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Los roles distintivos de las proteínas PHAP y la protimosina-alfa en una vía reguladora de la muerte
Xuejun Jiang1, Hyun-Eui Kim, Hongjun Shu
1Howard Hughes Medical Institute, Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
Science (New York, N.Y.)
|January 11, 2003
Resumen
Una nueva molécula pequeña, PETCM, activa la caspasa-3 en las células cancerosas mediante la modulación de la vía PHAP/ProT. Esta vía regula la apoptosis, con ProT inhibiendo y PHAP promoviendo la activación de la caspasa.
Área de la Ciencia:
- La bioquímica es la bioquímica.
- Biología Molecular Biología Molecular
- Investigación del cáncer Investigación del cáncer.
Sus antecedentes:
- La apoptosis es un proceso celular crítico a menudo desregulado en el cáncer.
- La activación de la caspasa iniciada por las mitocondrias es una vía clave en la apoptosis.
- La identificación de los reguladores de esta vía puede revelar nuevos objetivos terapéuticos.
Objetivo del estudio:
- Para identificar pequeñas moléculas que activan la caspasa-3 en las células cancerosas.
- Para dilucidar la vía molecular que regula la activación de la caspasa iniciada por las mitocondrias.
- Comprender las funciones de las proteínas PHAP y la protimosina-alfa en la apoptosis.
Principales métodos:
- Cribado de alto rendimiento para identificar activadores de caspasa-3.
- Fraccionamiento bioquímico para aislar componentes de la vía.
- Interferencia de ARN para evaluar la función génica.
- Análisis de la actividad de la caspasa.
Principales resultados:
- Se identificó una pequeña molécula, alfa- ((triclorometil) -4-piridinetanol (PETCM), como un activador de la caspasa-3.
- PETCM modula una vía que involucra las proteínas PHAP supresoras de tumores y la oncoproteína protimosina-alfa (ProT).
- PHAP promueve la activación de la caspasa-9, mientras que ProT la inhibe al bloquear la formación de apoptosomas; PETCM alivia la inhibición de ProT.
- Eliminar las células sensibilizadas por ProT a la apoptosis inducida por rayos UV y eludir la necesidad de PETCM.
Conclusiones:
- PETCM activa la caspasa-3 al aliviar la inhibición mediada por ProT de la formación de apoptosomas.
- La vía PHAP/ProT es un regulador crítico de la apoptosis iniciada por las mitocondrias.
- La oncoproteína ProT y el supresor tumoral PHAP juegan roles opuestos en la regulación de la apoptosis.
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