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La ARN polimerasa II se asocia con los genes activos durante la replicación del ADN
Tyler K Fenstermaker1, Svetlana Petruk1, Sina K Kovermann2
1Department of Biochemistry and Molecular Biology, Sidney Kimmel Medical College, Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA, USA.
Nature
|July 19, 2023
Resumen
La ARN polimerasa II (Pol II) se reasocia rápidamente con los genes activos inmediatamente después de la replicación del ADN, reanudando la transcripción sin necesidad de marcas epigenéticas. Esto sugiere que Pol II permanece cerca del ADN durante la replicación.
Área de la Ciencia:
- Biología molecular
- La epigenética
- Regulación genética
Sus antecedentes:
- Se cree que la maquinaria de transcripción se desprende durante la replicación del ADN.
- Se cree que las marcas epigenéticas mantienen la memoria transcripcional y reconstruyen la cromatina.
- Se cree que la ARN polimerasa II (Pol II) se recluta después de la reconstrucción de la cromatina.
Objetivo del estudio:
- Para investigar cuándo y cómo Pol II es reclutado de nuevo a cadenas de ADN hija.
- Para entender la transición de la replicación del ADN a la reanudación de la transcripción.
Principales métodos:
- Investigación experimental del comportamiento de Pol II después del paso de la bifurcación.
- Análisis de la asociación del complejo Pol II con las hebras de ADN nacientes.
Principales resultados:
- Pol II, con proteínas de transcripción y ARN inmaduro, se vuelve a asociar con genes activos en las hebras líderes y rezagadas inmediatamente después de la replicación.
- La transcripción se reanuda rápidamente en el ADN naciente.
- Una interacción Pol II-PCNA puede retener el complejo de transcripción cerca del ADN.
Conclusiones:
- El complejo Pol II transcripcionalmente activo puede permanecer muy cerca del ADN durante la replicación.
- Las marcas epigenéticas podrían no ser esenciales para reclutar Pol II a ADN recién sintetizado.
- Los hallazgos desafían el modelo establecido de acoplamiento transcripción-replicación.
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