A limiting factor mediates the differential activation of promoters by the human progesterone receptor isoforms.
The two transcription activation functions (TAFs) of the human progesterone receptor (hPR) have been characterized. TAF-1, located in the N-terminal region A/B, has been narrowed down to a 91-amino acid sequence, which is sufficient for transcription activation in chimeras with the GAL4 DNA binding domain. Both hPR TAF-1 and TAF-2 activate a minimal promoter in yeast. No autonomous TAF could be found in the N-terminal 164 amino acids (designated AB3) which are responsible for the differential activation of promoters by the hPR isoforms A and B. Reduction of the target gene promoter complexity did not alter this differential activation, indicating that AB3 does not require additional promoter-bound factors to exert its effect. Instead, the cell specificity of AB3 and its ability to squelch hPR-induced transcription suggest that this differential isoform activity is due to the effect of a limiting factor which binds to region AB3.
Meyer
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Laboratoire de Génétique Moléculaire des Eucaryotes, Centre National de la Recherche Scientifique, Faculté de Médecine, Strasbourg, France.
Quirin-Stricker
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C
Lerouge
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Bocquel
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Gronemeyer
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H
D000595:Amino Acid Sequence; D001483:Base Sequence; D004247:DNA / Q000235:genetics; D005800:Genes, Fungal; D006801:Humans; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D011980:Receptors, Progesterone / Q000378:metabolism*; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics; D016415:Sequence Alignment; D014157:Transcription Factors / Q000378:metabolism*; D014158:Transcription, Genetic; D001616:beta-Galactosidase / Q000378:metabolism
D011980:Receptors, Progesterone; D011994:Recombinant Proteins; D014157:Transcription Factors; D004247:DNA; D001616:beta-Galactosidase