Antiviral type III CRISPR signalling via conjugation of ATP and SAM
These videos have been matched automatically. Contact us if they are not relevant.
These videos have been matched automatically. Contact us if they are not relevant.
View abstract on PubMed
Summary
This summary is machine-generated.Type III-B CRISPR systems in Bacteroides fragilis use S-adenosyl methionine-AMP (SAM-AMP) for antiviral defense, not cyclic oligoadenylates. This novel second messenger targets membrane proteins, offering new insights into prokaryotic immunity.
Area Of Science
- Molecular Biology
- Microbiology
- Immunology
Background
- Prokaryotic CRISPR systems provide adaptive immunity against mobile genetic elements.
- Type III CRISPR systems utilize CRISPR RNA and Cas10 to detect and eliminate foreign nucleic acids.
- Some type III systems involve uncharacterized proteins like CorA and phosphodiesterases for defense.
Purpose Of The Study
- To investigate the antiviral defense mechanism of the CorA-associated type III-B (Cmr) CRISPR system from Bacteroides fragilis.
- To elucidate the signaling molecules and effectors involved in the B. fragilis Cmr system's immune response.
- To characterize the novel second messenger generated by this CRISPR system.
Main Methods
- Expression of the B. fragilis Cmr CRISPR system in Escherichia coli.
- Analysis of signaling molecules produced upon activation of the CRISPR system.
- Biochemical characterization of the interaction between the generated molecule and the CorA effector.
Main Results
- The B. fragilis Cmr system confers immunity against mobile genetic elements in E. coli.
- Instead of cyclic oligoadenylates, the system generates S-adenosyl methionine-AMP (SAM-AMP) by conjugating ATP to S-adenosyl methionine (SAM).
- SAM-AMP binds to the CorA effector, potentially disrupting membrane integrity and leading to cell dormancy or death.
Conclusions
- SAM-AMP is a novel class of second messenger involved in prokaryotic antiviral signaling.
- The B. fragilis Cmr system represents a distinct mechanism of type III CRISPR immunity.
- Degradation of SAM-AMP by specific enzymes provides a potential 'off switch' for the immune response.
These videos have been matched automatically. Contact us if they are not relevant.
These videos have been matched automatically. Contact us if they are not relevant.
Related Concept Videos
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...
Bacteria and archaea are susceptible to viral infections just like eukaryotes; therefore, they have developed a unique adaptive immune system to protect themselves. Clustered regularly interspaced short palindromic repeats and CRISPR-associated proteins (CRISPR-Cas) are present in more than 45% of known bacteria and 90% of known archaea.
The CRISPR-Cas system stores a copy of foreign DNA in the host genome and uses it to identify the foreign DNA upon reinfection. CRISPR-Cas has three different...
Genome editing technologies allow scientists to modify an organism’s DNA via the addition, removal, or rearrangement of genetic material at specific genomic locations. These types of techniques could potentially be used to cure genetic disorders such as hemophilia and sickle cell anemia. One popular and widely used DNA-editing research tool that could lead to safe and effective cures for genetic disorders is the CRISPR-Cas9 system. CRISPR-Cas9 stands for Clustered Regularly Interspaced...
The CRISPR-Cas system serves as a bacterial defense mechanism against invading genetic elements such as viruses and plasmids, forming the foundation for its adaptation as a powerful genome-editing tool. Originally discovered in prokaryotes, this system has been repurposed to revolutionize genetic engineering across a wide range of organisms, including plants, animals, and humans. The core component, Cas9, is an endonuclease derived from Streptococcus pyogenes, capable of introducing...
Bacterial conjugation is a mechanism of horizontal gene transfer that enables the exchange of genetic material between bacterial cells through direct contact. This process is facilitated by a donor cell carrying a conjugative plasmid, which encodes genes necessary for pilus formation, DNA replication, and transfer. The conjugative plasmid plays a central role in initiating and executing the transfer of genetic material.The tra region of the conjugative plasmid encodes proteins responsible for...
Small interfering RNAs, or siRNAs, are short regulatory RNA molecules that can silence genes post-transcriptionally, as well as the transcriptional level in some cases. siRNAs are important for protecting cells against viral infections and silencing transposable genetic elements.
In the cytoplasm, siRNA is processed from a double-stranded RNA, which comes from either endogenous DNA transcription or exogenous sources like a virus. This double-stranded RNA is then cleaved by the...