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Aislamiento de coactivadores asociados con la proteína de unión a TATA que media la activación de la transcripción
B D Dynlacht1, T Hoey, R Tjian
1Howard Hughes Medical Institute, Department of Molecular and Cell Biology, University of California, Berkeley 94720.
Cell
|August 9, 1991
Resumen
La activación del factor de transcripción NTF-1 en Drosophila requiere factores asociados a TFIID (TAF), no sólo TBP. Los TAF son coactivadores esenciales para la transcripción dirigida por NTF-1, distintos de la actividad basal.
Área de la Ciencia:
- Biología Molecular Biología Molecular
- Biología del desarrollo Biología del desarrollo.
- Genética La genética.
Sus antecedentes:
- La regulación transcripcional es crucial para el desarrollo.
- Los factores selectivos de promotores interactúan con el mecanismo de transcripción.
- NTF-1 es un factor de transcripción regulado en el desarrollo clave en Drosophila.
Objetivo del estudio:
- Para aclarar los requisitos para la activación transcripcional por NTF-1.
- Para identificar los componentes específicos del aparato de transcripción involucrado en la función NTF-1.
Principales métodos:
- Ensayos de transcripción reconstituidos utilizando factores basales de Drosophila fraccionados.
- Sedimentación del gradiente de glicerol para analizar la composición del complejo TFIID.
- Inmunoprecipitación para aislar y caracterizar los factores asociados a la TBP (TAF).
Principales resultados:
- La activación de NTF-1 requiere factores dentro de la fracción TFIID distintos de la proteína purificada de unión a TATA (TBP).
- TFIID es un complejo de TBP y al menos seis factores asociados a TBP (TAF).
- TBP que carece de TAF apoya la transcripción basal pero no la activación de NTF-1; la adición de TAF restaura la activación.
Conclusiones:
- Los factores asociados a TBP (TAF) son coactivadores esenciales para la activación transcripcional mediada por NTF-1.
- Los polipéptidos TAF específicos confieren una función de coactivador, destacando su papel más allá de la transcripción basal.
- Este estudio aclara el mecanismo molecular de la activación del factor de transcripción del desarrollo en Drosophila.
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