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Analysis of Termination of Transcription Using BrUTP-strand-specific Transcription Run-on (TRO) Approach
Published on: March 12, 2017
La exonucleasa de la levadura Rat1 promueve la terminación de la transcripción por la ARN polimerasa II
Minkyu Kim1, Nevan J Krogan, Lidia Vasiljeva
1Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, 240 Longwood Avenue, Boston, Massachusetts 02115, USA.
Nature
|November 27, 2004
Resumen
La fosforilación del dominio carboxiterminal de la ARN polimerasa II regula el procesamiento del ARNm. La exonucleasa Rat1/Rai1 degrada el ARN 3, lo que desencadena la terminación de la transcripción en los sitios de poliadenilación.
Área de la Ciencia:
- Biología Molecular Biología Molecular
- Expresión génica de la expresión génica.
- Procesamiento de ARN Procesamiento de ARN
Sus antecedentes:
- El dominio carboxiterminal (CTD) de la ARN polimerasa II (RNApII) coordina la transcripción con el procesamiento del ARNm a través de patrones de fosforilación.
- La fosforilación específica de CTD, como la serina 2, recluta factores de poliadenilación esenciales tanto para el procesamiento del ARNm como para la terminación de la transcripción.
Objetivo del estudio:
- Investigar las funciones de Rtt103 y la exonucleasa Rat1/Rai1 en la terminación de la transcripción.
- Para dilucidar el mecanismo de acoplamiento de la escisión del sitio de poliadenilación a la terminación de la transcripción de la ARN polimerasa II.
Principales métodos:
- Estudios de localización de Rtt103 y Rat1/Rai1 en los extremos 3' del gen.
- Análisis de la estabilidad del ARN y la terminación de la transcripción en células mutantes (rat1-1, rai1Delta).
Principales resultados:
- Rtt103 y Rat1/Rai1 se localizan en los extremos 3' de los genes codificadores de proteínas.
- Las mutaciones en Rat1 o Rai1 conducen a la estabilización del ARN aguas abajo de los sitios de poliadenilación.
- Los defectos de terminación se observan en numerosos genes en ausencia de Rat1/Rai1.1. funcional.
Conclusiones:
- La escisión del sitio de poliadenilación es un requisito previo para la degradación del ARN aguas abajo por la exonucleasa Rat1/Rai1.
- La degradación del ARN 3′ aguas abajo por Rat1/Rai1 es un evento clave que desencadena la terminación de la transcripción.
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