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Updated: Dec 11, 2025
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Single-Molecule Diffusion and Assembly on Polymer-Crowded Lipid Membranes
Published on: July 19, 2022
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An ESCRT-III Polymerization Sequence Drives Membrane Deformation and Fission
Anna-Katharina Pfitzner1, Vincent Mercier2, Xiuyun Jiang3
1Department of Biochemistry, University of Geneva, 1211 Geneva, Switzerland.
Cell
|August 20, 2020
Summary
The endosomal sorting complex required for transport-III (ESCRT-III) drives membrane fission through sequential subunit polymerization and Vps4-powered turnover. Changes in ESCRT-III filament structure and subunit exchange catalyze membrane deformation and final fission.
Area of Science:
- Cell Biology
- Molecular Biology
- Biophysics
Background:
- The endosomal sorting complex required for transport-III (ESCRT-III) is crucial for membrane fission in cellular processes like autophagy and cell division.
- The precise mechanism by which ESCRT-III catalyzes membrane scission remains largely unknown.
Purpose of the Study:
- To elucidate the mechanism of membrane fission mediated by ESCRT-III.
- To characterize the dynamic structural changes and subunit exchange within ESCRT-III polymers during fission.
Main Methods:
- Sequential polymerization assays of ESCRT-III subunits.
- Analysis of subunit exchange dynamics, including Vps4 ATPase activity.
- In vitro membrane deformation and fission experiments.
Main Results:
- ESCRT-III polymerization, driven by recruitment and Vps4 turnover, induces membrane deformation and fission.
- Exchange of Vps24 for Did2 causes a polymer-membrane interface tilt, transitioning spirals to helical filaments.
- A Did2-Ist1 co-polymer forms, constricting membrane necks and promoting fission from within.
Conclusions:
- ESCRT-III utilizes stepwise changes in filament structure and mechanical properties, mediated by subunit exchange, to catalyze membrane fission.
- The dynamic remodeling of ESCRT-III filaments is key to achieving membrane scission.
- This study reveals a detailed mechanism for ESCRT-III-mediated membrane fission.
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