S2F, a leaf-specific trans-acting factor, binds to a novel cis-acting element and differentially activates the RPL21 gene.
Plant Cell
; 9(8): 1469-79, 1997 Aug.
Article
em En
| MEDLINE
| ID: mdl-9286115
ABSTRACT
Tissue-specific factors control the differential expression of nuclear genes encoding plastid proteins. To identify some of these factors, the light-independent spinach RPL21 gene encoding the plastid ribosomal protein L21 was chosen as a model. The RPL21 promoter organization was defined by transient and stable transfections of RPL21 promoter deletion mutants fused to a reporter gene. The following results were obtained. (1) We identified a strong core promoter, spanning the transcription start site region, sufficient to drive high levels of gene expression. (2) We identified two non-overlapping positive and negative domains, located upstream from the core promoter region, that modulate core promoter activity independently of light. (3) We found that the positive domain contains a new cis-acting element, the S2 site, related to but different from the light-responsive GT-1 binding site. We show that the S2 site binds a leaf-specific nuclear factor (named S2F). The S2 site is conserved in the promoter region of many nuclear genes encoding plastid proteins. Experiments with transgenic tobacco plants confirmed that the S2 site is critical for positive domain activity in leaf tissues. The S2 site is thus identified as a new tissue-specific, light-independent regulatory element.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Proteínas de Plantas
/
Plantas Tóxicas
/
Proteínas Ribossômicas
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Nicotiana
/
Transativadores
/
Genes de Plantas
Tipo de estudo:
Prognostic_studies
Idioma:
En
Revista:
Plant Cell
Assunto da revista:
BOTANICA
Ano de publicação:
1997
Tipo de documento:
Article
País de afiliação:
França