ESCRT-III protein requirements for HIV-1 budding

Cell Host Microbe. 2011 Mar 17;9(3):235-242. doi: 10.1016/j.chom.2011.02.004.

Abstract

Two early-acting components of the cellular ESCRT pathway, ESCRT-I and ALIX, participate directly in HIV-1 budding. The membrane fission activities of ESCRT-III subunits are also presumably required, but humans express 11 different CHMP/ESCRT-III proteins whose functional contributions are not yet clear. We therefore depleted cells of each of the different CHMP proteins and protein families and examined the effects on HIV-1 budding. Virus release was profoundly inhibited by codepletion of either CHMP2 or CHMP4 family members, resulting in ≥100-fold titer reductions. CHMP2A and CHMP4B proteins bound one another, and this interaction was required for budding. By contrast, virus release was reduced only modestly by depletion of CHMP3 and CHMP1 proteins (2- to 8-fold titer reductions) and was unaffected by depletion of other human ESCRT-III proteins. HIV-1 budding therefore requires only a subset of the known human ESCRT-III proteins, with the CHMP2 and CHMP4 families playing key functional roles.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Endosomal Sorting Complexes Required for Transport / genetics
  • Endosomal Sorting Complexes Required for Transport / metabolism*
  • HIV Infections / metabolism
  • HIV Infections / virology*
  • HIV-1 / growth & development*
  • HIV-1 / pathogenicity
  • Models, Molecular
  • Mutagenesis, Site-Directed
  • Protein Interaction Domains and Motifs
  • RNA Interference
  • Recombinant Proteins / metabolism
  • Two-Hybrid System Techniques
  • Virus Assembly
  • Virus Release*

Substances

  • CHMP2A protein, human
  • CHMP2B protein, human
  • CHMP4A protein, human
  • CHMP4B protein, human
  • Endosomal Sorting Complexes Required for Transport
  • Recombinant Proteins
  • Snf7-3 protein, human