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Inhibición del microARN de la iniciación de la traducción in vitro al dirigirse al complejo cap-binding eIF4FF
Géraldine Mathonnet1, Marc R Fabian, Yuri V Svitkin
1Department of Biochemistry and McGill Cancer Center, McGill University, Montreal, Quebec, Canada, H3G 1Y6.
Science (New York, N.Y.)
|July 28, 2007
Resumen
Los microARN (miRNA) reprimen la iniciación de la traducción temprano en el silenciamiento de genes. Esta inhibición ocurre antes de la desestabilización del ARN mensajero (ARNm), revelando el mecanismo primario de acción del miARN.
Área de la Ciencia:
- Biología Molecular Biología Molecular
- Regulación genética Reglamento genético.
- La bioquímica es la bioquímica.
Sus antecedentes:
- Los microARN (miARN) son reguladores clave de la expresión génica en los animales.
- Se debaten los mecanismos precisos del silenciamiento de genes mediado por miRNA, incluida la inhibición de la traducción y la desestabilización del mRNA.
Objetivo del estudio:
- Para investigar los primeros eventos moleculares desencadenados por miRNAs durante el silenciamiento de genes.
- Diferenciar entre la inhibición de la traducción y la desestabilización del ARNm como funciones primarias del ARNm.
Principales métodos:
- Desarrollo de un sistema de traducción in vitro utilizando extracto libre de células de Krebs-2 ascites de ratón.
- Análisis de la respuesta del miRNA y el destino del mRNA en los primeros 15 minutos de incubación.
Principales resultados:
- Se demostró que los miRNA let-7 endógenos reprimen la iniciación de la traducción, específicamente el reconocimiento de 5' cap.
- Esta represión traslacional se produjo rápidamente (en 15 minutos) sin desestabilización observable del ARNm.
- La inhibición de la iniciación de la traducción es el evento molecular inicial mediado por miRNAs.
Conclusiones:
- El silenciamiento de genes mediado por miRNA comienza principalmente con la inhibición de la iniciación de la traducción.
- La degradación del ARNm puede servir como un mecanismo secundario para reforzar el silenciamiento de genes.
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