Cofactor and glycosylation preferences for in vitro prion conversion are predominantly determined by strain conformation
Cofactor and glycosylation preferences for in vitro prion conversion are predominantly determined by strain conformation
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DOI：
10.1371/journal.ppat.1008495
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发表时间：
2020-04-01
期刊：
影响因子：
6.7
通讯作者：
Supattapone, Surachai
中科院分区：
文献类型：
--
作者：
Burke, Cassandra M.;Walsh, Daniel J.;Supattapone, Surachai
朊病毒疾病是由宿主编码的糖蛋白PrPC错误折叠成致病性构象异构体PrPSc引起的。感染性朊病毒可以以不同的菌株存在，由独特的PrPSc构象组成，产生菌株特异性生物学特性，包括PrPSc在整个大脑中积累的独特模式。朊病毒株从不同的动物物种显示不同的辅因子和PrPC糖型的偏好，有效地在体外繁殖，但它是未知的，这些分子的偏好是否指定由氨基酸序列的PrPC基板或由构象的PrPSc种子。为了区分这两种可能性，我们使用银行田鼠PrPC繁殖仓鼠或小鼠朊病毒（具有不同的辅因子和糖基化偏好）与一个单一的，共同的底物。我们使用（1）磷脂或RNA辅因子分子，或（2）二糖基化或非糖基化的银行田鼠PrPC底物进行了重建的sPMCA反应。我们发现，朊病毒菌株从任何一个物种都能够有效地使用银行田鼠PrPC基板时，反应含有相同的PrPC糖型或辅因子分子的首选PrPSc种子在其宿主物种繁殖。因此，我们得出结论，这是输入PrPSc种子的构象，而不是PrPC底物的氨基酸序列，主要决定物种特异性辅因子和糖基化偏好。这些结果支持的假设，株特异性的朊病毒嗜神经性模式产生的差异分布的辅因子分子和/或PrPC糖型朊病毒复制过程中的选择。
Prion diseases are caused by the misfolding of a host-encoded glycoprotein, PrPC, into a pathogenic conformer, PrPSc. Infectious prions can exist as different strains, composed of unique conformations of PrPSc that generate strain-specific biological traits, including distinctive patterns of PrPSc accumulation throughout the brain. Prion strains from different animal species display different cofactor and PrPC glycoform preferences to propagate efficiently in vitro, but it is unknown whether these molecular preferences are specified by the amino acid sequence of PrPC substrate or by the conformation of PrPSc seed. To distinguish between these two possibilities, we used bank vole PrPC to propagate both hamster or mouse prions (which have distinct cofactor and glycosylation preferences) with a single, common substrate. We performed reconstituted sPMCA reactions using either (1) phospholipid or RNA cofactor molecules, or (2) di- or un-glycosylated bank vole PrPC substrate. We found that prion strains from either species are capable of propagating efficiently using bank vole PrPC substrates when reactions contained the same PrPC glycoform or cofactor molecule preferred by the PrPSc seed in its host species. Thus, we conclude that it is the conformation of the input PrPSc seed, not the amino acid sequence of the PrPC substrate, that primarily determines species-specific cofactor and glycosylation preferences. These results support the hypothesis that strain-specific patterns of prion neurotropism are generated by selection of differentially distributed cofactors molecules and/or PrPC glycoforms during prion replication.