Autophagy pathway intersects with HIV-1 biosynthesis and regulates viral yields in macrophages

J Cell Biol. 2009 Jul 27;186(2):255-68. doi: 10.1083/jcb.200903070.

Abstract

Autophagy is a cytoplasmic degradative pathway that can participate in biosynthetic processes, as in the yeast Cvt pathway, but is more commonly known for its functions in removing damaged or surplus organelles and macromolecular complexes. Here, we find that autophagy intersects with human immunodeficiency virus (HIV) biogenesis, mirroring the above dichotomy. Early, nondegradative stages of autophagy promoted HIV yields. HIV Gag-derived proteins colocalized and interacted with the autophagy factor LC3, and autophagy promoted productive Gag processing. Nevertheless, when autophagy progressed through maturation stages, HIV was degraded. This, however, does not occur, as the HIV protein Nef acts as an antiautophagic maturation factor through interactions with the autophagy regulatory factor Beclin 1, thus protecting HIV from degradation. The dual interaction of HIV with the autophagy pathway enhances viral yields by using the early stages while inhibiting the late stages of autophagy. The role of Nef in the latter process enhances yields of infectious HIV and may be of significance for progression to clinical AIDS.

Publication types

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

MeSH terms

  • Animals
  • Apoptosis Regulatory Proteins / genetics
  • Apoptosis Regulatory Proteins / metabolism
  • Autophagy / physiology*
  • Autophagy-Related Protein 7
  • Beclin-1
  • Biomarkers / metabolism
  • Cell Line
  • HIV-1 / physiology*
  • Humans
  • Macrophages / ultrastructure
  • Macrophages / virology*
  • Membrane Proteins / genetics
  • Membrane Proteins / metabolism
  • Microtubule-Associated Proteins / genetics
  • Microtubule-Associated Proteins / metabolism
  • RNA, Small Interfering / genetics
  • RNA, Small Interfering / metabolism
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / metabolism
  • Ubiquitin-Activating Enzymes / genetics
  • Ubiquitin-Activating Enzymes / metabolism
  • Virus Replication / physiology*
  • gag Gene Products, Human Immunodeficiency Virus / genetics
  • gag Gene Products, Human Immunodeficiency Virus / metabolism
  • nef Gene Products, Human Immunodeficiency Virus / genetics
  • nef Gene Products, Human Immunodeficiency Virus / metabolism

Substances

  • Apoptosis Regulatory Proteins
  • BECN1 protein, human
  • Beclin-1
  • Biomarkers
  • MAP1LC3A protein, human
  • Membrane Proteins
  • Microtubule-Associated Proteins
  • RNA, Small Interfering
  • Recombinant Fusion Proteins
  • gag Gene Products, Human Immunodeficiency Virus
  • nef Gene Products, Human Immunodeficiency Virus
  • nef protein, Human immunodeficiency virus 1
  • ATG7 protein, human
  • Autophagy-Related Protein 7
  • Ubiquitin-Activating Enzymes