Prof. Ailong Ke, molecular biology and genetics, together with the Brouns Lab at Felt University of Technology in the Netherlands, recently discovered a relationship between a family of proteases and CRISPR that could change our understanding of gene editing technology.
CRISPR is a genetic engineering tool that identifies and alters a specific segment of DNA. The most common type of CRISPR systems are RNA-directed nucleases, in which a “guide RNA” directs the associated nucleus to the desired segment of the genome for editing of the genome through base-pairing interactions.
Today, CRISPR is used in agriculture and even in mosquito genome editing to curb the spread of malaria. Although CRISPR is more commonly used in non-human organisms, there are clinical trials to test if CRISPR can fix genetic defects and mutations that cause diseases and diseases like cancer.
One of the most dangerous aspects of CRISPR is that it directly interferes with the gene sequence, permanently altering the organism’s genome. For example, errors in gene editing can result in chromosome deletions, typically leading to severe mental and physical disabilities.
These genetic changes could also cause unwanted mutations in heritable genes, which can then be passed on to future generations.
Although there is great potential for RNA-directed nuclease CRISPR systems, the low percentage of errors is still significant enough for researchers to caution against its use in humans. However, Ke and Brouns’ recent discovery of “Craspase,” a CRISPR-driven caspase mediator between protease-caspase and CRISPR, is less risky.
Caspases are able to trigger cells to undergo programmed cell death and safely remove them. Craspase is a system that uses CRISPR RNA-directed RNA-activated protease to edit proteins instead of using RNA guide nucleases to edit the genome bases directly.
These proteases were once thought to be eukaryote-specific, but this has now been disproved by Ke and co-workers when they found that bacteria – a type of prokaryote – also have these caspase proteases, which mediate cell-programmed death, indicative of their primitive nature nature indicates.
Ke explained that there is a lot of anticipation for Craspase because it will not edit and cleave base pairs directly on the genome, but rather will cleave the proteins made by the nucleotides.
Ke said that mistakes made when breaking down proteins with “Craspase” have minimal effects on the organism. He also added that CRISPR is inherently more dangerous because it uses enzymes that cleave the building blocks of RNA and DNA, permanently altering genetic information.
“That’s why people get really excited when they see RNA-driven proteases, because we’re cleaving proteins,” Ke said. “If we make a mistake, it doesn’t matter. This allows us to achieve the same therapeutic result in many cases without having to worry about passing errors on to the next generation.”
The ability to cleave proteins rather than directly edit the genome has many implications for the future of gene therapy. This is a safer alternative that allows for more diverse uses of the tool.
This tool can also be programmed to trigger the cell death pathway, slow down the growth of a pathway, or turn on a pathway. Ke and his team were able to analyze macromolecules at atomic resolution, allowing for precise analysis and a deeper understanding of how these proteases work.
Although CRISPR is still in clinical testing and Craspase has yet to be used in healthcare settings, Ke is hopeful about the direction the gene-editing technology is taking. He hopes that one day Craspase can be used in medical procedures.
“I think biology is entering a new era,” Ke said. “So I think that with these powerful tools, we will be able to develop therapeutics and new strategies against disease, aging and other outstanding problems.” With more powerful solutions, we can reach our goals faster.”