Inserting the Ftz homeodomain into engrailed creates a dominant transcriptional repressor that specifically turns off Ftz target genes in vivo.
Development
; 121(6): 1801-13, 1995 Jun.
Article
em En
| MEDLINE
| ID: mdl-7600995
ABSTRACT
The Engrailed homeodomain protein is an 'active' or dominant transcriptional repressor in cultured cells. In contrast, the Fushi Tarazu homeodomain protein is an activator, both in cultured cells and in Drosophila embryos, where it activates several known target genes, including its own gene. This auto-activation has been shown to depend on targeting to a fushi tarazu enhancer by the Fushi Tarazu homeodomain. We combined Fushi Tarazu targeting and Engrailed active repression in a chimeric regulator, EFE. When EFE is ubiquitously expressed, it overrides endogenous Fushi Tarazu and causes a fushi tarazu mutant phenotype. Normal Fushi Tarazu target genes are affected as they are in fushi tarazu mutants. One such target gene is repressed by EFE even where Fushi Tarazu is not expressed, suggesting that the repression is active. This is confirmed by showing that the in vivo activity of EFE depends on a domain that is required for active repression in culture. A derivative that lacks this domain, while it cannot repress the endogenous fushi tarazu gene, can still reduce the activity of the fushi tarazu autoregulatory enhancer, suggesting that it competes with endogenous Fushi Tarazu for binding sites in vivo. However, this passive repression is much less effective than active repression.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Proteínas Repressoras
/
Fatores de Transcrição
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Genes Homeobox
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Proteínas de Homeodomínio
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Regulação da Expressão Gênica no Desenvolvimento
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Drosophila
/
Hormônios de Inseto
Limite:
Animals
Idioma:
En
Revista:
Development
Ano de publicação:
1995
Tipo de documento:
Article