Researchers at the Delft University of Technology have discovered a new CRISPR-Cas system that is able to cut viral RNA at molecular precision. The team expect that this discovery will create many opportunities to develop new applications in genetic research and biotechnology.
Bacterial Immune System: The Attack on Viruses
Bacteria, just like us, can be at risk of being infected by viruses. Over billions of years of evolution, bacterial cells have developed ingenious immune systems to defend themselves against these infections. One of these immune systems is CRISPR-Cas. Over the past decade, CRISPR-Cas has been adapted for use in many research areas such as genetic disorders.
Since its discovery, CRISPR-Cas has excited the research community as it is currently the fastest, cheapest and most accurate DNA editing technique available. Previous work has focused on developing CRISPR-Cas systems that edit DNA strands. However, a research group at the Delft University of Technology, have now discovered a new CRISPR-Cas system that is able to cut RNA. This discovery, published in Science, opens doors for a new range of possibilities for genetic research and biotechnology.
Discovery of the Type III CRISPR-Cas
Type III CRISPR – Cas proteins use multi-protein complexes containing a single CRISPR RNA molecule to guide RNA recognition and cut single-stranded RNA. These are widespread among bacteria. The team at the Stan Brounus lab discovered a new type III CRISPR-Cas protein (type III – Effector) in Candidatus ‘Scaldinua brodae’. Due to its large size and repeated subunits, the team nicknamed the CRISPR protein gRAMP (Gaint Repeat Associated Mysterious Protein).
How CRISPR-Cas Defends the Bacterium
The CRISPR-Cas has several unique biological properties. For example, it consists of one large protein that cuts the RNA from an invading virus at two sites, destroying the RNA. If this is not effective in killing the virus, the CRISPR-Cas protein then initiates cell death of the bacterium. Effectively the bacterium commits suicide to stop the production of new virus particles. Therefore, halting the spread of the virus to the surrounding bacteria.
Much research is still needed to understand the workings of this newly discovered CRISPR-Cas system. Nevertheless, it is anticipated that these findings will have many practical applications in research. The researchers expect that this CRISPR protein will be used as ‘molecular precision’ scissors to cut RNA.
“We also see possibilities for converting the CRISPR protein into a kind of switch we can use to activate molecules, for example, a bioactive compound, at times when they are really needed,” senior author, Stan Brouns, said.
This novel CRISPR-Cas system has many future applications in genetic research and biotechnology. In the past CRISPR-Cas systems have been praised for revolutionising research. There is no doubt that this system could do the same.
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