Interferon Regulatory Factor 3 (IRF3)

Interferon regulatory factor 3 is a member of the interferon regulatory transcription factor (IRF) family. IRF3 is found in an inactive cytoplasmic form that upon serine/threonine phosphorylation forms a complex with CREBBP. This complex translocates to the nucleus and activates the transcription of interferons alpha and beta, as well as other interferon-induced genes.

The IRF3 gene is present in a single copy in the human genome. Northern blot analysis detected a 1.6-kb constitutively expressed IRF3 transcript. The deduced 427-amino acid IRF3 protein is 34 to 40% identical to other members of the IRF family in the N-terminal region. Au et al. (1995) showed that IRF3 is a 50-kD protein.