Functional association of cyclophilin A with HIV-1 virions

Nature. 1994 Nov 24;372(6504):363-5. doi: 10.1038/372363a0.


Cyclophilins are a family of proteins that bind the immunosuppressant cyclosporin A, possess peptidyl-prolyl cis-trans isomerase activity, and assist in the folding of proteins. Human cyclophilins A and B are host cell proteins that bind specifically to the HIV-1 Gag polyprotein p55gag in vitro. Here we report that viral particles formed by p55gag, in contrast to particles formed by the Gag polyproteins of other retroviruses, contain significant amounts of cyclophilin A. Sequences in the capsid domain of p55gag are both required and sufficient for the virion-association of cyclophilin A. The association of cyclophilin A with HIV-1 virions was inhibited in a dose-dependent manner by cyclosporin A as well as by SDZ NIM811 ([Melle-4]cyclosporin), a non-immunosuppressive analogue of cyclosporin A. Drug-induced reductions in virion-associated cyclophilin A levels were accompanied by reductions in virion infectivity, indicating that the association is functionally relevant. Moreover, SDZ NIM811 inhibited the replication of HIV-1 but was inactive against SIVMAC, a primate immunodeficiency virus closely related to HIV-1, which does not incorporate cyclophilin A.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Isomerases / metabolism*
  • Amino Acid Isomerases / pharmacology
  • Carrier Proteins / metabolism*
  • Carrier Proteins / pharmacology
  • Cell Line
  • Cyclosporine / pharmacology
  • Gene Products, gag / genetics
  • Gene Products, gag / metabolism
  • HIV-1 / drug effects
  • HIV-1 / metabolism*
  • HeLa Cells
  • Humans
  • Peptidylprolyl Isomerase
  • Protein Precursors / genetics
  • Protein Precursors / metabolism
  • Retroviridae / drug effects
  • Retroviridae / metabolism
  • Simian Immunodeficiency Virus / drug effects
  • Virion / metabolism*
  • Virus Replication / drug effects


  • Carrier Proteins
  • Gene Products, gag
  • Protein Precursors
  • p55 gag precursor protein, Human immunodeficiency virus 1
  • Cyclosporine
  • (melle-4)cyclosporin
  • Amino Acid Isomerases
  • Peptidylprolyl Isomerase