A novel TBP-associated factor of SL1 functions in RNA polymerase I transcription.
EMBO J
; 26(6): 1560-8, 2007 Mar 21.
Article
en En
| MEDLINE
| ID: mdl-17318177
ABSTRACT
In mammalian RNA polymerase I transcription, SL1, an assembly of TBP and associated factors (TAFs), is essential for preinitiation complex formation at ribosomal RNA gene promoters in vitro. We provide evidence for a novel component of SL1, TAF(I)41 (MGC5306), which functions in Pol I transcription. TAF(I)41 resides at the rDNA promoter in the nucleolus and co-purifies and co-immunoprecipitates with SL1. TAF(I)41 immunodepletion from nuclear extracts dramatically reduces Pol I transcription; addition of SL1 restores the ability of these extracts to support Pol I transcription. In cells, siRNA-mediated decreased expression of TAF(I)41 leads to loss of SL1 from the rDNA promoter in vivo, with concomitant loss of Pol I from the rDNA and reduced synthesis of the pre-rRNA. Extracts from these cells support reduced levels of Pol I transcription; addition of SL1 to the extracts raises the level of Pol I transcription. These data suggest that TAF(I)41 is integral to transcriptionally active SL1 and imply a role for SL1, including the TAF(I)41 subunit, in Pol I recruitment and, therefore, preinitiation complex formation in vivo.
Texto completo:
1
Bases de datos:
MEDLINE
Asunto principal:
Transcripción Genética
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ARN Polimerasa I
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Proteínas del Complejo de Iniciación de Transcripción Pol1
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Factores Asociados con la Proteína de Unión a TATA
Tipo de estudio:
Risk_factors_studies
Límite:
Humans
Idioma:
En
Revista:
EMBO J
Año:
2007
Tipo del documento:
Article
País de afiliación:
Reino Unido