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Updated: May 24, 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
Two independent switches regulate cytoplasmic dynein's processivity and directionality
Wilhelm J Walter1, Michael P Koonce, Bernhard Brenner
1Molecular and Cellular Physiology, Hannover Medical School, Carl-Neuberg-Strasse 1, 30625 Hannover, Germany.
Summary
Cytoplasmic dynein, a versatile motor protein, moves along microtubules in four distinct ways. Its direction and processivity are controlled by phosphate and magnesium ion concentrations, revealing new regulatory mechanisms.
Area of Science:
- Cell Biology
- Biophysics
- Molecular Motors
Background:
- Cytoplasmic dynein is a crucial microtubule-based motor protein involved in diverse cellular processes like division and transport.
- Unlike other motor proteins, dynein utilizes a single heavy chain for multiple functions, necessitating complex regulatory mechanisms.
Purpose of the Study:
- To investigate the fundamental motor functions of cytoplasmic dynein.
- To elucidate the regulatory mechanisms controlling dynein's movement modes.
Main Methods:
- Utilized an advanced optical trap technique to analyze dynein's motion at the single-molecule level.
- Manipulated concentrations of phosphate and magnesium ions to probe regulatory switches.
Main Results:
- Demonstrated that cytoplasmic dynein generates discrete power strokes and can move processively in both plus and minus directions along microtubules.
- Identified two key regulatory switches: one phosphate-dependent for directionality and one magnesium-dependent for processivity.
- Showed that these switches can be independently or jointly controlled by ion concentrations.
Conclusions:
- Cytoplasmic dynein exhibits four basic modes of motion: processive/nonprocessive and forward/reverse movement.
- Phosphate and magnesium ions act as critical regulators, controlling dynein's directionality and processivity.
- These findings provide significant insights into the cellular regulation and stepping mechanism of cytoplasmic dynein.
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