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.
Original language | English (US) |
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Pages (from-to) | 27-32 |
Number of pages | 6 |
Journal | Biochimica et Biophysica Acta - Gene Structure and Expression |
Volume | 1517 |
Issue number | 1 |
DOIs | |
State | Published - Dec 15 2000 |
Keywords
- Estrogen
- Ovalbumin
- Repression
- Tissue-specific regulation
ASJC Scopus subject areas
- Structural Biology
- Biophysics
- Biochemistry
- Genetics