Transcriptional regulation of human Rev-erbalpha gene expression by the orphan nuclear receptor retinoic acid-related orphan receptor alpha.
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.
Raspè
Eric
E
UR 545 INSERM, Institut Pasteur de Lille, 1 Rue du Pr. Calmette, 59019 Lille, France.
Mautino
Gisèle
G
Duval
Caroline
C
Fontaine
Coralie
C
Duez
Hélène
H
Barbier
Olivier
O
Monte
Didier
D
Fruchart
Jamila
J
Fruchart
Jean-Charles
JC
Staels
Bart
B
D000256:Adenoviridae / Q000235:genetics; D001665:Binding Sites; D002460:Cell Line; D002843:Chromatin / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism*; D019281:Dimerization; D005786:Gene Expression Regulation; D006801:Humans; D009154:Mutation; D056953:Nuclear Receptor Subfamily 1, Group D, Member 1; D057094:Nuclear Receptor Subfamily 1, Group F, Member 1; D010957:Plasmids / Q000378:metabolism; D011233:Precipitin Tests; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D014176:Protein Biosynthesis; D012333:RNA, Messenger / Q000378:metabolism; D018160:Receptors, Cytoplasmic and Nuclear / Q000378:metabolism*; D011994:Recombinant Proteins / Q000378:metabolism; D013997:Time Factors; D015534:Trans-Activators / Q000378:metabolism*; D014158:Transcription, Genetic; D014212:Tretinoin / Q000378:metabolism*
D002843:Chromatin; D004268:DNA-Binding Proteins; C064353:NR1D1 protein, human; D056953:Nuclear Receptor Subfamily 1, Group D, Member 1; D057094:Nuclear Receptor Subfamily 1, Group F, Member 1; D012333:RNA, Messenger; C539738:RORA protein, human; D018160:Receptors, Cytoplasmic and Nuclear; D011994:Recombinant Proteins; D015534:Trans-Activators; D014212:Tretinoin