Motor-driven microtubule diffusion in a photobleached dynamical coordinate system
Creators
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1.
California Institute of Technology
Abstract
A hallmark feature of active matter systems is the ability of individual elements to interact and organize over length scales exceeding that of the constituent molecular players. However, the nature of internal redistribution that occurs in the bulk of the collective is less clear. Using light-dimerizable kinesin motors to spatially control the formation and contraction of a microtubule network, we deliberately photobleach a grid pattern onto the filament network serving as a transient and dynamic coordinate system to observe the deformation and translation of the remaining fluorescent squares of microtubules. We find that the network contracts at a rate set by motor speed but is accompanied by a diffusive-like spread throughout the bulk of the contracting network with effective diffusion constant two orders of magnitude lower than that for freely diffusing microtubules. We further find that on micron scales, the diffusive timescale is only a factor of ≈3 slower than that of advection regardless of conditions, showing that the global contraction and long-time relaxation from this diffusive behavior are both motor-driven but exhibit local competition within the network bulk.
Copyright and License
Copyright © 2025 the Author(s). Published by PNAS. This article is distributed under Creative Commons Attribution-NonCommercial-NoDerivatives License 4.0(CC BY-NC-ND).
Acknowledgement
We thank members of the Rob Phillips lab for useful discussions. We would also like to thank the David Van Valen and Rebecca Voorhees labs for providing resources for performing the protein expression and purification. We also thank Justin Bois, Griffin Chure, Peter Foster, Sebastian Fürthauer, Victor Gomez, Stephan Grill, Catherine Ji, Frank Jülicher, Matthias Merkel, Daniel Needleman, Leïla Perié, Henk Postma, Madan Rao, Shahriar Shadkhoo, and Fan Yang. This work was supported by 1R35 GM118043 and 2R35 GM118043 Maximizing Investigators’ Research Awards (to R.P.).
Funding
This work was supported by 1R35 GM118043 and 2R35 GM118043 Maximizing Investigators’ Research Awards (to R.P.).
Contributions
S.H., H.J.L., and R.P. designed research; S.H., H.J.L., and B.N. performed research; S.H., H.J.L., R.A.B., and A.I.D. contributed new reagents/analytic tools; S.H. and A.I.D. analyzed data; and S.H., H.J.L., R.A.B., M.T., and R.P. wrote the paper.
Data Availability
All data and code are publicly available. Raw image files and COMSOL simulation file can be downloaded from the CaltechDATA research data repository under the DOI: https://doi.org/10.22002/f23ds-f2v87 (52). Analyzed data files and code generated by Python (for analyses) and BeanShell Scripts and C# (for hardware communication) for the work presented here are available on the dedicated GitHub repository under the DOI: https://doi.org/10.5281/zenodo.12806576 (53).
Code Availability
Analyzed data files and code generated by Python (for analyses) and BeanShell Scripts and C# (for hardware communication) for the work presented here are available on the dedicated GitHub repository under the DOI: https://doi.org/10.5281/zenodo.12806576 (53).
Conflict of Interest
The authors declare no competing interest.
Supplemental Material
Appendix 01 (PDF)
Files
hirokawa-et-al-2025-motor-driven-microtubule-diffusion-in-a-photobleached-dynamical-coordinate-system.pdf
Additional details
Identifiers
- PMID
- 40489609
- PMCID
- PMC12184364
Related works
- Describes
- Journal Article: 40489609 (PMID)
- Journal Article: PMC12184364 (PMCID)
- Is new version of
- Discussion Paper: arXiv:2408.11216 (arXiv)
- Is supplemented by
- Dataset: 10.22002/f23ds-f2v87 (DOI)
- Software: 10.5281/zenodo.12806576 (DOI)
Funding
- National Institutes of Health
- 1R35 GM118043
- National Institutes of Health
- 2R35 GM118043
Dates
- Submitted
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2024-08-29
- Accepted
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2025-04-30
- Available
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2025-06-09Available online
Caltech Custom Metadata
- Caltech groups
- Division of Biology and Biological Engineering (BBE) , Division of Engineering and Applied Science (EAS) , Division of Physics, Mathematics and Astronomy (PMA)
- Publication Status
- Published