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Tunnelling nanotube formation is driven by Eps8/IRSp53-dependent linear actin polymerization
J Michael Henderson1,2, Nina Ljubojevic1,3, Sevan Belian1,4
1Membrane Traffic and Pathogenesis Unit, Department of Cell Biology and Infection, CNRS UMR 3691, Université de Paris, Institut Pasteur, Paris, France.
The EMBO Journal
|November 27, 2023
Summary
Tunnelling nanotubes (TNTs) form via actin extension, exceeding filopodia length. Inhibiting branched actin pathways promotes linear actin growth, favoring TNT formation and intercellular communication.
Area of Science:
- Cell Biology
- Cytoskeleton Dynamics
- Intercellular Communication
Background:
- Tunnelling nanotubes (TNTs) are actin-based cell structures facilitating intercellular communication.
- The mechanisms governing TNT formation and their length regulation beyond filopodia remain unclear.
Purpose of the Study:
- To elucidate the molecular mechanisms of TNT formation and length control.
- To identify key regulators of actin polymerization in TNTs.
Main Methods:
- Micropatterning and advanced microscopy techniques.
- Optical tweezer-based force measurements.
- Proteomic analysis and protein interaction studies.
Main Results:
- TNTs extend via outward actin polymerization, achieving lengths greater than filopodia.
- Branched actin pathways (Arp2/3-dependent) limit TNT length and occurrence.
- Inhibition of Arp2/3 enhances TNT formation by favoring linear actin polymerization, involving Eps8 and IRSp53.
Conclusions:
- TNT formation is regulated by the balance between branched and linear actin polymerization pathways.
- Eps8 and IRSp53 play crucial roles in TNT formation by promoting linear actin growth.
- Targeting these pathways could modulate TNT-mediated intercellular communication.
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