Kinesin Kip2 enhances microtubule growth in vitro through length-dependent feedback on polymerization and catastrophe

eLife

Aliona Bogdanova¹  Erik Schäffer²  Dimitris Liakopoulos³  Anita Jannasch⁴  Anneke Hibbel⁵  Mohammed Mahamdeh⁵  Marko Storch⁵  Jonathon Howard⁶ 

[1] Institute of Biochemistry, ETH Zurich, Zurich, Switzerland;Zentrum für Molekularbiologie der Pflanzen, Eberhard-Karls-Universität, Tübingen, Germany;Department of Life Sciences, Imperial College London, London, United Kingdom;Department of Molecular Biophysics & Biochemistry, Yale University, New Haven, United States;Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany;Zentrum für Molekularbiologie der Pflanzen, Eberhard-Karls-Universität, Tübingen, Germany;

关键词: microtubule dynamics;    motor protein;    length regulation;    positive feedback;   

DOI  :  10.7554/eLife.10542

来源: DOAJ

【 摘 要 】

The size and position of mitotic spindles is determined by the lengths of their constituent microtubules. Regulation of microtubule length requires feedback to set the balance between growth and shrinkage. Whereas negative feedback mechanisms for microtubule length control, based on depolymerizing kinesins and severing proteins, have been studied extensively, positive feedback mechanisms are not known. Here, we report that the budding yeast kinesin Kip2 is a microtubule polymerase and catastrophe inhibitor in vitro that uses its processive motor activity as part of a feedback loop to further promote microtubule growth. Positive feedback arises because longer microtubules bind more motors, which walk to the ends where they reinforce growth and inhibit catastrophe. We propose that positive feedback, common in biochemical pathways to switch between signaling states, can also be used in a mechanical signaling pathway to switch between structural states, in this case between short and long polymers.

【 授权许可】

Unknown