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Proteína S-nitrosilación selectiva de la proteína objetivo por reconocimiento de motivos de secuencia.
Jie Jia1, Abul Arif1, Fulvia Terenzi1
1Department of Cellular and Molecular Medicine, The Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA.
Cell
|November 24, 2014
Resumen
Los investigadores descubrieron un nuevo complejo proteico que modifica las proteínas utilizando óxido nítrico (NO). Este complejo, que involucra a la sintasa de óxido nítrico inducible (iNOS), S100A8 y S100A9, se dirige con precisión a sitios específicos de proteínas, similar a la fosforilación.
Área de la Ciencia:
- La bioquímica es la bioquímica.
- Biología Molecular Biología Molecular
- La señalización celular de las células.
Sus antecedentes:
- La S-nitrosilación es una modificación posttranslacional mediada por óxido nítrico (NO) clave que regula la función celular.
- Si bien se conocen numerosas proteínas S-nitrosiladas, las enzimas (S-nitrosilasas) y los mecanismos para la modificación selectiva del sitio siguen sin caracterizarse en gran medida.
Objetivo del estudio:
- Para identificar y caracterizar nuevos complejos de S-nitrosilasa.
- Aclarar los mecanismos subyacentes a la S-nitrosilación selectiva del sitio.
- Para identificar los motivos de secuencia reconocidos por las S-nitrosilasas.
Principales métodos:
- Análisis proteómico para identificar proteínas S-nitrociladas.
- Análisis bioquímicos para caracterizar la actividad enzimática y la formación de complejos.
- Mutagénesis dirigida al sitio para determinar el papel de los motivos de secuencia específicos.
Principales resultados:
- Se identificó un nuevo complejo heterotrimérico de síntesis de óxido nítrico inducible (iNOS), S100A8 y S100A9 como una S-nitrosilasa inducible por estímulo.
- S100A9 actúa como una transnitrosilasa, transfiriendo NO de iNOS a las proteínas diana.
- S100A8 y S100A9 colaboran para dirigir la selección del sitio, reconociendo un motivo I/L-X-C-X2-D/E conservado.
- El análisis proteómico identificó nuevos blancos proteicos de este complejo iNOS-S100A8/A9.
Conclusiones:
- El complejo iNOS-S100A8/A9 representa un mecanismo primario para la S-nitrosilación dependiente del estímulo.
- La S-nitrosilación selectiva del sitio, mediada por motivos de secuencia específicos, es paralela a los mecanismos de fosforilación de proteínas.
- Este descubrimiento proporciona nuevos conocimientos sobre las vías de señalización del NO y la regulación de las proteínas.
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