Saccharomyces cerevisiae Med9 comprises two functionally distinct domains that play different roles in transcriptional regulation.
Genes Cells
; 14(1): 53-67, 2009 Jan.
Article
em En
| MEDLINE
| ID: mdl-19077037
ABSTRACT
Mediator is one of the most important co-activators that function in eukaryotic transcriptional regulation. In Saccharomyces cerevisiae, Mediator is comprised of 25 subunits belonging to four structurally distinct modules Head, Middle, Tail, and Cyc-C. Although each module plays a critical role in the regulation of a distinct set of genes, the precise molecular mechanisms remain unclear. To gain new insight into the role of the less-characterized Middle module, we analyzed the function of Med9 by constructing a set of mutants and subjecting them to a range of in vivo and in vitro assays. Our results demonstrate that Med9 has two functional domains. The species-specific amino-terminal half (aa 1-63) plays a regulatory role in transcriptional regulation in vivo and in vitro. In contrast, the well-conserved carboxy-terminal half (aa 64-149) has a more fundamental function involved in direct binding to the amino-terminal portions of Med4 and Med7 and the assembly of Med9 into the Middle module. Importantly, activator-dependent recruitment of TBP and Taf11 to the promoter is differentially affected in med9 extracts and in extracts lacking Mediator. Add-back experiments indicate that some unidentified factor(s) in med9 extracts may impact the binding of TFIID to the promoter.
Texto completo:
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Base de dados:
MEDLINE
Assunto principal:
Saccharomyces cerevisiae
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Fatores de Transcrição
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Transcrição Gênica
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Regulação Fúngica da Expressão Gênica
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Proteínas de Saccharomyces cerevisiae
Idioma:
En
Revista:
Genes Cells
Assunto da revista:
BIOLOGIA MOLECULAR
Ano de publicação:
2009
Tipo de documento:
Article
País de afiliação:
Japão