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La remodelación de la membrana inducida por la proteína relacionada con la dinamina Drp1 estimula la oligomerización
Sylvie Montessuit1, Syam Prakash Somasekharan, Oihana Terrones
1Department of Cell Biology, University of Geneva, Sciences III, 30 quai Ernest Ansermet, 1211 Geneva 4, Switzerland.
Cell
|September 21, 2010
Resumen
La proteína Drp1 ayuda a la oligomerización de Bax y a la liberación del citocromo c durante la apoptosis promoviendo el enlazamiento de la membrana. Esta función es independiente de su actividad de la GTPasa, ofreciendo nuevos conocimientos sobre los mecanismos de muerte celular.
Área de la Ciencia:
- Biología celular Biología celular.
- Biología Molecular Biología Molecular
- La bioquímica es la bioquímica.
Sus antecedentes:
- La oligomerización de la proteína Bax es crítica para la apoptosis, iniciando la permeabilización de la membrana externa mitocondrial y la liberación del citocromo c.
- La fisión mitocondrial, mediada por Drp1 (proteína relacionada con la dinamina 1), acompaña estos eventos apoptóticos, pero su papel preciso no está claro.
Objetivo del estudio:
- Para aclarar el mal entendido mecanismo por el cual Drp1 influye en la liberación del citocromo c.
- Investigar el papel de Drp1 en la oligomerización de Bax y su contribución a la apoptosis.
Principales métodos:
- Ensayos in vitro de enlace de membrana y ensayos de hemifusión.
- Análisis bioquímico de la oligomerización de Bax.
- Estudios celulares que incluyen mutantes de Drp1 (R247A/E) y la oligomerización de Bax.
Principales resultados:
- Drp1 estimula la oligomerización de Bax inducida por tBid y la liberación del citocromo c promoviendo el enlazamiento de la membrana y la hemifusión in vitro.
- Esta función de Drp1 es independiente de su actividad de la GTPasa y depende de la arginina 247 y la cardiolipina.
- La sobreexpresión de un mutante Drp1 (R247A/E) en las células retrasa la oligomerización de Bax y la posterior muerte celular.
Conclusiones:
- Drp1 posee una nueva función en la promoción de la oligomerización de Bax y la liberación del citocromo c, independiente de su papel canónico en la fisión mitocondrial.
- Los hallazgos destacan la importancia del contacto de la membrana y las interacciones específicas proteína-lípido en la regulación de las vías de señalización apoptótica.
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