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Updated: Jan 16, 2026
10:46
Motility of Single Molecules and Clusters of Bi-Directional Kinesin-5 Cin8 Purified from S. cerevisiae Cells
Published on: February 2, 2022
2.9K
Dimeric Cin8 motors have an inherent plus-end bias and weak inter-head coordination
Himanshu Pandey1, Tzu-Chen Ma1, Eric Bonventre2
1Department of Biomedical Engineering, Pennsylvania State University, University Park, Pennsylvania, USA.
Biorxiv : the Preprint Server for Biology
|October 3, 2025
Summary
Fungal kinesin-5 (Cin8) motor proteins show bidirectional movement. Researchers found that the neck-coil domain
Area of Science:
- Cell Biology
- Molecular Motors
- Biophysics
Background:
- Kinesin-5 motors are crucial for mitotic spindle assembly.
- Fungal kinesin-5 (Cin8) motors display bidirectional motility, but the molecular basis is unknown.
Purpose of the Study:
- Investigate the molecular mechanisms underlying bidirectional motility in fungal kinesin-5 (Cin8).
- Determine the role of the neck-coil region in coordinating Cin8 motor activity and directional switching.
Main Methods:
- Created and analyzed two Cin8 dimers with varying neck-coil domains.
- Studied motility, ATPase kinetics, and microtubule binding dynamics.
- Compared behavior on yeast and bovine microtubules.
Main Results:
- Cin8 dimers exhibited net plus-end directed motility with undirected movements, mimicking wild-type plus-ended state.
- Fast minus-end motility observed in tetramers was absent in dimers.
- Native neck-coil flexibility contributes to bidirectional stepping; sustained minus-end movement requires other regions.
Conclusions:
- The native Cin8 neck-coil domain's flexibility is essential for bidirectional stepping.
- Regions outside the motor domain are necessary for sustained minus-end motility.
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