Structurally similar but functionally distinct factors, IRF-1 and IRF-2, bind to the same regulatory elements of IFN and IFN-inducible genes

Cell. 1989 Aug 25;58(4):729-39. doi: 10.1016/0092-8674(89)90107-4.


Viral infections commonly induce expression of type I interferon (IFN) genes. The induction is transient and involves transcriptional activation wherein a positive factor, IRF-1, binds to upstream regulatory cis elements. In the present study we report the isolation of a cDNA encoding a novel factor, termed IRF-2, that interacts with the same nucleotide sequence elements as IRF-1. Both genes are inducible not only by virus but also by IFN. Unlike IRF-1, IRF-2 does not function as an activator; rather, it suppresses the function of IRF-1 under certain circumstances. Our results suggest that transcription of the IFN and IFN-inducible genes is regulated by two similar trans-acting factors that apparently compete for the same cis-acting recognition sequences, but which have opposite effects.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Binding Sites
  • Cloning, Molecular
  • DNA / genetics
  • DNA-Binding Proteins / physiology*
  • Enhancer Elements, Genetic
  • Gene Expression Regulation
  • Interferon Regulatory Factor-1
  • Interferon Regulatory Factor-2
  • Interferons / genetics*
  • Mice
  • Molecular Sequence Data
  • Phosphoproteins*
  • Proteins / genetics*
  • Regulatory Sequences, Nucleic Acid
  • Repressor Proteins / physiology
  • Transcription Factors / physiology*


  • DNA-Binding Proteins
  • Interferon Regulatory Factor-1
  • Interferon Regulatory Factor-2
  • Irf1 protein, mouse
  • Irf2 protein, mouse
  • Phosphoproteins
  • Proteins
  • Repressor Proteins
  • Transcription Factors
  • DNA
  • Interferons

Associated data

  • GENBANK/J03168