Interaction of Huntingtin-associated protein with dynactin P150Glued
Interaction of Huntingtin-associated protein with dynactin P150Glued
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DOI：
10.1523/jneurosci.18-04-01261.1998
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发表时间：
1998-02-15
影响因子：
5.3
通讯作者：
Li, XJ
中科院分区：
文献类型：
--
作者：
Li, SH;Gutekunst, CA;Li, XJ
亨廷顿蛋白是亨廷顿舞蹈病（HD）基因的蛋白质产物，携带在亨廷顿舞蹈病（HD）中扩增的多聚谷氨酰胺重复序列（bbbb36个单位）。亨廷顿蛋白相关蛋白（HAP1）是一种神经元蛋白，与亨廷顿蛋白结合，与多谷氨酰胺重复序列相关。与亨廷顿蛋白一样，HAP1也被发现是一种与膜细胞器相关的细胞质蛋白，这表明存在一种包括HAP1、亨廷顿蛋白和其他蛋白的蛋白复合物。利用酵母双杂交系统，我们发现HAP1还结合动力蛋白P150(glue) (P150),,,,,,,,,,，这是细胞质动力蛋白的辅助蛋白，参与膜细胞器的微管依赖性逆行运输。体外结合实验表明，huntingtin和P150都选择性地结合到谷胱甘肽转移酶(GST)-HAP1融合蛋白上。免疫沉淀实验表明P150和亨廷顿蛋白与HAP1在大鼠脑细胞质中共沉淀。Western blot分析显示，HAP1在大鼠脑微管中富集，并与P150和亨廷顿蛋白在蔗糖梯度中进行同质。免疫荧光显示转染的HAP1在人胚胎肾（HEK） 293细胞中与P150和亨廷顿蛋白共定位。我们认为HAP1， P150和亨廷顿蛋白存在于一个蛋白复合物中，该蛋白复合物可能参与动力蛋白-动力蛋白相关的细胞内运输。
Huntingtin is the protein product of the gene for Huntington's disease (HD) and carries a polyglutamine repeat that is expanded in HD (>36 units). Huntingtin-associated protein (HAP1) is a neuronal protein and binds to huntingtin in association with the polyglutamine repeat. Like huntingtin, HAP1 has been found to be a cytoplasmic protein associated with membranous organelles, suggesting the existence of a protein complex including HAP1, huntingtin, and other proteins. Using the yeast two-hybrid system, we found that HAP1 also binds to dynactin P150(Glued) (P150),,,,,,,,,, an accessory protein for cytoplasmic dynein that participates in microtubule-dependent retrograde transport of membranous organelles. An in vitro binding assay showed that both huntingtin and P150 selectively bound to a glutathione transferase (GST)-HAP1 fusion protein. An immunoprecipitation assay demonstrated that P150 and huntingtin coprecipitated with HAP1 from rat brain cytosol. Western blot analysis revealed that HAP1 was enriched in rat brain microtubules and comigrated with P150 and huntingtin in sucrose gradients. Immunofluorescence showed that transfected HAP1 colocalized with P150 and huntingtin in human embryonic kidney (HEK) 293 cells. We propose that HAP1, P150, and huntingtin are present in a protein complex that may participate in dynein-dynactin-associated intracellular transport.