IRF5: Proteins and Enzymes

Interferon regulator transcription factors (IRF) are a family characterized by a helix-turn-helix DNA binding domain enriched in tryptophan repeats. IRF family members show diverse cellular regulation of interferon-stimulated gene transcription, viral-mediated gene activation, apoptosis, differentiation, and cellular growth. IRF2 functions as a regulator of type I interferons influencing cellular proliferation and immune response through transcriptional regulation. IRF2 competitively inhibits IRF1 gene activation, as well as, stimulating transcription on its own. Human IRF3 is a transcription factor that binds the interferon-sensitive response element (ISRE) and is activated by Toll-like receptors, TLR3 and TLR4.

IRF5 is a member of the IRF family of transcription factors, a family characterized by a helix-turn-helix DNA binding domain enriched in tryptophan repeats. IRF family members show diverse cellular regulation of interferon-stimulated gene transcription, viral-mediated gene activation, apoptosis, differentiation, and cellular growth. IRF5, along with IRF7, are the key mediators of TLR signaling. IRF5 forms heterodimers with IRF3 both of which are necessary for interferon gene transcription. IRF5 knock out mice indicate that IRF5 is critical for induction of apoptosis.