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Updated: Aug 20, 2026

Motility of Single Molecules and Clusters of Bi-Directional Kinesin-5 Cin8 Purified from S. cerevisiae Cells
Published on: February 2, 2022
The kinesin Eg5 drives poleward microtubule flux in Xenopus laevis egg extract spindles
David T Miyamoto1, Zachary E Perlman, Kendra S Burbank
1Department of Systems Biology, Harvard Medical School, Boston, MA 02115, USA. miyamoto@post.harvard.edu
Abstract:
Although mitotic and meiotic spindles maintain a steady-state length during metaphase, their antiparallel microtubules slide toward spindle poles at a constant rate. This "poleward flux" of microtubules occurs in many organisms and may provide part of the force for chromosome segregation. We use quantitative image analysis to examine the role of the kinesin Eg5 in poleward flux in metaphase Xenopus laevis egg extract spindles. Pharmacological inhibition of Eg5 results in a dose-responsive slowing of flux, and biochemical depletion of Eg5 significantly decreases the flux rate. Our results suggest that ensembles of nonprocessive Eg5 motors drive flux in metaphase Xenopus extract spindles.
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