Transcriptional activation and repression by cellular DNA-binding protein C/EBP.
A putative transcription factor, C/EBP, isolated from rat liver nuclei, has been shown to bind to at least two different sequence motifs: the CCAAT promoter domain and a core sequence [GTGG(T/A)(T/A)(T/A)G] common to many viral enhancers, including simian virus 40 and human hepatitis B virus. It has been proposed that C/EBP might function as a positive transcription factor by facilitating the communication between promoter and enhancer elements through its dual binding activities to DNA. Surprisingly, results from three different approaches suggest that C/EBP functions as a transcriptional repressor to hepatitis B virus and simian virus 40. Further investigation indicated that C/EBP can function as both a transcriptional activator and a repressor, depending on the reporter gene system.
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Department of Biochemistry and Biophysics, School of Medicine, University of Pennsylvania, Philadelphia 19104-6059.
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D001483:Base Sequence; D022762:CCAAT-Enhancer-Binding Proteins; D004268:DNA-Binding Proteins / Q000502:physiology; D015967:Gene Expression Regulation, Viral / Q000502:physiology*; D006515:Hepatitis B virus / Q000235:genetics* / Q000502:physiology; D006801:Humans; D008099:Liver / Q000378:metabolism; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000502:physiology*; D012097:Repressor Proteins / Q000502:physiology*; D013539:Simian virus 40 / Q000235:genetics / Q000502:physiology; D013937:Thymidine Kinase / Q000235:genetics; D014157:Transcription Factors / Q000502:physiology*; D014162:Transfection; D014779:Virus Replication / Q000235:genetics
D022762:CCAAT-Enhancer-Binding Proteins; D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D012097:Repressor Proteins; D014157:Transcription Factors; D013937:Thymidine Kinase