The mitotic kinesin-14 Ncd drives directional microtubule-microtubule sliding.
During mitosis and meiosis, the bipolar spindle facilitates chromosome segregation through microtubule sliding as well as microtubule growth and shrinkage. Kinesin-14, one of the motors involved, causes spindle collapse in the absence of kinesin-5 (Refs 2, 3), participates in spindle assembly and modulates spindle length. However, the molecular mechanisms underlying these activities are not known. Here, we report that Drosophila melanogaster kinesin-14 (Ncd) alone causes sliding of anti-parallel microtubules but locks together (that is, statically crosslinks) those that are parallel. Using single molecule imaging we show that Ncd diffuses along microtubules in a tail-dependent manner and switches its orientation between sliding microtubules. Our results show that kinesin-14 causes sliding and expansion of an anti-parallel microtubule array by dynamic interactions through the motor domain on the one side and the tail domain on the other. This mechanism accounts for the roles of kinesin-14 in spindle organization.
Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany.
Gero
G
Fink
Lukasz
L
Hajdo
Krzysztof J
KJ
Skowronek
Cordula
C
Reuther
Andrzej A
AA
Kasprzak
Stefan
S
Diez
D000818:Animals; D001692:Biological Transport / Q000502:physiology; D029721:Drosophila Proteins; D004331:Drosophila melanogaster / Q000235:genetics / Q000378:metabolism*; D016547:Kinesins; D008870:Microtubules / Q000378:metabolism*; D020409:Molecular Motor Proteins / Q000235:genetics / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D008941:Spindle Apparatus / Q000378:metabolism*
D029721:Drosophila Proteins; D020409:Molecular Motor Proteins; D011993:Recombinant Fusion Proteins; C066696:ncd protein, Drosophila; D016547:Kinesins