瘙痒
病毒学
生物
传染源
核酸
基因
传染性海绵状脑病
传染性
致死性家族性失眠
淀粉样蛋白(真菌学)
病菌
病毒
遗传学
朊蛋白
疾病
医学
病理
植物
作者
Jacob I. Ayers,Nick A. Paras,Stanley B. Prusiner
出处
期刊:Emerging topics in life sciences
[Portland Press]
日期:2020-08-17
卷期号:4 (2): 155-167
被引量:32
摘要
Prions were initially discovered in studies of scrapie, a transmissible neurodegenerative disease (ND) of sheep and goats thought to be caused by slow viruses. Once scrapie was transmitted to rodents, it was discovered that the scrapie pathogen resisted inactivation by procedures that modify nucleic acids. Eventually, this novel pathogen proved to be a protein of 209 amino acids, which is encoded by a chromosomal gene. After the absence of a nucleic acid within the scrapie agent was established, the mechanism of infectivity posed a conundrum and eliminated a hypothetical virus. Subsequently, the infectious scrapie prion protein (PrPSc) enriched for β-sheet was found to be generated from the cellular prion protein (PrPC) that is predominantly α-helical. The post-translational process that features in nascent prion formation involves a templated conformational change in PrPC that results in an infectious copy of PrPSc. Thus, prions are proteins that adopt alternative conformations, which are self-propagating and found in organisms ranging from yeast to humans. Prions have been found in both Alzheimer's (AD) and Parkinson's (PD) diseases. Mutations in APP and α-synuclein genes have been shown to cause familial AD and PD. Recently, AD was found to be a double prion disorder: both Aβ and tau prions feature in this ND. Increasing evidence argues for α-synuclein prions as the cause of PD, multiple system atrophy, and Lewy body dementia.
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