Interferon-Regulatory Factor Transcription Factors

The interferon-regulatory factor (IRF) family of transcription factors is part of the winged helix-turn-helix DNA-binding domain superfamily. Members of this family share a highly conserved 120 amino acid DNA-binding domain at the amino-terminus that recognizes interferon (IFN)-stimulated response element (ISRE) consensus DNA sequences. ISREs are found in promoters of type I IFNs, type I IFN-induced genes, and many other genes involved in immunity and oncogenesis. The carboxy-terminus of IRFs, except IRF1 and IRF2, is homologous to the carboxy-terminus of Smad proteins. IRFs have distinct roles in developmental processes including hematopoietic cell development, cell cycle regulation, and apoptosis. IRFs are also involved in many immune processes, including anti-bacterial and innate immunity, Th1-cell responses, attenuation of type I IFN responses, B-cell development and function, dendritic cell development, and inflammation.