Structurally similar but functionally distinct factors, IRF-1 and IRF-2, bind to the same regulatory elements of IFN and IFN-inducible genes.
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.
Harada
H
H
Institute for Molecular and Cellular Biology, Osaka University, Japan.
Fujita
T
T
Miyamoto
M
M
Kimura
Y
Y
Maruyama
M
M
Furia
A
A
Miyata
T
T
Taniguchi
T
T
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D003001:Cloning, Molecular; D004247:DNA / Q000235:genetics; D004268:DNA-Binding Proteins / Q000502:physiology*; D004742:Enhancer Elements, Genetic; D005786:Gene Expression Regulation; D050856:Interferon Regulatory Factor-1; D050836:Interferon Regulatory Factor-2; D007372:Interferons / Q000235:genetics*; D051379:Mice; D008969:Molecular Sequence Data; D010750:Phosphoproteins; D011506:Proteins / Q000235:genetics*; D012045:Regulatory Sequences, Nucleic Acid; D012097:Repressor Proteins / Q000502:physiology; D014157:Transcription Factors / Q000502:physiology*
D004268:DNA-Binding Proteins; D050856:Interferon Regulatory Factor-1; D050836:Interferon Regulatory Factor-2; C494258:Irf1 protein, mouse; C494230:Irf2 protein, mouse; D010750:Phosphoproteins; D011506:Proteins; D012097:Repressor Proteins; D014157:Transcription Factors; D004247:DNA; D007372:Interferons