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Updated: Jan 14, 2026
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In Vitro Reconstitution of the Actin Cytoskeleton Inside Giant Unilamellar Vesicles
Published on: August 25, 2022
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Dynamic shape remodeling of vesicles by internal active filaments
Arash Karaei Shiraz1, Amir H Bahrami1
1Living Matter and Biophysics, UNAM-National Nanotechnology Research Center and Institute of Materials Science & Nanotechnology, Bilkent University, Ankara, Turkey.
Biophysical Journal
|October 23, 2025
Summary
Cellular structures dynamically remodel using active cytoskeletal forces. Simulations reveal novel pathways for generating unstable, dynamic membrane shapes like branched tubes, advancing understanding of cell morphology.
Area of Science:
- Cell Biology
- Biophysics
- Computational Biology
Background:
- Living cells utilize active cytoskeletal forces to generate dynamic membrane structures like filopodia and lamellipodia for environmental interaction.
- Understanding the formation and dynamics of these cellular structures is crucial for comprehending cell behavior and function.
Purpose of the Study:
- To investigate vesicle shape remodeling driven by internal active filaments and osmotic volume changes.
- To identify the morphological behavior of vesicles across varying volumes and filament properties.
Main Methods:
- Non-equilibrium simulations of dynamically triangulated vesicles under constrained volume.
- Analysis of vesicle morphology influenced by filament concentration, mobility, stiffness, and length.
Main Results:
- Simulations revealed dynamic, unstable vesicle structures including branched tubes, sheet-tubes, and compartmentalized vesicles.
- Unstable branched tubes were observed under low vesicle volume and low filament mobility, with restructuring accelerating as mobility decreased.
- Branched tubes formation was dependent on active, anisotropic filaments and disappeared with filament shortening and loss of anisotropy.
Conclusions:
- Identified novel non-equilibrium pathways for generating unstable, dynamic cellular structures.
- Provided insights into complex organelle morphologies and cellular protrusions.
- Suggested new mechanisms for actively shaping synthetic membrane systems.
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