Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1992382 | The Journal of Steroid Biochemistry and Molecular Biology | 2006 | 9 Pages |
Abstract
Aromatase protein is synthesized in response to gonadotropins that activate expression of their target genes via the cAMP second messenger system. The â882/+103Â 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 â208 to â200Â bp is the main element required for the activation of the rabbit PII by cAMP and that (ii) both nuclear receptor element sites; NREA (â133/â126Â bp) and NREB (â188/â181Â 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.
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Authors
Thomas Andrieu, Colette Féral, Michael Joubert, Annie Benhaim, Hervé Mittre,