Phospho-IRF3 (Ser396) Recombinant Rabbit mAb (S-5480)

Phospho-IRF3 (Ser396) refers to the activated form of Interferon Regulatory Factor 3 (IRF-3), a critical transcription factor in the innate immune system, specifically phosphorylated at serine residue 396 within its C-terminal regulatory domain. This post-translational modification is primarily catalyzed by the kinases TBK1 and IKKε following the detection of viral pathogens by pattern recognition receptors such as TLR3, TLR4, or cytosolic sensors like RIG-I and MDA5. Upon phosphorylation at Ser396, IRF-3 undergoes a conformational change that disrupts its autoinhibitory state, promoting homodimerization and subsequent translocation from the cytoplasm into the nucleus. Once inside the nucleus, the phospho-IRF-3 dimer binds to interferon-stimulated response elements (ISREs) in the promoter regions of target genes, driving the robust transcription of type I interferons (particularly IFN-β) and other antiviral cytokines, thereby establishing an essential antiviral state to limit viral replication and spread.