Direct Observation of the Myosin Va Recovery Stroke That Contributes to Unidirectional Stepping along Actin
2011
How Myosin Va Moves Along Actin Filaments
publication
Evidence: high
Author Information
Author(s): Katsuyuki Shiroguchi, Hong-Fu Chin, Daniel E. Hannemann, Eiji Muneyuki, Emilio De La Cruz
Primary Institution: Harvard University
Hypothesis
The study investigates how myosin Va bends its 'ankle' before each step to maintain unidirectional movement along actin filaments.
Conclusion
The study reveals that myosin Va flexes its head by about 90 degrees, which is crucial for its ability to step forward along actin filaments.
Supporting Evidence
- The myosin Va head flexes by about 90 degrees when exposed to ATP, which is essential for its movement.
- Myosin Va typically stays in the new flexed position for around 40 seconds, allowing it to prepare for the next step.
- The study provides direct observation of the recovery stroke, a key step in myosin's movement along actin.
Takeaway
Myosin Va is like a tiny motor that moves along a track, and it needs to bend its head just right to keep moving forward.
Methodology
The researchers immobilized single myosin molecules and used UV light to release ATP, observing the movement of the myosin heads under a microscope.
Digital Object Identifier (DOI)
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