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Interferon regulatory factor 9/IRF-9

Function

Transcription factor that plays an essential role in anti-viral immunity. It mediates signaling by type I IFNs (IFN-alpha and IFN-beta). Following type I IFN binding to cell surface receptors, Jak kinases (TYK2 and JAK1) are activated, leading to tyrosine phosphorylation of STAT1 and STAT2. IRF9/ISGF3G associates with the phosphorylated STAT1:STAT2 dimer to form a complex termed ISGF3 transcription factor, that enters the nucleus. ISGF3 binds to the IFN stimulated response element (ISRE) to activate the transcription of interferon stimulated genes, which drive the cell in an antiviral state.

Involvement in disease

Immunodeficiency 65

IMD65

An autosomal recessive immunologic disorder characterized by recurrent viral infections from early infancy. Clinical consequences are pneumonia, bronchiectasis, and septic shock. Affected individuals have lymphopenia or hypogammaglobulinemia, particularly during infection, and impaired cellular type I interferon response. Patients may have adverse response to vaccination with live attenuated vaccines.

None

The disease is caused by variants affecting the gene represented in this entry.

Post-translational modifications

(Microbial infection) Ubiquitinated by Herpes simplex virus 2 E3 ubiquitin ligase ICP22.

Sequence similarities

Belongs to the IRF family.

Cellular localization

  • Cytoplasm
  • Nucleus
  • Translocated into the nucleus upon activation by IFN-alpha/beta.

Alternative names

ISGF3G, IRF9, Interferon regulatory factor 9, IRF-9, IFN-alpha-responsive transcription factor subunit, ISGF3 p48 subunit, Interferon-stimulated gene factor 3 gamma, Transcriptional regulator ISGF3 subunit gamma, ISGF-3 gamma

Target type

Proteins

Primary research area

Immunology & Infectious Disease

Other research areas

  • Immuno-oncology

Molecular weight

43696Da