Control of c-Jun activity by interaction of a cell-specific inhibitor with regulatory domain delta: differences between v- and c-Jun.
Analysis of transcriptional activation properties of c-Jun chimeras in different cell lines suggests that it contains an activator domain (A1) that is negatively regulated by a cell type-specific inhibitor. A regulatory domain of c-Jun, delta, previously identified by in vitro experiments, also regulates transcriptional activation by c-Jun in vivo. The delta domain facilitates or stabilizes the interaction of the cellular inhibitor with A1. v-Jun, which lacks delta, is a stronger transcriptional activator than c-Jun, since its activity is not efficiently repressed by the cellular inhibitor. In vitro transcription with chimeric Jun proteins and extracts from different cell types confirms that the A1 and delta domains are repressed in a cell type-specific manner. These findings implicate a specific cellular factor in the negative regulation of c-Jun activity and suggest a molecular basis for the observed difference in transcriptional properties between v-Jun and c-Jun.
Baichwal
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Howard Hughes Medical Institute, University of California, Berkeley 94720.
Tjian
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D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D004268:DNA-Binding Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics; D005786:Gene Expression Regulation; D005809:Genes, Regulator; D006367:HeLa Cells / Q000378:metabolism; D006801:Humans; D008969:Molecular Sequence Data; D015345:Oligonucleotide Probes; D016759:Oncogene Protein p65(gag-jun); D010957:Plasmids; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D016755:Proto-Oncogene Proteins c-jun; D011993:Recombinant Fusion Proteins / Q000302:isolation & purification / Q000378:metabolism; D015682:Retroviridae Proteins, Oncogenic / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D014157:Transcription Factors / Q000037:antagonists & inhibitors / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D014158:Transcription, Genetic
D004268:DNA-Binding Proteins; D015345:Oligonucleotide Probes; D016759:Oncogene Protein p65(gag-jun); D016755:Proto-Oncogene Proteins c-jun; D011993:Recombinant Fusion Proteins; D015682:Retroviridae Proteins, Oncogenic; D014157:Transcription Factors; D011505:Protein-Tyrosine Kinases