Crossword clues for prion
Longman Dictionary of Contemporary English
The Collaborative International Dictionary
Prion \Pri"on\ (pr[=e]"[o^]n), n. any of several types of protein particle lacking nucleic acid, believed to be the cause of certain slow-developing infectious diseases such as scapie in sheep, and Creutzfeldt-Jakob disease and Kuru in humans. [informal]
Douglas Harper's Etymology Dictionary
petrel-like bird, 1848, from Greek prion "a saw," related to priein, prizein "to saw, to be cut in pieces." So called for its bill.
Wiktionary
Etymology 1 n. (context molecular biology English) A self-propagating misfolded conformer of a protein that is responsible for a number of diseases that affect the brain and other neural tissue. Etymology 2
n. A petrel of the genus ''Pachyptila''.
WordNet
n. (microbiology) an infectious protein particle similar to a virus but lacking nucleic acid; thought to be the agent responsible for scrapie and other degenerative diseases of the nervous system
Wikipedia
The prions (or whalebirds) are small petrels in the genera Pachyptila and Halobaena. They form one of the four groups within the Procellariidae (also referred to as the prions), along with the gadfly petrels, shearwaters and fulmarine petrels. The name comes from the Greek , meaning " saw", a reference of the serrated edges of the birds' saw-like bill.
They are found in the Southern Ocean and breed on a number of subantarctic islands. Prions grow long, and have blue-grey upper parts and white underparts. Three species of prion have flattened bills with a fringe of lamellae that act as strainers for zooplankton. All prions are marine and feed on small crustacea such as copepods, ostracods, decapods, and krill, as well as some fish such as myctophids and nototheniids.
A prion is an infectious agent composed entirely of protein material, called PrP (short for prion protein), that can fold in multiple, structurally distinct ways, at least one of which is transmissible to other prion proteins, leading to disease that is similar to viral infection. They are suspected to be the cause of transmissible spongiform encephalopathies (TSEs) among other diseases.
Prions were initially identified as the causative agent in animal TSEs such as bovine spongiform encephalopathy (BSE)—known popularly as "mad cow disease"—and scrapie in sheep. Human prion diseases include Creutzfeldt–Jakob disease (CJD) and its variant (vCJD), Gerstmann–Sträussler–Scheinker syndrome, fatal familial insomnia, and kuru. A 2015 study concluded that multiple system atrophy (MSA), a rare human neurodegenerative disease, is caused by a misfolded version of a protein called alpha-synuclein, and is therefore also classifiable as a prion disease. Several yeast proteins have been identified as having prionogenic properties as well.
A protein as a standalone infectious agent stands in contrast to all other known infectious agents such as viruses, bacteria, fungi, and parasites, all of which contain nucleic acids ( DNA, RNA, or both). For this reason, a minority of researchers still consider the prion/TSE hypothesis unproven. All known prion diseases in mammals affect the structure of the brain or other neural tissue; all are currently untreatable and universally fatal.
Prions may propagate by transmitting their misfolded protein state: When a prion enters a healthy organism, it induces existing, properly folded proteins to convert into the misfolded prion form. In this way, the prion acts as a template to guide the misfolding of more proteins into prion form. In yeast, this refolding is assisted by chaperone proteins such as Hsp104p. These refolded prions can then go on to convert more proteins themselves, leading to a chain reaction resulting in large amounts of the prion 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. Amyloid aggregates are fibrils, growing at their ends, and replicate when breakage causes two growing ends to become four growing ends. The incubation period of prion diseases is determined by the exponential growth rate associated with prion replication, which is a balance between the linear growth and the breakage of aggregates. The propagation of the prion depends on the presence of normally folded protein in which the prion can induce misfolding; animals that do not express the normal form of the prion protein can neither develop nor transmit the disease.
Prion aggregates are extremely stable and accumulate in infected tissue, causing tissue damage and cell death. This structural stability means that prions are resistant to denaturation by chemical and physical agents, making disposal and containment of these particles difficult. Prion structure varies slightly between species, but nonetheless prion replication is subject to occasional epimutation and natural selection just like other forms of replication.
Usage examples of "prion".
They hypothesized through the study of yeast that prions may hold the key to genetic mutations, even play a role in evolution.
After isolating the immortalizing traits from teratoma sources, I proposed that viral, retroviral, and even prion vectors might be engineered to transfer the selected traits into the human genome.
Prions were particulate and subviral in size, so since certain viruses could be airborne, why not certain Prions?
No one seems to know where these prions originally come from, but when they get into your system they wreak havoc.
We found entries about all kinds of human prion diseases-kuru, Creutzfeldt-Jakob disease, Gerstmann-Straussler syndrome-and the veterinary syndromes, scrapie and bovine spongiform encephalopathy, but it's all old, old stuff.
Mr Fortescue, though freely admitting the justice of Dr Maturin's observations in general, had indeed been more fortunate, particularly in respect of the great albatross, Diomedea exulans, to which the Doctor had so feelingly referred: he had been cast away on Tristan da Cunha, where he had lived with and upon albatrosses, thousands and thousands of albatrosses, to say nothing of the penguins, terns, skuas, prions, the indigenous gallinule and a hitherto nondescript finch.
A prion is a smallish protein molecule that can act as a catalyst for the formation of more protein molecules just like itself.
And there were others helping in the search, working ahead of him on the frontiers, and beside him in related fields, from the small—virology, where the inquiries into tiny forms such as prions and viroids were revealing even smaller forms, almost too partial to be called life: virids, viris, virs, vis, vs, all of which might have relevance to the larger problem.
And there were others helping in the search, working ahead of him on the frontiers, and beside him in related fields, from the small-virology, where the inquiries into tiny forms such as prions and viroids were revealing even smaller forms, almost too partial to be called life: virids, viris, virs, vis, vs, all of which might have relevance to the larger problem.
When a yeast cell divides, it copies its DNA to each half, but it shares the prions (which can be topped up by converting other proteins).
When a yeast cell divides, it copies its DNA to each half, but it shares the prions (which can be topped up by converting other pro.