Depletion of cellular cholesterol inhibits membrane binding and higher-order multimerization of human immunodeficiency virus type 1 Gag

Virology. 2007 Mar 30;360(1):27-35. doi: 10.1016/j.virol.2006.10.011. Epub 2006 Nov 13.

Abstract

Recent studies have suggested that the plasma membrane contains cholesterol-enriched microdomains known as lipid rafts. HIV-1 Gag binds raft-rich regions of the plasma membrane, and cholesterol depletion impairs HIV-1 particle production. In this study, we sought to define the block imposed by cholesterol depletion. We observed that membrane binding and higher-order multimerization of Gag were markedly reduced upon cholesterol depletion. Fusing to Gag a highly efficient, heterologous membrane-binding sequence reversed the defects in Gag-membrane binding and multimerization caused by cholesterol depletion, indicating that the impact of reducing the membrane cholesterol content on Gag-membrane binding and multimerization can be circumvented by increasing the affinity of Gag for membrane. Virus release efficiency of this Gag derivative was minimally affected by cholesterol depletion. Altogether, these results are consistent with the hypothesis that cholesterol-enriched membrane microdomains promote HIV-1 particle production by facilitating both Gag-membrane binding and Gag multimerization.

Publication types

  • Research Support, N.I.H., Intramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cholesterol / metabolism*
  • Gene Products, gag / metabolism*
  • HIV Infections / virology*
  • HIV-1 / chemistry
  • HIV-1 / physiology*
  • HeLa Cells
  • Humans
  • Membrane Microdomains / metabolism*
  • Membrane Microdomains / virology
  • Protein Binding
  • Virus Replication / physiology

Substances

  • Gene Products, gag
  • Cholesterol