Transcriptional regulation of human Rev-erbalpha gene expression by the orphan nuclear receptor retinoic acid-related orphan receptor alpha.
J Biol Chem
; 277(51): 49275-81, 2002 Dec 20.
Article
em En
| MEDLINE
| ID: mdl-12377782
ABSTRACT
The Rev-erb and retinoic acid-related orphan receptors (ROR) are two related families of orphan nuclear receptors that recognize similar response elements but have opposite effects on transcription. Recently, the Rev-erbalpha gene promoter has been characterized and shown to harbor a functional Rev-erbalpha-binding site known as Rev-DR2, responsible for negative feedback down-regulation of promoter activity by Rev-erbalpha itself. The present study aimed to investigate whether Rev-erbalpha gene expression is regulated by RORalpha. Gel shift analysis demonstrated that in vitro translated hRORalpha1 protein binds to the Rev-DR2 site, both as monomer and dimer. Chromatin immunoprecipitation assays demonstrated that binding of RORalpha to this site also occurred in vivo in human hepatoma HepG2 cells. The Rev-DR2 site was further shown to be functional as it conferred hRORalpha1 responsiveness to a heterologous promoter and to the natural human Rev-erbalpha gene promoter in these cells. Mutation of this site in the context of the natural Rev-erbalpha gene promoter abolished its activation by RORalpha, indicating that this site plays a key role in hRORalpha1 action. Finally, adenoviral overexpression of hRORalpha1 in HepG2 cells led to enhanced hRev-erbalpha mRNA accumulation, further confirming the physiological importance of RORalpha1 in the regulation of Rev-erbalpha expression.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Transcrição Gênica
/
Tretinoína
/
Transativadores
/
Receptores Citoplasmáticos e Nucleares
/
Proteínas de Ligação a DNA
Limite:
Humans
Idioma:
En
Revista:
J Biol Chem
Ano de publicação:
2002
Tipo de documento:
Article
País de afiliação:
França