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bioRxiv · 10.1101/2022.04.12.487901

Structural basis of CHMP2A-CHMP3 ESCRT-III polymer assembly and membrane cleavage

Azad, K.·Guilligay, D.·Boscheron, C.·Maity, S.·De Franceschi, N.·Sulbaran, G.·Effantin, G.·Wang, H.·Kleman, J.-P.·Bassereau, P.·Schoehn, G.·Roos, W.·Desfosses, A.·Weissenhorn, W.
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Abstract

The endosomal sorting complex required for transport (ESCRT) is a highly conserved protein machinery that drives a divers set of physiological and pathological membrane remodeling processes. However, the structural basis of ESCRT-III polymers stabilizing, constricting and cleaving negatively curved membranes is yet unknown. Here we present cryo electron microscopy structures of membrane-coated CHMP2A-CHMP3 filaments of two different diameters at 3.3 and 3.6 [A] resolution. The structures reveal helical filaments assembled by CHMP2A-CHMP3 heterodimers in the open ESCRT-III conformation, which generates a partially positive charged membrane interaction surface, positions short N-terminal motifs for membrane interaction and the C-terminal VPS4 target sequence towards the tube interior. Inter-filament interactions are electrostatic, which facilitate filament sliding upon VPS4-mediated polymer remodeling. Fluorescence microscopy as well as high speed atomic force microscopy imaging corroborate that CHMP2A-CHMP3 polymers and VPS4 can constrict and cleave narrow membrane tubes, thus acting as a minimal membrane fission machinery.

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Azad, K., Guilligay, D., Boscheron, C., Maity, S., De Franceschi, N., Sulbaran, G., Effantin, G., Wang, H., Kleman, J.-P., Bassereau, P., Schoehn, G., Roos, W., Desfosses, A., Weissenhorn, W.. 2022-04-12. Structural basis of CHMP2A-CHMP3 ESCRT-III polymer assembly and membrane cleavage. https://doi.org/10.1101/2022.04.12.487901

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