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Un mecanismo para el control de la síntesis de proteínas por el adenovirus VA RNAI
Cell
|February 14, 1986
Resumen
La infección por adenovirus detiene la síntesis de proteínas a través de la fosforilación de elF-2, desencadenada por el inhibidor de la síntesis de proteínas (DAI) activado por dsRNA. El ARNII viral normalmente impide la activación del DAI, pero falla cuando está ausente.
Área de la Ciencia:
- Biología Molecular Biología Molecular
- Virología Virología.
- Biología celular Biología celular.
Sus antecedentes:
- La infección por adenovirus en las células HeLa conduce a un fallo en la síntesis de proteínas debido a una iniciación defectuosa.
- Este defecto es causado por la fosforilación de la subunidad alfa del factor de iniciación elF-2.
Objetivo del estudio:
- Para identificar la proteína quinasa específica responsable de la fosforilación de la subunidad alfa elF-2 durante la infección por adenovirus.
- Para dilucidar el papel del ARNVI asociado al virus (ARNVI VA) en la regulación de este proceso.
Principales métodos:
- Ensayos basados en células utilizando células HeLa infectadas por adenovirus (tipo salvaje y mutante Ad5 dl331).
- Identificación de la quinasa responsable a través de ensayos bioquímicos.
- Análisis de la producción de dsRNA y su papel en la activación de la quinasa.
Principales resultados:
- El inhibidor de la síntesis de proteínas activado por dsRNA (DAI) fue identificado como la quinasa fosforiladora elF-2 alfa.
- La DAI se activa en células infectadas con el mutante Ad5 dl331 deficiente en ARNIA VA, pero no con el adenovirus de tipo salvaje.
- La activación de DAI ocurre durante la fase tardía de la infección y está mediada por el dsRNA producido durante la transcripción simétrica del genoma viral.
- VA RNAI antagoniza la activación de DAI por el dsRNA pero no puede inhibir DAI ya activado.
Conclusiones:
- El estudio identifica a DAI como la quinasa clave que media el cierre traslacional en las células infectadas por adenovirus que carecen de ARNVI VA.
- VA RNAI actúa como un regulador viral crucial, impidiendo la activación de DAI por el dsRNA viral.
- Se propone un mecanismo en el que la naturaleza de doble cadena de VA RNAI es clave para su función inhibidora contra la activación de DAI.
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