The new CasX: All You Need to Know About this CRISPR-Associated Protein
A new foundation for gene editing
The Process
When changing a lightbulb, it is a known two-step process. You remove the dead light bulb and replace it with a new one. This concept is universally used with all defective objects: batteries, car tires, or any broken items. Scientists are applying this concept to genetics, but with a couple of steps in between.
To fight off sickness, the human immune system defends your body from invading bacteria and viruses that will cause harm. CRISPR-associated proteins (Cas) are proteins that edit genes. They work in a similar way to viruses; they “remember” infecting viruses and prevent future entry into the cell.
Specifically, Cas defends the cell by cutting DNA strands of the infecting organism and storing its complementary strand. This process of “remembering” infecting viruses is known as acquired immunity, which is more commonly recognized in vaccinations. Although vaccines have prevented millions of deaths, certain viruses can not be cured by them. With the use of Cas, scientists may be able to cure the viruses that vaccines fail to cure. These unique features of Cas allow for it to be an incredibly useful tool for scientists to use regarding genome editing.
The New Discovery
Seven years ago, Cas9 was founded in the Doudna Lab in California. Cas9 is a tool that allows us to modify the genome. With Cas9, you can go into a human genome, find a defective strand of DNA, and change it. That sounds ideal, but the most recent discovery calls for different obstacles that we can now overcome that initially presented themselves to be impossible to surpass. In February 2019, researchers at UC Berkeley discovered a probable game changer in genome editing called CasX. As mysterious as it may sound,
CasX is “a novel molecule that allows us to modify the genome in ways that were not possible,”
said Benjamin Oakes, current Entrepreneurial Fellow at the Innovative Genomics Institute, and former UC Berkeley graduate student. “We can build genome editing tools off of [CasX]” and create hope for cures to genetic diseases.
CasX and its Capabilities
The most useful characteristic of CasX is its size. “It being smaller opens up a lot of doors” to being able to successfully help genetic diseases. For example, if you had Breast Cancer, a genetic disease, CasX could potentially be used to defeat cancer. The way in which it would work differently from other treatments is that since it is a small protein, it can be inserted into carriers that do not have a lot of space. These carriers can then be inserted into you, the patient, and CasX can go in and make changes to your genome which remove the tumor. Due to a few limitations, this has not been done yet, but “we’re just expanding the toolbox to encompass more possibilities,” says Oakes. And at the pace of current scientific research, discoveries like these are coming soon.
What does this all mean?
“This means that all of a sudden the possibility opens up to putting a CasX into a [carrier] and delivering that to treat genetic disease”
This discovery as a whole “provide[s] another foundation” and opens up the possibilities for different genetic diseases to be cured. Currently, through discoveries such as these, labs have begun work on hemophilia. To put this into perspective, “the first wave of gene therapies have been successful and are starting to ramp up” which means that the future in gene editing is bright. Honestly, you better jump on the Cas train now before it leaves you behind.
Reference: JJ Liu et al., Nature, 2019
This story is part of advances in biological sciences, a science communication platform that aims to explain ground-breaking science in the field of biology, medicine, biotechnology, neuroscience and genetics to literally everyone. Scientific understanding has too many barriers, let’s break them down!
