Recruitment dynamics of ESCRT-III and Vps4 to endosomes and implications for reverse membrane budding
- Medical University of Innsbruck, Austria
- Harvard Medical School, United States
- European Molecular Biology Laboratory, Germany
- Boston Children's Hospital, United States
- University of Utah, United States
Abstract
The ESCRT machinery mediates reverse membrane scission. By quantitative fluorescence lattice light-sheet microscopy, we have shown that ESCRT-III subunits polymerize rapidly on yeast endosomes, together with the recruitment of at least two Vps4 hexamers. During their 3-45 second lifetimes, the ESCRT-III assemblies accumulated 75-200 Snf7 and 15-50 Vps24 molecules. Productive budding events required at least two additional Vps4 hexamers. Membrane budding was associated with continuous, stochastic exchange of Vps4 and ESCRT-III components, rather than steady growth of fixed assemblies, and depended on Vps4 ATPase activity. An all-or-none step led to final release of ESCRT-III and Vps4. Tomographic electron microscopy demonstrated that acute disruption of Vps4 recruitment stalled membrane budding. We propose a model in which multiple Vps4 hexamers (four or more) draw together several ESCRT-III filaments. This process induces cargo crowding and inward membrane buckling, followed by constriction of the nascent bud neck and ultimately ILV generation by vesicle fission.
Data availability
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Data from: Recruitment dynamics of ESCRT-III and Vps4 to endosomes and implications for reverse membrane buddingAvailable at Dryad Digital Repository under a CC0 Public Domain Dedication.
Article and author information
Author details
Funding
National Institutes of Health (GM075252)
- Tomas Kirchhausen
Austrian Science Fund (Y444-B12)
- David Teis
Austrian Science Fund (P30263)
- David Teis
Austrian Science Fund (W1101-B18)
- David Teis
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Copyright
© 2017, Adell et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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Recruitment dynamics of ESCRT-III and Vps4 to endosomes and implications for reverse membrane budding
eLife 6:e31652.
https://doi.org/10.7554/eLife.31652
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