Transcriptional activation of the H-ferritin gene in differentiated Caco-2 cells parallels a change in the activity of the nuclear factor Bbf.
Biochem J
; 311 ( Pt 3): 769-73, 1995 Nov 01.
Article
em En
| MEDLINE
| ID: mdl-7487931
ABSTRACT
In this paper, we examine the mechanisms that regulate the expression of the heavy (H) ferritin subunit in the colon carcinoma Caco-2 cell line allowed to differentiate spontaneously in vitro. The differentiation process of these cells in continuous culture is accompanied by an accumulation of the mRNA coding for the apoferritin H chain. The analysis of Caco-2 subclones stably transfected with an H-chain promoter-chloramphenicol acetyltransferase (CAT) construct revealed that the mRNA increase is paralleled by an enhanced transcription of the H gene, driven by the -100 to +4 region of the H promoter. The H gene transcriptional activation seems to be a specific feature of differentiated Caco-2 cells, since the activity of other promoters did not change upon differentiation. The -100 to +4 region of the H promoter binds a transcription factor called Bbf (B-box binding factor); electrophoretic-mobility-shift-assay analyses showed that the retarded complex due to Bbf-H promoter interaction is significantly increased in the differentiated cells. We propose that the activation of H-ferritin gene expression may be associated with the establishment of a differentiated phenotype in Caco-2 cells, and that the H-ferritin gene transcriptional up-regulation is accompanied by a modification in the activity of the transcription factor Bbf.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Fatores de Transcrição
/
Ativação Transcricional
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Proteínas de Drosophila
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Proteínas de Ligação a DNA
/
Ferritinas
Limite:
Humans
Idioma:
En
Revista:
Biochem J
Ano de publicação:
1995
Tipo de documento:
Article
País de afiliação:
Itália