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Se inicia la activación de la transcripción mediada por exones
Ana Fiszbein1, Keegan S Krick1, Bridget E Begg1
1Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02138, USA.
Cell
|December 3, 2019
Resumen
El empalme de los exones internos influye en la expresión génica mediante la activación de los sitios de inicio de la transcripción (TSS). Este fenómeno de activación mediada por exones de iniciación de la transcripción (EMATS, por sus siglas en inglés) afecta la elección del promotor y los niveles de expresión génica en los mamíferos.
Área de la Ciencia:
- Biología molecular
- La genómica
- Biología evolutiva
Sus antecedentes:
- El procesamiento y la transcripción del ARN son procesos relacionados en los genes de los mamíferos.
- El empalme es un paso crítico en la maduración del ARN.
Objetivo del estudio:
- Describir la activación mediada por exones de las iniciaciones de transcripción (EMATS).
- Investigar el impacto del empalme de exones internos en la elección del promotor y la expresión génica.
- Comprender el papel del empalme en la evolución de los promotores alternativos.
Principales métodos:
- Estudios observacionales sobre la evolución genética y los sitios de inicio de la transcripción.
- Inhibición experimental del empalme de los exones.
- Creación experimental de nuevos exones empalmados.
Principales resultados:
- La ganancia evolutiva de los exones internos se correlaciona con nuevos sitios de inicio de transcripción (TSS) y un aumento de la expresión génica.
- La inhibición del empalme de exones disminuyó la transcripción de los promotores proximales.
- Los nuevos exones empalmados activaron la transcripción de los promotores crípticos.
- Los promotores débiles aguas arriba de los exones empalmados mostraron los efectos más fuertes.
Conclusiones:
- El empalme recluta maquinaria de transcripción localmente, influyendo en la elección de TSS.
- La ganancia, pérdida y cambios regulatorios de exones contribuyen a la evolución de promotores alternativos y la expresión génica en los mamíferos.
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