Transcription factors (interferon regulatory factors) that control interferon gene expression and are themselves interferon-inducible. IRF1 (325 aa) is a transcriptional activator for the type I interferon genes, IRF2 (349 aa) represses the action of IRF1. IRF1 maps to 5q31 (see 5q minus syndrome) and is a tumour suppressor; loss of heterozygosity at the IRF1 locus occurs frequently in human gastric cancer. The IRF3 gene encodes a protein (427 aa) that binds specifically to the interferon-stimulated response element (ISRE) but not to the IRF-1 binding site. IRF4 (lymphocyte-specific IRF; multiple myeloma oncogene-1, 451 aa) negatively regulates toll-like receptor signalling by selectively competing with IRF5 (495 aa). Mutation in the IRF6 gene can cause van der Woude's syndrome and popliteal pterygium syndrome. IRF7 (503 aa) is critical for induction of type I interferon. IRF-8 (interferon consensus sequence-binding protein, ICSBP, 426 aa) is only expressed in cells of the immune system. IRF-9 (interferon-stimulated transcription factor 3-γ, ISGF3G, 393 aa) is activated in the cytoplasm following interferon-α binding.
Subjects: Medicine and Health.