Dominant negative mutant of c-Jun inhibits NF-AT transcriptional activity and prevents IL-2 gene transcription.
Expression of the transcription complex AP-1, composed of Jun and Fos family members, can be induced by a variety of stimuli. In lymphocytes, AP-1 transcriptional activity increases after TCR ligation and plays an important role in T cell activation events such as lymphokine secretion. To explore the requirements for AP-1 in IL-2 production, the AP-1 complex was targeted with a dominant negative mutant c-Jun protein, TAM-67, from which the transactivation domain has been deleted. In transient transfections of Jurkat cells, TAM-67 efficiently inhibited endogenous AP-1 transcriptional activity and blocked the activity of a reporter construct containing the 5' regulatory region of the IL-2 gene. TAM-67 also inhibited the transcriptional activity of nuclear factor-AT (NF-AT), whereas the NF-kappa B, NF-IL-2A, and the proximal TRE-like sites were relatively unaffected. The use of this dominant negative transcription factor suggests that: 1) transactivation-defective nuclear factors represent a novel approach to study the functional consequences of nuclear protein interactions on gene transcription; 2) the proximal TRE-like site from the IL-2 promoter is different from the consensus TRE; and 3) AP-1 plays an important role in the transcriptional activation mediated by the NF-AT binding complex.
Petrak
D
D
Laboratory of Immune Cell Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892.
Memon
S A
SA
Birrer
M J
MJ
Ashwell
J D
JD
Zacharchuk
C M
CM
D001483:Base Sequence; D017931:DNA Primers / Q000737:chemistry; D004268:DNA-Binding Proteins / Q000502:physiology*; D005786:Gene Expression Regulation; D005799:Genes, Dominant; D016758:Genes, jun; D007376:Interleukin-2 / Q000235:genetics*; D008969:Molecular Sequence Data; D016328:NF-kappa B / Q000502:physiology; D050778:NFATC Transcription Factors; D009687:Nuclear Proteins; D016755:Proto-Oncogene Proteins c-jun / Q000502:physiology*; D012333:RNA, Messenger / Q000235:genetics; D012045:Regulatory Sequences, Nucleic Acid; D014157:Transcription Factors / Q000502:physiology*; D014158:Transcription, Genetic
D017931:DNA Primers; D004268:DNA-Binding Proteins; D007376:Interleukin-2; D016328:NF-kappa B; D050778:NFATC Transcription Factors; D009687:Nuclear Proteins; D016755:Proto-Oncogene Proteins c-jun; D012333:RNA, Messenger; D014157:Transcription Factors