The hsp70 gene CCAAT-binding factor mediates transcriptional activation by the adenovirus E1a protein.
Expression of the human hsp70 gene is cell cycle regulated and is inducible by both serum and the adenovirus E1a protein (K. Milarski and R. Morimoto, Proc. Natl. Acad. Sci. USA 83:9517-9521, 1986; M. C. Simon, K. Kitchener, H.-T. Kao, E. Hickey, L. Weber, R. Voellmy, N. Heintz, and J. R. Nevins, Mol. Cell. Biol. 7:2884-2890, 1987; B. Wu, H. Hurst, N. Jones, and R. Morimoto, Mol. Cell. Biol. 6:2994-2999, 1986; B. Wu and R. Morimoto, Proc. Natl. Acad. Sci. USA 82:6070-6074, 1985). This regulated expression is predominantly controlled by the CCAAT element at position -70 relative to the transcriptional initiation site (G. Williams, T. McClanahan, and R. Morimoto, Mol. Cell. Biol. 9:2574-2587, 1989; B. Wu, H. Hurst, N. Jones, and R. Morimoto, Mol. Cell. Biol. 6:2994-2999, 1986). A corresponding CCAAT-binding factor (CBF) of 999 amino acids has recently been cloned and shown to stimulate transcription selectively from the hsp70 promoter in a CCAAT element-dependent manner (L. Lum, L. Sultzman, R. Kaufman, D. Linzer, and B. Wu, Mol. Cell. Biol. 10:6709-6717, 1990). We report here that the first 192 residues of CBF, when fused to the DNA-binding domain of the heterologous activator GAL-4, are necessary and sufficient to mediate E1a-dependent transcriptional activation. E1a and CBF exhibit complex formation in vitro, suggesting that an in vivo interaction between these proteins may be relevant to the well-characterized E1a-induced transcriptional activation of the hsp70 promoter.
Lum
L S
LS
Department of Biochemistry, Molecular Biology and Cell Biology, Northwestern University, Evanston, Illinois 60208.
Hsu
S
S
Vaewhongs
M
M
Wu
B
B
D017456:Adenovirus Early Proteins; D000818:Animals; D001665:Binding Sites; D022762:CCAAT-Enhancer-Binding Proteins; D016466:CHO Cells; D002478:Cells, Cultured; D002522:Chlorocebus aethiops; D006224:Cricetinae; D004252:DNA Mutational Analysis; D004268:DNA-Binding Proteins / Q000502:physiology*; D005786:Gene Expression Regulation; D006360:Heat-Shock Proteins / Q000235:genetics*; D006801:Humans; D066298:In Vitro Techniques; D046911:Macromolecular Substances; D009856:Oncogene Proteins, Viral / Q000502:physiology*; D013045:Species Specificity; D013329:Structure-Activity Relationship; D014158:Transcription, Genetic; D015533:Transcriptional Activation; D014162:Transfection
D017456:Adenovirus Early Proteins; D022762:CCAAT-Enhancer-Binding Proteins; D004268:DNA-Binding Proteins; D006360:Heat-Shock Proteins; D046911:Macromolecular Substances; D009856:Oncogene Proteins, Viral