Science: Kawaiilong team reveals mechanism of action of new CRISPR tool capable of cutting proteins

CRISPR-Cas gene editing technology has long been one of the most widely used technologies in the field of life sciences.

On August 26, 2022, Cornell University's Lovely Dragon Laboratory and Stan JJ Brouns Laboratory of Delft University of Technology, the Netherlands, published in the journal Science: Craspase is a CRISPR RNA-guided, RNA activated protease research paper

This paper reports that Craspase (a new system of CRISPR-coupled protease, CRISPR associated Caspase) is a gRNA-guided targeting and is activated by the targeting RNA.

In recent years, thanks to the explosive growth of the gene pool, more and more new systems related to CRISPR-Cas have been discovered

The CRISPR-associated protein of this system is named Cas7-11, which also has a nice name: gRAMP (Giant Repeat Associated Mysterious Protein)

The biggest highlight of this system is the protease TPR-CHAT near its CRISPR-Cas system.

With the aid of cryo-electron microscopy, Dr.

Figure 1: Schematic diagram of the structure of the giant wonder protein gRAMP

Next, Dr.

Figure 2: Craspase protease is activated by RNA-targeted mechanisms

Through atomic-resolution structural comparisons, the team found that, compared with the resting state, after targeting "non-matching" non-I-sequence RNAs, the protease activity catalyzed the doublet histidine-cysteine ​​distance from 6.

The last key question, what is the substrate for this protease? Through in vivo and in vitro screening, the team successfully screened the Craspase system protease substrate, named Csx30

Figure three

The CRISPR-Cas system first uses Cas1-Cas2 to ingest DNA fragments from bacteriophages and integrate them into their own CRISPR regions to form spacers

Regarding this issue, on August 18th and August 22nd, on the bioRxiv preprint website, Hiroshi Nishimasu of the University of Tokyo, Japan, and Jonathan S.

And a paper titled: Structural and functional insights into the type III-E CRISPR-Cas immunity by Prof.

The two studies observed consistent phenomena in the species Desulfonema ishimotonii and Candidatus "Scalindua brodae" (the same species used in this Science paper from the Kaililong lab), respectively
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After PFS non-matching RNA targeting, both activate the Caspase-like protease and cleave the protein substrate Csx30
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And both papers also clearly confirmed that Csx30 induces cell death after cleavage by Craspase
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In general, this Science paper from the Kawaii Long Lab comprehensively describes how the Craspase system is guided by guide RNA and is subject to the detailed mechanism of the protease activity activated by the targeted RNA.
After activation, the protein cleaves the protein substrate and induces Cells die, so this tool has the potential to serve as a new precision medicine tool in the future
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In addition, if more diversity in protease specificity evolves, it is expected to open a new chapter in protein-directed degradation
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Original source:

CHUNYI HU, et al.
Craspase is a CRISPR RNA-guided, RNA-activated protease.
SCIENCE, 25 Aug 2022.