Kip3, the yeast kinesin-8, is required for clustering of kinetochores at metaphase.
In Saccharomyces cerevisiae, chromosome congression clusters kinetochores on either side of the spindle equator at metaphase. Many organisms require one or more kinesin-8 molecular motors to achieve chromosome alignment. The yeast kinesin-8, Kip3, has been well studied in vitro but a role in chromosome congression has not been reported. We investigated Kip3's role in this process using semi-automated, quantitative fluorescence microscopy and time-lapse imaging and found that Kip3 is required for congression. Deletion of KIP3 increases inter-kinetochore distances and increases the variability in the position of sister kinetochores along the spindle axis during metaphase. Kip3 does not regulate spindle length and is not required for kinetochore-microtubule attachment. Instead, Kip3 clusters kinetochores on the metaphase spindle by tightly regulating kinetochore microtubule lengths.
Wargacki
Megan M
MM
Department of Biochemistry, University of Washington, Seattle, WA, USA.
Tay
Jessica C
JC
Muller
Eric G
EG
Asbury
Charles L
CL
Davis
Trisha N
TN
D005456:Fluorescent Dyes / Q000378:metabolism; D017353:Gene Deletion; D016547:Kinesins / Q000378:metabolism*; D018386:Kinetochores / Q000378:metabolism*; D008677:Metaphase; D008870:Microtubules / Q000378:metabolism; D009154:Mutation / Q000235:genetics; D010641:Phenotype; D021381:Protein Transport; D012441:Saccharomyces cerevisiae / Q000166:cytology* / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism*; D008941:Spindle Apparatus / Q000378:metabolism
C075342:CIN8 protein, S cerevisiae; D005456:Fluorescent Dyes; C108256:KIP3 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D016547:Kinesins