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La detección de la tensión por la Aurora B quinasa es independiente de la localización del centrómero basada en
Christopher S Campbell1, Arshad Desai
1Ludwig Institute for Cancer Research and Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, California 92037, USA.
Nature
|April 23, 2013
Resumen
La segregación cromosómica se basa en las adherencias adecuadas del huso. Este estudio muestra que la activación de la quinasa Aurora B, no la localización del centrómero, es clave para la correcta biorientación y segregación cromosómica.
Área de la Ciencia:
- Biología celular Biología celular.
- Biología Molecular Biología Molecular
- Genética La genética.
Sus antecedentes:
- La segregación precisa del genoma requiere la biorientación cromosómica en el eje.
- La aurora B quinasa, parte del complejo de pasajeros cromosómicos (CPC), asegura la biorientación.
- Se cree que la localización del centrómero interno del CPC es crucial para la estabilización dependiente de la tensión de los accesorios de los microtúbulos.
Objetivo del estudio:
- Investigar el papel de la localización del centrómero interno para la función CPC en la segregación cromosómica.
- Para determinar si la activación de la quinasa Aurora B es suficiente para la biorientación cromosómica, independientemente de la localización del centromero.
Principales métodos:
- Diseñó una subunidad truncada Sli15 (INCENP) del CPC de la levadura en ciernes, eliminando la asociación de centrómeros internos.
- Se evaluó la segregación cromosómica durante la mitosis y la meiosis con el Sli15.15 truncado.
- Investigó la localización de Sli15 truncado y Sli15 de longitud completa bajo condiciones específicas de fosforilación (Cdk1/Cdc28).
Principales resultados:
- El Sli15 truncado que carecía de asociación centromérica interna apoyó la segregación cromosómica adecuada tanto en la mitosis como en la meiosis.
- El Sli15 truncado suprimió los fenotipos de deleción de las proteínas clave del centrómero interno (Bir1, Nbl1, Bub1, Sgo1).
- El Sli15 truncado localizado en los microtúbulos del huso y la orientación prematura de microtúbulos del Sli15 de longitud completa también rescataron la viabilidad.
Conclusiones:
- La localización del CPC en el centrómero interno no es esencial para la biorientación cromosómica.
- La activación de la quinasa Aurora B, lograda a través del agrupamiento en cromatina o microtúbulos, es suficiente para garantizar la correcta biorientación y segregación de los cromosomas.
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