Evidence for an enhanced transcription-dependent de novo synthesis of C/EBPbeta in the LPS activation of the chicken lysozyme gene.
C/EBPbeta has been shown to mediate the lipopolysaccharide (LPS)-induced expression of the lysozyme gene through enhanced binding to the -6.1-kb lysozyme enhancer. In this study, we describe the LPS regulation of the C/EBPbeta gene in myelomonocytic HD11 cells. Northern analysis showed that the steady state level of C/EBPbeta mRNA increased in response to LPS. The half life of C/EBPbeta mRNA of about 1 h in HD11 cells was not affected by exposure to LPS. Nuclear run-on transcription experiments with isolated nuclei revealed that the rate of C/EBPbeta gene transcription was enhanced by LPS, demonstrating that the C/EBPbeta gene in HD11 cells was regulated at the transcriptional level in response to LPS. Furthermore, the LPS-induced binding activity of C/EBPbeta to the -6.1-kb lysozyme enhancer was dependent not only on protein synthesis, but also on transcription. Thus, these results suggested that the LPS-induced binding activity to the -6.1-kb lysozyme enhancer in HD11 cells was regulated by an enhanced transcription-dependent de novo synthesis of C/EBPbeta.
Goethe
R
R
Institut für Kleintierforschung (FAL), Celle, Germany.
Phi-van
L
L
D000818:Animals; D022762:CCAAT-Enhancer-Binding Proteins; D002461:Cell Line, Transformed; D002645:Chickens; D004268:DNA-Binding Proteins / Q000096:biosynthesis / Q000235:genetics*; D003609:Dactinomycin / Q000031:analogs & derivatives / Q000494:pharmacology; D006207:Half-Life; D008070:Lipopolysaccharides / Q000494:pharmacology; D009113:Muramidase / Q000235:genetics* / Q000378:metabolism; D009687:Nuclear Proteins / Q000096:biosynthesis / Q000235:genetics*; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000378:metabolism; D014158:Transcription, Genetic / Q000187:drug effects*
D022762:CCAAT-Enhancer-Binding Proteins; D004268:DNA-Binding Proteins; D008070:Lipopolysaccharides; D009687:Nuclear Proteins; D012333:RNA, Messenger; C030013:cactinomycin; D003609:Dactinomycin; D009113:Muramidase