Video Experimental Relacionado
Updated: Jan 19, 2026
11:31
Establishment of a High-throughput Setup for Screening Small Molecules That Modulate c-di-GMP Signaling in Pseudomonas aeruginosa
Published on: June 30, 2016
9.1K
La señalización cíclica de GMP-AMP protege a las bacterias contra la infección viral
Daniel Cohen1, Sarah Melamed1, Adi Millman1
1Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel.
Nature
|September 19, 2019
Resumen
Las bacterias utilizan la señalización cíclica de GMP-AMP (cGAMP), que involucra a la GMP-AMP sintasa cíclica (cGAS), como una defensa contra las infecciones de los fagos. Este antiguo sistema microbiano desencadena la muerte celular para evitar la reproducción viral, antecedente de vías antivirales animales similares.
Área de la Ciencia:
- Microbiología
- Inmunología
- Biología molecular
Sus antecedentes:
- La vía cíclica GMP-AMP sintasa (cGAS) -STING es crucial para la inmunidad innata en los animales, ya que detecta el ADN citosólico para iniciar respuestas antivirales.
- La señalización cíclica de GMP-AMP (cGAMP) se ha observado en bacterias, y algunos estudios muestran que activa las fosfolipasas que degradan las membranas bacterianas.
Objetivo del estudio:
- Para investigar el papel biológico de la señalización de cGAMP en las bacterias.
- Identificar los componentes y mecanismos de los sistemas de defensa de los antifagos bacterianos en los que interviene la cGAMP.
Principales métodos:
- Análisis genético de un operón de cuatro genes que codifica el cGAS bacteriano, la fosfolipasa y las enzimas similares a las eucariotas.
- Evaluación de la resistencia del fago conferida por el operón identificado.
- Investigar el papel de cGAMP en el desencadenamiento de la actividad de la fosfolipasa y la muerte celular tras la infección de los fagos.
Principales resultados:
- Se identificó un sistema de defensa antifago bacteriano común, que comprende un operón de cuatro genes con cGAS bacteriano y enzimas asociadas.
- Este sistema confiere resistencia contra diversos fagos al producir cGAMP al momento de la infección, activando una fosfolipasa que compromete la integridad de la membrana y conduce a la muerte celular.
- Las versiones divergentes de este sistema están presentes en más del 10% de los genomas procariotas, con variantes que emplean diferentes efectores que también proporcionan protección a los fagos.
Conclusiones:
- Los sistemas bacterianos cGAMP-cGAS representan un mecanismo de defensa antiguo y generalizado contra los fagos.
- La vía antiviral eucariota cGAS-STING probablemente evolucionó a partir de estas estrategias de defensa microbiana primordiales.
Videos de Conceptos Relacionados
01:09GPCRs Regulate Adenylyl Cylase Activity
7.3K
Some GPCRs transmit signals through adenylyl cyclase (AC), a transmembrane enzyme. AC helps synthesize second messenger cyclic adenosine monophosphate (cAMP). AC catalyzes cyclization reaction and converts ATP to cAMP by releasing a pyrophosphate. The pyrophosphate is further hydrolyzed to phosphate by the enzyme pyrophosphatase, which drives cAMP synthesis to completion. However, cAMP is rapidly degraded to 5′ AMP by the enzymes phosphodiesterase (PDE), preventing overstimulation of...
7.3K
01:16Viral Replication: Lysogenic Cycle
1.4K
The lysogenic cycle is a crucial viral replication strategy that allows bacteriophages to persist within host cells without immediately destroying them. This process is primarily observed in temperate phages, such as bacteriophage lambda (λ), which infects Escherichia coli. The cycle allows the viral genome to persist across bacterial generations while keeping host cells viable.Integration of the Viral GenomeUpon infection, bacteriophage lambda attaches to the bacterial surface and injects...
1.4K
01:30Bacterial Signaling
40.1K
Bacterial signaling can occur within bacteria (intracellular) or between bacteria (intercellular). At times, a group of bacteria behaves like a community. To achieve this, they engage in quorum sensing, the perception of higher cell density that causes changes in gene expression. Quorum sensing involves both extracellular and intracellular signaling. The signaling cascade starts with a molecule called an autoinducer (AI). Individual bacteria produce AIs that move out of the bacterial cell...
40.1K
01:23Stringent Response in E. coli
304
Bacterial growth is closely tied to nutrient availability, with cells proliferating exponentially under favorable conditions and entering a stationary phase when resources become scarce. This transition is mediated by a regulatory mechanism known as the stringent response, which allows bacteria to adapt to nutrient deprivation by modulating gene expression and metabolic activity.During nutrient scarcity, intracellular amino acid levels decline. It results in the accumulation of uncharged tRNAs...
304
01:20Viral Replication: Lytic Cycle
1.3K
Bacteriophages, or phages, are viruses that specifically infect bacteria. Among them, T-even bacteriophages, such as T4, exhibit a well-characterized lytic replication cycle in Escherichia coli (E. coli). This process ensures the rapid proliferation of the virus while ultimately leading to the destruction of the bacterial host.Attachment and DNA InjectionThe infection process begins with the recognition and binding of the T4 phage to the E. coli cell surface. Tail fibers of the phage...
1.3K
01:23The Antiviral System of Bacteria and Archaea: CRISPR
630
CRISPR stands for Clustered Regularly Interspaced Short Palindromic Repeats is a adaptive immune system found in bacteria and archaea that protects against viral infections. This system enables prokaryotic cells to identify, remember, and neutralize foreign genetic elements, primarily bacteriophages, by storing fragments of the invader’s DNA as a genetic memory.The CRISPR immune response begins during an initial infection. Cas (CRISPR-associated) proteins play a central role in this...
630