1. Cloning and characterization of lipopolysaccharide-induced tumor necrosis factor alpha factor promoter.
- Author
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Shiomi N, Myokai F, Naruishi K, Oyaizu K, Senoo K, Yamaguchi T, Amar S, and Takashiba S
- Subjects
- 5' Flanking Region, Base Sequence, Binding Sites, Cell Line, Tumor, Cell Nucleus metabolism, Cloning, Molecular, Consensus Sequence, DNA metabolism, Humans, Kinetics, Lipopolysaccharides immunology, Molecular Sequence Data, Nuclear Proteins metabolism, Oligonucleotides metabolism, RNA, Messenger genetics, RNA, Messenger metabolism, Transcription Factors metabolism, Transcription Initiation Site, Transcription, Genetic, Nuclear Proteins genetics, Promoter Regions, Genetic genetics, Transcription Factors genetics
- Abstract
We have recently identified lipopolysaccharide tumor-induced tumor necrosis factor alpha factor (LITAF) as a novel transcription factor controlling necrosis factor (TNF)-alpha expression in the human monocytic cell line, THP-1. To characterize the human (h) LITAF promoter, we isolated a 1.2-kb DNA fragment and followed this by a screening of human genomic DNA with a hLITAF cDNA probe. A 34-bp sequence domain located from nucleotides -74 to -43 in the hLITAF promoter exhibited the highest basal reporter gene activity; however, the activity was not elevated by lipopolysaccharide (LPS) stimulation. The sequence domain included a consensus sequence for hepatocyte nuclear factor (HNF)-3alpha, regulating the transcription of many kinds of genes. Interestingly, the DNA sequence position between -542 and -538 in the hLITAF promoter contained the CTCCC motif, which has been reported to act as a specific binding site for hLITAF protein. Electrophoretic mobility shift assays demonstrated that LPS induced the binding of THP-1 nuclear factors to a 22 bp probe containing the CTCCC motif. In addition, hLITAF mRNA and nuclear hLITAF protein increased significantly in the THP-1 cells immediately after LPS stimulation. These results suggest that the consensus sequence for HNF-3alpha, or a nuclear binding protein to the CTCCC motif, may play an important role in regulating LPS-dependent LITAF transcription.
- Published
- 2006
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