IRF-5 Recombinant Rabbit mAb (S-3056-28)

IRF-5 (Interferon Regulatory Factor 5) is a 54 kDa transcription factor that contains an N-terminal DNA-binding domain with a characteristic tryptophan pentad repeat, a C-terminal IRF-association domain essential for homo- and heterodimerization with other IRFs or cofactors, and multiple phosphorylation and ubiquitination sites that regulate its stability and subcellular localization; upon TLR7/8 or TLR9 signaling in myeloid cells, or RLR signaling in fibroblasts, IRF-5 is phosphorylated by IKKα/β and TBK1, leading to its nuclear translocation where it binds to IFN-stimulated response elements (ISREs) and initiates transcription of type I interferons (especially IFN-α subtypes), pro-inflammatory cytokines such as IL-6, TNF-α, and IL-12p35, and genes involved in antiviral and antitumor responses, thereby positioning IRF-5 as a central node in the innate immune response that links pathogen sensing to polarization of macrophages toward the M1 phenotype and differentiation of Th1 cells, while genetic variants and altered expression of IRF-5 have been associated with autoimmune diseases including systemic lupus erythematosus, rheumatoid arthritis, and multiple sclerosis, and with prognosis in certain cancers, making IRF-5 a potential therapeutic target for modulating immune balance.