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La activación de un factor de transcripción ligado a la membrana por el procesamiento regulado ubiquitina /
T Hoppe1, K Matuschewski, M Rape
1Department of Molecular Cell Biology, Max Planck Institute for Biochemistry, Martinsried, Germany.
Cell
|September 28, 2000
Resumen
Dos proteínas de levadura, SPT23 y MGA2, se activan por el procesamiento de ubiquitina / proteosoma, no por proteólisis intramembrana. Esta nueva vía sugiere que las piscinas de ácidos grasos regulan la activación de las proteínas de la membrana.
Área de la Ciencia:
- Biología celular Biología celular.
- Biología Molecular Biología Molecular
- La bioquímica es la bioquímica.
Sus antecedentes:
- El procesamiento de proteínas de membrana integral es crucial para las funciones celulares como la regulación y señalización de esteroles.
- La proteólisis intramembrana regulada (RIP) es el mecanismo establecido para procesar estas proteínas.
- Los ejemplos incluyen la señalización Notch, la respuesta proteica desplegada y el procesamiento APP en la enfermedad de Alzheimer.
Objetivo del estudio:
- Investigar el mecanismo de activación de los factores de transcripción de levadura SPT23 y MGA2.
- Para determinar si SPT23 y MGA2 utilizan RIP o una vía de procesamiento alternativa.
- Comprender el papel de SPT23 y MGA2 en la regulación de los procesos celulares y su posible vínculo con la composición de la membrana.
Principales métodos:
- Análisis del procesamiento de SPT23 y MGA2 en levaduras.
- Investigando el papel del sistema ubiquitina/proteosoma en la activación de SPT23 y MGA2.
- Evaluación de la regulación del procesamiento de SPT23 por grupos de ácidos grasos.
Principales resultados:
- SPT23 y MGA2 se sintetizan como precursores inactivos localizados en la ER/membrana nuclear.
- La activación se produce a través del procesamiento dependiente de la ubiquitina / proteosoma, distinto del RIP.
- El procesamiento dependiente del proteasoma de SPT23 está modulado por los niveles de ácidos grasos celulares.
Conclusiones:
- La activación de SPT23 y MGA2 representa un nuevo mecanismo no RIP para el procesamiento de proteínas de membrana.
- Esta vía pone de relieve la participación del sistema ubiquitina/proteosoma en la regulación de los factores de transcripción.
- Las piscinas de ácidos grasos pueden actuar como sensores de la composición de la membrana, influyendo en la activación de SPT23.
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