Torque generation of kinesin motors is governed by the stability of the neck domain

Mol Cell. 2012 Apr 27;46(2):147-58. doi: 10.1016/j.molcel.2012.04.005.

Abstract

In long-range transport of cargo, prototypical kinesin-1 steps along a single protofilament on the microtubule, an astonishing behavior given the number of theoretically available binding sites on adjacent protofilaments. Using a laser trap assay, we analyzed the trajectories of several representatives from the kinesin-2 class on freely suspended microtubules. In stark contrast to kinesin-1, these motors display a wide range of left-handed spiraling around microtubules and thus generate torque during cargo transport. We provide direct evidence that kinesin's neck region determines the torque-generating properties. A model system based on kinesin-1 corroborates this result: disrupting the stability of the neck by inserting flexible peptide stretches resulted in pronounced left-handed spiraling. Mimicking neck stability by crosslinking significantly reduced the spiraling of the motor up to the point of protofilament tracking. Finally, we present a model that explains the physical basis of kinesin's spiraling around the microtubule.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Biological Transport
  • Kinesin / chemistry
  • Kinesin / metabolism
  • Kinesin / physiology*
  • Microtubules / chemistry
  • Microtubules / metabolism
  • Models, Biological*
  • Molecular Sequence Data
  • Protein Stability
  • Protein Structure, Tertiary
  • Sequence Alignment
  • Torque

Substances

  • Kinesin