The Molecules of HIV

Note: this site last updated in 2006


An article from "The Molecules of HIV" (c) Dan Stowell

The "vif" gene codes for "virion infectivity factor", a protein that increases the infectivity of the HIV particle.

The protein is found inside HIV-infected cells, and it works by interfering with one of the immune system's defences - a cellular protein called APOBEC3G. Basically what happens is that vif sticks to APOBEC3G and encourages the cell to degrade it, preventing it doing its job of sneaking into newly-formed virus particles and making them non-productive (see the APOBEC3G page for more information).

This has been verified in experiments. If you can create a HIV virus with the Vif protein missing (we would call this a "delta-Vif" strain of HIV), then it can still infect a cell - but the new virus particles produced from that cell contain APOBEC3G and therefore aren't very effective at infecting other cells.


  • vif protein size: 23 kD

Journal articles about Vif:

  • Navarro F, Landau NR (2004) Recent insights into HIV-1 Vif. Current Opinion in Immunology 16 (4): 477-482
  • Rose KM, Marin M, Kozak SL, et al. (2004) The viral infectivity factor (Vif) of HIV-1 unveiled. Trends in Molecular Medicine 10 (6): 291-297
  • Argyris EG, Pomerantz RJ (2004) HIV-1 Vif versus APOBEC3G: newly appreciated warriors in the ancient battle between virus and host. Trends in Microbiology 12 (4): 145-148

Written by
Dan Stowell

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