Prion
hideA prion (pronounced /ˈpriː.ɒn/ ( listen)) is an infectious agent that is composed of protein. To date, all such agents that have been discovered propagate by transmitting a mis-folded protein state; the protein does not itself self-replicate and the process is dependent on the presence of the polypeptide in the host organism. The mis-folded form of the prion protein has been implicated in a number of diseases in a variety of mammals, including bovine spongiform encephalopathy (BSE, also known as "mad cow disease") in cattle and Creutzfeldt-Jakob disease (CJD) in humans. All known prion diseases affect the structure of the brain or other neural tissue, and all are currently untreatable and are always fatal. In general usage, prion refers to the theoretical unit of infection. In scientific notation, PrPC refers to the endogenous form of prion protein (PrP), which is found in a multitude of tissues, while PrPSC refers to the misfolded form of PrP, that is responsible for the formation of amyloid plaques that lead to neurodegeneration.
Prions are hypothesized to infect and propagate by refolding abnormally into a structure which is able to convert normal molecules of the protein into the abnormally structured form. All known prions induce the formation of an amyloid fold, in which the protein polymerises into an aggregate consisting of tightly packed beta sheets. This altered structure is extremely stable and accumulates in infected tissue, causing tissue damage and cell death. This stability means that prions are resistant to denaturation by chemical and physical agents, making disposal and containment of these particles difficult.
Proteins showing prion-type behavior are also found in some fungi and this has been important in helping to understand mammalian prions. However, fungal prions do not appear to cause disease in their hosts and may even confer an evolutionary advantage through a form of protein-based inheritance.
The word prion is a compound word derived from the initial letters of the words proteinaceous and infectious, with -on added by analogy to the word virion.
For more information about Prion, read the full article at
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News tagged with prion
Researchers find new piece of BSE puzzle
Nov 20, 2009 |
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A new treatment route for bovine spongiform encephalopathy (BSE) and its human form Creutzfeldt Jakob disease (CJD) could be a step closer based on new results from scientists at the University of Leeds. The team has found ...
The protein Srebp2 drives cholesterol formation in prion-infected neuronal cells
Nov 18, 2009 |
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Prions are causing fatal and infectious diseases of the nervous system, such as the mad cow disease (BSE), scrapie in sheep or Creutzfeldt-Jakob disease in humans. Scientists of Helmholtz Zentrum München and Technische Universität ...
First direct information about the prion's molecular structure reported
Oct 05, 2009 |
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(PhysOrg.com) -- A collaboration between scientists at Vanderbilt University and the University of California, San Francisco has led to the first direct information about the molecular structure of prions. ...
Scientists uncover evolutionary origins of prion disease gene
Sep 28, 2009 |
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A University of Toronto-led team has uncovered the evolutionary ancestry of the prion gene, which may reveal new understandings of how the prion protein causes diseases such as bovine spongiform encephalopathy (BSE), also ...
Gene mutation alone causes transmissible prion disease
Medicine & Health / Neuroscience
Aug 26, 2009 |
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For the first time, Whitehead Institute researchers have shown definitively that mutations associated with prion diseases are sufficient to cause a transmissible neurodegenerative disease.
Impaired transport in neurons triggers prion disease
Aug 21, 2009 |
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A new study shows that nervous system integrity and axonal properties may play a key role in prion diseases. The findings, from researchers at the Rudolf Virchow Center and the Institute of Virology of the University of Würzburg, ...
Prion protein identified as a novel early pancreatic cancer biomarker
Aug 17, 2009 |
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Mad cow disease is caused by the accumulation of an abnormal protein, the prion, in the brain of an affected patient. Outside of the brain, very little is known about prions. Case Western Reserve University School of Medicine, ...
Species barrier may protect macaques from chronic wasting disease
Jul 30, 2009 |
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Data from an ongoing multi-year study suggest that people who consume deer and elk with chronic wasting disease (CWD) may be protected from infection by an inability of the CWD infectious agent to spread to people. The results ...
A penny for your prions: Researchers study link between copper, mad cow disease
Jun 25, 2009 |
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(PhysOrg.com) -- North Carolina State University researchers have discovered a link between copper and the normal functioning of prion proteins, which are associated with transmissible spongiform encephalopathy ...
Scientists devise accelerated method to determine infectious prion strains
May 29, 2009 |
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Current tests to identify specific strains of infectious prions, which cause a range of transmissible diseases (such as mad cow) in animals and humans, can take anywhere from six months to a year to yield results - a time-lag ...
Study points to disruption of copper regulation as key to prion diseases
Apr 17, 2009 |
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(PhysOrg.com) -- An investigation of a rare, inherited form of Creutzfeldt-Jakob disease suggests that disrupted regulation of copper ions in the brain may be a key factor in this and other prion diseases.
Prions serve as important source of variation in nature
Apr 02, 2009 |
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Special proteins known as prions, which are perhaps best known as the agents of mad cow and other neurodegenerative diseases, can also serve as an important source of beneficial variation in nature, confirms a new study in ...
Prion discovery gives clue to control of mass gene expression
Mar 13, 2009 |
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The discovery in common brewer's yeast of a new, infectious, misfolded protein -- or prion -- by University of Illinois at Chicago molecular biologists raises new questions about the roles played by these curious molecules, ...
Iron is involved in prion disease-associated neuronal demise
Mar 13, 2009 |
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Imbalance of iron homeostasis is a common feature of prion disease-affected human, mouse, and hamster brains, according to a new study by Dr. Neena Singh and colleagues at Case Western Reserve University School of Medicine, ...
What drove the cow mad? Lessons from a tiny fish
Mar 10, 2009 |
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For over twenty years, scientists have known that a normal protein in the brain, PrP, or prion protein, can turn harmful and cause deadly illnesses like Creutzfeldt-Jakob disease (CJD) in humans, and bovine spongiform encephalopathy ...
