Huntingtin-associated protein 1 (HAP1) interacts with the p150(Glued) subunit of dynactin
Huntingtin-associated protein 1 (HAP1) interacts with the p150(Glued) subunit of dynactin
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DOI：
10.1093/hmg/6.13.2205
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发表时间：
1997-12-01
影响因子：
3.5
通讯作者：
Ross, CA
中科院分区：
文献类型：
--
作者：
Engelender, S;Sharp, AH;Ross, CA
亨廷顿舞蹈病（HD）是一种遗传性神经退行性疾病，由亨廷顿舞蹈病蛋白亨廷顿蛋白中聚谷氨酰胺重复序列扩增引起。亨廷顿蛋白在细胞内的定位包括与细胞骨架元件和囊泡的关联。我们之前发现了一种蛋白质（HAP1），它以谷氨酰胺重复长度依赖的方式与亨廷顿蛋白结合。我们现在报道HAP1与细胞骨架蛋白，即dynactin的p150（glue）亚基和中心周围蛋白PCM-1相互作用。结构预测表明，HAP1和相互作用的蛋白质都有很高的概率形成盘绕的线圈。我们检测了HAP1与p150（glue）的相互作用。通过将p150（glue）与固定在谷胱甘肽- sepharose微球上的HAP1- gst融合蛋白结合，证实了HAP1与p150(glue)（氨基酸879-1150）的结合。此外，HAP1与脑提取物中的p150（glue）共免疫沉淀，表明这种相互作用在体内发生。与HAP1一样，p150（glue）在大脑神经元中高度表达，两种蛋白都富集于神经末梢富含囊泡的部分。用共聚焦显微镜对ngf处理的PC12细胞进行双标记免疫荧光实验，发现HAP1和p150（glue）部分共定位。这些结果表明，HAP1可能作为一种接头蛋白，利用卷曲的线圈介导细胞骨架蛋白、囊泡蛋白和运动蛋白之间的相互作用。因此，HAP1和亨廷顿蛋白可能在细胞内的囊泡运输中发挥作用，这种功能的破坏可能导致HD患者的神经元功能障碍和死亡。
Huntington's disease (HD) is an inherited neurodegenerative disease caused by expansion of a polyglutamine repeat in the HD protein huntingtin. Huntingtin's localization within the cel includes an association with cytoskeletal elements and vesicles. We previously identified a protein (HAP1) which binds to huntingtin in a glutamine repeat length-dependent manner. We now report that HAP1 interacts with cytoskeletal proteins, namely the p150(Glued) subunit of dynactin and the pericentriolar protein PCM-1. Structural predictions indicate that both HAP1 and the interacting proteins have a high probability of forming coiled coils. We examined the interaction of HAP1 with p150(Glued). Binding of HAP1 to p150(Glued) (amino acids 879-1150) was confirmed in vitro by binding of p150(Glued) to a HAP1-GST fusion protein immobilized on glutathione-Sepharose beads. Also, HAP1 co-immunoprecipitated with p150(Glued) from brain extracts, indicating that the interaction occurs in vivo. Like HAP1, p150(Glued) is highly expressed in neurons in brain and both proteins are enriched in a nerve terminal vesicle-rich fraction. Double label immunofluorescence experiments in NGF-treated PC12 cells using confocal microscopy revealed that HAP1 and p150(Glued) partially co-localize. These results suggest that HAP1 might function as an adaptor protein using coiled coils to mediate interactions among cytoskeletal, vesicular and motor proteins. Thus, HAP1 and huntingtin may play a role in vesicle trafficking within the cell and disruption of this function could contribute to the neuronal dysfunction and death seen in HD.