Multiple κB sites in the human IFN-β locus recruit NF-κB RelA. (A) Binding of recombinant purified RelA/p50 to radioactively labeled probes corresponding to the respective κB sites. (B) EMSA supershift analysis of protein-DNA binding in nuclear extracts from resting or LPS-stimulated MDDCs using antibodies against RelA, p50, and c-Rel. The identified complexes are likely to be (1) p50 homodimer, (2) RelA/p50 heterodimer, and (3) RelA/c-Rel heterodimer and RelA/RelA homodimer. (C) RelA recruitment to IFN-β ehanceosome (promoter) and clusters 1, 2, and 3 in MDDCs from multiple blood donors. Data shown are the mean ± SEM of 8 independent experiments normalized against levels of RelA recruitment at 0 hours. *P < .05, ***P < .001 (Student t test). (D) H3K4me1 modification presence at IFN-β ehanceosome (promoter), cluster 3 and a transcriptionally inactive intergenic region in MDDCs. Data are normalized to total histone 3 levels and presented as mean values ± SD from a representative of 4 independent donors.