Prions are unique elements in biology, being able to transmit biological information from one organism to another in the absence of nucleic acids. They have been identified as self-replicating proteinaceous agents responsible for the onset of rare and fatal neurodegenerative disorders-known as transmissible spongiform encephalopathies, or prion diseases-which affect humans and other animal spec...

While prions probably interact with the innate immune system immediately following infection, little is known about this initial confrontation. Here we investigated incunabular events in lymphotropic and intranodal prion trafficking by following highly enriched, fluorescent prions from infection sites to draining lymph nodes. We detected biphasic lymphotropic transport of prions from the initia...

Most yeast prions (infectious proteins) are amyloids, linear β-sheet-rich polymers of a single protein with the β-strands perpendicular to the long axis of the filament. A single prion protein can form any of many different prion variants, differing in structure and biological properties, but with the same amino acid sequence. The folded in-register parallel β-sheet architecture we have shown f...

Although disease-causing prions are an extreme pathogenic aberration in protein behavior, emerging evidence places them at the end of a broad spectrum of ordered protein aggregates with diverse biological roles. This Select highlights recent findings on prions, including mutations that push proteins with prion-like domains over the threshold to pathogenicity in degenerative disorders, a vertebr...

By biological and medical criteria, prions are infectious agents; however, many of their properties differ profoundly from those of conventional microbes. Prions are "encoded" by alterations in protein conformation rather than in nucleic acid or amino acid sequence. New epidemic prion diseases (bovine spongiform encephalopathy and new variant Creutzfeldt-Jakob disease) have recently emerged und...

Prion diseases in humans and animals are due to conformational conversion of PrP(C), a cellular glycoprotein of unknown function, into PrP(Sc), an isoform that appears to be infectious in the absence of nucleic acids. Proteins that behave as prions are also found in yeast and filamentous fungi. Although there is now strong experimental support for the hypothesis that prions are infectious prote...

The epizootic prion disease of cattle, bovine spongiform encephalopathy (BSE), causes variant Creutzfeldt-Jakob disease (vCJD) in humans following dietary exposure. While it is assumed that all cases of vCJD attributed to a dietary aetiology are related to cattle BSE, sheep and goats are susceptible to experimental oral challenge with cattle BSE prions and farmed animals in the UK were undoubte...

While prions are protein-based infectious agents, yeast prions are protein-based genetic elements of the baker’s yeast Saccharomyces cerevisiae [1]. Most yeast prions are amyloid protein aggregates that spread during mitosis through the cytosolic transmission of small, self-templating pieces called propagons. Propagons continue to recruit free protein monomers, perpetuating the prion phenotype ...

The prion hypothesis postulates that the infectious agent in transmissible spongiform encephalopathies (TSEs) is an unorthodox protein conformation based agent. Recent successes in generating mammalian prions in vitro with bacterially expressed recombinant prion protein provide strong support for the hypothesis. However, whether the pathogenic properties of synthetically generated prion (rec-Pr...

Chronic wasting disease (CWD) affects cervids and is the only known prion disease to affect free-ranging wildlife populations. CWD spread continues unabated, and exact mechanisms of its seemingly facile spread among deer and elk across landscapes in North America remain elusive. Here we confirm that naturally contaminated soil contains infectious CWD prions that can be transmitted to susceptibl...