S. pombe kinesins-8 promote both nucleation and catastrophe of microtubules.

The kinesins-8 were originally thought to be microtubule depolymerases, but are now emerging as more versatile catalysts of microtubule dynamics. We show here that S. pombe Klp5-436 and Klp6-440 are non-processive plus-end-directed motors whose in vitro velocities on S. pombe microtubules at 7 and 2...

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Main Authors: Muriel Erent, Douglas R Drummond, Robert A Cross
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2012-01-01
Series:PLoS ONE
Online Access:https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0030738&type=printable
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author Muriel Erent
Douglas R Drummond
Robert A Cross
author_facet Muriel Erent
Douglas R Drummond
Robert A Cross
author_sort Muriel Erent
collection DOAJ
description The kinesins-8 were originally thought to be microtubule depolymerases, but are now emerging as more versatile catalysts of microtubule dynamics. We show here that S. pombe Klp5-436 and Klp6-440 are non-processive plus-end-directed motors whose in vitro velocities on S. pombe microtubules at 7 and 23 nm s(-1) are too slow to keep pace with the growing tips of dynamic interphase microtubules in living S. pombe. In vitro, Klp5 and 6 dimers exhibit a hitherto-undescribed combination of strong enhancement of microtubule nucleation with no effect on growth rate or catastrophe frequency. By contrast in vivo, both Klp5 and Klp6 promote microtubule catastrophe at cell ends whilst Klp6 also increases the number of interphase microtubule arrays (IMAs). Our data support a model in which Klp5/6 bind tightly to free tubulin heterodimers, strongly promoting the nucleation of new microtubules, and then continue to land as a tubulin-motor complex on the tips of growing microtubules, with the motors then dissociating after a few seconds residence on the lattice. In vivo, we predict that only at cell ends, when growing microtubule tips become lodged and their growth slows down, will Klp5/6 motor activity succeed in tracking growing microtubule tips. This mechanism would allow Klp5/6 to detect the arrival of microtubule tips at cells ends and to amplify the intrinsic tendency for microtubules to catastrophise in compression at cell ends. Our evidence identifies Klp5 and 6 as spatial regulators of microtubule dynamics that enhance both microtubule nucleation at the cell centre and microtubule catastrophe at the cell ends.
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spelling doaj-art-08f0e54cb3c84de9927429210b84e2cc2025-08-20T03:09:47ZengPublic Library of Science (PLoS)PLoS ONE1932-62032012-01-0172e3073810.1371/journal.pone.0030738S. pombe kinesins-8 promote both nucleation and catastrophe of microtubules.Muriel ErentDouglas R DrummondRobert A CrossThe kinesins-8 were originally thought to be microtubule depolymerases, but are now emerging as more versatile catalysts of microtubule dynamics. We show here that S. pombe Klp5-436 and Klp6-440 are non-processive plus-end-directed motors whose in vitro velocities on S. pombe microtubules at 7 and 23 nm s(-1) are too slow to keep pace with the growing tips of dynamic interphase microtubules in living S. pombe. In vitro, Klp5 and 6 dimers exhibit a hitherto-undescribed combination of strong enhancement of microtubule nucleation with no effect on growth rate or catastrophe frequency. By contrast in vivo, both Klp5 and Klp6 promote microtubule catastrophe at cell ends whilst Klp6 also increases the number of interphase microtubule arrays (IMAs). Our data support a model in which Klp5/6 bind tightly to free tubulin heterodimers, strongly promoting the nucleation of new microtubules, and then continue to land as a tubulin-motor complex on the tips of growing microtubules, with the motors then dissociating after a few seconds residence on the lattice. In vivo, we predict that only at cell ends, when growing microtubule tips become lodged and their growth slows down, will Klp5/6 motor activity succeed in tracking growing microtubule tips. This mechanism would allow Klp5/6 to detect the arrival of microtubule tips at cells ends and to amplify the intrinsic tendency for microtubules to catastrophise in compression at cell ends. Our evidence identifies Klp5 and 6 as spatial regulators of microtubule dynamics that enhance both microtubule nucleation at the cell centre and microtubule catastrophe at the cell ends.https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0030738&type=printable
spellingShingle Muriel Erent
Douglas R Drummond
Robert A Cross
S. pombe kinesins-8 promote both nucleation and catastrophe of microtubules.
PLoS ONE
title S. pombe kinesins-8 promote both nucleation and catastrophe of microtubules.
title_full S. pombe kinesins-8 promote both nucleation and catastrophe of microtubules.
title_fullStr S. pombe kinesins-8 promote both nucleation and catastrophe of microtubules.
title_full_unstemmed S. pombe kinesins-8 promote both nucleation and catastrophe of microtubules.
title_short S. pombe kinesins-8 promote both nucleation and catastrophe of microtubules.
title_sort s pombe kinesins 8 promote both nucleation and catastrophe of microtubules
url https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0030738&type=printable
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