Negro A, Ballarin C, Bertoli A, Massimino M L, Sorgato M C
Dipartimento di Chimica Biologica, Centro C.N.R., di Studio delle Biomembrane and C.R.I.B.I., Università di Padova, Padova, 35121, Italy.
Mol Cell Neurosci. 2001 Mar;17(3):521-38. doi: 10.1006/mcne.2000.0953.
Prion diseases are probably caused by an abnormal form of a cellular glycoprotein, the prion protein. Recent evidence suggests that the prion strain causing BSE has been transmitted to humans, thereby provoking a variant form of Creutzfeldt-Jacob disease. In this work, we analyzed the behavior of normal and malformed isoforms of the bovine PrP in transfected mammalian cell lines. Biochemical and immunocytochemical assays were complimented with imaging of live cells expressing fusion constructs between PrP and GFP. Bovine homologues of human E200K and D178N (129M) mutations were used as models of pathogenic isoforms. We show that the GFP does not impair the metabolism of native and mutant bPrPs and is thus a valid marker of PrP cellular distribution. We also show that each amino acid replacement provokes alterations in the cell sorting and processing of bPrP. These are different from those ascribed to both murine mutant homologues. However, human and bovine PrPs carrying the D178N genotype had similar cellular behavior.
朊病毒疾病可能由一种细胞糖蛋白（朊病毒蛋白）的异常形式引起。最近的证据表明，导致牛海绵状脑病的朊病毒毒株已传播给人类，从而引发了变异型克雅氏病。在这项研究中，我们分析了转染的哺乳动物细胞系中正常和畸形牛朊病毒蛋白异构体的行为。生化和免疫细胞化学分析辅以对表达朊病毒蛋白与绿色荧光蛋白融合构建体的活细胞的成像。人类E200K和D178N（129M）突变的牛同源物被用作致病异构体的模型。我们表明，绿色荧光蛋白不会损害天然和突变型牛朊病毒蛋白的代谢，因此是朊病毒蛋白细胞分布的有效标记。我们还表明，每个氨基酸替换都会引发牛朊病毒蛋白细胞分选和加工的改变。这些与归因于两种小鼠突变同源物的改变不同。然而，携带D178N基因型的人类和牛朊病毒蛋白具有相似的细胞行为。
