title: Amyloid aggregates of the HET-s prion protein are infectious.
abstract: The [Het-s] infectious element of the filamentous fungus Podospora anserina is a prion. We have recently reported that recombinant HET-s protein aggregates in vitro into amyloid fibers. In vivo, the protein aggregates specifically in the [Het-s] prion strains. Here, we show that biolistic introduction of aggregated recombinant HET-s protein into fungal cells induces emergence of the [Het-s] prion with a high frequency. Thus, we demonstrate that prion infectivity can be created de novo, in vitro from recombinant protein in this system. Although the amyloid filaments formed from HET-s could transmit [Het-s] efficiently, neither the soluble form of the protein nor amorphous aggregates would do so. In addition, we have found that (i) [Het-s] infectivity correlates with the ability to convert HET-s to amyloids in vitro, (ii) [Het-s] infectivity is resistant to proteinase K digestion, and (iii) HET-s aggregates formed in vivo in [Het-s] strains have the ability to convert the recombinant protein to aggregates. Together, our data designate the HET-s amyloids as the molecular basis of [Het-s] prion propagation.
authors.affiliation: Laboratoire de Génétique Moléculaire des Champignons, Institut de Biochimie et de Génétique Cellulaires, Unité Mixte de Recherche 5095, Centre National de la Recherche Scientifique, Université de Bordeaux 2, France. ML.Maddelein@ibgc.u-bordeaux2.fr
authors.forename: Marie-Lise
authors.initials: ML
authors.lastname: Maddelein
authors.forename: Suzana
authors.initials: S
authors.lastname: Dos Reis
authors.forename: Stéphane
authors.initials: S
authors.lastname: Duvezin-Caubet
authors.forename: Bénédicte
authors.initials: B
authors.lastname: Coulary-Salin
authors.forename: Sven J
authors.initials: SJ
authors.lastname: Saupe
mesh_terms: D000682:Amyloid / Q000737:chemistry / Q000378:metabolism*; D019470:Biolistics; D019286:Endopeptidase K; D004926:Escherichia coli / Q000235:genetics; D005656:Fungal Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D011328:Prions / Q000378:metabolism* / Q000472:pathogenicity; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D020037:Sordariales / Q000254:growth & development / Q000472:pathogenicity / Q000502:physiology*
chemical_list: D000682:Amyloid; D005656:Fungal Proteins; C083891:HET-S protein, Podospora anserina; D011328:Prions; D011994:Recombinant Proteins; D019286:Endopeptidase K