Cook D G, Sung J C, Golde T E, Felsenstein K M, Wojczyk B S, Tanzi R E, Trojanowski J Q, Lee V M, Doms R W
Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia 19104, USA.
Proc Natl Acad Sci U S A. 1996 Aug 20;93(17):9223-8. doi: 10.1073/pnas.93.17.9223.
Mutations in the recently identified presenilin 1 gene on chromosome 14 cause early onset familial Alzheimer disease (FAD). Herein we describe the expression and analysis of the protein coded by presenilin 1 (PS1) in NT2N neurons, a human neuronal model system. PS1 was expressed using recombinant Semliki Forest virions and detected by introduced antigenic tags or antisera to PS1-derived peptides. Immunoprecipitation revealed two major PS1 bands of approximately 43 and 50 kDa, neither of which were N-glycosylated or O-glycosylated. Immunoreactive PS1 was detected in cell bodies and dendrites of NT2N neurons but not in axons or on the cell surface. PS1 was also detected in BHK cells, where it was also intracellular and colocalized with calnexin, a marker for the rough endoplasmic reticulum. A mutant form of PS1 linked to FAD did not differ from the wild-type protein at the light microscopic level. The model system described here will enable studies of the function of PS1 in human neurons and the role of mutant PS1 in FAD.
最近在14号染色体上发现的早老素1基因的突变会导致早发性家族性阿尔茨海默病（FAD）。在此我们描述了早老素1（PS1）编码的蛋白质在NT2N神经元（一种人类神经元模型系统）中的表达和分析。PS1通过重组Semliki森林病毒颗粒进行表达，并通过引入的抗原标签或针对PS1衍生肽的抗血清进行检测。免疫沉淀显示出两条主要的PS1条带，大小约为43 kDa和50 kDa，两者均未进行N-糖基化或O-糖基化。在NT2N神经元的细胞体和树突中检测到免疫反应性PS1，但在轴突或细胞表面未检测到。在BHK细胞中也检测到了PS1，它同样位于细胞内，并与钙连接蛋白共定位，钙连接蛋白是粗面内质网的标志物。与FAD相关的PS1突变形式在光学显微镜水平上与野生型蛋白没有差异。这里描述的模型系统将有助于研究PS1在人类神经元中的功能以及突变型PS1在FAD中的作用。
