The protein tyrosine kinase Fyn activates transcription from the HIV promoter via activation of NF kappa B-like DNA-binding proteins

Int Immunol. 1995 Nov;7(11):1851-9. doi: 10.1093/intimm/7.11.1851.


Protein tyrosine kinase p59fyn (Fyn) associates with the TCR-CD3 complex, which suggests that Fyn plays a significant role in the signal transduction involving TCR complex. In addition to cellular genes, viral promoters such as the HIV long terminal repeat (LTR) are also activated upon T cell activation. To elucidate the functional significance of Fyn in the expression of viral promoters, we transfected a Fyn-expression vector together with a reporter plasmid containing the chloramphenicol acetyltransferase gene driven by HIV LTR into a human T cell line, Jurkat. In this assay, Fyn stimulated the promoter in HIV LTR when the transfected cells were treated with both concanavalin A and PMA as an antigen-mimic stimulation. This activation required the intact SH2 domain of Fyn. Mutational analysis of HIV LTR showed that the NF kappa B binding sites were responsible for this effect. Electrophoretic mobility shift assays and UV cross-linking experiments showed that activation of T cells by anti-CD3 antibody induced four kappa B-binding proteins (50, 60, 65 and 100 kDa) in Fyn-overexpressing cells more efficiently than in the parental cells. Our results suggested that Fyn was able to regulate expression of a subset of genes via kappa B-binding proteins upon T cell activation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Base Sequence
  • Binding Sites / genetics
  • DNA-Binding Proteins / biosynthesis
  • DNA-Binding Proteins / genetics*
  • Gene Expression Regulation*
  • HIV / genetics*
  • Humans
  • Leukemia, T-Cell
  • Molecular Sequence Data
  • NF-kappa B / biosynthesis
  • NF-kappa B / genetics*
  • Promoter Regions, Genetic / drug effects*
  • Protein-Tyrosine Kinases / genetics*
  • Protein-Tyrosine Kinases / physiology
  • Proto-Oncogene Proteins / genetics*
  • Proto-Oncogene Proteins / physiology
  • Proto-Oncogene Proteins c-fyn
  • Repetitive Sequences, Nucleic Acid / drug effects
  • Transcription, Genetic / drug effects*
  • Transcriptional Activation / drug effects
  • Tumor Cells, Cultured


  • DNA-Binding Proteins
  • NF-kappa B
  • Proto-Oncogene Proteins
  • Protein-Tyrosine Kinases
  • FYN protein, human
  • Proto-Oncogene Proteins c-fyn