title: Ad4BP/SF-1 regulates cyclic AMP-induced transcription from the proximal promoter (PII) of the human aromatase P450 (CYP19) gene in the ovary.
abstract: Aromatase P450, which is responsible for the metabolism of C19 steroids to estrogens, is expressed in the pre-ovulatory follicles and corpora lutea of ovulatory women by means of a promoter proximal to the start of translation (PII). To understand how this transcription is controlled by cAMP, we constructed chimeric constructs containing deletion mutations of the proximal promoter 5'-flanking DNA fused to the rabbit beta-globin reporter gene. Assay of reporter gene transcription in transfected bovine granulosa and luteal cells revealed that cAMP-stimulated transcription was lost upon deletion from -278 to -100 base pairs, indicating the presence of a functional cAMP-responsive element in this region; however, no classical cAMP-responsive element was found. Mutation of an AGGTCA motif located at -130 base pairs revealed that this element is crucial for cAMP-stimulated reporter gene transcription. When a single copy of this element was placed upstream of a heterologous promoter, it could act as a weak cAMP-response element. Supershift electrophoretic mobility shift assay and UV cross-linking established that Ad4BP/SF-1 binds to this hexameric element. Ad4BP/SF-1 mRNA and protein levels and DNA binding activity are increased in forskolin-treated luteal cells. We conclude that cAMP-stimulated transcription of human aromatase P450 in the ovary is due, at least in part, to increased levels and DNA binding activity of Ad4BP/SF-1.
authors.affiliation: Cecil H. and Ida Green Center for Reproductive Biology Sciences, University of Texas Southwestern Medical Center, Dallas 75235-9051, USA.
authors.forename: M D
authors.initials: MD
authors.lastname: Michael
authors.forename: M W
authors.initials: MW
authors.lastname: Kilgore
authors.forename: K
authors.initials: K
authors.lastname: Morohashi
authors.forename: E R
authors.initials: ER
authors.lastname: Simpson
mesh_terms: D000818:Animals; D001141:Aromatase / Q000235:genetics*; D001483:Base Sequence; D002417:Cattle; D002478:Cells, Cultured; D000242:Cyclic AMP / Q000502:physiology*; D004247:DNA; D004268:DNA-Binding Proteins / Q000502:physiology*; D005260:Female; D051717:Fushi Tarazu Transcription Factors; D018398:Homeodomain Proteins; D006801:Humans; D008969:Molecular Sequence Data; D010053:Ovary / Q000166:cytology / Q000201:enzymology*; D011401:Promoter Regions, Genetic; D018160:Receptors, Cytoplasmic and Nuclear; D054339:Steroidogenic Factor 1; D014157:Transcription Factors / Q000502:physiology*; D014158:Transcription, Genetic / Q000502:physiology*
chemical_list: D004268:DNA-Binding Proteins; D051717:Fushi Tarazu Transcription Factors; D018398:Homeodomain Proteins; D018160:Receptors, Cytoplasmic and Nuclear; D054339:Steroidogenic Factor 1; D014157:Transcription Factors; D004247:DNA; D000242:Cyclic AMP; D001141:Aromatase