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Un nuevo homólogo de la proteína quinasa esencial para la clasificación de proteínas en el vacío de tipo lisosoma de
P K Herman1, J H Stack, J A DeModena
1Division of Biology, California Institute of Technology, Pasadena 91125.
Cell
|January 25, 1991
Resumen
La proteína quinasa Vps15 es crucial para dirigir las enzimas a la vacuola de la levadura. Las mutaciones que afectan su actividad quinasa interrumpen este proceso, lo que indica que la fosforilación regula la clasificación de las proteínas.
Área de la Ciencia:
- Biología celular Biología celular.
- Biología Molecular Biología Molecular
- La bioquímica es la bioquímica.
Sus antecedentes:
- La vacuola de la levadura es esencial para los procesos celulares.
- El suministro eficiente de hidrolasas a la vacuola es crítico.
- El papel de las proteínas quinasas específicas en la clasificación vacuolar de proteínas no se entiende completamente.
Objetivo del estudio:
- Para investigar la función del gen VPS15 y su proteína codificada, Vps15p.
- Para determinar el papel de la actividad de la quinasa Vps15p en la clasificación de proteínas a la vacuola de levadura.
- Para dilucidar el mecanismo por el cual Vps15p media la entrega de proteínas vacuolares.
Principales métodos:
- Mutagénesis dirigida al sitio del dominio de la quinasa Vps15p.
- Análisis de la secreción de hidrolasa vacuolar en cepas mutantes.
- Ensayos de fosforilación in vivo.
- Fraccionamiento subcelular y estudios de asociación bioquímica.
Principales resultados:
- Las mutaciones puntuales en el dominio de la quinasa Vps15p conducen a la secreción de proteasas vacuolares.
- La fosforilación in vivo de Vps15p está deteriorada en los mutantes del dominio de la quinasa.
- Vps15p está asociado periféricamente con un compartimiento de Golgi tardío o vesícula.
- Vps15p contiene una señal de miristoilación de consenso, lo que sugiere una modificación lipídica.
Conclusiones:
- La actividad de la quinasa Vps15p es esencial para una clasificación eficiente de proteínas vacuolares.
- La fosforilación de proteínas mediada por Vps15p probablemente actúa como un interruptor regulador en el transporte intracelular.
- Vps15p puede funcionar en el Golgi o en el transporte mediado por vesículas a la vacuola.
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