Titre
Identification of two steroid-responsive promoters of different strength controlled by the same estrogen-responsive element in the 5'-end region of the Xenopus laevis vitellogenin gene A1.
Type
article
Institution
UNIL/CHUV/Unisanté + institutions partenaires
Périodique
Auteur(s)
Tremea, F.
Auteure/Auteur
Batistuzzo de Medeiros, S.R.
Auteure/Auteur
ten Heggeler-Bordier, B.
Auteure/Auteur
Germond, J.E.
Auteure/Auteur
Seiler-Tuyns, A.
Auteure/Auteur
Wahli, W.
Auteure/Auteur
Liens vers les personnes
Liens vers les unités
ISSN
0888-8809[print], 0888-8809[linking]
Statut éditorial
Publié
Date de publication
1989-10
Volume
3
Numéro
10
Première page
1596
Dernière page/numéro d’article
1609
Langue
anglais
Notes
Publication types: In Vitro ; Journal Article ; Research Support, Non-U.S. Gov't
Publication Status: ppublish
Publication Status: ppublish
Résumé
A structural and functional analysis of the 5'-end region of the Xenopus laevis vitellogenin gene A1 revealed two transcription initiation sites located 1.8 kilobases apart. A RNA polymerase II binding assay indicates that both promoters form initiation complexes efficiently. In vitro, using a transcription assay derived from a HeLa whole-cell extract, the upstream promoter is more than 10-fold stronger than the downstream one. In contrast, both promoters have a similar strength in a HeLa nuclear extract. In vivo, that is in estrogen-stimulated hepatocytes, it is the downstream promoter homologous to the one used by the other members of the vitellogenin gene family, which is 50-fold stronger than the upstream promoter. Thus, if functional vitellogenin mRNA results from this latter activity, it would contribute less than 1% to the synthesis of vitellogenin by fully induced Xenopus hepatocytes expressing the four vitellogenin genes. In contrast, both gene A1 promoters are silent in uninduced hepatocytes. Transfection experiments using the Xenopus cell line B3.2 in which estrogen-responsiveness has been introduced reveal that the strong downstream promoter is controlled by an estrogen responsive element (ERE) located 330 bp upstream of it. The upstream promoter can also be controlled by the same ERE. Since the region comprising the upstream promoter is flanked by a 200 base pair long inverted repeat with stretches of homology to other regions of the X. laevis genome, we speculate that it might have been inserted upstream of the vitellogenin gene A1 by a recombination event and consequently brought under control of the ERE lying 1.5 kilobases downstream.
Sujets
PID Serval
serval:BIB_1169D84CEA5D
PMID
Open Access
Oui
Date de création
2008-01-24T15:04:33.504Z
Date de création dans IRIS
2025-05-20T15:19:34Z