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La activación dependiente de Sir2 de la acetil-CoA sintetasa por desacetilación de la lisina activa
V J Starai1, I Celic, R N Cole
1Department of Bacteriology, University of Wisconsin, Madison, WI 53706-1567, USA.
Science (New York, N.Y.)
|December 21, 2002
Resumen
La acetilación regula la actividad de la enzima acetil-CoA sintetasa (Acs) en Salmonella mediante la modificación de la lisina-609. Esta modificación postraslacional es revertida por la proteína CobB Sir2, revelando un mecanismo regulador común.
Área de la Ciencia:
- La bioquímica es la bioquímica.
- Biología Molecular Biología Molecular
- Enzimología Enzimología.
Sus antecedentes:
- La acetil-coenzima A (CoA) sintetasa (Acs) es una enzima metabólica crucial tanto en procariotas como en eucariotas.
- Acs sintetiza el acetil CoA a partir del acetato, el trifosfato de adenosina (ATP) y el CoA, con la participación de un intermediario monofosfato de acetil-adenosina (AMP).
Objetivo del estudio:
- Para investigar la regulación post-traducional de la actividad de la enzima Salmonella enterica Acs.
- Identificar el mecanismo específico y los factores regulatorios involucrados en la modulación de Acs.
Principales métodos:
- Se emplearon inmunoblotación y espectrometría de masas para analizar la actividad de la enzima Acs.
- Investigó el papel de la acetilación y la proteína CobB Sir2 en la regulación de Acs.
Principales resultados:
- La actividad de la enzima Salmonella enterica Acs está regulada por la acetilación posttranslacional en la lisina-609.
- La acetilación inhibe la síntesis de adenilato intermedio pero no la formación de tioesteros.
- La activación de los Acs acetilados requiere la actividad de la desacetilasa de la proteína CobB Sir2.
Conclusiones:
- La acetilación de lisina es un mecanismo regulador común tanto en procariotas como en eucariotas.
- Los hallazgos sugieren que la acetilación modula las enzimas formadoras de AMP, incluidas las sintetasas de péptidos no ribosómicos y las sintetasas de acil-CoA.
- Amplía la comprensión de las funciones de la proteína Sir2 en el silenciamiento de genes, la estabilidad cromosómica y el envejecimiento.
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