Chromosome congression by Kinesin-5 motor-mediated disassembly of longer kinetochore microtubules.
During mitosis, sister chromatids congress to the spindle equator and are subsequently segregated via attachment to dynamic kinetochore microtubule (kMT) plus ends. A major question is how kMT plus-end assembly is spatially regulated to achieve chromosome congression. Here we find in budding yeast that the widely conserved kinesin-5 sliding motor proteins, Cin8p and Kip1p, mediate chromosome congression by suppressing kMT plus-end assembly of longer kMTs. Of the two, Cin8p is the major effector and its activity requires a functional motor domain. In contrast, the depolymerizing kinesin-8 motor Kip3p plays a minor role in spatial regulation of yeast kMT assembly. Our analysis identified a model where kinesin-5 motors bind to kMTs, move to kMT plus ends, and upon arrival at a growing plus end promote net kMT plus-end disassembly. In conclusion, we find that length-dependent control of net kMT assembly by kinesin-5 motors yields a simple and stable self-organizing mechanism for chromosome congression.
Gardner
Melissa K
MK
Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN 55455, USA.
Bouck
David C
DC
Paliulis
Leocadia V
LV
Meehl
Janet B
JB
O'Toole
Eileen T
ET
Haase
Julian
J
Soubry
Adelheid
A
Joglekar
Ajit P
AP
Winey
Mark
M
Salmon
Edward D
ED
Bloom
Kerry
K
Odde
David J
DJ
D015825:Chromosomes, Fungal / Q000378:metabolism; D049452:Green Fluorescent Proteins / Q000378:metabolism; D016547:Kinesins / Q000378:metabolism*; D018386:Kinetochores / Q000378:metabolism*; D008869:Microtubule-Associated Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008870:Microtubules / Q000378:metabolism*; D020409:Molecular Motor Proteins; D009154:Mutation; D017434:Protein Structure, Tertiary; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
C075342:CIN8 protein, S cerevisiae; C431747:KIP1 protein, S cerevisiae; C108256:KIP3 protein, S cerevisiae; D008869:Microtubule-Associated Proteins; D020409:Molecular Motor Proteins; D029701:Saccharomyces cerevisiae Proteins; D049452:Green Fluorescent Proteins; D016547:Kinesins