Prion-Prion Interactions

Derkatch, Irina L.; Liebman, Susan W.

doi:10.4161/pri.1.3.4837

Cited by 44 publications

(53 citation statements)

References 109 publications

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“…44 and references therein), which is also supported by our findings that (i) [PIN + ] can function in a heterologous cellular environment lacking other yeast factors, and (ii) New1-CFP and NM-YFP aggregates appear to colocalize before the formation of twisted ribbons consisting of NM-YFP but no detectable New1-CFP. In addition to providing a heterologous system in which to study prion biology, the demonstration that the E. coli cytoplasm can support the formation of infectious amyloid raises the possibility that endogenous bacterial proteins exist that might take advantage of this capacity to function as epigenetic switches.…”

Section: Discussionsupporting

confidence: 84%

Conversion of a yeast prion protein to an infectious form in bacteria

Garrity

Sivanathan

Dong

et al. 2010

Proc. Natl. Acad. Sci. U.S.A.

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Prions are infectious, self-propagating protein aggregates that have been identified in evolutionarily divergent members of the eukaryotic domain of life. Nevertheless, it is not yet known whether prokaryotes can support the formation of prion aggregates. Here we demonstrate that the yeast prion protein Sup35 can access an infectious conformation in Escherichia coli cells and that formation of this material is greatly stimulated by the presence of a transplanted [PSI + ] inducibility factor, a distinct prion that is required for Sup35 to undergo spontaneous conversion to the prion form in yeast. Our results establish that the bacterial cytoplasm can support the formation of infectious prion aggregates, providing a heterologous system in which to study prion biology.Sup35 | [PSI + ] inducibility factor | amyloid P rions are infectious, self-propagating protein aggregates that have been implicated in a group of devastating mammalian neurodegenerative diseases (1). The discovery of a prion-like phenomenon in yeast and other fungi has led to profound advances in the understanding of prion biogenesis (2, 3). Prion proteins in mammals as well as fungi typically form highly structured β sheet-rich fibrils, known as amyloids, upon conversion to the infectious, prion form (4, 5, 1-3). However, unlike mammalian prions, yeast prions do not result in cell death, but instead act as heritable, protein-based genetic elements, conferring on the cell new phenotypic traits that are propagated epigenetically (6, 7). Although work over the last 15 years has uncovered a growing number of prions and prospective prion proteins in evolutionarily divergent members of the fungal kingdom (8-14), it is not yet known how pervasive prions are in nature; more specifically, it is not known whether bacteria contain prions or whether the bacterial cytoplasm can support the formation of prions. The study of yeast prions has revealed an essential interplay between prion proteins and cellular chaperone proteins (15, 16); thus, it is of particular interest to learn whether the bacterial chaperone environment is permissive for the formation of prion-like aggregates.To investigate whether the bacterial cytoplasm can support the formation of infectious amyloid, we sought to determine whether a yeast prion protein could access an infectious conformation in Escherichia coli cells. A particularly well-characterized prion in Saccharomyces cerevisiae, the [PSI + ] prion, is formed by the essential translation termination factor Sup35, which assembles into amyloid aggregates when it converts to the prion form (17; see also refs. 3 and 6). Upon conversion, the ability of Sup35 to participate in translation termination is impaired, and as a result, strains containing Sup35 in the prion form (designated [PSI + ] strains) manifest a nonsense-suppression phenotype due to significant stop-codon read-through (6). Like other yeast prion proteins, Sup35 has a modular structure, with a distinct priondetermining region (PrD) that is necessary to enable the protein to c...

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Section: Discussionsupporting

confidence: 84%

Conversion of a yeast prion protein to an infectious form in bacteria

Garrity

Sivanathan

Dong

et al. 2010

Proc. Natl. Acad. Sci. U.S.A.

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“…For some prions, the frequency of prion induction by transient overproduction changes dramatically, depending upon the presence of other (heterologous) prions or prion-like aggregates. The best-studied and most dramatic example of this is the induction of [PSI + ], which is greatly enhanced by the presence of the [PIN + ] prion, other QN-rich prions, or QN-rich proteins in an aggregated state (Derkatch et al 1997Derkatch and Liebman 2007).…”

Section: Prion Induction By Overproductionmentioning

confidence: 99%

Prions in Yeast

2012

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The concept of a prion as an infectious self-propagating protein isoform was initially proposed to explain certain mammalian diseases. It is now clear that yeast also has heritable elements transmitted via protein. Indeed, the "protein only" model of prion transmission was first proven using a yeast prion. Typically, known prions are ordered cross-b aggregates (amyloids). Recently, there has been an explosion in the number of recognized prions in yeast. Yeast continues to lead the way in understanding cellular control of prion propagation, prion structure, mechanisms of de novo prion formation, specificity of prion transmission, and the biological roles of prions. This review summarizes what has been learned from yeast prions.

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“…10 35 To investigate these plausible scenarios, we examined the dynamics of [PSI + ] aggregates by semi-denaturing detergentagarose gel electrophoresis (SDD-AGE) and fluorescence correlation spectroscopy (FCS) using strains with GFP integrated in the endogenous SUP35 ORF. 33,52 In the SDD-AGE analysis, to our surprise, the average size of detergent-resistant Sup35-GFP ([PSI + ]) aggregates increased after overproduction of Rnq1Δ100.…”

Section: A Bipolar Activity Of [Ure3] Prionmentioning

confidence: 99%