Dynamic Subunit Turnover in ESCRT-III Assemblies Is Regulated by Vps4 to Mediate Membrane Remodelling During Cytokinesis

Nat Cell Biol. 2017 Jul;19(7):787-798. doi: 10.1038/ncb3559. Epub 2017 Jun 12.

Abstract

The endosomal sorting complex required for transport (ESCRT)-III mediates membrane fission in fundamental cellular processes, including cytokinesis. ESCRT-III is thought to form persistent filaments that over time increase their curvature to constrict membranes. Unexpectedly, we found that ESCRT-III at the midbody of human cells rapidly turns over subunits with cytoplasmic pools while gradually forming larger assemblies. ESCRT-III turnover depended on the ATPase VPS4, which accumulated at the midbody simultaneously with ESCRT-III subunits, and was required for assembly of functional ESCRT-III structures. In vitro, the Vps2/Vps24 subunits of ESCRT-III formed side-by-side filaments with Snf7 and inhibited further polymerization, but the growth inhibition was alleviated by the addition of Vps4 and ATP. High-speed atomic force microscopy further revealed highly dynamic arrays of growing and shrinking ESCRT-III spirals in the presence of Vps4. Continuous ESCRT-III remodelling by subunit turnover might facilitate shape adaptions to variable membrane geometries, with broad implications for diverse cellular processes.

Publication types

  • Video-Audio Media

MeSH terms

  • ATPases Associated with Diverse Cellular Activities
  • Cytokinesis*
  • Endosomal Sorting Complexes Required for Transport / genetics
  • Endosomal Sorting Complexes Required for Transport / metabolism*
  • Endosomes / enzymology*
  • Endosomes / ultrastructure
  • HeLa Cells
  • Humans
  • Intracellular Membranes / enzymology*
  • Intracellular Membranes / ultrastructure
  • Microscopy, Atomic Force
  • RNA Interference
  • Signal Transduction
  • Time Factors
  • Transfection
  • Vacuolar Proton-Translocating ATPases / genetics
  • Vacuolar Proton-Translocating ATPases / metabolism*

Substances

  • CHMP2A protein, human
  • CHMP3 protein, human
  • CHMP4A protein, human
  • CHMP4B protein, human
  • Endosomal Sorting Complexes Required for Transport
  • Vacuolar Proton-Translocating ATPases
  • ATPases Associated with Diverse Cellular Activities
  • VPS4A protein, human