title: The absence of a functional nuclear receptor element A (NREA) in the promoter II of the aromatase P450 gene in rabbit granulosa cells.
abstract: Aromatase protein is synthesized in response to gonadotropins that activate expression of their target genes via the cAMP second messenger system. The -882/+103 bp region of the rabbit ovarian promoter (PII) was ligated to a luciferase vector and transfected into granulosa cells to elucidated the mechanism by which cAMP stimulates transcription. Deletions and mutational experiments indicate that (i) a cAMP-response element-like sequence (CLS) present at -208 to -200 bp is the main element required for the activation of the rabbit PII by cAMP and that (ii) both nuclear receptor element sites; NREA (-133/-126 bp) and NREB (-188/-181 bp) do not participate to the cAMP-dependent activity of the PII. The replacement of the specific rabbit NREA site by the human NREA site increases two-fold the cAMP response and indicates that trans-activating factors are present in rabbit granulosa cells. This study shows for the first time an efficient aromatase transcription occurs in granulosa cells in absence of a consensus NREA site. In addition a comparative study has been performed on the sheep aromatase promoter where sites deviate from rabbit. Mutagenesis experiments suggest that some of them are involved in the cAMP-induced response of the rabbit PII.
authors.affiliation: Laboratoire de Biochimie, EA 2608-USC INRA 2006, Université, Esplanade de la Paix, 14032 Caen Cedex, France. thomandrieu@yahoo.fr
authors.forename: Thomas
authors.initials: T
authors.lastname: Andrieu
authors.forename: Colette
authors.initials: C
authors.lastname: Féral
authors.forename: Michael
authors.initials: M
authors.lastname: Joubert
authors.forename: Annie
authors.initials: A
authors.lastname: Benhaim
authors.forename: Hervé
authors.initials: H
authors.lastname: Mittre
mesh_terms: D000818:Animals; D001141:Aromatase / Q000235:genetics*; D001483:Base Sequence; D002478:Cells, Cultured; D000242:Cyclic AMP / Q000235:genetics; D005260:Female; D006107:Granulosa Cells / Q000201:enzymology*; D018398:Homeodomain Proteins / Q000235:genetics; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D011817:Rabbits; D018160:Receptors, Cytoplasmic and Nuclear / Q000235:genetics; D012689:Sequence Homology, Nucleic Acid; D012756:Sheep / Q000235:genetics*; D054339:Steroidogenic Factor 1; D014157:Transcription Factors / Q000235:genetics; D014158:Transcription, Genetic; D015533:Transcriptional Activation; D014162:Transfection
chemical_list: D018398:Homeodomain Proteins; D018160:Receptors, Cytoplasmic and Nuclear; D054339:Steroidogenic Factor 1; D014157:Transcription Factors; D000242:Cyclic AMP; D001141:Aromatase