Cdc42 and mDia3 regulate microtubule attachment to kinetochores.
During mitosis, the mitotic spindle, a bipolar structure composed of microtubules (MTs) and associated motor proteins, segregates sister chromatids to daughter cells. Initially some MTs emanating from one centrosome attach to the kinetochore at the centromere of one of the duplicated chromosomes. This attachment allows rapid poleward movement of the bound chromosome. Subsequent attachment of the sister kinetochore to MTs growing from the other centrosome results in the bi-orientation of the chromosome, in which interactions between kinetochores and the plus ends of MTs are formed and stabilized. These processes ensure alignment of chromosomes during metaphase and their correct segregation during anaphase. Although many proteins constituting the kinetochore have been identified and extensively studied, the signalling responsible for MT capture and stabilization is unclear. Small GTPases of the Rho family regulate cell morphogenesis by organizing the actin cytoskeleton and regulating MT alignment and stabilization. We now show that one member of this family, Cdc42, and its effector, mDia3, regulate MT attachment to kinetochores.
Yasuda
Shingo
S
Department of Pharmacology, Kyoto University Faculty of Medicine, Kyoto 606-8501, Japan.
Oceguera-Yanez
Fabian
F
Kato
Takayuki
T
Okamoto
Muneo
M
Yonemura
Shigenobu
S
Terada
Yasuhiko
Y
Ishizaki
Toshimasa
T
Narumiya
Shuh
S
D000818:Animals; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D000080865:Formins; D016244:Guanosine 5'-O-(3-Thiotriphosphate) / Q000378:metabolism; D006153:Guanosine Diphosphate / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D018386:Kinetochores / Q000378:metabolism*; D051379:Mice; D008870:Microtubules / Q000378:metabolism*; D008938:Mitosis / Q000187:drug effects; D009154:Mutation; D041681:NIH 3T3 Cells; D015398:Signal Transduction / Q000187:drug effects; D008941:Spindle Apparatus / Q000378:metabolism; D020764:cdc42 GTP-Binding Protein / Q000378:metabolism*; D020741:rho GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism
D002352:Carrier Proteins; C491463:Diap2 protein, mouse; D000080865:Formins; D006153:Guanosine Diphosphate; D016244:Guanosine 5'-O-(3-Thiotriphosphate); D020764:cdc42 GTP-Binding Protein; D020741:rho GTP-Binding Proteins