Anti-CRISPR | Uncovering viral sabotage of host CRISPR-Cas immune systems

Summary
CRISPR-Cas immune system represents one of the most effective weapons against mobile genetic elements in the host defense arsenal. Bacteriophages (phages) armed with anti-CRISPR proteins can, however, inhibit CRISPR immunity by sabotaging components of the immune system with evolutionary advantages. This proposal sets out to discover novel phage-encoded anti-CRISPR proteins and understand the molecular mechanisms of the inhibitory processes.
I will focus on novel anti-CRISPR proteins for Cas9-containing type II CRISPR-Cas systems in lactic acid bacteria (LAB). I expect anti-CRISPR proteins to be present in phages for LAB, for which the CRISPR system is an important line of defense. It is highly plausible that LAB-infecting phages have evolved to possess anti-CRISPR proteins. However, none of anti-CRISPR proteins against type II CRISPR have been described so far. To identify novel type II anti-CRISPR proteins encoded by phage genomes and explore novel features of the anti-CRISPR proteins, I will establish high-throughput screening methods using an integrated approach consisting of metagenomics, bioinformatics and mass spectrometry. After identifying candidate anti-CRISPR proteins, I will uncover the underlying molecular mechanisms of these viral anti-CRISPR proteins utilizing state-of-the-art single-molecule fluorescence methodologies.
The fierce virus–host arms race has resulted in high diversity of distinct prokaryotic CRISPR-Cas systems. Therefore, I anticipate that my high-throughput screening will lead to discovery of remarkably diverse anti-CRISPR proteins, specifically anti-CRISPR variants targeting Cas9. The proposed combination of viral diversity screening and single-molecule approaches will reveal novel mechanisms of anti-CRISPR activity that are difficult to obtain by traditional biochemistry, will impact potential applications of Cas9, and will provide unique insights into the host-virus arms race.
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More information & hyperlinks
Web resources: https://cordis.europa.eu/project/id/753528
Start date: 15-01-2018
End date: 14-01-2020
Total budget - Public funding: 177 598,80 Euro - 177 598,00 Euro
Cordis data

Original description

CRISPR-Cas immune system represents one of the most effective weapons against mobile genetic elements in the host defense arsenal. Bacteriophages (phages) armed with anti-CRISPR proteins can, however, inhibit CRISPR immunity by sabotaging components of the immune system with evolutionary advantages. This proposal sets out to discover novel phage-encoded anti-CRISPR proteins and understand the molecular mechanisms of the inhibitory processes.
I will focus on novel anti-CRISPR proteins for Cas9-containing type II CRISPR-Cas systems in lactic acid bacteria (LAB). I expect anti-CRISPR proteins to be present in phages for LAB, for which the CRISPR system is an important line of defense. It is highly plausible that LAB-infecting phages have evolved to possess anti-CRISPR proteins. However, none of anti-CRISPR proteins against type II CRISPR have been described so far. To identify novel type II anti-CRISPR proteins encoded by phage genomes and explore novel features of the anti-CRISPR proteins, I will establish high-throughput screening methods using an integrated approach consisting of metagenomics, bioinformatics and mass spectrometry. After identifying candidate anti-CRISPR proteins, I will uncover the underlying molecular mechanisms of these viral anti-CRISPR proteins utilizing state-of-the-art single-molecule fluorescence methodologies.
The fierce virus–host arms race has resulted in high diversity of distinct prokaryotic CRISPR-Cas systems. Therefore, I anticipate that my high-throughput screening will lead to discovery of remarkably diverse anti-CRISPR proteins, specifically anti-CRISPR variants targeting Cas9. The proposed combination of viral diversity screening and single-molecule approaches will reveal novel mechanisms of anti-CRISPR activity that are difficult to obtain by traditional biochemistry, will impact potential applications of Cas9, and will provide unique insights into the host-virus arms race.

Status

CLOSED

Call topic

MSCA-IF-2016

Update Date

28-04-2024
Geographical location(s)
Structured mapping
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EU-Programme-Call
Horizon 2020
H2020-EU.1. EXCELLENT SCIENCE
H2020-EU.1.3. EXCELLENT SCIENCE - Marie Skłodowska-Curie Actions (MSCA)
H2020-EU.1.3.2. Nurturing excellence by means of cross-border and cross-sector mobility
H2020-MSCA-IF-2016
MSCA-IF-2016