The basic leucine zipper domain of c-Jun functions in transcriptional activation through interaction with the N terminus of human TATA-binding protein-associated factor-1 (human TAF(II)250).
We previously reported that c-Jun binds directly to the N-terminal 163 amino acids of Homo sapiens TATA-binding protein-associated factor-1 (hsTAF1), causing a derepression of transcription factor IID (TFIID)-driven transcription (Lively, T. N., Ferguson, H. A., Galasinski, S. K., Seto, A. G., and Goodrich, J. A. (2001) J. Biol. Chem. 276, 25582-25588). This region of hsTAF1 binds TATA-binding protein to repress TFIID DNA binding and transcription. Here we show that the basic leucine zipper domain of c-Jun, which allows for DNA binding and homodimerization, is necessary and sufficient for interaction with hsTAF1. Interestingly, the isolated basic leucine zipper domain of c-Jun was able to derepress TFIID-directed basal transcription in vitro. Moreover, when the N-terminal region of hsTAF1 was added to in vitro transcription reactions and overexpressed in cells, it blocked c-Jun activation. c-Fos, another basic leucine zipper protein, did not interact with hsTAF1, but c-Fos/c-Jun heterodimers did bind the N terminus of hsTAF1. Our studies show that, in addition to dimerization and DNA binding, the well characterized basic leucine zipper domain of c-Jun functions in transcriptional activation by binding to the N terminus of hsTAF1 to derepress transcription.
Lively
Tricia N
TN
Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309-0215, USA.
Nguyen
Tuan N
TN
Galasinski
Shelly K
SK
Goodrich
James A
JA
D000595:Amino Acid Sequence; D000818:Animals; D019556:COS Cells; D004247:DNA / Q000737:chemistry; D019281:Dimerization; D004305:Dose-Response Relationship, Drug; D005982:Glutathione Transferase / Q000378:metabolism; D051548:Histone Acetyltransferases; D006801:Humans; D016350:Leucine Zippers; D008954:Models, Biological; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry; D010957:Plasmids / Q000378:metabolism; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism; D016755:Proto-Oncogene Proteins c-jun / Q000737:chemistry*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012492:Salts / Q000494:pharmacology; D035381:TATA-Binding Protein Associated Factors / Q000737:chemistry* / Q000378:metabolism; D035362:Transcription Factor TFIID / Q000737:chemistry* / Q000378:metabolism; D014158:Transcription, Genetic; D015533:Transcriptional Activation
D010455:Peptides; D016760:Proto-Oncogene Proteins c-fos; D016755:Proto-Oncogene Proteins c-jun; D011993:Recombinant Fusion Proteins; D012492:Salts; D035381:TATA-Binding Protein Associated Factors; D035362:Transcription Factor TFIID; D004247:DNA; D051548:Histone Acetyltransferases; D005982:Glutathione Transferase; C069001:TATA-binding protein associated factor 250 kDa