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CRISPR sabotage.

van der Oost J, Brouns SJ - Genome Biol. (2015)

Bottom Line: The biological arms race generally involves the rapid co-evolution of anti-virus systems in host organisms and of anti-anti-virus systems in their viral parasites.The CRISPR-Cas system is an example of a prokaryotic immune system in which such co-evolution occurs, as was recently demonstrated by the characterization of a set of viral anti-CRISPR proteins.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Microbiology, Wageningen University, Dreijenplein, 6703, HB, Wageningen, The Netherlands. john.vanderoost@wur.nl.

ABSTRACT
The biological arms race generally involves the rapid co-evolution of anti-virus systems in host organisms and of anti-anti-virus systems in their viral parasites. The CRISPR-Cas system is an example of a prokaryotic immune system in which such co-evolution occurs, as was recently demonstrated by the characterization of a set of viral anti-CRISPR proteins.

No MeSH data available.


Related in: MedlinePlus

Virus-encoded inhibitors of antiviral defense systems. a RNA viruses that infect various plants, insects and mammals encode proteins that inhibit essential proteins in the RNA interference pathway, such as Dicer and Argonaute (AGO), a subunit of the RNA-induced silencing complex (RISC). Furthermore, these viruses may produce proteins that will mask double-stranded RNA (dsRNA) so that Dicer activity does not occur or that will sequester any small interfering RNA (siRNA) molecules produced. b Bacteriophage P1 co-injects DarA and DarB to mask restriction sites in the phage genome. Bacteriophage T7 encodes Ocr, which mimics the DNA phosphate backbone and sequesters both the EcoKI restriction enzyme (R) and its corresponding methylase (M). Bacteriophage Lambda encodes Ral, which hyperactivates the DNA methylase to protect phage DNA before it can be restricted. c Anti-CRISPR proteins encoded by Pseudomonas prophages (AcrF1–AcrF3) bind CRISPR-RNA–effector complexes and the nuclease Cas3 to prevent them from binding and cleaving target dsDNAs
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Fig1: Virus-encoded inhibitors of antiviral defense systems. a RNA viruses that infect various plants, insects and mammals encode proteins that inhibit essential proteins in the RNA interference pathway, such as Dicer and Argonaute (AGO), a subunit of the RNA-induced silencing complex (RISC). Furthermore, these viruses may produce proteins that will mask double-stranded RNA (dsRNA) so that Dicer activity does not occur or that will sequester any small interfering RNA (siRNA) molecules produced. b Bacteriophage P1 co-injects DarA and DarB to mask restriction sites in the phage genome. Bacteriophage T7 encodes Ocr, which mimics the DNA phosphate backbone and sequesters both the EcoKI restriction enzyme (R) and its corresponding methylase (M). Bacteriophage Lambda encodes Ral, which hyperactivates the DNA methylase to protect phage DNA before it can be restricted. c Anti-CRISPR proteins encoded by Pseudomonas prophages (AcrF1–AcrF3) bind CRISPR-RNA–effector complexes and the nuclease Cas3 to prevent them from binding and cleaving target dsDNAs

Mentions: Many eukaryotic viruses — for example, plant and insect viruses — carry suppressors of RNAi on their viral genomes to sabotage the RNAi immune system (Fig. 1a). The mechanisms that these suppressors employ are very diverse, ranging from the inhibition of small interfering RNA (siRNA) production, to the formation of unproductive siRNA, sequestering of host siRNA, interference with host gene regulation, and direct inhibition or inactivation of RNAi protein components [5–7].Fig. 1


CRISPR sabotage.

van der Oost J, Brouns SJ - Genome Biol. (2015)

Virus-encoded inhibitors of antiviral defense systems. a RNA viruses that infect various plants, insects and mammals encode proteins that inhibit essential proteins in the RNA interference pathway, such as Dicer and Argonaute (AGO), a subunit of the RNA-induced silencing complex (RISC). Furthermore, these viruses may produce proteins that will mask double-stranded RNA (dsRNA) so that Dicer activity does not occur or that will sequester any small interfering RNA (siRNA) molecules produced. b Bacteriophage P1 co-injects DarA and DarB to mask restriction sites in the phage genome. Bacteriophage T7 encodes Ocr, which mimics the DNA phosphate backbone and sequesters both the EcoKI restriction enzyme (R) and its corresponding methylase (M). Bacteriophage Lambda encodes Ral, which hyperactivates the DNA methylase to protect phage DNA before it can be restricted. c Anti-CRISPR proteins encoded by Pseudomonas prophages (AcrF1–AcrF3) bind CRISPR-RNA–effector complexes and the nuclease Cas3 to prevent them from binding and cleaving target dsDNAs
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4638106&req=5

Fig1: Virus-encoded inhibitors of antiviral defense systems. a RNA viruses that infect various plants, insects and mammals encode proteins that inhibit essential proteins in the RNA interference pathway, such as Dicer and Argonaute (AGO), a subunit of the RNA-induced silencing complex (RISC). Furthermore, these viruses may produce proteins that will mask double-stranded RNA (dsRNA) so that Dicer activity does not occur or that will sequester any small interfering RNA (siRNA) molecules produced. b Bacteriophage P1 co-injects DarA and DarB to mask restriction sites in the phage genome. Bacteriophage T7 encodes Ocr, which mimics the DNA phosphate backbone and sequesters both the EcoKI restriction enzyme (R) and its corresponding methylase (M). Bacteriophage Lambda encodes Ral, which hyperactivates the DNA methylase to protect phage DNA before it can be restricted. c Anti-CRISPR proteins encoded by Pseudomonas prophages (AcrF1–AcrF3) bind CRISPR-RNA–effector complexes and the nuclease Cas3 to prevent them from binding and cleaving target dsDNAs
Mentions: Many eukaryotic viruses — for example, plant and insect viruses — carry suppressors of RNAi on their viral genomes to sabotage the RNAi immune system (Fig. 1a). The mechanisms that these suppressors employ are very diverse, ranging from the inhibition of small interfering RNA (siRNA) production, to the formation of unproductive siRNA, sequestering of host siRNA, interference with host gene regulation, and direct inhibition or inactivation of RNAi protein components [5–7].Fig. 1

Bottom Line: The biological arms race generally involves the rapid co-evolution of anti-virus systems in host organisms and of anti-anti-virus systems in their viral parasites.The CRISPR-Cas system is an example of a prokaryotic immune system in which such co-evolution occurs, as was recently demonstrated by the characterization of a set of viral anti-CRISPR proteins.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Microbiology, Wageningen University, Dreijenplein, 6703, HB, Wageningen, The Netherlands. john.vanderoost@wur.nl.

ABSTRACT
The biological arms race generally involves the rapid co-evolution of anti-virus systems in host organisms and of anti-anti-virus systems in their viral parasites. The CRISPR-Cas system is an example of a prokaryotic immune system in which such co-evolution occurs, as was recently demonstrated by the characterization of a set of viral anti-CRISPR proteins.

No MeSH data available.


Related in: MedlinePlus