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Simultaneous Visualization of the Dynamics of Crosslinked and Single Microtubules In Vitro by TIRF Microscopy
Published on: February 18, 2022
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Microtubule catastrophe from protofilament dynamics.
V Jemseena1, Manoj Gopalakrishnan
1Department of Physics, Indian Institute of Technology Madras, Chennai 600036, India.
Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics
|October 16, 2013
Summary
The guanosine triphosphate- (GTP) tubulin cap loss triggers microtubule catastrophe. This study models GTP cap dynamics, finding that 2-3 protofilament cap losses initiate microtubule shrinkage.
Area of Science:
- Biophysics
- Cell Biology
- Computational Biology
Background:
- Microtubule dynamics are crucial for eukaryotic cell function.
- The guanosine triphosphate- (GTP) tubulin cap's disappearance is linked to microtubule catastrophe (shrinkage).
- Previous models focused on stochastic GTP cap dynamics.
Purpose of the Study:
- To investigate a discrete stochastic model of GTP cap dynamics.
- To analyze the factors influencing protofilament and microtubule catastrophe.
- To compare model predictions with experimental observations.
Main Methods:
- Applied a discrete stochastic model of GTP cap dynamics to single protofilaments.
- Calculated protofilament catastrophe frequency using perturbative and analytical approaches.
- Extended analysis to whole microtubules using numerical simulations and steady-state assumptions.
Main Results:
- Protofilament catastrophe behavior shows similar asymptotic behavior across models at high growth velocities.
- Microtubule catastrophe requires the loss of GTP caps in 2-3 protofilaments.
- Model predictions align with analyzed experimental results.
Conclusions:
- The loss of GTP tubulin caps in a small number of protofilaments is a critical determinant of microtubule catastrophe.
- The discrete stochastic model provides a robust framework for understanding microtubule dynamics.
- This research offers insights into the molecular mechanisms governing microtubule stability.
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