RT Journal Article
SR Electronic
T1 A helical assembly of human ESCRT-I scaffolds reverse-topology membrane scission
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 2020.01.31.927327
DO 10.1101/2020.01.31.927327
A1 Thomas G. Flower
A1 Yoshinori Takahashi
A1 Arpa Hudait
A1 Kevin Rose
A1 Nicholas Tjahjono
A1 Alexander Pak
A1 Adam L. Yokom
A1 Xinwen Liang
A1 Hong-Gang Wang
A1 Fadila Bouamr
A1 Gregory A. Voth
A1 James H. Hurley
YR 2020
UL http://biorxiv.org/content/early/2020/02/01/2020.01.31.927327.abstract
AB 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.