Dual regulation of the Drosophila hsp26 promoter in vitro.
Nucleic Acids Res
; 23(13): 2479-87, 1995 Jul 11.
Article
em En
| MEDLINE
| ID: mdl-7630725
Efficient heat shock induction of Drosophila hsp26 gene transcription in vivo requires binding sites for heat shock factor (HSF) and GAGA factor (GAF) close to the TATA box (proximal elements) as well as 350 bp upstream of the start site of transcription (distal elements). We have evaluated the contribution of hsp26 promoter sequences to transcriptional activity in extracts from either heat shocked or unstressed fly embryos. Efficient transcription in either extract was governed by distinct regulatory principles. Transcription in extracts from unstressed embryos relied solely on GAGA elements which efficiently counteracted repression by abundant non-specific DNA-binding proteins. Transcription in extracts from heat shocked embryos depended only a little on GAGA elements, relying mainly on functional HSEs. Constitutively active recombinant HSF or native factor in an extract from heat shocked embryos was able to truly activate transcription essentially via proximal HSEs, but not when bound to distal sites. These two modes of regulation in vitro may correspond to the two functional states of the promoter before and after heat shock in vivo.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Regulação da Expressão Gênica
/
Regiões Promotoras Genéticas
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Proteínas de Drosophila
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Drosophila
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Proteínas de Choque Térmico
Limite:
Animals
Idioma:
En
Revista:
Nucleic Acids Res
Ano de publicação:
1995
Tipo de documento:
Article
País de afiliação:
Alemanha