MOLECULAR BIOLOGY OF THE MENKES SYNDROME GENE

描述：铜是原核生物和非生物体内必需的微量元素。 真核细胞。它的氧化潜能是正常的 30多种已知的酶在电子传递中的作用， 神经递质、结缔组织和自由基清除系统。 然而，尽管铜是生命所必需的，但它存在时是剧毒的。 太多了。因此，生物体进化出了精确的机制， 调节铜的动态平衡。然而，人们对此知之甚少 调节这种微妙平衡的哺乳动物基因。对这一点的理解 基因的克隆大大加强了复杂的过程。 两种遗传性疾病，门克斯和威尔逊病，其中铜 分布不均是主要的代谢缺陷。两者都被发现是 与P型有很强同源性的铜结合跨膜ATPase 细菌的ATPase，并在库珀运输中发挥作用。在当前的 在项目期，克隆了孟克斯病的基因(ATP7A；MNK)，并 人们开始研究它的结构、功能和在铜中的作用 动态平衡。在确定该基因以来的发现中，基本的 MNK基因的结构已被确定并发现非常相似 与肝豆状核变性S病基因(ATP7B；WND)的同源性较高。MNK蛋白已经被 免疫荧光定位于高尔基体网络。此外， 同源小鼠基因已被克隆并用于显示斑驳的 小鼠突变体为研究孟克斯提供了有价值的动物模型 疾病。在这一应用中，建议扩展研究范围 MNK基因及其蛋白产物的鉴定 与哺乳动物铜稳态有关的新基因。特定的 目的是：(1)证明MNK在细胞内的定位 正常和铜负荷条件下蛋白质的电子显微镜观察； (2)进行发育表达模式的比较研究 MNK和WND基因在正常和突变小鼠中的表达；(3)利用 用于结构成分分析的MNK基因表达载体 参与表达、铜通道和蛋白质定位；以及(4) 鉴定和分离铜转运和铜转运相关的新基因 哺乳动物细胞的动态平衡。这些研究将建立在已取得的进展的基础上 在过去的5年里，并将大大增加对 哺乳动物体内铜的动态平衡及MNK基因在其中的作用 在门克斯病中。

DESCRIPTION: Copper is an essential trace element in both prokaryotic and eukaryotic cells. Its oxidative potential is required for the normal function of over 30 known enzymes in the electron transport, neurotransmitter, connective tissue and free-radical scavenger systems. However, while copper is essential for life, it is highly toxic when present in excess. Therefore, organisms have evolved exact mechanisms for regulating copper homeostasis. Little is known, however, about the mammalian genes that regulate this fine balance. The understanding of this complex process has been greatly enhanced by the cloning of genes causing two genetic disorders, Menkes and Wilson's diseases, in which copper maldistribution is the major metabolic defect. Both have been found to be copper-binding transmembrane ATPases with strong homology to the P-type ATPases of bacteria and to function in cooper transport. During the current project period, the gene (ATP7A;MNK) for Menkes disease was cloned and studies were begun to investigate its structure, function and role in copper homeostasis. Among the findings since identifying the gene, the basic structure of the MNK gene has been determined and found to be very similar to that of the Wilson s disease gene (ATP7B; WND). The MNK protein has been localized to the Golgi network by immunofluorescence. In addition, the homologous mouse gene has been cloned and used to show that the mottled mouse mutants provide valuable animal models for the study of Menkes disease. In this application, studies are proposed to extend characterization of the MNK gene and its protein product and to identify novel related genes involved in copper homeostasis in mammals. Specific aims are: (1) to demonstrate the intracellular localization of the MNK protein by electron microscopy under normal and copper loading conditions; (2) to perform a comparative study of the developmental expression patterns of the MNK and WND genes in normal and mutant mice; (3) to utilize expression constructs of the MNK gene for analysis of structural components involved in expression, copper channeling and protein localization; and (4) to identify and isolate novel related genes involved in copper transport and homeostasis in mammalian cells. These studies will build upon progress made over the past 5 years and will significantly add to the understanding of copper homeostasis in mammals and the role of the MNK gene in this balance and in Menkes disease.