Characterization of a dominant negative mutant form of the HNF-4 orphan receptor.
Nucleic Acids Res
; 24(15): 2930-5, 1996 Aug 01.
Article
en En
| MEDLINE
| ID: mdl-8760876
The HNF-4 orphan receptor is a member of the nuclear receptor family of transcription factors and a major regulator of genes involved in carbohydrate and lipid metabolism. As an initial step in characterizing the role of HNF-4 in the regulation of metabolism, we have generated a dominant negative form of HNF-4 (DN-HNF-4) that contains a defective DNA-binding domain. In gel mobility shift assays, DN-HNF-4 did not bind an oligonucleotide probe representing an essential HNF-4 binding site, C3P contained in the human apo CIII promoter, but did prevent the binding of two recombinant isoforms, HNF-4alpha1 and HNF-4alpha2, as well as naturally-occurring HNF-4. DN-HNF-4 had no effect on the binding of PPARgamma-RXRalpha heterodimers to a PPAR response element. In transfected HepG2 cells, DN-HNF-4 dramatically reduced constitutive transcriptional activity of the human apo CIII promoter and abolished the positive transcriptional activity caused by plasmids expressing either isoform of HNF-4. These results indicate that DN-HNF-4 is a selective dominant negative mutant which forms defective heterodimers with wild-type HNF-4, thereby preventing DNA binding and subsequent transcriptional activation by HNF-4.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Fosfoproteínas
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Factores de Transcripción
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Receptores Citoplasmáticos y Nucleares
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Proteínas de Unión al ADN
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Mutación
Límite:
Animals
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Humans
Idioma:
En
Revista:
Nucleic Acids Res
Año:
1996
Tipo del documento:
Article
País de afiliación:
Estados Unidos
Pais de publicación:
Reino Unido