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Un Rac fotoactivado genéticamente codificado controla la motilidad de las células vivas
Yi I Wu1, Daniel Frey, Oana I Lungu
1Department of Pharmacology, University of North Carolina, Chapel Hill, North Carolina 27599, USA. yiwu@med.unc.edu
Nature
|August 21, 2009
Resumen
Los investigadores desarrollaron el Rac1 fotoactivado (PA-Rac1) para el control preciso del comportamiento celular utilizando la luz. Esta herramienta genéticamente codificada permite la manipulación reversible de la actividad de Rac1, impactando la motilidad celular y la dinámica citoesquelética.
Área de la Ciencia:
- Biología celular Biología celular.
- La bioquímica es la bioquímica.
- Biología Molecular Biología Molecular
Sus antecedentes:
- El control preciso de la actividad proteica en el espacio y el tiempo es crucial para el comportamiento celular, pero sigue siendo un desafío.
- Los métodos existentes para la activación de proteínas inducida por la luz a menudo implican luz UV tóxica, cambios irreversibles o técnicas de carga celular invasivas.
Objetivo del estudio:
- Desarrollar un Rac1 (PA-Rac1) codificado genéticamente y fotoactivado para un preciso control espacio-temporal de la dinámica citoesquelética de la actina.
- Investigar las funciones de Rac1 en la motilidad celular, la formación de protuberancias y la regulación de RhoA.
Principales métodos:
- La codificación genética del Rac1 fotoactivado (PA-Rac1) mediante la fusión de mutantes de Rac1 con el dominio luz-oxígeno-voltaje (LOV).
- Utilizando luz visible (458 o 473 nm) para la activación e inactivación reversible de PA-Rac1.1.
- Emplear PA-Rac1 para inducir protuberancias celulares localizadas, arrugas y controlar la dirección del movimiento celular.
Principales resultados:
- PA-Rac1 permitió la activación reversible y repetible utilizando luz visible, lo que condujo a protuberancias celulares y arrugas precisamente localizadas.
- La activación/inactivación localizada de Rac1 controlaba la motilidad y direccionalidad celular, con miosina implicada en la direccionalidad y PAK en la protuberancia.
- PA-Rac1 reveló que Rac1 inhibe RhoA en los fibroblastos embrionarios de ratón, con esta inhibición modulada en las protuberancias y arrugas.
Conclusiones:
- La PA-Rac1 genéticamente codificada proporciona una herramienta poderosa y no invasiva para el control espacio-temporal de la actividad de Rac1 y la dinámica citoesquelética.
- Rac1 juega un papel crítico en la protrusión celular, la motilidad y la direccionalidad, e inhibe la actividad de RhoA.
- Los conocimientos sobre la interacción LOV-Rac facilitan la extensión de esta tecnología de fotoactivación a otras proteínas.
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