Details

Autor(en) / Beteiligte

• Schwind, Abigail M.
• Walsh, Daniel J.
• Burke, Cassandra M.
• Supattapone, Surachai

Titel

Phospholipid cofactor solubilization inhibits formation of native prions

Ist Teil von

• Journal of neurochemistry, 2023-09, Vol.166 (5), p.875-884

Ort / Verlag

England: Blackwell Publishing Ltd

Erscheinungsjahr

2023

Quelle

Free E-Journal (出版社公開部分のみ）

Beschreibungen/Notizen

• Cofactor molecules are required to generate infectious mammalian prions in vitro. Mouse and hamster prions appear to have different cofactor preferences: Whereas both mouse and hamster prions can use phosphatidylethanolamine (PE) as a prion cofactor, only hamster prions can also use single‐stranded RNA as an alternative cofactor. Here, we investigated the effect of detergent solubilization on rodent prion formation in vitro. We discovered that detergents that can solubilize PE (n‐octylglucoside, n‐octylgalactoside, and CHAPS) inhibit mouse prion formation in serial protein misfolding cyclic amplification (sPMCA) reactions using bank vole brain homogenate substrate, whereas detergents that are unable to solubilize PE (Triton X‐100 and IPEGAL) have no effect. For all three PE‐solubilizing detergents, inhibition of RML mouse prion formation was only observed above the critical micellar concentration (CMC). Two other mouse prion strains, Me7 and 301C, were also inhibited by the three PE‐solubilizing detergents but not by Triton X‐100 or IPEGAL. In contrast, none of the detergents inhibited hamster prion formation in parallel sPMCA reactions using the same bank vole brain homogenate substrate. In reconstituted sPMCA reactions using purified substrates, n‐octylglucoside inhibited hamster prion formation when immunopurified bank vole PrPC substrate was supplemented with brain phospholipid but not with RNA. Interestingly, phospholipid cofactor solubilization had no effect in sPMCA reactions using bacterially expressed recombinant PrP substrate, indicating that the inhibitory effect of solubilization requires PrPC post‐translational modifications. Overall, these in vitro results show that the ability of PE to facilitate the formation of native but not recombinant prions requires phospholipid bilayer integrity, suggesting that membrane structure may play an important role in prion formation in vivo. The propagation of infectious mammalian prions in vitro requires cofactors, such as phospholipid or RNA molecules. Here, we report that the ability of phospholipids to act as prion cofactors for the conversion of GPI‐anchored native prion protein substrate (PrPC) into its infectious conformation (PrPSc) is inhibited by phospholipid solubilization. These results suggest that bilayer membrane architecture may play an important role in prion formation.