CANDIDATE GENE ANALYSIS--INTEGRATIVE EFFORT TO CLONE NIEMANN-PICK TYPE C DISEASE

尼曼-匹克C型（NPC）是一种 自体隐性遗传的神经内脏障碍，其特征为 神经功能衰退（进行性认知障碍，共济失调， 肌张力障碍、吞咽困难、构音障碍、癫痫发作、紧张症和痴呆） 以及胆固醇沉积症导致的肝脾肿大。的 最近克隆了在NPC中突变的基因（NPC-1）， 被发现是一种功能未知的膜蛋白，但可能 参与胆固醇稳态，由于存在一种 蛋白质中的甾醇敏感结构域序列。为了研究 蛋白质在胆固醇运输中的功能和作用， 体内平衡，我们已经成功地产生了6个多克隆抗体 针对蛋白质的不同片段。这些抗体被 用于鉴定NPC 1蛋白的亚细胞定位， 研究其在胆固醇存在或不存在的情况下的活性。在 此外，NPC 1蛋白与蠕虫的NPC 1蛋白具有同源性 （C. elegans）序列。为了利用蠕虫系统，无效突变体 通过EMU诱变产生。两个同源基因 已经成功地锁定了目标， 以异常表型为特征。

Niemann-Pick type C (NPC) is an autosmal-recessive, neurovisceral disorder that is marked by neurological decline (progressive cognitive impairment, ataxia, dystonia, dysphagia, dysarthria, seizures, cataplexy and dementia) and hepatosplenomegaly resulting from cholesterol lipidosis. The gene (NPC-1) that is mutated in NPC was recently cloned and was found to be a membrane protein of unknown function but possibly involved in cholesterol homeostasis due to the presence of a sterol-sensing domain sequence in the protein. In order to study the function and role of the protein in cholesterol trafficking and homeostasis, we have succesfully generated 6 polyclonal antibodies against various segments of the protein. These antibodies are being used to identify subcellular localization of the NPC1 protein and to study its activity in the presence or absence of cholesterol. In addition, the NPC1 protein showed sequence homologies to worm (C. elegans) sequences. To exploit the worm system, null mutants were generated by EMU mutagenesis. The two homologous genes in worms have been successfully targeted and are now being characetrized for abnormal phenotype.