Prion

A Prion is a protein that can misfold and induce normal proteins of the same type to also misfold, leading to cellular death and neurodegenerative disease.

• AKA: Proteinaceous Infectious Particle, PrPSc.
• Context:
  • It can typically convert Normal Prion Protein into misfolded prion proteins through protein conformation change.
  • It can typically induce Protein Misfolding without requiring nucleic acids as genetic material.
  • It can typically form Prion Aggregates that disrupt cellular functions and cause neuronal damage.
  • It can typically resist Protease Enzymes that would normally break down protein structures.
  • It can typically transmit Prion Diseases through infectious pathways despite lacking conventional pathogen components.
  • ...
  • It can often accumulate in Brain Tissue forming amyloid deposits and creating spongiform lesions.
  • It can often propagate through Self-Replication Processes using template-directed misfolding mechanisms.
  • It can often persist in Environmental Conditions that would inactivate conventional pathogens.
  • It can often cross Species Barriers causing zoonotic prion diseases through interspecies transmission.
  • ...
  • It can range from being a Sporadic Prion to being an Acquired Prion, depending on its origin mechanism.
  • It can range from being a Simple Prion Structure to being a Complex Prion Structure, depending on its protein configuration.
  • It can range from being a Pathogenic Prion to being a Functional Prion, depending on its biological role.
  • ...
  • It can have Prion Strain Variations through conformational differences despite identical amino acid sequences.
  • It can have Long Incubation Periods before causing clinical symptoms in prion disease.
  • It can have Extreme Resistance Propertys against standard sterilization procedures and decontamination methods.
  • ...
• Examples:
  • Prion Types, such as:
    • Human Prions, such as:
      • Creutzfeldt-Jakob Disease Prion that causes sporadic prion disease.
      • Variant Creutzfeldt-Jakob Disease Prion that causes acquired prion disease.
      • Gerstmann-Sträussler-Scheinker Syndrome Prion that causes genetic prion disease.
      • Fatal Familial Insomnia Prion that causes inherited prion disease.
      • Kuru Prion that causes ritualistic transmission prion disease.
    • Animal Prions, such as:
      • Bovine Spongiform Encephalopathy Prion that causes mad cow disease.
      • Scrapie Prion that affects sheep prion disease.
      • Chronic Wasting Disease Prion that affects deer prion disease.
      • Transmissible Mink Encephalopathy Prion that affects mink prion disease.
    • Functional Prions, such as:
      • HET-s Prion that regulates fungal heterokaryon incompatibility.
      • CPEB Prion-like Protein that regulates synaptic protein synthesis.
  • Prion Formation Mechanisms, such as:
    • Spontaneous Prion Formation through random misfolding events.
    • Genetic Prion Formation through prion protein gene mutations.
    • Infectious Prion Formation through exogenous prion exposure.
  • ...
• Counter-Examples:
  • Conventional Pathogens, which contain genetic material unlike prions.
  • Normal Protein Conformers, which maintain stable protein structures rather than inducing protein misfolding.
  • Non-Transmissible Protein Aggregates, which form protein deposits but lack infectious capability.
  • Viral Particles, which require nucleic acid replication rather than protein conformation change.
• See: Transmissible Spongiform Encephalopathy, Protein Misfolding, Amyloid, Neurodegenerative Disease, Major Prion Protein, Proteinopathy, Cellular Death, Protein Tertiary Structure, Stanley Prusiner.

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References

2025

• (Wikipedia, 2025) ⇒ https://en.wikipedia.org/wiki/Prion Retrieved:2025-3-21.
  • A prion () is a misfolded protein that induces misfolding in normal variants of the same protein, leading to cellular death. Prions are responsible for prion diseases, known as transmissible spongiform encephalopathy (TSEs), which are fatal and transmissible neurodegenerative diseases affecting both humans and animals. These proteins can misfold sporadically, due to genetic mutations, or by exposure to an already misfolded protein, leading to an abnormal three-dimensional structure that can propagate misfolding in other proteins. The term prion comes from "proteinaceous infectious particle". Unlike other infectious agents such as viruses, bacteria, and fungi, prions do not contain nucleic acids (DNA or RNA). Prions are mainly twisted isoforms of the major prion protein (PrP), a naturally occurring protein with an uncertain function. They are the hypothesized cause of various TSEs, including scrapie in sheep, chronic wasting disease (CWD) in deer, bovine spongiform encephalopathy (BSE) in cattle (mad cow disease), and Creutzfeldt–Jakob disease (CJD) in humans. All known prion diseases in mammals affect the structure of the brain or other neural tissues. These diseases are progressive, have no known effective treatment, and are invariably fatal. Most prion diseases were thought to be caused by PrP until 2015 when a prion form of alpha-synuclein was linked to multiple system atrophy (MSA). Prions are also linked to other neurodegenerative diseases like Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis (ALS), which are sometimes referred to as prion-like diseases. Prions are a type of intrinsically disordered protein that continuously changes conformation unless bound to a specific partner, such as another protein. Once a prion binds to another in the same conformation, it stabilizes and can form a fibril, leading to abnormal protein aggregates called amyloids. These amyloids accumulate in infected tissue, causing damage and cell death. The structural stability of prions makes them resistant to denaturation by chemical or physical agents, complicating disposal and containment, and raising concerns about iatrogenic spread through medical instruments.

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