HUNTINGTON AND VESICLE TRANSPORT

亨廷顿氏病会导致运动和认知功能障碍 大脑中纹状体和皮质神经元的变性和死亡 它的受害者在15-20年内。基因突变是一种扩展的 亨廷顿蛋白N-末端的多谷氨酸区。该功能 野生型亨廷顿蛋白及其致病机制的研究 突变的亨廷顿蛋白是未知的。我们观察到了一种异常情况 亨廷顿在先天性巨噬细胞病变神经元中的蓄积和转运 大脑。突变的亨氏蛋白积累的相似模式也出现在 携带亨廷顿蛋白基因的克隆纹状体细胞 一个扩大的聚谷氨酰胺区域。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- 介导的内吞作用。突变的亨廷顿，就像野生型的亨廷顿， 与富含网状蛋白的膜相关联。我们的总体假设是 突变的Huntintin通过它的直接作用导致神经元功能障碍 受体介导的内吞作用及其异常对其的影响 积累和运输。我们提出了一系列关于克隆的研究 探索野生型亨廷顿蛋白与纹状体细胞的关系 分析多聚谷氨酰胺的后果 亨廷顿扩张对内皮细胞功能的影响(目标2)，并评价 积累突变的亨廷丁和亨廷顿蛋白的亚细胞隔间 导致细胞死亡(目标3)。我们的研究将包括技术 在共聚焦免疫荧光显微镜下，免疫金/电子 显微镜、亚细胞膜分离、免疫分离和 蛋白质印迹。结果将确定亚细胞过程 参与了HD的发病机制，并将导致合理的策略 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.