Involvement of mPOU (Brn-5), a class VI POU protein, in the gene expression of Pit-1 as well as PRL.
Mol Cell Endocrinol
; 280(1-2): 20-9, 2008 Jan 02.
Article
en En
| MEDLINE
| ID: mdl-17933456
ABSTRACT
PRL is mainly expressed in the pituitary and its gene expression is regulated by a variety of transcription factors including Pit-1. Brn-5 is a transcription factor that binds to Pit-1 binding elements and stimulates PRL reporter gene expression. In this study, the role of Brn-5 was examined. RNA interference (RNAi) against Brn-5 leaded to reduction in PRL content of GH3 cells, indicating endogenous Brn-5 may play a role in PRL gene expression. Furthermore Brn-5 RNAi decreased Pit-1 mRNA. Transfection of expression vectors for mPOU (human ortholog of Brn-5) modestly but significantly stimulated activities of PRL-Luc and Pit-1-Luc reporter genes in GH3 and HEK 293 cells. In addition, mPOU showed synergistic action with Pit-1 and CBP on PRL-Luc expression. mPOU-FL, a splicing variant of mPOU, showed weaker activity than mPOU. Chip assay suggested binding of mPOU to PRL and Pit-1 promoters of genomic DNA. Taken together, these results suggest that mPOU (Brn-5) enhances PRL gene expression directly in association with Pit-1 and CBP, and indirectly via the activation of Pit-1 gene expression.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Hipófisis
/
Prolactina
/
Regulación de la Expresión Génica
/
Factores del Dominio POU
/
Factor de Transcripción Pit-1
/
Lactotrofos
Límite:
Animals
/
Humans
Idioma:
En
Revista:
Mol Cell Endocrinol
Año:
2008
Tipo del documento:
Article
País de afiliación:
Japón