Prions - What happens when your proteins turn on you?

10-10-2025

Proteins are a diverse type of macromolecule that serve as catalysts, allow cell signaling, help us fight infection, and more. They are essential to our bodies. The shape of a protein determines its function, but what happens when a protein folds incorrectly, inhibiting it from doing its job correctly?

What are prions?

Prions mainly refer to misfolded PRP proteins. PRP is produced in most organisms and is found in most cells. When PRP folds incorrectly, it is called PRPsc, or a prion, which can then “infect” other PRP molecules, causing them to fold incorrectly as well. These misfolded proteins can cause buildup of aggregates in cells and their rough endoplasmic reticulum. This buildup is extremely hard to remove and eventually leads to apoptosis. This cell death leads to Transmissible Spongiform Encepalopathies (TSEs), or Prion Diseases. These diseases include Creutzfeldt-jakob disease (CJD), Fatal Familial Insomnia, and Kuru Disease. TSEs affect brain tissue, causing tiny holes to form in the tissue, giving it a sponge-like texture. These diseases are all caused by PRP, but they manifest in different ways. Fatal Familial Insomnia results in increasingly worse insomnia over time, while CJD can present as early onset dementia. This difference in symptoms is likely caused by the location of the structural change of PRP along with the location of aggregate build up in the body. However, when any prion disease occurs, there is nothing the human immune system can do to fight it, which is what makes it so dangerous. 

What do we know about prions?

I find prion diseases so interesting because of how little we know about them. We don't know what the structure of  a prion looks like despite improved imaging. This is partly why we  have such a hard time developing a treatment for prion diseases. We don’t know what causes the PRP protein to mutate, but once it does, nothing can be done to stop progression of the disease. We also don’t know what PRP’s regular function is. This raises the question of whether PRP is even a necessary protein in humans. However, if PRP were unnecessary, if it had no function except to mutate into prions and kill us, why would it remain in our genome through time? Even so, experiments show that PRP may not be necessary to humans. This mystery surrounding these proteins has drawn me in and consumed my thoughts for the past week. 

What does this mean for us in the future?

Prion diseases are rare, but studying them is important to understanding the human body. There is so much we do not know about prions. Studying them can allow us to deepen our understanding of what happens when our bodies turn on themselves, thus potentially enabling us to deepen our understanding of our genome and why we have preserved PRP through time. Currently, there is much research being conducted on potential treatments for prion diseases. One trial attempted to treat prions with a drug called quinacrine. The drug decreased the amount of prions in mice at first, until the prions developed resistance to the quinacrine. Other trials investigate the implementation of anti-prions, which form aggregates as well. However, the body can handle these aggregates better than prion aggregates, stopping the body from showing symptoms of prion disease. Other trials are researching the possibility of removing PRP from the body altogether. 

Since this phenomenon is so new, very little is known about the diseases and ways to prevent them. This sense of novelty can cause many to look down on the scientific community. However, science is not a subject of instant gratification. The fact that it takes time to research and develop new concepts, technologies, and solutions is what makes it so rewarding. As we find out more about the disease and work towards a treatment, cure, or preventative measure, I believe that prions have the potential to underscore the importance and beauty of scientific research, inquiry, and developments.