Protrudin Regulates Endoplasmic Reticulum Morphology and Function Associated with the Pathogenesis of Hereditary Spastic Paraplegia
Protrudin Regulates Endoplasmic Reticulum Morphology and Function Associated with the Pathogenesis of Hereditary Spastic Paraplegia
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DOI：
10.1074/jbc.m113.528687
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发表时间：
2014-05-09
影响因子：
4.8
通讯作者：
Nakayama, Keiichi I.
中科院分区：
文献类型：
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作者：
Hashimoto, Yutaka;Shirane, Michiko;Nakayama, Keiichi I.
背景：某些遗传性痉挛性截瘫（HSP）相关蛋白具有发夹结构域并调节内质网（ER）网络的形态。结果：pronudin具有发夹结构域，可与热休克蛋白相关蛋白相互作用。结论：普鲁肽调节内质网形态和功能。意义：在某些HSP个体中产生的突变体突起蛋白容易形成微聚集体，诱导内质网应激。突起蛋白是一种调节神经元中极化囊泡运输的膜蛋白。突起蛋白基因（ZFYVE27）在遗传性痉挛性截瘫（HSP）患者的一个亚群中发生突变，因此突起蛋白也被称为痉挛性截瘫（SPG） 33。我们现在已经产生了在神经元特异性启动子控制下表达双表位标记的突起蛋白转基因的小鼠，我们已经从这些小鼠的大脑中分离出高度纯化的含有突起蛋白的复合物进行蛋白质组学分析，以鉴定与突起蛋白相关的蛋白质。发现proudin与其他热刺蛋白相关蛋白相互作用，包括髓磷脂蛋白脂质蛋白1 （SPG2）、atlastin-1 （SPG3A）、REEP1 （SPG31）、REEP5（类似于REEP1）、Kif5A （SPG10）、Kif5B、Kif5C和网状结构1、3和4（类似于网状结构2、SPG12）。膜拓扑分析表明，突起蛋白的三个疏水片段中的一个形成了类似于其他SPG蛋白的疏水发夹结构域。研究发现，突起蛋白主要定位于管状内质网（ER），强迫表达突起蛋白促进了管状内质网的形成和稳定。在一部分HSP患者中发现的突起蛋白（G191V）突变体表现出细胞内稳定性增加，表达该突变体的细胞对内质网应激的易感性增加。因此，我们的研究结果表明，突起蛋白有助于内质网形态和功能的调节，其突变解除是HSP的致病缺陷。
Background: Certain hereditary spastic paraplegia (HSP)-related proteins possess hairpin domains and regulate the morphology of the endoplasmic reticulum (ER) network. Results: Protrudin possesses a hairpin domain and interacts with HSP-related proteins. Conclusion: Protrudin regulates ER morphology and function. Significance: Mutant protrudin produced in certain individuals with HSP is prone to form microaggregates that induce ER stress.Protrudin is a membrane protein that regulates polarized vesicular trafficking in neurons. The protrudin gene (ZFYVE27) is mutated in a subset of individuals with hereditary spastic paraplegia (HSP), and protrudin is therefore also referred to as spastic paraplegia (SPG) 33. We have now generated mice that express a transgene for dual epitope-tagged protrudin under control of a neuron-specific promoter, and we have subjected highly purified protrudin-containing complexes isolated from the brain of these mice to proteomics analysis to identify proteins that associate with protrudin. Protrudin was found to interact with other HSP-related proteins including myelin proteolipid protein 1 (SPG2), atlastin-1 (SPG3A), REEP1 (SPG31), REEP5 (similar to REEP1), Kif5A (SPG10), Kif5B, Kif5C, and reticulon 1, 3, and 4 (similar to reticulon 2, SPG12). Membrane topology analysis indicated that one of three hydrophobic segments of protrudin forms a hydrophobic hairpin domain similar to those of other SPG proteins. Protrudin was found to localize predominantly to the tubular endoplasmic reticulum (ER), and forced expression of protrudin promoted the formation and stabilization of the tubular ER network. The protrudin(G191V) mutant, which has been identified in a subset of HSP patients, manifested an increased intracellular stability, and cells expressing this mutant showed an increased susceptibility to ER stress. Our results thus suggest that protrudin contributes to the regulation of ER morphology and function, and that its deregulation by mutation is a causative defect in HSP.