APOBEC3 proteins can copackage and comutate HIV-1 genomes

Nucleic Acids Res. 2016 Sep 19;44(16):7848-65. doi: 10.1093/nar/gkw653. Epub 2016 Jul 20.

Abstract

Although APOBEC3 cytidine deaminases A3G, A3F, A3D and A3H are packaged into virions and inhibit viral replication by inducing G-to-A hypermutation, it is not known whether they are copackaged and whether they can act additively or synergistically to inhibit HIV-1 replication. Here, we showed that APOBEC3 proteins can be copackaged by visualization of fluorescently-tagged APOBEC3 proteins using single-virion fluorescence microscopy. We further determined that viruses produced in the presence of A3G + A3F and A3G + A3H, exhibited extensive comutation of viral cDNA, as determined by the frequency of G-to-A mutations in the proviral genomes in the contexts of A3G (GG-to-AG) and A3D, A3F or A3H (GA-to-AA) edited sites. The copackaging of A3G + A3F and A3G + A3H resulted in an additive increase and a modest synergistic increase (1.8-fold) in the frequency of GA-to-AA mutations, respectively. We also identified distinct editing site trinucleotide sequence contexts for each APOBEC3 protein and used them to show that hypermutation of proviral DNAs from seven patients was induced by A3G, A3F (or A3H), A3D and A3G + A3F (or A3H). These results indicate that APOBEC3 proteins can be copackaged and can comutate the same genomes, and can cooperate to inhibit HIV replication.

MeSH terms

  • APOBEC Deaminases
  • Adult
  • Cell Line
  • Cytidine Deaminase
  • Cytosine Deaminase / metabolism*
  • Genome, Viral*
  • HIV Infections / metabolism
  • HIV Infections / virology
  • HIV-1 / genetics*
  • Humans
  • Male
  • Mutation / genetics*
  • Mutation Rate
  • Nucleotides / genetics
  • Proviruses / physiology
  • Sequence Analysis, DNA
  • Virion / metabolism
  • vif Gene Products, Human Immunodeficiency Virus / metabolism

Substances

  • Nucleotides
  • vif Gene Products, Human Immunodeficiency Virus
  • Cytosine Deaminase
  • APOBEC Deaminases
  • APOBEC3 proteins, human
  • Cytidine Deaminase