Bae Eun-Jin, Lee Cheolsoon, Lee He-Jin, Kim Seokjoong, Lee Seung-Jae
Department of Biomedical Science and Technology, School of Medicine, Konkuk University, Seoul 143-701, Korea. ; Institute of Biomedical Science and Technology, School of Medicine, Konkuk University, Seoul 143-701, Korea.
Institute of Biomedical Science and Technology, School of Medicine, Konkuk University, Seoul 143-701, Korea. ; Department of Anatomy, School of Medicine, Konkuk University, Seoul 143-701, Korea.
Exp Neurobiol. 2014 Dec;23(4):365-71. doi: 10.5607/en.2014.23.4.365. Epub 2014 Dec 12.
Parkinson's disease is a multifactorial disorder with several genes linked to the familial types of the disease. ATP13A2 is one of those genes and encode for a transmembrane protein localized in lysosomes and late endosomes. Previous studies suggested the roles of this protein in lysosomal functions and cellular ion homeostasis. Here, we set out to investigate the role of ATP13A2 in lysosomal function and in metabolism of α-synuclein, another PD-linked protein whose accumulation is implicated in the pathogenesis. We generated non-sense mutations in both copies of ATP13A2 gene in SH-SY5Y human neuroblastoma cells. We examined lysosomal function of ATP13A2-/- cells by measuring the accumulation of lysosomal substrate proteins, such as p62 and polyubiquitinated proteins, induction of acidic compartments, and degradation of ectopically introduced dextran. None of these measures were altered by ATP13A2 deficiency. The steady-state levels of α-synuclein in cells or secretion of this protein were unaltered either in ATP13A2-/- compared to the normal cells. Therefore, the proposed roles of ATP13A2 in lysosomal functions may not be generalized and may depend on the cellular context. The ATP13A2-/- cells generated in the current study may provide a useful control for studies on the roles of PD genes in lysosomal functions.
帕金森病是一种多因素疾病，有多个基因与该疾病的家族型相关。ATP13A2是其中一个基因，编码一种定位于溶酶体和晚期内体的跨膜蛋白。先前的研究表明该蛋白在溶酶体功能和细胞离子稳态中发挥作用。在此，我们着手研究ATP13A2在溶酶体功能以及α-突触核蛋白代谢中的作用，α-突触核蛋白是另一种与帕金森病相关的蛋白，其积累与发病机制有关。我们在SH-SY5Y人神经母细胞瘤细胞的ATP13A2基因的两个拷贝中产生了无义突变。我们通过测量溶酶体底物蛋白（如p62和多聚泛素化蛋白）的积累、酸性区室的诱导以及异位引入的葡聚糖的降解来检测ATP13A2基因敲除细胞的溶酶体功能。ATP13A2基因缺陷并未改变这些指标中的任何一项。与正常细胞相比，ATP13A2基因敲除细胞中α-突触核蛋白的稳态水平或该蛋白的分泌也未改变。因此，ATP13A2在溶酶体功能中所提出的作用可能无法一概而论，可能取决于细胞环境。本研究中产生的ATP13A2基因敲除细胞可能为研究帕金森病相关基因在溶酶体功能中的作用提供有用的对照。
