Diffusive Movement of Processive Kinesin‐1 on Microtubules
Open Access
- 10 September 2009
- Vol. 10 (10), 1429-1438
- https://doi.org/10.1111/j.1600-0854.2009.00964.x
Abstract
The processive motor kinesin‐1 moves unidirectionally toward the plus end of microtubules. This process can be visualized by total internal reflection fluorescence microscopy of kinesin bound to a carboxylated quantum dot (Qdot), which acts both as cargo and label. Surprisingly, when kinesin is bound to an anti‐HIS Qdot, it shows diffusive movement on microtubules, which decreased in favor of processive runs with increasing salt concentration. This observation implies that kinesin movement on microtubules is governed by its conformation, as it is well established that kinesin undergoes a salt‐dependent transition from a folded (inactive) to an extended (active) molecule. A truncated kinesin lacking the last 75 amino acids (kinesin‐ΔC) showed both processive and diffusive movement on microtubules. The extent of each behavior depends on the relative amounts of ADP and ATP, with purely diffusive movement occurring in ADP alone. Taken together, these data imply that folded kinesin.ADP can exist in a state that diffuses along the microtubule lattice without expending energy. This mechanism may facilitate the ability of kinesin to pick up cargo, and/or allow the kinesin/cargo complex to stay bound after encountering obstacles.Keywords
This publication has 39 references indexed in Scilit:
- The diffusive interaction of microtubule binding proteinsCurrent Opinion in Cell Biology, 2009
- Diffusion and Directed Movement: IN VITRO MOTILE PROPERTIES OF FISSION YEAST KINESIN-14 Pkl1Journal of Biological Chemistry, 2008
- Activation of mitotic kinesin by microtubule bundlingThe Journal of cell biology, 2008
- Microtubule cross-linking triggers the directional motility of kinesin-5The Journal of cell biology, 2008
- The kinesin-1 motor protein is regulated by a direct interaction of its head and tailProceedings of the National Academy of Sciences of the United States of America, 2008
- CENP-E combines a slow, processive motor and a flexible coiled coil to produce an essential motile kinetochore tetherThe Journal of cell biology, 2008
- Myosin Va maneuvers through actin intersections and diffuses along microtubulesProceedings of the National Academy of Sciences of the United States of America, 2007
- Two binding partners cooperate to activate the molecular motor Kinesin-1The Journal of cell biology, 2007
- Kinesin-1 structural organization and conformational changes revealed by FRET stoichiometry in live cellsThe Journal of cell biology, 2007
- Myosin V Walks Hand-Over-Hand: Single Fluorophore Imaging with 1.5-nm LocalizationScience, 2003