Cloning, expression, and transcriptional properties of the human enhancer factor TEF-1.
We describe the cDNA encoding the SV40 transcriptional enhancer factor 1 (TEF-1) and show that its translation initiates exclusively at an AUU codon in vivo. Cloned TEF-1, which is unrelated to other known transcription factors, specifically binds the SV40 GT-IIC and Sph enhansons. Cloned TEF-1 does not activate these enhansons in lymphoid MPC11 cells where they are known to be inactive, but represses the endogenous HeLa TEF-1 activity in vivo and in vitro. Repression is also observed with chimeras where the DNA-binding domain of the GAL4 activator replaces that of TEF-1, showing that repression results from interference/squelching. Such chimeras stimulate transcription in HeLa, but not in MPC11, cells in vivo and in HeLa cell extracts in vitro. However, high concentrations result in self-interference/squelching. These results strongly suggest that the trans-activation function of TEF-1 is mediated by a highly limiting, possible cell-specific, titratable transcriptional intermediary factor(s).
Xiao
J H
JH
Laboratoire de Génétique Moléculaire des Eucaryotes du CNRS, Unité 184 de Génie Génétique et de Biologie, Faculté de Médecine, Strasbourg, France.
Davidson
I
I
Matthes
H
H
Garnier
J M
JM
Chambon
P
P
D000595:Amino Acid Sequence; D001483:Base Sequence; D015152:Blotting, Northern; D003001:Cloning, Molecular / Q000379:methods; D003062:Codon / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D006367:HeLa Cells / Q000502:physiology; D006801:Humans; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009687:Nuclear Proteins; D015345:Oligonucleotide Probes; D010957:Plasmids; D014176:Protein Biosynthesis; D012333:RNA, Messenger / Q000235:genetics / Q000302:isolation & purification; D011994:Recombinant Proteins / Q000302:isolation & purification / Q000378:metabolism; D013539:Simian virus 40 / Q000235:genetics; D000091262:TEA Domain Transcription Factors; D014157:Transcription Factors / Q000235:genetics*; D014158:Transcription, Genetic; D014162:Transfection; D016335:Zinc Fingers / Q000235:genetics; D001616:beta-Galactosidase / Q000235:genetics / Q000378:metabolism
D003062:Codon; D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D015345:Oligonucleotide Probes; D012333:RNA, Messenger; D011994:Recombinant Proteins; D000091262:TEA Domain Transcription Factors; C057182:TEAD1 protein, human; D014157:Transcription Factors; D001616:beta-Galactosidase