Cross talk in hormonally regulated gene transcription through induction of estrogen receptor ubiquitylation.

ABSTRACT: Estrogen tightly regulates the levels of circulating gonadotropins, but a direct effect of estrogen receptor alpha (ERalpha) on the mammalian LHbeta gene has remained poorly defined. We demonstrate here that ERalpha can associate with the LHbeta promoter through interactions with Sf-1 and Pitx1 without requiring an estrogen response element (ERE). We show that gonadotropin-releasing hormone (GnRH) promotes ERalpha ubiquitylation and also degradation while stimulating expression of ubc4. GnRH also increases the association and lengthens the cycling time of ERalpha on the LHbeta promoter. The ERalpha association and transactivation of the LHbeta gene, as well as ERalpha degradation, are increased following ubc4 overexpression, while the effects of GnRH are abated following ubc4 knockdown. Ou

SUBMITTER: Luo M 

PROVIDER: S-EPMC1190261 | biostudies-literature | 2005 Aug

REPOSITORIES: biostudies-literature