Protein aggregation into insoluble deposits protects from oxidative stress

Protein misfolding and aggregation have been associated with the onset of neurodegenerative disorders. Recent studies demonstrate that the aggregation process can result in a high diversity of protein conformational states, however the identity of the specific species responsible for the cellular da...

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Detalles Bibliográficos
Autores: Carija, Anita|||0000-0001-5972-7448, Navarro, Susanna|||0000-0001-8160-9536, Sánchez de Groot, Natalia|||0000-0002-0492-5532, Ventura, Salvador|||0000-0002-9652-6351
Tipo de recurso: artículo
Fecha de publicación:2017
País:España
Institución:Universitat Autònoma de Barcelona
Repositorio:Dipòsit Digital de Documents de la UAB
Idioma:inglés
OAI Identifier:oai:ddd.uab.cat:186208
Acceso en línea:https://ddd.uab.cat/record/186208
https://dx.doi.org/urn:doi:10.1016/j.redox.2017.03.027
Access Level:acceso abierto
Palabra clave:ROS, reactive oxygen species
FITC, fluorescein isothiocyanate
FC, flow cytometry
PI, protein inclusion, PK, proteinase k
GFP, Green Fluorescent Protein
IP, propidium iodide
Protein aggregation
Oxidative stress
Amyloid peptide
Protein inclusions
Yeast
Descripción
Sumario:Protein misfolding and aggregation have been associated with the onset of neurodegenerative disorders. Recent studies demonstrate that the aggregation process can result in a high diversity of protein conformational states, however the identity of the specific species responsible for the cellular damage is still unclear. Here, we use yeast as a model to systematically analyse the intracellular effect of expressing 21 variants of the amyloid-ß-peptide, engineered to cover a continuous range of intrinsic aggregation propensities. We demonstrate the existence of a striking negative correlation between the aggregation propensity of a given variant and the oxidative stress it elicits. Interestingly, each variant generates a specific distribution of protein assemblies in the cell. This allowed us to identify the aggregated species that remain diffusely distributed in the cytosol and are unable to coalesce into large protein inclusions as those causing the highest levels of oxidative damage. Overall, our results indicate that the formation of large insoluble aggregates may act as a protective mechanism to avoid cellular oxidative stress. The scheme represents three different scenarios that can occur in a yeast cell upon Aβ42-GFP peptide expression. Scenario I: Soluble Aβ42-GFP species that neither form protein inclusions, nor diffuse aggregates, are not dangerous for the cell; Scenario II: Aβ42-GFP species that do not form protein inclusions but form diffuse aggregates, which can cause intracellular oxidative stress, are hazardous for the cell; Scenario III: Aβ42-GFP species that form protein inclusions are not deleterious for the cell, suggesting that the formation of these big aggregates acts as a protective strategy against oxidative stress.