The pallid gene encodes a novel, syntaxin 13-interacting protein involved in platelet storage pool deficiency
The pallid gene encodes a novel, syntaxin 13-interacting protein involved in platelet storage pool deficiency
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DOI：
10.1038/15507
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发表时间：
1999-11-01
期刊：
影响因子：
30.8
通讯作者：
Gitschier, J
中科院分区：
文献类型：
--
作者：
Huang, LP;Kuo, YM;Gitschier, J
苍白(Pa)是13只血小板储存池缺陷(Spd)小鼠突变体1、2、3中的一个。PA动物表现为出血时间延长、色素稀释、肾脏溶酶体酶升高、血清α1抗胰蛋白酶活性低下和耳石形成异常2、4、5、6。与其他此类突变体一样，pa小鼠的特征表明细胞器生物合成存在缺陷。在这里，我们描述了帕金森病小鼠缺陷基因的物理定位、位置克隆、突变和功能分析。它编码一种无处不在的表达、高度带电的172个氨基酸的蛋白质(称为pallidin)，与已知蛋白质没有同源性。我们在苍白的突变体中检测到该基因第69密码子的无义突变。在酵母双杂交筛选中，我们发现Pallidin与Synaxin 13相互作用，Synaxin 13是一种T-SNARE蛋白，介导囊泡对接和融合7，8。我们通过免疫共沉淀实验证实了这种相互作用。免疫荧光研究证实，pallidin的细胞分布与synaxin 13重叠。虽然mocha和珍珠spd突变体在AP-3中存在缺陷(参考文献9，10)，但我们的发现表明pa spd突变体在更下游的囊泡运输事件中存在缺陷：即囊泡对接和融合。
Pallid (pa) is 1 of 13 platelet storage pool deficiency (SPD) mouse mutants 1, 2, 3. pa animals suffer from prolonged bleeding time, pigment dilution, kidney lysosomal enzyme elevation, serum α 1-antitrypsin activity deficiency and abnormal otolith formation 2, 4, 5, 6. As with other mouse mutants of this class, characterization of pa mice suggests a defect in organelle biosynthesis. Here we describe the physical mapping, positional cloning, and mutational and functional analysis of the gene that is defective in pa mice. It encodes a ubiquitously expressed, highly charged 172–amino-acid protein (termed pallidin) with no homology to known proteins. We detected a nonsense mutation at codon 69 of this gene in the pallid mutant. In a yeast two-hybrid screen, we discovered that pallidin interacts with syntaxin 13, a t-SNARE protein that mediates vesicle-docking and fusion 7, 8. We confirmed this interaction by co-immunoprecipitation assay. Immunofluorescence studies corroborate that the cellular distribution of pallidin overlaps that of syntaxin 13. Whereas the mocha and pearl SPD mutants have defects in Ap-3 (Refs 9, 10), our findings suggest that pa SPD mutants are defective in a more downstream event of vesicle-trafficking: namely, vesicle-docking and fusion.