The COUP-adjacent repressor (CAR) element participates in the tissue-specific expression of the ovalbumin gene.
Biochim Biophys Acta
; 1517(1): 27-32, 2000 Dec 15.
Article
in En
| MEDLINE
| ID: mdl-11118613
ABSTRACT
The ovalbumin (Ov) gene is an excellent model for the study of tissue-specific gene regulation as it is only active in the estrogen-stimulated oviduct. Previous studies have demonstrated that the negative regulatory element (NRE) in the Ov gene 5'-flanking region is responsible for silencing the gene in oviduct in the absence of steroids. Linker scanning analysis defined an element within the NRE designated the COUP-adjacent repressor (CAR) element as a repressor of Ov gene expression. However, the role of the CAR element in non-oviduct tissues has not been addressed. Using transient transfection analysis of various Ov 5'-flanking region constructs into the estrogen-responsive chicken hepatocyte cell line LMH/2A, we demonstrate that Ov gene expression is not induced by estrogen and that an active repressor element exists in the NRE. Deletion analysis indicates that the region from -134 to -87, which includes the CAR element, mediates this repression. Mutation of the CAR element relieves repression, leading to high levels of gene expression. These data support a model where the inhibition of Ov gene expression in non-oviduct cells is a combination of the lack of essential positive factors and the presence of an active repressor, which binds to the CAR element.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Repressor Proteins
/
Transcription Factors
/
Receptors, Steroid
/
Ovalbumin
/
Gene Expression Regulation
/
DNA-Binding Proteins
Type of study:
Prognostic_studies
Limits:
Animals
Language:
En
Journal:
Biochim Biophys Acta
Year:
2000
Type:
Article
Affiliation country:
United States