Skip to main content
Move the World.
crispr gene editing

Lead image © phonlamaiphoto / Adobe Stock

Move over CRISPR Cas9, here comes CasΦ, a small but mighty new gene editing protein. 

The discovery of CRISPR Cas9, the most widely used CRISPR gene editing system, made huge waves in medicine and biotech over the last decade. It's hard to imagine anything surpassing it, but CasΦ (pronounced "Cas-phi") could be another game-changer.

The CRISPR gene editing proteins, or Cas proteins, are DNA "scissors" naturally found in bacteria and archaea. Their biological role is to fight off viruses by destroying their DNA and cutting it out of their genomes. Researchers redirected that function toward clipping disease-causing mutations out of DNA for gene therapy and other kinds of genetic engineering.

Its trim proportions enable it to reach areas of the human genome that most CRISPR gene editing proteins cannot.

There are a handful of other CRISPR Cas systems, but the large size of their proteins makes them all too cumbersome to access the smallest nooks and crannies of the human genome.

Until now, anyway. Jennifer Doudna, one of the original discoverers of CRISPR, and her team at the University of California Berkeley have found a new Cas protein in a bacteriophage, a type of virus that infects bacteria.

The new protein, CasΦ, which they described in the journal Science, uses CRISPR to do the opposite of what it normally does, attacking bacteria by inserting genetic material into their genomes. It is about half the size of Cas9, but don't be fooled by its small size. Its trim proportions enable it to reach areas of the human genome that most CRISPR gene editing proteins cannot.

So far, accessing the DNA in living cells has been the most significant barrier for using the CRISPR gene editing system. To solve this problem, scientists package CRISPR's Cas protein and guide RNA into a virus, which will carry it to cells and then to the targeted regions of DNA for editing. But it's not a foolproof solution. Sometimes the virus is too small to carry the bulky Cas, and the system doesn't work.

"When we think about how CRISPR will be applied in the future, that is really one of the most important bottlenecks to the field right now: delivery," Doudna told Genetic Engineering News.

Enter the stealthy CasΦ. The travel-sized protein can more readily sneak past roadblocks that Cas proteins are too large to penetrate.

"You can only pack a really small Cas9 into such a virus to deliver it. If you would have other CRISPR-Cas systems that are really compact, compared to Cas9, that gives you enough space for additional elements: different proteins fused to the Cas protein, DNA repair templates or other factors that regulate the Cas protein and control the gene editing outcome," said Berkeley geneticist Patrick Pausch.

Earlier this month, researchers edited human mitochondrial DNA for the first time. Once again, researchers are finding ways to build on CRISPR gene editing technology and reach new areas of the human genome that CRISPR Cas9 was never able to.

If CRISPR reigns as the Swiss Army knife of genetic engineering, then CasΦ adds another functional tool, opening up new opportunities for researching and treating genetic disorders.

Up Next

Dispatches
CRISPR Edits Out Autistic Traits in Mice
CRISPR Edits Out Autistic Traits in Mice
Dispatches
CRISPR Edits Out Autistic Traits in Mice
The technique could also open up treatments for Huntington's, schizophrenia, and epilepsy.

The technique could also open up treatments for Huntington's, schizophrenia, and epilepsy.

Dispatches
Are "CRISPR Kids" the New "Test-Tube Babies"?
Are
Dispatches
Are "CRISPR Kids" the New "Test-Tube Babies"?
Forty years later, IVF shows how fears about new technology can fade.
By Patricia Stapleton

Forty years later, IVF shows how fears about new technology can fade.

Genetics
Gene Writing: A New Type of Genetic Engineering
Gene Writing
Genetics
Gene Writing: A New Type of Genetic Engineering
Startup Tessera Therapeutics has developed gene writing, a new approach to genetic engineering that it says overcomes CRISPR’s shortcomings.

Startup Tessera Therapeutics has developed gene writing, a new approach to genetic engineering that it says overcomes CRISPR’s shortcomings.

CRISPR
Scientists Use CRISPR to Reverse Diabetes in Mice
reverse diabetes
CRISPR
Scientists Use CRISPR to Reverse Diabetes in Mice
Scientists have used CRISPR to correct a diabetes-causing mutation in stem cells and then use those cells to reverse diabetes in mice.

Scientists have used CRISPR to correct a diabetes-causing mutation in stem cells and then use those cells to reverse diabetes in mice.

Opinion
A Molecular Biologist Discusses the Morality of Genetic Engineering
A Molecular Biologist Discusses the Morality of Gene Editing
Opinion
A Molecular Biologist Discusses the Morality of Genetic Engineering
Molecular biologist Daisy Robinton speaks out on our moral imperative to solve some of humanity's greatest health threats.
By Daisy Robinton, Ph.D.

Molecular biologist Daisy Robinton speaks out on our moral imperative to solve some of humanity's greatest health threats.

Genetics
Gene Editing Corrects Deafness-Causing Mutation in Mice
Gene Editing
Genetics
Gene Editing Corrects Deafness-Causing Mutation in Mice
Using a promising new technique for gene editing — base editing — researchers corrected a deafness-causing genetic mutation in mice.

Using a promising new technique for gene editing — base editing — researchers corrected a deafness-causing genetic mutation in mice.

Microbiology
The First (and Only) Creature Known to Eat Viruses
protists
Microbiology
The First (and Only) Creature Known to Eat Viruses
Despite their abundance, nothing we know of eats viruses. But new research suggests microbes called protists might.

Despite their abundance, nothing we know of eats viruses. But new research suggests microbes called protists might.

Climate Change
Sending Heat to Space to Reverse Global Warming
radiative cooling
Climate Change
Sending Heat to Space to Reverse Global Warming
This high-tech material could reverse global warming by using radiative cooling to lower the Earth’s rising temperature.

This high-tech material could reverse global warming by using radiative cooling to lower the Earth’s rising temperature.

Superhuman
Hunting Down His Son’s Killer
Hunting Down His Son’s Killer
Watch Now
Superhuman
Hunting Down His Son’s Killer
For years, there was no diagnosis, no treatment, and no cure — because his son's disease had never been seen before. That wasn't going to stop this dad.
Watch Now

What do you do when there are no experts to turn to? For computer scientist Matt Might, the answer was obvious: you become the expert. When doctors couldn't figure out his son's disease, he found a way to crack the code. Matt's son, Bertrand, suffers from an extremely rare genetic disease, called NGLY1 deficiency, which causes chronic seizures, liver problems, and developmental delays. In fact, it was so rare that Bertrand...