Regulation of Apobec3F and human immunodeficiency virus type 1 Vif by Vif-Cul5-ElonB/C E3 ubiquitin ligase

J Virol. 2005 Aug;79(15):9579-87. doi: 10.1128/JVI.79.15.9579-9587.2005.

Abstract

The human cytidine deaminase Apobec3F (h-A3F), a protein related to the previously recognized antiviral factor Apobec3G (h-A3G), has antiviral activity against human immunodeficiency virus type 1 (HIV-1) that is suppressed by the viral protein Vif. The mechanism of HIV-1 Vif-mediated suppression of h-A3F is not fully understood. Here, we demonstrate that while h-A3F, like h-A3G, was able to suppress primate lentiviruses other than HIV-1 (simian immunodeficiency virus from African green monkeys [SIVagm] and Rhesus macaques [SIVmac]), the interaction between Vif proteins and h-A3F appeared to differ from that with h-A3G. H-A3F showed no change in its species specificity against HIV-1 or SIVagm Vif when a negatively charged amino acid was replaced with a lysine at position 128, a residue critical for h-A3G recognition by HIV-1 Vif. However, HIV-1 Vif, but not SIVagm Vif, was able to bind h-A3F and induce its polyubiquitination and degradation through the Cul5-containing E3 ubiquitin ligase. Interference with Cul5-E3 ligase function by depletion of Cul5, through RNA interference or overexpression of Cul5 mutants, blocked the ability of HIV-1 Vif to suppress h-A3F. A BC-box mutant of HIV-1 Vif that failed to recruit Cul5-E3 ligase but was still able to interact with h-A3F failed to suppress h-A3F. Interestingly, interference with Cul5-E3 ligase function or overexpression of h-A3F or h-A3G also increased the stability of HIV-1 Vif, suggesting that like the substrate molecules h-A3F and h-A3G, the substrate receptor protein Vif is itself also regulated by Cul5-E3 ligase. Our results indicate that Cul5-E3 ligase appears to be a common pathway hijacked by HIV-1 Vif to defeat both h-A3F and h-A3G. Developing inhibitors to disrupt the interaction between Vif and Cul5-E3 ligase could be therapeutically useful, allowing multiple host antiviral factors to suppress HIV-1.

Publication types

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

MeSH terms

  • Antiviral Agents / metabolism
  • Antiviral Agents / physiology*
  • Cell Line
  • Cullin Proteins / genetics
  • Cullin Proteins / metabolism*
  • Cytosine Deaminase / metabolism
  • Cytosine Deaminase / physiology*
  • Gene Deletion
  • Gene Products, vif / metabolism*
  • HIV-1 / physiology*
  • Humans
  • Lentiviruses, Primate / physiology
  • Ubiquitin-Protein Ligase Complexes / metabolism
  • Ubiquitin-Protein Ligases / metabolism*
  • Virus Replication
  • vif Gene Products, Human Immunodeficiency Virus

Substances

  • Antiviral Agents
  • CUL5 protein, human
  • Cullin Proteins
  • Gene Products, vif
  • vif Gene Products, Human Immunodeficiency Virus
  • Ubiquitin-Protein Ligase Complexes
  • Ubiquitin-Protein Ligases
  • APOBEC3F protein, human
  • Cytosine Deaminase