Premium
Identification and Characterization of Nuclear Factor κB Binding Sites in the Murine bcl ‐χ Promoter
Author(s) -
Glasgow J. N.,
Wood T.,
PerezPolo J. R.
Publication year - 2000
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1046/j.1471-4159.2000.0751377.x
Subject(s) - transcription factor , biology , microbiology and biotechnology , promoter , electrophoretic mobility shift assay , binding site , p50 , dna binding site , mutant , caat box , signal transduction , transcription (linguistics) , gene expression , gene , genetics , linguistics , philosophy
Abstract: Signal transduction pathways that mediate neuronal commitment to apoptosis involve the nuclear factor κB (NF‐κB) transcription factor. Bcl‐X L is a potent regulator of apoptosis in the CNS and is highly expressed in the developing and adult brain. We identified three putative NF‐κB DNA binding sequences clustered upstream of the brain‐specific transcription start site in the upstream promoter region. Recombinant p50/p50 and NF‐κB proteins from nuclear extracts bound to these sites as determined by electrophoretic mobility shift assay and biotin‐oligonucleotide/streptavidin affinity assays. NF‐κB overexpression, coupled with bcl‐x promoter/reporter assays using a series of murine bcl‐x promoter and deletion mutants, has identified the downstream 1.1 kb of the bcl‐x promoter as necessary for basal promoter activity and induction by NF‐κB. The mutagenic removal of NF‐κB binding sites individually or in combination revealed altered response patterns to p49/p65 and p50/p65 overexpression. These results support the hypothesis that NF‐κB can act to enhance Bcl‐X L expression via highly selective interactions, where NF‐κB binding and bcl‐x promoter activation are dependent on both DNA binding site sequence and NF‐κB subunit composition. Our data suggest that molecular events associated with NF‐κB promote regulation of neuronal apoptosis in the developing or injured CNS.