Kinetochores generate microtubules with distal plus ends: their roles and limited lifetime in mitosis.
In early mitosis, microtubules can be generated at kinetochores as well as at spindle poles. However, the role and regulation of kinetochore-derived microtubules have been unclear. In general, metaphase spindle microtubules are oriented such that their plus ends bind to kinetochores. However, we now have evidence that, during early mitosis in budding yeast, microtubules are generated at kinetochores with distal plus ends. These kinetochore-derived microtubules interact along their length with microtubules that extend from a spindle pole, facilitating kinetochore loading onto the lateral surface of spindle pole microtubules. Once kinetochores are loaded, microtubules are no longer generated at kinetochores, and those that remain disappear rapidly and do not contribute to the metaphase spindle. Stu2 (the ortholog of vertebrate XMAP215/ch-TOG) localizes to kinetochores and plays a central role in regulating kinetochore-derived microtubules. Our work provides insight into microtubule generation at kinetochores and the mechanisms that facilitate initial kinetochore interaction with spindle pole microtubules.
Wellcome Trust Centre for Gene Regulation & Expression, University of Dundee, Dundee DD1 5EH, UK.
Etsushi
E
Kitamura
Kozo
K
Tanaka
Shinya
S
Komoto
Yoko
Y
Kitamura
Claude
C
Antony
Tomoyuki U
TU
Tanaka
D002503:Centromere / Q000235:genetics / Q000378:metabolism; D005800:Genes, Fungal; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D018386:Kinetochores / Q000378:metabolism*; D008869:Microtubule-Associated Proteins / Q000235:genetics / Q000378:metabolism; D008870:Microtubules / Q000378:metabolism*; D008938:Mitosis / Q000502:physiology*; D009154:Mutation; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000166:cytology* / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction; D008941:Spindle Apparatus / Q000378:metabolism; D014404:Tubulin / Q000235:genetics / Q000378:metabolism
D008869:Microtubule-Associated Proteins; D011993:Recombinant Fusion Proteins; C109414:STU2 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D014404:Tubulin; D049452:Green Fluorescent Proteins