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Updated: Jun 14, 2025
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Substrate Generation for Endonucleases of CRISPR/Cas Systems
Published on: September 8, 2012
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Diversos genes virales cas antagonizan la inmunidad CRISPR
Mark A Katz1, Edith M Sawyer1, Luke Oriolt1
1Department of Microbiology, University of Washington, Seattle, WA, USA.
Nature
|September 4, 2024
Resumen
Los investigadores descubrieron nuevas proteínas anti-CRISPR (Acr) en Listeria que se dirigen a los sistemas inmunológicos CRISPR-Cas de las bacterias. Estos Acr evolucionan a partir de los genes Cas, ofreciendo un amplio espectro de control sobre las tecnologías de edición del genoma.
Área de la Ciencia:
- Microbiología
- Biología molecular
- La genética
Sus antecedentes:
- Los sistemas CRISPR-Cas procariotas proporcionan inmunidad adaptativa contra los fagos y los plásmidos.
- Las proteínas anti-CRISPR (Acrs) contrarrestan la inmunidad CRISPR-Cas inhibiendo la actividad de la proteína Cas.
- Los orígenes evolutivos y los mecanismos de inhibición de amplio espectro de Acrs siguen siendo en gran medida desconocidos.
Objetivo del estudio:
- Investigar el contenido de Acr y la especificidad de inhibición en diversos aislamientos de Listeria.
- Identificar las nuevas familias de genes Acr y sus orígenes.
- Explorar la evolución de los Acrs a través de la cooptación de genes cas.
Principales métodos:
- Análisis de los sistemas CRISPR-Cas en los aislados de Listeria.
- Identificación y caracterización de nuevas familias de genes de acr.
- Investigando bases de datos de secuencias virales para genes huérfanos.
- Verificación funcional de los homólogos Acr y Cas identificados.
Principales resultados:
- Descubrió 11 nuevas y 4 familias conocidas de genes acr en Listeria, codificadas por elementos móviles.
- Identificaron dos Acrs con homología a las proteínas Cas tipo I-B, una formando un complejo de interferencia defectuoso.
- Se encontró un homólogo de Cas de tipo I-B que inhibe el CRISPR de tipo VI dirigido al ARN a través de la degradación del ARNcr.
- Se ha verificado un homólogo de amplio espectro de cas3 que inhibe la inmunidad CRISPR de los tipos I-B, II-A y VI-A.
Conclusiones:
- Proporcionó evidencia directa para la evolución de Acr a través de la cooptación de genes cas.
- Se han identificado nuevos Acr con potencial para el control de amplio espectro de tecnologías de edición del genoma.
- Comprensión ampliada de la subversión y evolución del sistema CRISPR-Cas.
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