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Motor-driven marginal band coiling promotes cell shape change during platelet activation
Boubou Diagouraga1, Alexei Grichine, Arnold Fertin
1Institut Albert Bonniot, Institut National de la Santé et de la Recherche Médicale U823; and 2 Techniques de l'Ingénierie Médicale et de la Complexité-Informatique, Mathématiques et Applications, Grenoble, Centre National de la Recherche Scientifique Unité Mixte de Recherche 5525; Université Joseph Fourier-Grenoble 1, F-38041 Grenoble, France.
The Journal of Cell Biology
|January 15, 2014
Summary
Platelet activation involves a microtubule ring (MB) extending, not contracting, due to motor proteins. This coiling mechanism drives the cell shape change during vessel injury response.
Area of Science:
- Cell biology
- Hematology
- Biophysics
Background:
- Platelets maintain a discoid shape via a marginal band (MB) of microtubules.
- Platelet activation involves a disc-to-sphere shape transition, crucial for hemostasis.
Purpose of the Study:
- To investigate the mechanism of MB dynamics during platelet activation.
- To elucidate the role of microtubule motors in platelet shape change.
Main Methods:
- Microscopy techniques to visualize microtubule structures.
- Biochemical assays to study motor protein activity.
- Computational modeling of microtubule dynamics.
Main Results:
- Antagonistic microtubule motors maintain the resting MB.
- Dynein-mediated microtubule sliding causes MB extension during activation.
- MB coiling induces platelet spherical shape, followed by new ring formation.
Conclusions:
- Platelet shape change is driven by MB extension and coiling, not contraction.
- Microtubule motor activity is central to regulating platelet morphology.
- This reveals novel mechanisms of cellular shape regulation.
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