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Fosforilación y activación de p70s6k por PDK1
N Pullen1, P B Dennis, M Andjelkovic
1Friedrich Miescher Institute, Maulbeerstrasse 66, CH-4058, Basel, Switzerland.
Science (New York, N.Y.)
|February 21, 1998
Resumen
Los mitógenos activan p70s6k, una proteína quinasa clave, promoviendo su fosforilación. La quinasa dependiente de fosfoinosítidos 1 (PDK1) directamente fosforila y activa p70s6k, lo que tiene un impacto en la síntesis de proteínas.
Área de la Ciencia:
- Biología Molecular Biología Molecular
- La señalización celular de las células.
- La bioquímica es la bioquímica.
Sus antecedentes:
- p70s6k (70 kDa proteína ribosómica S6 quinasa) la activación por mitógenos aumenta la traducción de los ARNm que codifican el mecanismo de síntesis de proteínas.
- La activación de p70s6k requiere una fosforilación jerárquica, siendo la treonina 229 (Thr229) en el dominio catalítico un sitio crucial.
- La fosforilación de Thr308 por la proteína kinasa 1 (PDK1) dependiente de los fosfoinosítidos es esencial para la activación de la proteína kinasa B (PKB).
Objetivo del estudio:
- Para investigar el papel de PDK1 en la activación de p70s6k.
- Para aclarar el vínculo regulatorio entre p70s6k y las vías de señalización de PKB.
- Para determinar si PDK1 directamente fosforila y activa el p70s6k.
Principales métodos:
- Pruebas in vitro de quinasa para evaluar la actividad de PDK1 en p70s6k.
- Experimentos in vivo para evaluar el efecto de PDK1 en la activación de p70s6k en un contexto celular.
- Uso de PDK1 catalíticamente inactivo para sondear su papel específico en la vía de activación.
Principales resultados:
- Se encontró que PDK1 fosforila selectivamente el p70s6k en Thr229.9.
- PDK1 demostró la capacidad de activar p70s6k tanto in vitro como in vivo.
- La PDK1 catalíticamente inactiva inhibió la activación p70s6k inducida por la insulina, confirmando el papel esencial de la PDK1.
Conclusiones:
- PDK1 es un activador de p70s6k, que lo fosforila en el punto Thr229.9.
- Este hallazgo establece un vínculo regulador directo entre PDK1 y p70s6k, que afecta a la síntesis de proteínas.
- El papel de PDK1 en la activación de p70s6k proporciona información sobre las vías de señalización mitogénica.
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