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Preparation of Segmented Microtubules to Study Motions Driven by the Disassembling Microtubule Ends
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Preparation of Segmented Microtubules to Study Motions Driven by the Disassembling Microtubule Ends

Published on: March 15, 2014

Microtubule depolymerization by the Kinesin-8 motor Kip3p: a mathematical model

L E Hough1, Anne Schwabe, Matthew A Glaser

  • 1Physics Department, University of Colorado at Boulder, Boulder, Colorado, USA.

Biophysical Journal
|April 23, 2009
PubMed

Insights

Kinesin-8 proteins shorten microtubules by moving along them. This study models kinesin-8 activity, revealing processive depolymerization and length-dependent microtubule shortening crucial for cellular control.

Area of Science:

  • Cell Biology
  • Molecular Motors
  • Cytoskeleton Dynamics

Background:

  • Kinesin-8 proteins are crucial for regulating microtubule (MT) length in cells.
  • They possess both MT depolymerization activity and plus-end directed motility.

Purpose of the Study:

  • To develop a simple model of kinesin-8 activity incorporating directional motion and MT plus-end destabilization.
  • To quantitatively analyze kinesin-8's effect on stabilized MT length dynamics.

Main Methods:

  • Development of a mathematical model for kinesin-8 motor activity.
  • Quantitative comparison of model predictions with experimental data of MT length over time.
  • Analysis of MT length fluctuations to infer depolymerization processivity.

Main Results:

  • The model accurately reproduces experimental MT length-versus-time traces, including length-dependent depolymerization.
  • Experimental data suggests kinesin-8 depolymerizes processively, removing multiple tubulin dimers per motor.
  • MT length fluctuations correlate with depolymerization processivity.

Conclusions:

  • Kinesin-8 exhibits processive depolymerization, contributing to microtubule length control.
  • Length-dependent depolymerization occurs for shorter microtubules and is sensitive to motor concentration.
  • The model provides insights into the mechanism of kinesin-8-mediated microtubule dynamics.

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