Niemann-Pick C1 is a late endosome-resident protein that transiently associates with lysosomes and the trans-Golgi network
Niemann-Pick C1 is a late endosome-resident protein that transiently associates with lysosomes and the trans-Golgi network
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DOI：
10.1006/mgme.1999.2882
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发表时间：
1999-09-01
影响因子：
3.8
通讯作者：
Ioannou, YA
中科院分区：
文献类型：
--
作者：
Higgins, ME;Davies, JP;Ioannou, YA
C型尼曼-匹克（NPC）病是一种严重的细胞变性疾病，其特征是未酯化的胆固醇在内体/溶酶体系统中积聚。最近的主要致病基因，NPC 1，被确定，但很少有线索关于其潜在的功能（S）可以从其预测的氨基酸序列。因此，致力于表征NPC 1蛋白的亚细胞位置。用FLAG标记的NPC 1 cDNA进行的初步研究表明，NPC 1是一种与细胞质囊泡群体的膜相关的糖蛋白。使用抗NPC 1多克隆抗体的免疫荧光显微镜证实了这一分析。双标记免疫荧光显微镜和亚细胞分级分离研究表明，NPC 1协会主要与晚期内体（Rab 9 GTP酶阳性囊泡），并在较小程度上，与溶酶体和trans-Golgi网络。当用U18666 A处理细胞阻断胆固醇从溶酶体流出时，NPC 1的位置从晚期内体转移到高尔基体网络和溶酶体。U18666 A处理小鼠肝匀浆的亚细胞分级证实了这些观察结果。这些数据表明，U18666 A可以抑制NPC 1从溶酶体到晚期内体的逆行转运，随后转移到transGolgi网络。(C)北京：科学出版社.
Niemann-Pick type C (NPC) disease is a severe cell lipidosis characterized by the accumulation of unesterified cholesterol in the endosomal/lysosomal system. Recently the primary disease-causing gene, NPC1, was identified, but few clues regarding its potential function(s) could be derived from its predicted amino acid sequence. Therefore, efforts were directed at characterizing the subcellular location of the NPC1 protein. Initial studies with a FLAG-tagged NPC1 cDNA demonstrated that NPC1 is a glycoprotein that associates with the membranes of a population of cytoplasmic vesicles. Immunofluorescence microscopy using anti-NPC1 polyclonal antibodies confirmed this analysis. Double-label immunofluorescence microscopy and subcellular fractionation studies indicated that NPC1 associates predominantly with late endosomes (Rab9 GTPase-positive vesicles) and, to a lesser extent, with lysosomes and the trans-Golgi network. When cholesterol egress from lysosomes was blocked by treatment of cells with U18666A, the NPC1 location shifted from late endosomes to the trans-Golgi network and lysosomes. Subcellular fractionation of liver homogenates from U18666A-treated mice confirmed these observations. These data suggest that U18666A may inhibit the retrograde transport of NPC1 from lysosomes to late endosomes for subsequent transfer to the trans Golgi network. (C) 1999 Academic Press.