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Live Cell Imaging to Assess the Dynamics of Metaphase Timing and Cell Fate Following Mitotic Spindle Perturbations
Published on: September 20, 2019
PICH, una ATPasa de la familia SNF2 asociada al centrómero, está regulada por Plk1 y se requiere para el punto de
Christoph Baumann1, Roman Körner, Kay Hofmann
1Department of Cell Biology, Max Planck Institute of Biochemistry, D-82152 Martinsried, Germany.
Cell
|January 16, 2007
Resumen
Los investigadores descubrieron la Plk1-interacting checkpoint helicase (PICH), una proteína clave en la división celular, que controla la tensión entre las cinetocoras hermanas para garantizar una segregación cromosómica precisa durante la mitosis.
Área de la Ciencia:
- Biología celular Biología celular.
- Biología Molecular Biología Molecular
- Genética La genética.
Sus antecedentes:
- El punto de control de ensamblaje del huso (SAC) asegura una segregación cromosómica precisa al prevenir el inicio de la anafase hasta que todos los cromosomas estén correctamente unidos al huso mitótico.
- Plk1 es una quinasa crucial involucrada en varias etapas de la mitosis, incluida la regulación de la SAC y la segregación cromosómica.
Objetivo del estudio:
- Identificar nuevos socios de interacción y sustratos de Plk1 involucrados en la regulación mitótica.
- Para dilucidar la función de PICH en los accesorios de kinetochore-microtubules y la señalización del punto de control del huso.
Principales métodos:
- Coinmunoprecipitación para identificar las proteínas que interactúan con Plk1.
- Microscopía de inmunofluorescencia para visualizar la localización de PICH durante la mitosis.
- Interferencia de ARN (RNAi) para agotar PICH y evaluar su efecto en la segregación cromosómica y el punto de control del huso.
- Ensayos bioquímicos para analizar la fosforilación PICH y la unión al ADN.
Principales resultados:
- PICH, un miembro de la familia de la ATPasa SNF2, interactúa con y es fosforilado por Plk1.1.
- PICH se localiza en los cinetocoros y centrómeros durante la prometafase y forma hilos dependientes de la tensión entre los cinetocoros hermanos.
- El agotamiento de PICH conduce a la pérdida de Mad2 de los cinetocoros, anula el punto de control del husillo y causa una masiva segregación errónea cromosómica.
- Los hilos positivos para PICH representan cromatina centromérica estirada, sensible a la DNasa y exacerbada por la pérdida de cohesión o la inhibición de la topoisomerasa II.
Conclusiones:
- PICH es un componente novedoso y esencial del punto de control de ensamblaje del husillo.
- PICH funciona al unirse al ADN centromérico para monitorear la tensión entre los cinetocoros hermanos, asegurando así una segregación cromosómica precisa.
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