Reconstitution of selective HIV-1 RNA packaging in vitro by membrane-bound Gag assemblies

Elife. 2016 Jun 25;5:e14663. doi: 10.7554/eLife.14663.

Abstract

HIV-1 Gag selects and packages a dimeric, unspliced viral RNA in the context of a large excess of cytosolic human RNAs. As Gag assembles on the plasma membrane, the HIV-1 genome is enriched relative to cellular RNAs by an unknown mechanism. We used a minimal system consisting of purified RNAs, recombinant HIV-1 Gag and giant unilamellar vesicles to recapitulate the selective packaging of the 5' untranslated region of the HIV-1 genome in the presence of excess competitor RNA. Mutations in the CA-CTD domain of Gag which subtly affect the self-assembly of Gag abrogated RNA selectivity. We further found that tRNA suppresses Gag membrane binding less when Gag has bound viral RNA. The ability of HIV-1 Gag to selectively package its RNA genome and its self-assembly on membranes are thus interdependent on one another.

Keywords: HIV-1; SHAPE; biophysics; giant unilamellar vesicles; human; structural biology; viral genome packaging; virus assembly.

Publication types

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

MeSH terms

  • HIV-1 / physiology*
  • Humans
  • RNA, Viral / metabolism*
  • Unilamellar Liposomes / metabolism*
  • Virus Assembly*
  • gag Gene Products, Human Immunodeficiency Virus / metabolism*

Substances

  • RNA, Viral
  • Unilamellar Liposomes
  • gag Gene Products, Human Immunodeficiency Virus