A conserved role for kinesin-5 in plant mitosis.
The mitotic spindle of vascular plants is assembled and maintained by processes that remain poorly explored at a molecular level. Here, we report that AtKRP125c, one of four kinesin-5 motor proteins in arabidopsis, decorates microtubules throughout the cell cycle and appears to function in both interphase and mitosis. In a temperature-sensitive mutant, interphase cortical microtubules are disorganized at the restrictive temperature and mitotic spindles are massively disrupted, consistent with a defect in the stabilization of anti-parallel microtubules in the spindle midzone, as previously described in kinesin-5 mutants from animals and yeast. AtKRP125c introduced into mammalian epithelial cells by transfection decorates microtubules throughout the cell cycle but is unable to complement the loss of the endogenous kinesin-5 motor (Eg5). These results are among the first reports of any motor with a major role in anastral spindle structure in plants and demonstrate that the conservation of kinesin-5 motor function throughout eukaryotes extends to vascular plants.
Bannigan
Alex
A
Biology Department, University of Massachusetts, Amherst, MA 01003, USA.
Scheible
Wolf-Rüdiger
WR
Lukowitz
Wolfgang
W
Fagerstrom
Carey
C
Wadsworth
Patricia
P
Somerville
Chris
C
Baskin
Tobias I
TI
D000818:Animals; D017360:Arabidopsis / Q000166:cytology* / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D002470:Cell Survival; D002874:Chromosome Mapping; D048749:Cytokinesis; D017343:Genes, Plant; D007399:Interphase; D016547:Kinesins / Q000378:metabolism*; D018613:Microscopy, Confocal; D008870:Microtubules / Q000378:metabolism; D008938:Mitosis; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D018517:Plant Roots / Q000166:cytology; D011418:Prophase; D021381:Protein Transport; D008941:Spindle Apparatus / Q000378:metabolism; D013552:Swine
D016547:Kinesins