| Autor: |
Mitra A; B CUBE-Center for Molecular Bioengineering, Technische Universität Dresden, 01307, Dresden, Germany.; Max Planck Institute of Molecular Cell Biology and Genetics, 01307, Dresden, Germany.; Department of Physics and Astronomy, and LaserLaB Amsterdam, Vrije Universiteit Amsterdam, 1081HV, Amsterdam, The Netherlands., Meißner L; B CUBE-Center for Molecular Bioengineering, Technische Universität Dresden, 01307, Dresden, Germany., Gandhimathi R; B CUBE-Center for Molecular Bioengineering, Technische Universität Dresden, 01307, Dresden, Germany.; Institut für Biochemie, ETH Zürich, 8093, Zürich, Switzerland., Renger R; B CUBE-Center for Molecular Bioengineering, Technische Universität Dresden, 01307, Dresden, Germany.; Max Planck Institute of Molecular Cell Biology and Genetics, 01307, Dresden, Germany., Ruhnow F; B CUBE-Center for Molecular Bioengineering, Technische Universität Dresden, 01307, Dresden, Germany.; School of Biosciences, University of Melbourne, Parkville, VIC, 3010, Australia., Diez S; B CUBE-Center for Molecular Bioengineering, Technische Universität Dresden, 01307, Dresden, Germany. stefan.diez@tu-dresden.de.; Max Planck Institute of Molecular Cell Biology and Genetics, 01307, Dresden, Germany. stefan.diez@tu-dresden.de.; Cluster of Excellence Physics of Life, Technische Universität Dresden, 01062, Dresden, Germany. stefan.diez@tu-dresden.de. |
| Abstrakt: |
Within the mitotic spindle, kinesin motors cross-link and slide overlapping microtubules. Some of these motors exhibit off-axis power strokes, but their impact on motility and force generation in microtubule overlaps has not been investigated. Here, we develop and utilize a three-dimensional in vitro motility assay to explore kinesin-14, Ncd, driven sliding of cross-linked microtubules. We observe that free microtubules, sliding on suspended microtubules, not only rotate around their own axis but also move around the suspended microtubules with right-handed helical trajectories. Importantly, the associated torque is large enough to cause microtubule twisting and coiling. Further, our technique allows us to measure the in situ spatial extension of the motors between cross-linked microtubules to be about 20 nm. We argue that the capability of microtubule-crosslinking kinesins to cause helical motion of overlapping microtubules around each other allows for flexible filament organization, roadblock circumvention and torque generation in the mitotic spindle. |
