The human estrogen receptor has two independent nonacidic transcriptional activation functions.
We have previously reported the presence of a hormone-inducible transcriptional activation function (TAF-2) within the region of the estrogen receptor (ER) that contains the hormone binding domain. We show here that the N-terminal A/B region of the ER contains an independent constitutive activation function (TAF-1) that exhibits cell type specificity since it activates transcription efficiently in chicken embryo fibroblasts, but only poorly in HeLa cells. By analyzing the ability of TAF-1, TAF-2, and the GAL4 and VP16 acidic activating domains (AADs) to homosynergize and heterosynergize with one another and with the factor binding to the upstream element (UE) of the adenovirus 2 major late promoter, we show that the activation properties of TAF-1 and TAF-2 are different and distinct from those of AADs, in agreement with the absence of acidic amino acid stretches in TAF-1 and TAF-2.
Tora
L
L
Laboratoire de Génétique Moléculaire des Eucaryotes du CNRS, Unité 184 de Biologie Moléculaire et de Génie Génétique de l'INSERM Institut de Chimie Biologique, Faculté de Médecine, Strasbourg, France.
White
J
J
Brou
C
C
Tasset
D
D
Webster
N
N
Scheer
E
E
Chambon
P
P
D000818:Animals; D001483:Base Sequence; D002642:Chick Embryo; D002678:Chimera; D004742:Enhancer Elements, Genetic; D005347:Fibroblasts / Q000378:metabolism; D005786:Gene Expression Regulation; D006367:HeLa Cells / Q000378:metabolism; D006801:Humans; D008969:Molecular Sequence Data; D009154:Mutation; D015345:Oligonucleotide Probes; D010957:Plasmids; D011960:Receptors, Estrogen / Q000235:genetics / Q000378:metabolism*; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic; D014162:Transfection
D015345:Oligonucleotide Probes; D011960:Receptors, Estrogen; D015534:Trans-Activators