BRCA1 cooperates with NUFIP and P-TEFb to activate transcription by RNA polymerase II.
Oncogene
; 23(31): 5316-29, 2004 Jul 08.
Article
en En
| MEDLINE
| ID: mdl-15107825
ABSTRACT
The tumor suppressor gene product BRCA1 is a component of the RNA polymerase II (pol II) holoenzyme that is involved, through binding to various regulatory proteins, in either activation or repression of transcription. Using a yeast two-hybrid screen, we have identified a human zinc-finger-containing protein NUFIP that interacts with BRCA1. The ubiquitous, stably expressed, nuclear protein NUFIP specifically stimulates activator-independent pol II transcription in vitro and in vivo. Immunodepletion of the endogenous NUFIP causes a marked decrease of pol II transcription, which is then shown to be restored by stable complex of ectopically produced NUFIP and associated factors. NUFIP not only interacts with BRCA1 but also associates with the positive elongation factor P-TEFb through interaction with the regulatory Cyclin T1 subunit. Cyclin T1 is required for BRCA1- and NUFIP-dependent synergistic activation of pol II transcription in 293 cells. Mutation of the zinc-finger domain abolishes the NUFIP-mediated transcriptional activation. We show that NUFIP is associated with preinitiation complexes, open transcription complexes, and elongation complexes. In addition, NUFIP facilitates ATP-dependent dissociation of hyperphosphorylated pol II from open transcription complexes in vitro.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Transcripción Genética
/
ARN Polimerasa II
/
Proteínas Nucleares
/
Proteínas de Unión al ARN
/
Proteína BRCA1
/
Factor B de Elongación Transcripcional Positiva
Tipo de estudio:
Prognostic_studies
Límite:
Humans
Idioma:
En
Revista:
Oncogene
Asunto de la revista:
BIOLOGIA MOLECULAR
/
NEOPLASIAS
Año:
2004
Tipo del documento:
Article
País de afiliación:
Reino Unido