Human immunodeficiency virus type 1 Gag protein binds to cyclophilins A and B

Cell. 1993 Jun 18;73(6):1067-78. doi: 10.1016/0092-8674(93)90637-6.


Retroviral Gag protein is capable of directing the assembly of virion particles independent of other retroviral elements and plays an important role early in the infection of a cell. Using the GAL4 two hybrid system, we screened a cDNA expression library and identified two host proteins, cyclophillins (CyPs) A and B, which interact specifically with the human immunodeficiency virus type 1 (HIV-1) Gag polyprotein Pr55gag. Glutathione S-transferase-CyP fusion proteins bind tightly to Pr55gag in vitro, as well as to the HIV-1 capsid protein p24. Cyclosporin A efficiently disrupts the Gag-CyPA interaction and less efficiently disrupts the Gag-CyPB interaction. The Gag-CyP interaction may be important for the HIV-1 life cycle and may be relevant to the pathology caused by this immunosuppressive virus.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Isomerases / metabolism*
  • Amino Acid Sequence
  • Base Sequence
  • Carrier Proteins / metabolism*
  • Cyclophilins*
  • Gene Products, gag / metabolism*
  • HIV-1 / metabolism
  • HIV-1 / pathogenicity*
  • Humans
  • Molecular Sequence Data
  • Peptidylprolyl Isomerase
  • Protein Binding
  • Recombinant Fusion Proteins / metabolism


  • Carrier Proteins
  • Gene Products, gag
  • Recombinant Fusion Proteins
  • cyclophilin B
  • Amino Acid Isomerases
  • Cyclophilins
  • Peptidylprolyl Isomerase