"Genome editing," which allows rewriting of the genetic information of life, is used in life science research around the world. The fact that the developers of one such genome editing technology, CRISPR-Cas9, won the 2020 Nobel Prize in Chemistry is still fresh in the mind.
However, CRISPR-Cas9 is by no means a perfected technology. Especially when it comes to curing intractable genetic disorders such as muscular dystrophy, there is much work to be done. For example, the aforementioned CRISPR-Cas9 has poor efficacy for genetic modification of the non-dividing cells of the muscles. Also, the gene which codes Cas9, plays the role of "scissors" in cutting genes and is relatively large in size. For that reason, there is difficulty in inserting the Cas9 gene into "viral vectors," transportation devices which carry editing tools to cells in the body.
Makoto Saito of the Broad Institute of MIT and Harvard, as a post-doc researcher at the lab of Feng Zhang who is the leading figure in CRISPR-Cas9, aims to make genome editing applicable to the cure of all genetic disorders.
In order to search for a protein that resembles Cas9, Saito does not use the lead of DNA sequencing, which is the conventional method, but uses the protein structure prediction AI "AlphaFold2." He has effectively identified several novel systems by leveraging the similarity in protein three-dimensional structures. Utilizing the discovered CAST system, he is also developing tools that insert genes using different principles from CRISPR-Cas9, which cuts DNA. Additionally, he discovered the protein Fanzor, which has half the genetic size of Cas9, contributing to the resolution of the size issue of insertion into the viral vector.
He aims to increase the efficiency of CAST and is attempting to clear the path to curing hereditary diseases. Saito is further continuing with his search for biological systems which may have practical applications to medicine. "I believe that I can provide people with useful bioengineering tools that go beyond genome editing." (Saito)