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El control circadiano de la transcripción de los cloroplastos mediante una señal de tiempo codificada nuclearmente
Zeenat B Noordally1, Kenyu Ishii, Kelly A Atkins
1SynthSys, University of Edinburgh, Edinburgh, UK.
Science (New York, N.Y.)
|March 16, 2013
Resumen
Los relojes circadianos de las plantas regulan la expresión génica de los cloroplastos a través del factor SIGMA FACTOR5 (SIG5). Esta proteína codificada por el núcleo controla la transcripción de los cloroplastos y las respuestas a la luz, integrando el tiempo nuclear y de los orgánulos para mejorar la fotosíntesis.
Área de la Ciencia:
- Biología molecular vegetal Biología molecular vegetal
- Biología circadiana Biología circadiana.
- Genética de las organas genética de las organas.
Sus antecedentes:
- Los ritmos circadianos en las plantas mejoran la fotosíntesis y la productividad.
- Se observan oscilaciones circadianas en las transcripciones codificadas por los cloroplastos, pero los mecanismos reguladores no están claros.
- Comprender la integración de la regulación circadiana nuclear y de los orgánulos es crucial.
Objetivo del estudio:
- Para dilucidar el mecanismo por el cual el oscilador circadiano codificado en el núcleo regula la expresión génica de los cloroplastos.
- Identificar el papel del FACTOR SIGMA5 (SIG5) en el control circadiano de la transcripción de los cloroplastos.
- Investigar cómo se comunica la información del tiempo circadiano entre el núcleo y los cloroplastos.
Principales métodos:
- Se han investigado los ritmos circadianos en la Arabidopsis thaliana.
- Utilizó técnicas de biología molecular para estudiar la expresión génica.
- Centrado en el papel del FACTOR SIGMA5 (SIG5) codificado nuclearmente en la regulación de los genes de los cloroplastos.
Principales resultados:
- El FACTOR SIGMA5 (SIG5) codificado nuclearmente controla los ritmos circadianos en la transcripción de varios genes de los cloroplastos.
- SIG5 media el control circadiano de la entrada de luz a un gen codificado por cloroplastos.
- Se identificó un mecanismo conservado para la comunicación circadiana entre los organelos.
Conclusiones:
- SIG5 es un componente clave que vincula el reloj circadiano nuclear a la expresión génica del cloroplasto.
- Este estudio revela una nueva vía para la integración de sistemas circadianos de núcleos y orgánulos.
- Estableció un nuevo nivel de integración entre los relojes circadianos eucariotas y los orgánulos de origen endosimbiótico.
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