Molecular mechanism of ATP-dependent copper transporters

描述(申请人提供)：该项目的主要目标是了解调控铜在人体细胞中运输和分布的分子和细胞机制。铜是人类生物体正常生长发育所必需的。铜失衡会导致严重的多系统紊乱，如门克斯病和威尔逊病。门克斯病和威尔逊病中受影响的基因分别编码铜转运酶ATP7A和ATP7B。转运铜的ATPase通过将铜输送到铜依赖的酶以及从细胞中输出多余的铜，在人类铜的动态平衡中发挥着核心作用。铜-ATPase的活性在分子和细胞水平上受到严格的调控。这一调控的分子机制尚不清楚，将在拟议的一系列实验中阐明，这些实验有四个具体目标。目的1比较铜伴侣蛋白Atox1对ATP7A和ATP7B的调节作用。目标2将确定氧化/还原对铜-ATPase活性的作用。目的3旨在了解激酶介导的磷酸化在调节铜-三磷酸腺苷酶活性和细胞内定位中的作用。目标4将描述一系列导致威尔逊病的突变，以剖析其分子和细胞后果。这一结果将阐明每种铜-ATPase对细胞铜平衡的相对贡献，以及疾病中一种铜-ATPase被另一种不完全代偿的生化基础。将开发用于分析细胞内铜转运体的新工具。这项研究的结果将有助于开发更好的诊断和治疗人类铜代谢障碍。 公共卫生相关性：该项目的重点是了解人类铜转运蛋白ATP7A和ATP7B的功能和调控，它们分别与门克斯病和威尔逊病相关。这些研究将确定调节细胞中铜转运蛋白活性的因素，并表征已知的致病突变的后果。这一结果将有助于改善人类铜代谢障碍的诊断和治疗。

DESCRIPTION (provided by applicant): The major goal of this project is to understand the molecular and cellular mechanisms that regulate the transport and distribution of copper in human cells. Copper is essential for normal growth and development of human organisms. Copper misbalance results in severe multi-system disorders exemplified by Menkes disease and Wilson's disease. The genes affected in Menkes disease and Wilson's disease code for the copper-transporting ATPases ATP7A and ATP7B, respectively. The copper-transporting ATPases play a central role in human copper homeostasis by delivering copper to the copper-dependent enzymes as well as exporting excess copper from cells. The activity of copper- ATPases is tightly regulated at the molecular and cellular level. The molecular mechanism of this regulation is poorly understood and will be elucidated in the proposed series of experiments, which have four specific aims. Aim 1 will compare the regulation of ATP7A and ATP7B by the copper chaperone Atox1. Aim 2 will determine the role of oxidation/reduction for the copper-ATPase activity. Aim 3 is designed to understand the role of a kinase-mediated phosphorylation in modulating the Cu- ATPases activity and intracellular localization. Aim 4 will characterize a series of Wilson's disease causing mutations to dissect their molecular and cellular consequences. The results will clarify the relative contribution of each copper-ATPase to cellular copper balance as well as the biochemical basis for incomplete compensation of one copper-ATPase by the other in disease. New tools for the analysis of copper transporters in cells will be developed. The results of this research will contribute to the development of better diagnostics and treatments for human disorders of copper metabolism. PUBLIC HEALTH RELEVANCE: The project focuses on understanding the function and regulation of human copper transporters ATP7A and ATP7B, associated with Menkes disease and Wilson's disease, respectively. The studies will identify factors that modulate the activity of the copper transporters in cells and characterize the consequences of known disease- causing mutations. The results will contribute to improved diagnostic and treatment of human disorders of copper metabolism.