Type I interferon receptor (IFNAR) complex with Janus kinase 1 (JAK1) and Tyrosine kinase 2 (TYK2) (IFNAR-JAK1-TYK2 complex)

The Type I interferon receptor (IFNAR) complex is a multi-subunit signaling unit essential for the innate immune response. It consists of two transmembrane chains, IFNAR1 and IFNAR2, which are physically associated with the cytoplasmic tyrosine kinases TYK2 and JAK1, respectively (UniProt P17181, P48551). Binding of Type I interferons, such as IFN-alpha or IFN-beta, triggers receptor dimerization and the subsequent activation of JAK1 and TYK2 through trans-phosphorylation (PubMed: 30518813). These activated kinases then phosphorylate STAT proteins, leading to the nuclear translocation of transcription factors that drive the expression of hundreds of interferon-stimulated genes (StatPearls: NBK545183). This pathway plays a critical role in antiviral defense and immune modulation, but its chronic overactivation is linked to the pathogenesis of autoimmune disorders like systemic lupus erythematosus (PubMed: 29104451). Pharmacological targeting of this complex includes the use of monoclonal antibodies like anifrolumab to block the receptor or small molecules like deucravacitinib to inhibit the associated kinases (DrugBank: DB11989, DB14954). Therapeutic modulation of this axis is effective in reducing inflammation but carries risks such as increased susceptibility to viral infections like herpes zoster (PubMed: 34343613).

Other names

IFN-alpha/beta receptor complexType I IFN receptorIFNAR1/IFNAR2/JAK1/TYK2 signaling unitInterferon-alpha/beta receptor

Drugs targeting this complex work by either binding to the extracellular domain of the receptor subunits (e.g., IFNAR1) to prevent ligand binding and dimerization, or by binding to the intracellular kinase domains of JAK1 or TYK2 to inhibit their catalytic activity and prevent the phosphorylation of downstream STAT proteins (PubMed: 30518813, DrugBank: DB11989).