title: Kinesin-8 effects on mitotic microtubule dynamics contribute to spindle function in fission yeast.
abstract: Kinesin-8 motor proteins destabilize microtubules. Their absence during cell division is associated with disorganized mitotic chromosome movements and chromosome loss. Despite recent work studying effects of kinesin-8s on microtubule dynamics, it remains unclear whether the kinesin-8 mitotic phenotypes are consequences of their effect on microtubule dynamics, their well-established motor activity, or additional, unknown functions. To better understand the role of kinesin-8 proteins in mitosis, we studied the effects of deletion of the fission yeast kinesin-8 proteins Klp5 and Klp6 on chromosome movements and spindle length dynamics. Aberrant microtubule-driven kinetochore pushing movements and tripolar mitotic spindles occurred in cells lacking Klp5 but not Klp6. Kinesin-8-deletion strains showed large fluctuations in metaphase spindle length, suggesting a disruption of spindle length stabilization. Comparison of our results from light microscopy with a mathematical model suggests that kinesin-8-induced effects on microtubule dynamics, kinetochore attachment stability, and sliding force in the spindle can explain the aberrant chromosome movements and spindle length fluctuations seen.
authors.affiliation: Department of Physics, University of Colorado at Boulder, Boulder, CO 80309.|Department of MCD Biology, University of Colorado at Boulder, Boulder, CO 80309.
authors.forename: Zachary R
authors.initials: ZR
authors.lastname: Gergely
authors.affiliation: Department of Physics, University of Colorado at Boulder, Boulder, CO 80309.
authors.forename: Ammon
authors.initials: A
authors.lastname: Crapo
authors.affiliation: Department of Physics, University of Colorado at Boulder, Boulder, CO 80309.
authors.forename: Loren E
authors.initials: LE
authors.lastname: Hough
authors.affiliation: Department of MCD Biology, University of Colorado at Boulder, Boulder, CO 80309.
authors.forename: J Richard
authors.initials: JR
authors.lastname: McIntosh
authors.affiliation: Department of MCD Biology, University of Colorado at Boulder, Boulder, CO 80309 mdb@colorado.edu.
authors.forename: Meredith D
authors.initials: MD
authors.lastname: Betterton
mesh_terms: D020090:Chromosome Segregation; D016547:Kinesins / Q000378:metabolism* / Q000502:physiology; D018386:Kinetochores / Q000378:metabolism; D008869:Microtubule-Associated Proteins / Q000378:metabolism* / Q000502:physiology; D008870:Microtubules / Q000378:metabolism / Q000502:physiology; D008938:Mitosis; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism / Q000502:physiology; D012568:Schizosaccharomyces / Q000378:metabolism / Q000502:physiology; D029702:Schizosaccharomyces pombe Proteins / Q000378:metabolism* / Q000502:physiology; D008941:Spindle Apparatus / Q000378:metabolism / Q000502:physiology
chemical_list: C108256:KIP3 protein, S cerevisiae; D008869:Microtubule-Associated Proteins; D029701:Saccharomyces cerevisiae Proteins; D029702:Schizosaccharomyces pombe Proteins; C469734:Klp5 protein, S pombe; C459102:Klp6 protein, S pombe; D016547:Kinesins