Liquid-liquid phase separation and fibrillation of the prion protein modulated by a high-affinity DNA aptamer.
FASEB J
; 34(1): 365-385, 2020 01.
Article
em En
| MEDLINE
| ID: mdl-31914616
Structural conversion of cellular prion protein (PrPC) into scrapie PrP (PrPSc) and subsequent aggregation are key events associated with the onset of transmissible spongiform encephalopathies (TSEs). Experimental evidence supports the role of nucleic acids (NAs) in assisting this conversion. Here, we asked whether PrP undergoes liquid-liquid phase separation (LLPS) and if this process is modulated by NAs. To this end, two 25-mer DNA aptamers, A1 and A2, were selected against the globular domain of recombinant murine PrP (rPrP90-231) using SELEX methodology. Multiparametric structural analysis of these aptamers revealed that A1 adopts a hairpin conformation. Aptamer binding caused partial unfolding of rPrP90-231 and modulated its ability to undergo LLPS and fibrillate. In fact, although free rPrP90-231 phase separated into large droplets, aptamer binding increased the number of droplets but noticeably reduced their size. Strikingly, a modified A1 aptamer that does not adopt a hairpin structure induced formation of amyloid fibrils on the surface of the droplets. We show here that PrP undergoes LLPS, and that the PrP interaction with NAs modulates phase separation and promotes PrP fibrillation in a NA structure and concentration-dependent manner. These results shed new light on the roles of NAs in PrP misfolding and TSEs.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Doenças Priônicas
/
Aptâmeros de Nucleotídeos
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Extração Líquido-Líquido
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Proteínas Priônicas
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Amiloide
Limite:
Animals
Idioma:
En
Revista:
FASEB J
Assunto da revista:
BIOLOGIA
/
FISIOLOGIA
Ano de publicação:
2020
Tipo de documento:
Article
País de afiliação:
Brasil
País de publicação:
Estados Unidos