The induction by estrogen of rat alpha 2u-globulin gene expression in mouse L-cells.
J Mol Endocrinol
; 20(1): 141-50, 1998 Feb.
Article
em En
| MEDLINE
| ID: mdl-9513090
ABSTRACT
Expression of the rat alpha 2u-globulin gene family is regulated in the adult male liver by a number of hormones, including growth hormone, thyroid hormone and several steroids. Upon injection into ovariectomized females, estrogens first induce alpha 2u-globulin expression and then suppress this gene after several days of hormone administration. To study this phenomenon, we developed a mouse L-cell line that expressed the human estrogen receptor. High levels of rat alpha 2u-globulin transcript were induced in stable transfectants of this line carrying a cloned alpha 2u-globulin gene, following exposure to 17 beta-estradiol. Since this induction was inhibited by cycloheximide, the response to estrogen, as to other steroids, appears to be secondary. Using genes with variously deleted 5'-upstream regions, sequences responsible for this induction were located between -730 bp and -223 bp relative to the start of transcription. Examination of the DNA in this region revealed that an estrogen receptor element was located at -590 bp in an area that is highly conserved in most known alpha 2u-globulin genes. Administration of both dexamethasone and estrogen produced a synergistic effect in this system. The induction of alpha 2u-globulin RNA by estrogen in L-cells may re-capitulate the initial response to estrogen in vivo, and therefore represents a good model system to seek the identity of the other factors required to effect full induction.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Alfa-Macroglobulinas
/
Regulação da Expressão Gênica
/
Estradiol
Tipo de estudo:
Prognostic_studies
Limite:
Animals
Idioma:
En
Ano de publicação:
1998
Tipo de documento:
Article