Kinesin-8 molecular motors: putting the brakes on chromosome oscillations

Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN 55455, USA.
Trends in cell biology (Impact Factor: 12.01). 08/2008; 18(7):307-10. DOI: 10.1016/j.tcb.2008.05.003
Source: PubMed


Recent studies suggest that the human Kinesin-8 molecular motor Kif18A has a role in chromosome congression. Specifically, these studies find that Kif18A promotes chromosome congression by attenuating chromosome oscillation magnitudes. Together with recent modeling work, in vitro studies, and the analysis of in vivo yeast data, these reports reveal how Kinesin-8 molecular motors might control chromosome oscillation amplitudes by spatially regulating the dynamic instability of microtubule plus-ends within the mitotic spindle.

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    • "Indeed, a subset of the kinesins, those in the kinesin-13 subfamily of which MCAK/Kif2 has been most intensively studied, are well-established MT depolymerases that recognize and promote the curved protofilament structure of depolymerizing MTs [78], [79]. The kinesin-8 family has also been implicated in regulating MT dynamics [80]. There are fewer kinesins that have been implicated in stabilizing MTs to generate long-lived and post-translationally modified MTs. "
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    • "Kinesin-13 plays a role in determining the size of microtubule-based structures and establishing proper chromosome-microtubule attachment in dividing cells (Wordeman, 2005). Kinesin-8 is required for proper chromosome alignment to the spindle equator during metaphase (Gardner et al., 2008; Su et al., 2011). TIRF-microscopy analysis with recombinant proteins and dynamic microtubules shows that both kinesin-13 (Helenius et al., 2006; Hunter et al., 2003) and kinesin-8 (Gupta et al., 2006; Varga et al., 2006) accumulate at the ends of dynamic microtubules, where they increase catastrophe frequency (Figures 3B and 3C). "
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    • "By contrast with the destabilizing/depolymerizing activities of kinesin-8s, the mechanistic basis for the stabilizing effects of kinesin-8s on microtubules has not been experimentally explored. There has been speculation that Kip3 might interact differently with the straight GTP-liganded tubulin on growing ends than it does with the bent GDP-liganded tubulin on shrinking ends (Gardner et al., 2008). We previously demonstrated that Kip3 accumulates on the plus ends of growing microtubules, when it destabilizes microtubules. "
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