Phospho-IRF3 (Ser386) Recombinant Rabbit mAb (S-3498)

Phospho-IRF3 (Ser386) refers to the activated form of interferon regulatory factor 3 (IRF3) phosphorylated at serine residue 386. IRF3 is a critical transcription factor in the innate immune response. Upon viral or bacterial infection, pattern recognition receptors (such as RIG-I, cGAS, or TLR3/4) in host cells recognize pathogen-associated molecular patterns, thereby activating the downstream kinases TBK1 and IKKε. These kinases directly phosphorylate multiple C-terminal serine/threonine residues of IRF3, among which phosphorylation of Ser386 is essential for IRF3 conformational change, dimerization, nuclear translocation, and transcriptional activity. Once phosphorylated at Ser386, IRF3 forms homodimers and translocates into the nucleus, where it binds to interferon-stimulated response elements (ISRE) and initiates the expression of type I interferons (such as IFN-β) and antiviral genes. Therefore, detecting the phosphorylation status of Ser386 is a common marker for monitoring IRF3 activation and assessing the level of innate immune responses, and is widely used in fields such as virology, autoimmune diseases, and vaccine development.