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Published on: January 26, 2019
Engineering the processive run length of the kinesin motor
K S Thorn1, J A Ubersax, R D Vale
1Department of Cellular and Molecular Pharmacology, University of California, San Francisco, California 94143, USA.
The Journal of Cell Biology
|November 22, 2000
Summary
Kinesin motor protein run length is controlled by its neck coiled-coil structure. Modifying this region with positive charges significantly increases processivity, suggesting electrostatic interactions with tubulin are key.
Area of Science:
- Molecular biology
- Cell biology
- Biophysics
Background:
- Kinesin is a processive molecular motor crucial for intracellular transport.
- Its hand-over-hand motion is key, but factors determining run length remain unclear.
Purpose of the Study:
- Investigate the role of the neck coiled-coil in kinesin's run length.
- Determine how structural modifications affect kinesin processivity.
Main Methods:
- Kinesin mutants with altered neck coiled-coil charge were created.
- Run length, ATPase activity, and motor velocity were measured.
- Effects of tubulin COOH-terminal cleavage and salt concentration were assessed.
Main Results:
- Positive charge in the neck coiled-coil increased kinesin run length up to fourfold.
- Negative charge decreased run length.
- Increased processivity was suppressed by tubulin COOH-terminal cleavage and high salt.
Conclusions:
- The kinesin neck coiled-coil modulates processivity via electrostatic interactions with tubulin's COOH terminus.
- Kinesin's run length may be evolutionarily optimized for in vivo function.
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