Pathologic prion protein infects cells by lipid-raft dependent macropinocytosis.
Pathologic prion protein infects cells by lipid-raft dependent macropinocytosis.
复制标题
DOI：
10.1371/journal.pone.0003314
复制
发表时间：
2008
期刊：
影响因子：
3.7
通讯作者：
Dowdy SF
中科院分区：
文献类型：
--
作者：
Wadia JS;Schaller M;Williamson RA;Dowdy SF
传染性海绵状脑病，包括人类的变异型克雅氏病（vCJD）和牛的牛海绵状脑病，是致命的神经退行性疾病，其特征是宿主细胞朊病毒蛋白（PrPC）错误折叠成传染性痒病（PrPSc）。然而，外源性PrPSc感染细胞的机制以及PrPC向PrPSc形式的病理转化发生的位置仍不确定。在这里，我们报告了类似于HIV-1 tat介导的肽转导的机制，成熟的，全长PrP包含一个保守的n端阳离子结构域，刺激脂筏依赖的细胞摄取，巨噬细胞。通过三种独立的方法抑制巨噬细胞增多症可阻止重组PrP的细胞摄取；但不影响重组PrP细胞表面结合。此外，阳离子n端PrP结构域与Cre重组酶报告蛋白的融合足以促进细胞摄取和从大蛋白酶体逃逸到细胞质中。在暴露于菌株RML PrPSc感染的脑浆液的N2a细胞中，抑制巨噬细胞增多足以阻止PrPC转化为病理PrPSc形式，这表明PrPC转化的关键决定因素发生在巨噬细胞内化之后，而不仅仅是通过膜关联。综上所述，这些观察结果提供了一种细胞机制，即外源性病理性PrPSc通过脂质筏依赖的巨噬细胞作用感染细胞。
Transmissible spongiform encephalopathies, including variant-Creutzfeldt-Jakob disease (vCJD) in humans and bovine spongiform encephalopathies in cattle, are fatal neurodegenerative disorders characterized by protein misfolding of the host cellular prion protein (PrPC) to the infectious scrapie form (PrPSc). However, the mechanism that exogenous PrPSc infects cells and where pathologic conversion of PrPC to the PrPSc form occurs remains uncertain. Here we report that similar to the mechanism of HIV-1 TAT-mediated peptide transduction, processed mature, full length PrP contains a conserved N-terminal cationic domain that stimulates cellular uptake by lipid raft-dependent, macropinocytosis. Inhibition of macropinocytosis by three independent means prevented cellular uptake of recombinant PrP; however, it did not affect recombinant PrP cell surface association. In addition, fusion of the cationic N-terminal PrP domain to a Cre recombinase reporter protein was sufficient to promote both cellular uptake and escape from the macropinosomes into the cytoplasm. Inhibition of macropinocytosis was sufficient to prevent conversion of PrPC to the pathologic PrPSc form in N2a cells exposed to strain RML PrPSc infected brain homogenates, suggesting that a critical determinant of PrPC conversion occurs following macropinocytotic internalization and not through mere membrane association. Taken together, these observations provide a cellular mechanism that exogenous pathological PrPSc infects cells by lipid raft dependent, macropinocytosis.
登录
查看更多内容
影响因子：
12.4
作者：
Nakase, I;Niwa, M;Futaki, S
通讯作者：
Futaki, S
影响因子：
5.3
作者：
Magalhaes, AC;Baron, GS;Caughey, B
通讯作者：
Caughey, B
影响因子：
4.6
作者：
Cai, SR;Xu, G;McLeod, HL
通讯作者：
McLeod, HL
影响因子：
6.6
作者：
Murriel, Christopher L;Dowdy, Steven F
通讯作者：
Dowdy, Steven F
影响因子：
20.3
作者：
Griffiths, Rebecca E.;Heesom, Kate J.;Anstee, David J.
通讯作者：
Anstee, David J.