Kinesins klp5(+) and klp6(+) are required for normal chromosome movement in mitosis.
Proper mitotic chromosome segregation requires dynamic interactions between spindle microtubules and kinetochores. Here we demonstrate that two related fission yeast kinesins, klp5(+) and klp6(+), are required for normal chromosome segregation in mitosis. Null mutants frequently lack a normal metaphase chromosome alignment. Chromosome pairs move back and forth along the spindle for an extended period prior to sister chromatid separation, a phenotype reminiscent of the loss of CENP-E in metazoans. Ultimately, sister chromatids segregate, regardless of chromosome position along the spindle, and viable daughter cells are usually produced. The initiation of anaphase B is sometimes delayed, but the rate of spindle elongation is similar to wildtype. Despite a delay, anaphase B often begins before anaphase A is completed. The klp5Delta and klp6Delta null mutants are synthetically lethal with a deletion of the spindle assembly checkpoint gene, bub1(+), several mutants in components of the anaphase promoting complex, and a cold sensitive allele of the kinetochore and microtubule-binding protein, Dis1p. Klp5p-GFP and Klp6p-GFP localize to kinetochores from prophase to the onset of anaphase A, but relocalize to the spindle midzone during anaphase B. These data indicate that Klp5p and Klp6p are kinetochore kinesins required for normal chromosome movement in prometaphase.
West
Robert R
RR
Department of Molecular, Cellular and Developmental Biology, University of Colorado, Boulder, Colorado 80309-0347, USA. robert.west@colorado.edu
Malmstrom
Terra
T
McIntosh
J Richard
JR
D002467:Cell Nucleus / Q000235:genetics* / Q000378:metabolism; D002478:Cells, Cultured; D002869:Chromosome Aberrations; D020090:Chromosome Segregation / Q000235:genetics*; D002875:Chromosomes / Q000235:genetics* / Q000378:metabolism; D029721:Drosophila Proteins; D005804:Genes, Lethal / Q000235:genetics; D018816:Genes, cdc / Q000502:physiology; D016547:Kinesins / Q000235:genetics* / Q000378:metabolism; D018386:Kinetochores / Q000378:metabolism; D008869:Microtubule-Associated Proteins / Q000235:genetics / Q000378:metabolism; D008870:Microtubules / Q000378:metabolism; D008938:Mitosis / Q000235:genetics*; D009154:Mutation / Q000235:genetics; D011494:Protein Kinases / Q000235:genetics / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases; D012568:Schizosaccharomyces / Q000235:genetics* / Q000378:metabolism; D029702:Schizosaccharomyces pombe Proteins / Q000235:genetics* / Q000378:metabolism; D008941:Spindle Apparatus / Q000378:metabolism
D029721:Drosophila Proteins; C090556:KLP68D protein, Drosophila; D008869:Microtubule-Associated Proteins; D029702:Schizosaccharomyces pombe Proteins; C094879:dis1 protein, S pombe; D011494:Protein Kinases; C090464:Bub1 spindle checkpoint protein; D017346:Protein Serine-Threonine Kinases; C459102:Klp6 protein, S pombe; D016547:Kinesins