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A Fluorescence-based Method to Study Bacterial Gene Regulation in Infected Tissues
Published on: February 19, 2019
AirSR, un sistema de dos componentes que contiene un grupo de [2Fe-2S], media la detección global de oxígeno y la
Fei Sun1, Quanjiang Ji, Marcus B Jones
1Department of Chemistry and Institute for Biophysical Dynamics, The University of Chicago, Chicago, Illinois 60637, USA.
Journal of the American Chemical Society
|November 30, 2011
Resumen
Staphylococcus aureus utiliza el sistema AirSR para detectar señales de oxidación a través de un grupo redox activo de hierro y azufre. Este sistema regula cientos de genes e impacta la resistencia a los antibióticos bajo condiciones de oxígeno limitado.
Área de la Ciencia:
- Microbiología Microbiología.
- Fisiología bacteriana fisiología bacteriana.
- La señalización de redox.
Sus antecedentes:
- La detección de oxígeno y la señalización redox son fundamentales para la fisiología bacteriana y las interacciones huésped-patógeno.
- Los sistemas de dos componentes son reguladores clave en las bacterias, a menudo respondiendo a las señales ambientales.
Objetivo del estudio:
- Aclarar la función y el mecanismo del sistema de dos componentes de Staphylococcus aureus AirSR en respuesta a las señales oxidativas.
- Investigar el papel del grupo de hierro-azufre en la actividad de la cinasa AirS y su impacto en la regulación génica y la resistencia a los antibióticos.
Principales métodos:
- Mutagénesis dirigida al sitio para estudiar el papel del racimo [2Fe-2S].
- Reconstitución in vitro del grupo [2Fe-2S] utilizando un homólogo de la cisteína desulfurasa.
- Ensayos de fosforilación para determinar la actividad de la quinasa.
- Análisis del transcriptoma (ARN-seq) para identificar los genes regulados.
- Pruebas de resistencia a los antimicrobianos.
Principales resultados:
- El clúster [2Fe-2S] en AirS es esencial para su actividad quinasa, siendo la forma oxidada [2Fe-2S](2+) completamente activa.
- La sobreoxidación o reducción del racimo inactiva AirS.
- La mutación de airR afecta la expresión de aproximadamente 355 genes en condiciones anaerobias.
- El mutante airR exhibe una mayor resistencia a H2O2, vancomicina, norfloxacina y ciprofloxacina bajo condiciones anaerobias.
Conclusiones:
- Staphylococcus aureus AirSR es un sistema regulador global dependiente de redox.
- El sistema utiliza un grupo redox activo de hierro y azufre en AirS para detectar señales oxidativas.
- AirSR juega un papel importante en la regulación de los genes y confiere resistencia a varios agentes en condiciones de oxígeno limitado.
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