Yeast prions form infectious amyloid inclusion bodies in bacteria

Background Prions were first identified as infectious proteins associated with fatal brain diseases in mammals. However, fungal prions behave as epigenetic regulators that can alter a range of cellular processes. These proteins propagate as self-perpetuating amyloid aggregates being an example of st...

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Detalles Bibliográficos
Autores: Espargaró Colomé, Alba, Villar Piqué, Anna, Sabaté Lagunas, Raimon, Ventura, Salvador
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2012
País:España
Institución:Universidad de Barcelona
Repositorio:Dipòsit Digital de la UB
OAI Identifier:oai:diposit.ub.edu:2445/191002
Acceso en línea:https://hdl.handle.net/2445/191002
Access Level:acceso abierto
Palabra clave:Prions
Bacteris
Proteïnes
Bacteria
Proteins
Descripción
Sumario:Background Prions were first identified as infectious proteins associated with fatal brain diseases in mammals. However, fungal prions behave as epigenetic regulators that can alter a range of cellular processes. These proteins propagate as self-perpetuating amyloid aggregates being an example of structural inheritance. The best-characterized examples are the Sup35 and Ure2 yeast proteins, corresponding to [PSI+] and [URE3] phenotypes, respectively. Results Here we show that both the prion domain of Sup35 (Sup35-NM) and the Ure2 protein (Ure2p) form inclusion bodies (IBs) displaying amyloid-like properties when expressed in bacteria. These intracellular aggregates template the conformational change and promote the aggregation of homologous, but not heterologous, soluble prionogenic molecules. Moreover, in the case of Sup35-NM, purified IBs are able to induce different [PSI+] phenotypes in yeast, indicating that at least a fraction of the protein embedded in these deposits adopts an infectious prion fold. Conclusions An important feature of prion inheritance is the existence of strains, which are phenotypic variants encoded by different conformations of the same polypeptide. We show here that the proportion of infected yeast cells displaying strong and weak [PSI+] phenotypes depends on the conditions under which the prionogenic aggregates are formed in E. coli, suggesting that bacterial systems might become useful tools to generate prion strain diversity.