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
Wikipedia.
This text uses material from Wikipedia and is available under the GNU Free Documentation License.
News tagged with prion
Tracking Down the Cause of Mad Cow Disease
Oct 07, 2008 |
4.6 / 5 (10) |
1
(PhysOrg.com) -- The cause of diseases such as BSE in cattle and Creutzfeld–Jakob disease in humans is a prion protein. This protein attaches to cell membranes by way of an anchor made of sugar and lipid components ...
Is there more to prion protein than mad cow disease?
Sep 30, 2008 |
4.4 / 5 (9) |
0
Prion protein, a form of protein that triggers BSE, is associated with other brain diseases in cattle, raising the possibility of a significant increase in the range of prion disease. Publishing their findings in the open ...
Study points to disruption of copper regulation as key to prion diseases
Apr 17, 2009 |
4.8 / 5 (8) |
1
(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.
Newresearch shows mad cow disease also caused by genetic mutation
Sep 12, 2008 |
4.8 / 5 (5) |
0
New findings about the causes of mad cow disease show that sometimes it may be genetic. "We now know it's also in the genes of cattle," said Juergen A. Richt, Regents Distinguished Professor of Diagnostic Medicine and Pathobiology ...
Scientists devise accelerated method to determine infectious prion strains
May 29, 2009 |
4.4 / 5 (5) |
1
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 ...
A penny for your prions: Researchers study link between copper, mad cow disease
Jun 25, 2009 |
4.8 / 5 (4) |
0
(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 ...
Antibody key to treating variant CJD, scientists find
Mar 04, 2009 |
5 / 5 (3) |
0
Scientists at the University of Liverpool have determined the atomic structure of the 'binding' between a brain protein and an antibody that could be key to treating patients with diseases such as variant CJD.
Prions serve as important source of variation in nature
Apr 02, 2009 |
4.7 / 5 (3) |
0
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 |
4.7 / 5 (3) |
1
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, ...
What drove the cow mad? Lessons from a tiny fish
Mar 10, 2009 |
4.3 / 5 (3) |
0
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 ...
Researchers find new piece in Alzheimer's puzzle
Feb 25, 2009 |
5 / 5 (2) |
2
Yale researchers have filled in a missing gap on the molecular road map of Alzheimer's disease. In the Feb. 26 issue of the journal Nature, the Yale team reports that cellular prion proteins trigger the process by which ...
Prion switching in response to environmental stress
Biology /
Nov 25, 2008 |
5 / 5 (2) |
2
If you have had a hard day at work, you may change your eating habits, perhaps favoring comfort food, but you don't suddenly develop the ability to eat the plate and cutlery. A new paper, published in this week's issue of ...
Protective pathway in stressed cells not so helpful when it comes to prions
Sep 15, 2008 |
5 / 5 (2) |
0
Scientists at the National Institutes of Health (NIH) have discovered that an important cellular quality control mechanism may actually be toxic to some brain cells during prion infection. The research, published by Cell ...
First direct information about the prion's molecular structure reported
Oct 05, 2009 |
4.5 / 5 (2) |
0
(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. ...
Family's inherited condition links prion diseases, Alzheimer's
Medicine & Health / Neuroscience
Dec 09, 2009 |
4.5 / 5 (2) |
0
(PhysOrg.com) -- A laboratory connection between Alzheimer's disease and brain-wasting diseases such as the human form of mad cow disease has moved into the clinic for what is believed to be the first time, manifesting itself ...
