When it comes to gene editing technology, CRISPR is typically the first thing that comes to mind, specifically CRISPR-Cas9. Yet most people don’t know that there’s more to CRISPR than just CRISPR-Cas9.
CRISPR is the part of the genome editing tool that dictates where DNA editing will be made. Cas9 is the protein that does the actual cutting. Which means there are always two parts to this tool.
CRISPR-Cas9 is the most widely used because Cas9 has always been the most preferred snipping protein. But that’s about to change with the discovery that another kind of protein might be better than Cas9.
In a paper recently published in the journal Science Advances, a group of scientists at the University of Texas Southwestern Medical Center describe how they were able to successfully use the protein to correct mutations associated with a condition known as Duchenne muscular dystrophy — a progressive disease that affects the muscle used for movement as well as the heart muscle, and typically results in fatal heart failure before the patient reaches the age of 30.
The protein is known as Cpf1. It’s much smaller than Cas9, which is what makes it easier to be put inside a virus, this in turn makes it easier to deliver to target cells. Additionally, Cpf1 recognizes a different DNA sequence than Cas9, which makes it more flexible.
Duchenne muscular dystrophy is caused by a mutation or an error that happens in one of the longest genes of the body, the dystrophin gene. If the dystrophin gene is flawed, the body can’t make the protein dystrophin, depriving the body of what functions as a kind of muscle fiber protector.
When the team used CRISPR-Cpf1 in mice models afflicted with Duchenne muscular dystrophy, symptoms like inflammation were successfully reversed. And when they used it in human heart muscle cells, they were able to fix key mutations, thereby preventing the disease from progressing.
Because of the length of the dystrophin gene, there are a number of spots where a mutation (or mutations) can occur, which makes the possibility of providing gene-editing treatment more flexible but crucial too. This is where CRISPR-Cpf1 can do better than CRISPR-Cas9. Cpf1 can pretty much get into cells that Cas9 cannot access.
As study co-author Dr. Rhonda Bassel-Duby explained in a statement they issued: “By either skipping a mutation region or precisely repairing a mutation in the gene, CRISPR-Cpf1-mediated genome editing not only corrects Duchenne muscular dystrophy mutations but also improves muscle contractility and strength.”
The results of the study have now opened the floodgates for further research on CRISPR-Cpf1 and which diseases and conditions it can best be used for.