Secretory Interleukin-1 Receptor Antagonist Gene Expression Requires both a PU.1 and a Novel Composite NF-κB/PU.1/ GA-binding Protein Binding Site

摘要: Abstract The human secretory interleukin-1 receptor antagonist (secretory IL-1Ra) gene is controlled through three lipopolysaccharide (LPS)-responsive promoter elements, one of which was identified as an NF-κB binding site. Sequence analysis the IL-1Ra a potential PU.1 site located between positions −80 and −90 on complementary strand overlapping Gel shift using this with nuclear extracts from RAW 264.7 macrophages demonstrated formation complexes, LPS-inducible two constitutive. inducible factor NF-κB, constitutive factors were GA-binding protein. Site-directed mutagenesis −93 to −79 region that mutation either 5′-half or PU.1/GA-binding protein half-site alone did not significantly decrease LPS responsiveness. However, disrupted all resulted in 50% A second centered at −230 by gel supershift assays. Mutation core GGAA LPS-responsive activity. both distal proximal response elements led almost complete loss These data therefore suggest regulation expression complex event involving interactions different transcription single cis-acting element sites are major for LPS-induced expression.