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Updated: Jun 7, 2025
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Visualizing Actin and Microtubule Coupling Dynamics In Vitro by Total Internal Reflection Fluorescence TIRF Microscopy
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Visualizing the Submolecular Organization of αβ-Tubulin Subunits on the Microtubule Inner Surface Using Atomic Force
Ayhan Yurtsever1, Hitoshi Asakawa1,2,3, Yukitoshi Katagiri2
1Nano Life Science Institute (WPI-NanoLSI), Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan.
Nano Letters
|November 21, 2024
Summary
This study reveals the inner structure of microtubules (MTs) using advanced AFM techniques. We mapped the arrangement of tubulin subunits, uncovering details about their connections and defects, crucial for cell function.
Area of Science:
- Cell Biology
- Biophysics
- Structural Biology
Background:
- Microtubules (MTs) are vital cytoskeletal polymers.
- Their function depends on the precise arrangement of tubulin heterodimers.
- Understanding MT structure is key to cellular processes like division and transport.
Purpose of the Study:
- To elucidate the submolecular arrangement of tubulin subunits on the inner microtubule surface.
- To identify structural defects and lateral contacts between protofilaments.
- To showcase the utility of frequency modulation atomic force microscopy (FM-AFM) in studying MTs.
Main Methods:
- Frequency modulation atomic force microscopy (FM-AFM) in liquid.
- Computational simulations.
- High-resolution imaging of microtubule inner surfaces.
Main Results:
- Revealed an undulating arrangement of protofilaments (PFs) on the inner MT surface.
- Confirmed alternating height variations due to tubulin orientations and bimodal lateral contacts.
- Directly identified structural defects caused by missing tubulin units.
Conclusions:
- Detailed submolecular structure of MTs provides insight into their functional properties.
- FM-AFM is a powerful tool for studying MTs and their interactions in a cellular context.
- Findings are essential for understanding microtubule dynamics and cellular mechanisms.
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