
D000941:Antigens / Q000378:metabolism; D002460:Cell Line; D018385:Centrosome / Q000378:metabolism*; D002843:Chromatin / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D008869:Microtubule-Associated Proteins / Q000235:genetics / Q000378:metabolism; D008870:Microtubules / Q000187:drug effects / Q000378:metabolism*; D008938:Mitosis / Q000502:physiology; D009154:Mutation / Q000235:genetics; D015739:Nocodazole / Q000494:pharmacology; D010766:Phosphorylation; D011485:Protein Binding; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000235:genetics; D008941:Spindle Apparatus / Q000378:metabolism; D014162:Transfection; D014404:Tubulin / Q000235:genetics / Q000378:metabolism*
D000941:Antigens; D002843:Chromatin; D008869:Microtubule-Associated Proteins; C509189:NEDD1 protein, human; D034741:RNA, Small Interfering; C112305:TUBGCP2 protein, human; D014404:Tubulin; C086178:pericentrin; D015739:Nocodazole