Related Experiment Video
Updated: Jul 4, 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
Single-headed mode of kinesin-5
Kuniyoshi Kaseda1, Isabelle Crevel, Keiko Hirose
1Molecular Motors Group, Marie Curie Research Institute, The Chart, Oxted, Surrey RH8 0TL, UK.
EMBO Reports
|June 17, 2008
Summary
Kinesin-5 motors (Eg5) drive microtubule sliding using a primarily single-headed mechanism, challenging previous assumptions about their processivity during cell division. This muscle-like model suggests one head is often redundant.
Area of Science:
- Cell Biology
- Molecular Motors
- Biophysics
Background:
- Kinesin-5 motors are crucial for cell division (mitosis and meiosis) by crosslinking and separating antiparallel microtubule half-spindles.
- Previous studies showed double-headed kinesin-5 (Eg5) dimers exhibit limited processive stepping along microtubules with poor head coordination.
Purpose of the Study:
- To investigate the mechanism of kinesin-5 (Eg5) driven microtubule sliding.
- To determine if kinesin-5 motors can operate via a nonprocessive mechanism.
Main Methods:
- Engineering and utilizing single-headed kinesin-5 (Eg5) dimers.
- Measuring microtubule sliding velocity driven by these engineered dimers.
Main Results:
- Single-headed Eg5 dimers achieved approximately 90% of wild-type microtubule sliding velocity.
- This indicates that Eg5 can effectively slide microtubules with one head being functionally redundant in each pair.
Conclusions:
- Eg5-driven microtubule sliding likely operates via a predominantly single-headed mechanism.
- A muscle-like model is proposed where most force generation involves single-headed interactions, with rare alternate-heads processivity.
Related Concept Videos
01:43The Movement of Organelles and Vesicles
In eukaryotic cells, cytoskeletal filaments such as actin, microtubules, and intermediate filaments form a mesh-like cytoskeletal network. These filaments serve as tracks for transporting cellular cargo. Specialized motor proteins use the chemical energy stored in adenosine triphosphate (ATP) for this transport. During interphase, microtubules are polarized, with the plus-end towards the cell periphery and the minus-end towards the cell center. Two microtubule-associated motor proteins,...
01:32Microtubule Associated Motor Proteins
Eukaryotic cells have different motor proteins for transporting various cargo within the cell. These motor proteins differ based on the filament they associate with, the direction they move within the cell, and the type of cargo they transport. Motor proteins that associate with microtubules are known as microtubule-associated motor proteins. There are two families of microtubule-associated motor proteins —Kinesins and Dyneins. Both these proteins assist in the transport of cellular cargos...
01:24Microtubules in Cell Motility
Microtubules are thick hollow cylindrical proteins that help form the cytoskeleton. Microtubules have varied roles in the cell. These filaments help form cellular appendages like cilia and flagella, which are responsible for locomotion. The cilia arise from basal bodies, separated from the main body by a membrane-like structure forming the transition zone. This zone is the gate for the entry of lipids and proteins, creating a unique composition of lipids and proteins in the ciliary membrane and...
01:24Microtubules in Cell Motility
Microtubules are thick hollow cylindrical proteins that help form the cytoskeleton. Microtubules have varied roles in the cell. These filaments help form cellular appendages like cilia and flagella, which are responsible for locomotion. The cilia arise from basal bodies, separated from the main body by a membrane-like structure forming the transition zone. This zone is the gate for the entry of lipids and proteins, creating a unique composition of lipids and proteins in the ciliary membrane and...
01:39Anaphase A and B
Microtubules form through the end-to-end polymerization of tubulin heterodimers. Kinetochore microtubules originate from the spindle poles, and their plus-ends connect with the kinetochores on sister-chromatids. Ndc80 protein complexes, present on the kinetochore, form low-affinity links with the plus end of these kinetochore microtubules.
Plus-end depolymerization releases tubulin heterodimers from the terminal region of the microtubule. As tubulin subunits are lost, the Ndc80 complexes detach...
Plus-end depolymerization releases tubulin heterodimers from the terminal region of the microtubule. As tubulin subunits are lost, the Ndc80 complexes detach...
01:05Mechanism of Ciliary Motion
The ciliary structures were first seen in 1647 by Antonie Leeuwenhoek while observing the protozoans. In lower organisms, these appendages are responsible for cell movement, while in higher organisms, these appendages help in the movement of the extracellular fluids within the body cavities.
The cilia are made up of microtubules in a 9+2 arrangement, with nine microtubule doublet ring bundles, surrounding a pair of central singlet microtubule bundles. The doublet microtubule bundles are...
The cilia are made up of microtubules in a 9+2 arrangement, with nine microtubule doublet ring bundles, surrounding a pair of central singlet microtubule bundles. The doublet microtubule bundles are...