HUNTINGTON AND VESICLE TRANSPORT

亨廷顿氏病导致运动和认知功能障碍， 大脑中的纹状体和皮质神经元变性和死亡 受害者的死亡率基因突变是一种扩大的 亨廷顿蛋白N末端的多聚谷氨酰胺区。 功能 野生型亨廷顿蛋白和HD发病机制引起的 突变的亨廷顿蛋白是未知的。 我们观察到一个异常的 亨廷顿蛋白在HD受影响神经元中的积累和转运 个脑袋 类似的突变亨廷顿蛋白积累模式出现在 用编码亨廷顿蛋白的cDNA转染克隆纹状体细胞， 扩展的多聚谷氨酰胺区。 已发表的研究和我们的初步研究 观察表明野生型亨廷顿蛋白可能在受体中起作用， 介导的内吞作用。 突变的亨廷顿蛋白，像野生型亨廷顿蛋白一样， 与富含网格蛋白的膜相关。 我们的总体假设是 突变的亨廷顿蛋白通过其直接的 对受体介导的内吞作用的影响及其异常 积累和运输。 我们提出了一系列的研究克隆 纹状体细胞，以探索野生型亨廷顿蛋白与 内体（Aimsl），以分析多聚谷氨酰胺 扩展亨廷顿蛋白对内吞功能的影响（目的2），并评估 积累突变亨廷顿蛋白的亚细胞区室 导致细胞死亡（目的3）。 我们的研究将包括 在共聚焦免疫荧光显微术中，免疫金/电子 显微镜、亚细胞膜分级分离、免疫分离和 Western印迹 结果将确定亚细胞过程 参与HD发病机制，并将导致一个合理的策略， 治疗这种毁灭性的疾病。

Huntington's disease causes motor and cognitive dysfunctions, the degeneration of striatal and cortical neurons in the brain, and death of its victim within 15-20 years. The genetic mutation is an expanded region of polyglutamines at the N-terminus of huntingtin. The function of wild-type huntingtin and the mechanism of HD pathogenesis caused by mutant huntingtin are unknown. We have observed an abnormal accumulation and transport of huntintin in affected neurons of the HD brain. Similar patterns of mutant huntintin accumulation appear in clonal striatal cells transfected with cDNAs encoding huntingtin with an expanded polyglutamine region. Published studies and our preliminary observations suggest that wild-type huntingtin may function in receptor- mediated endocytosis. Mutant huntintin, like wild-type huntingtin, associates with clathrin-enriched membranes. Our overall hypothesis is that mutant huntintin causes neuronal dysfunction through its direct effects on receptor-mediated endocytosis and by its abnormal accumulation and transport. We propose a series of studies in clonal striatal cells to explore wild-type huntingtin's association with endosomes (Aimsl), to analyze the consequences of polyglutamine expansion in huntintin on endocytic function (Aim 2), and to evaluate the subcellular compartments that accumulate mutant huntingtin and contribute to cell death (Aim 3). Our studies will include techniques in confocal immunofluorescence microscopy, immunogold/electron microscopy, subcellular membrane fractionation, immunoisolation and Western blot. The results will identify the subcellular processes involved in HD pathogenesis and will lead to a rational strategy for treatment of this devastating disorder.