IRF1 Protein, Human (His, Strep)

IRF 1 is a transcription regulator with remarkable functional diversity, involved in modulating cellular responses such as transcription of IFN and IFN-inducible genes, host defense against viral/bacterial infections, hematopoiesis, inflammation, immune responses, cell proliferation/differentiation, cell cycle regulation, and growth arrest/apoptosis following DNA damage. It activates or represses target genes by binding to interferon-stimulated response elements (ISREs) in their promoters, stimulating both innate and adaptive immunity. IRF 1 plays an essential role in IFNG-dependent immunity against mycobacteria and competes with the repressor ZBED2 for promoter binding. Its transcriptional targets include antiviral (e.g., IFN-alpha/beta, RIGI), antibacterial (e.g., GBP2, GBP5), antiproliferative (e.g., p53/TP53, CDKN1A), pro-apoptotic (e.g., BBC3/PUMA, CASP1), immune-related (e.g., IL7, IL12A/B), DNA repair (e.g., POLQ/POLH), MHC expression (e.g., TAP1, CIITA), and metabolic (e.g., ACOD1/IRG1) genes, while suppressing antiproliferation (e.g., BIRC5/survivin, CCNB1) and immune-suppressive (e.g., FOXP3, IL4) genes. It enhances p53/TP53 acetylation via EP300 recruitment and directly impacts NK cell maturation, macrophage IL12 production, Th1 development, and CD8+ T-cell maturation, while inhibiting Treg differentiation and promoting dendritic cell maturation. Additionally, it acts as a tumor suppressor by antagonizing tumor growth and stimulating antitumor immunity.