A helical assembly of human ESCRT-I scaffolds reverse-topology membrane scission

Flower, T. G.; Takahashi, Y.; Hudait, A.; Rose, K.; Tjahjono, N.; Pak, A.; Yokom, A. L.; Liang, X.; Wang, H.-G.; Bouamr, F.; Voth, G. A.; Hurley, J. H.

doi:10.1101/2020.01.31.927327

bioRxiv · 10.1101/2020.01.31.927327

A helical assembly of human ESCRT-I scaffolds reverse-topology membrane scission

Flower, T. G.·Takahashi, Y.·Hudait, A.·Rose, K.·Tjahjono, N.·Pak, A.·Yokom, A. L.·Liang, X.·Wang, H.-G.·Bouamr, F.·Voth, G. A.·Hurley, J. H.

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Abstract

The ESCRT complexes drive membrane scission in HIV-1 release, autophagosome closure, MVB biogenesis, cytokinesis, and other cell processes. ESCRT-I is the most upstream complex and bridges the system to HIV-1 Gag in virus release. The crystal structure of the headpiece of human ESCRT-I comprising TSG101:VPS28:VPS37B:MVB12A was determined, revealing an ESCRT-I helical assembly with a 12 molecule repeat. Electron microscopy confirmed that ESCRT-I subcomplexes form helical filaments in solution. Mutation of VPS28 helical interface residues blocks filament formation in vitro and autophagosome closure and HIV-1 release in human cells. Coarse grained simulations of ESCRT assembly at HIV-1 budding sites suggest that formation of a 12-membered ring of ESCRT-I molecules is a geometry-dependent checkpoint during late stages of Gag assembly and HIV-1 budding, and templates ESCRT-III assembly for membrane scission. These data show that ESCRT-I is not merely a bridging adaptor, but has an essential scaffolding and mechanical role in its own right.

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Flower, T. G., Takahashi, Y., Hudait, A., Rose, K., Tjahjono, N., Pak, A., Yokom, A. L., Liang, X., Wang, H.-G., Bouamr, F., Voth, G. A., Hurley, J. H.. 2020-02-01. A helical assembly of human ESCRT-I scaffolds reverse-topology membrane scission. https://doi.org/10.1101/2020.01.31.927327

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