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Evolución de las máquinas moleculares para la importación de proteínas en las mitocondrias
Pavel Dolezal1, Vladimir Likic, Jan Tachezy
1Department of Biochemistry & Molecular Biology, University of Melbourne, Parkville 3010, Australia.
Science (New York, N.Y.)
|July 22, 2006
Resumen
La evolución de las mitocondrias implicó la reutilización de la maquinaria bacteriana y la creación de novo de translocaciones de proteínas. Esto sugiere que todos los eucariotas descienden de un solo antepasado con protomitocondrias.
Área de la Ciencia:
- Biología celular Biología celular.
- Biología evolutiva Biología evolutiva.
- La bioquímica es la bioquímica.
Sus antecedentes:
- Las mitocondrias se originaron a partir de un endosimbionte bacteriano hace unos 2.000 millones de años.
- Las células eucariotas requerían una maquinaria de importación de proteínas para el endosimbionte.
- Algunos componentes de la translocación de proteínas bacterianas fueron probablemente cooptados.
Objetivo del estudio:
- Para investigar el origen y la evolución de la maquinaria de importación de proteínas mitocondriales.
- Para determinar si las translocaciones de proteínas mitocondriales tienen homólogos bacterianos.
- Para inferir la naturaleza de la célula eucariota ancestral.
Principales métodos:
- Análisis comparativo de genómica de los genomas de los eucariotas.
- Análisis bioinformático de secuencias de proteínas.
- Análisis filogenético de las subunidades de las translocasas.
Principales resultados:
- Las translocaciones de proteínas mitocondriales carecen de contrapartes bacterianas obvias.
- Subunidades similares de translocazas están presentes en todos los genomas eucariotas secuenciados.
- La evidencia sugiere una evolución de novo de las principales máquinas de importación de proteínas mitocondriales.
Conclusiones:
- Las translocaciones de importación de proteínas mitocondriales probablemente se crearon de novo.
- La presencia de estas translocaciones apunta a un único antepasado eucariota común.
- Este antepasado poseía una forma temprana de mitocondrias, denominadas "protomitocondrias".
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