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Requisito de la fosforilación dependiente de ATM de brca1 en la respuesta al daño del ADN a las rupturas de doble
1Verna and Mars McLean Department of Biochemistry and Molecular Biology, Howard Hughes Medical Institute, Department of Cell Biology, Baylor College of Medicine, Houston, TX 77030, USA.
Science (New York, N.Y.)
|November 5, 1999
Resumen
La ATM quinasa fosforila la proteína Brca1 después del daño del ADN, que es crucial para la respuesta celular a la radiación. Esta interacción ATM-Brca1 es vital para prevenir la hipersensibilidad a la radiación y puede explicar el papel de ATM en el cáncer de mama.
Área de la Ciencia:
- Biología Molecular Biología Molecular
- Investigación del cáncer Investigación del cáncer.
- La señalización celular.
Sus antecedentes:
- Brca1 (gen del cáncer de mama 1) es una proteína supresora de tumores involucrada en la reparación del ADN.
- El daño en el ADN desencadena la fosforilación de Brca1, pero las quinasas responsables no fueron completamente esclarecidas.
- ATM (mutado en ataxia telangiectasia) es una quinasa de punto de control clave activada por rupturas de doble cadena de ADN.
Objetivo del estudio:
- Para investigar el papel de ATM en la fosforilación de Brca1 en respuesta al daño del ADN.
- Para determinar si ATM interactúa directamente con y fosforila el Brca1.
- Para evaluar la importancia funcional de la fosforilación de Brca1 por ATM.
Principales métodos:
- Utilizó radiación ionizante para inducir daños en el ADN en las líneas celulares.
- Los ensayos de inmunoprecipitación empleados para detectar las interacciones proteína-proteína (ATM-Brca1).
- Se realizaron ensayos de quinasa in vitro para confirmar la fosforilación de Brca1.1 por el ATM.
- Evaluó la consecuencia funcional de la fosforilación de Brca1 utilizando una línea celular deficiente en Brca1 y construcciones mutadas de Brca1.
Principales resultados:
- La ATM quinasa es necesaria para la fosforilación de Brca1 después de la exposición a la radiación ionizante.
- ATM forma un complejo con Brca1 tanto in vivo como in vitro.
- ATM fosforilados Brca1 dentro de un dominio específico que contiene grupos de serina-glutamina.
- Un mutante de Brca1 que carece de sitios clave de fosforilación no logró rescatar la hipersensibilidad a la radiación en las células deficientes en Brca1.
Conclusiones:
- La fosforilación mediada por ATM de Brca1 es crítica para las respuestas celulares a las rupturas de doble cadena de ADN.
- Esta vía proporciona un vínculo molecular entre la función ATM y la etiología del cáncer de mama.
- Comprender esta interacción es importante para el desarrollo de terapias dirigidas contra el cáncer.
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