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La proteína efector de Legionella DrrA AMPyla el regulador de tráfico de membrana Rab1bb
Matthias P Müller1, Heide Peters, Julia Blümer
1Department of Physical Biochemistry, Max Planck Institute of Molecular Physiology, Dortmund, NRW, 44227, Germany.
Science (New York, N.Y.)
|July 24, 2010
Resumen
Legionella pneumophila utiliza la proteína DrrA para AMPylate (un tipo de modificación) Rab1b, una pequeña GTPasa. Esta modificación bloquea Rab1b en un estado activo, interrumpiendo el tráfico celular durante los Legionarios.
Área de la Ciencia:
- Microbiología Microbiología.
- Biología celular Biología celular.
- Biología Molecular Biología Molecular
Sus antecedentes:
- La enfermedad del legionario es causada por Legionella pneumophila.
- L. pneumophila interrumpe el tráfico vesicular de la célula huésped.
- Esta interrupción implica el reclutamiento de la pequeña GTPasa Rab1 a la vacuola que contiene Legionella.
Objetivo del estudio:
- Para investigar el mecanismo por el cual L. pneumophila manipula Rab1.
- Para identificar la actividad específica de la proteína DrrA de Legionella en Rab1.
Principales métodos:
- Análisis bioquímicos para determinar la actividad enzimática de DrrA.
- Análisis de la modificación de Rab1b utilizando técnicas como la espectrometría de masas.
- Investigando el efecto de DrrA en las proteínas activadoras de la GTPasa Rab1 (GAP).
Principales resultados:
- El dominio N-terminal de DrrA exhibe actividad de monofosforilación de adenosina (AMPilación).
- DrrA AMPylates Rab1b en la tirosina 77 en la región del interruptor II.
- Esta AMPilación impide la unión de las proteínas activadoras de la GTPasa, lo que lleva a la activación constitutiva de Rab1b.
Conclusiones:
- DrrA modifica directamente a Rab1b a través de la AMPilación, un nuevo mecanismo para la manipulación del huésped.
- La activación constitutiva de Rab1b por el DrrA interrumpe los procesos celulares normales.
- Comprender esta interacción proporciona información sobre la patogénesis de la enfermedad del legionario.
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