Data/hora: 11/06/2024 01:05:14

Provedor de dados: | 56
País: | Brazil
Título: | Association of hepatic nuclear factor-4 in the apolipoprotein B promoter: a preliminary report
Autores: | Nóvak,E.M.; Dantas,K.C.; Charbel,C.E.; Bydlowski,S.P.
Data: | 1998-11-01
Ano: | 1998
Palavras-chave: | Apolipoprotein B promoter; HNF-4; C/EBPa.
Resumo: | Previous studies have examined the arrangement of regulatory elements along the apolipoprotein B (apoB) promoter region (-3067 to +940) and a promoter fragment extending from nucleotides -150 to +124 has been demonstrated to be essential for transcriptional activation of the apoB gene in hepatic and intestinal cells. It has also been shown that transcriptional activation of apoB requires a synergistic interaction between hepatic nuclear factor-4 (HNF-4) and CCAAT/enhancer-binding protein a (C/EBPa) transcription factors. Here, we have examined the hypothesis that HNF-4 factor binding to DNA may induce a DNA helix bend, thus facilitating the communication with a C/EBPa factor located one helix turn from this HNF-4 factor in the apoB promoter. A gel electrophoretic mobility shift assay using wild type double-stranded oligonucleotides or modified wild type duplex oligonucleotides with 10 nucleotides inserted between HNF-4 and C/EBPa factor motifs showed similar retarded complexes, indicating that HNF-4 and C/EBPa factors interact independently of the distance between binding sites. However, when only one base, a thymidine, was inserted at the -71 position of the apoB promoter, the complex shift was completely abolished. In conclusion, these results regarding the study of the mechanisms involving the interaction between HNF-4 and C/EBPa factors in the apoB promoter suggest that the perfect 5'-CCCTTTGGA-3' motif is needed in order to facilitate the interaction between the two factors.
Tipo: | Info:eu-repo/semantics/other
Idioma: | Inglês
Identificador: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1998001100006
Editor: | Associação Brasileira de Divulgação Científica
Relação: | 10.1590/S0100-879X1998001100006
Formato: | text/html
Fonte: | Brazilian Journal of Medical and Biological Research  v.31 n.11 1998
Fonte: | info:eu-repo/semantics/openAccess