Molecular mechanism of ATP-dependent copper transporters

描述（由申请人提供）：该项目的主要目标是了解调节人体细胞中铜的运输和分布的分子和细胞机制。铜是人体正常生长发育所必需的。铜失衡导致严重的多系统疾病，如门克斯病和威尔逊病。受Menkes病和Wilson病影响的基因分别编码铜转运atp酶ATP7A和ATP7B。铜转运atp酶在人体铜稳态中发挥核心作用，它将铜传递给依赖铜的酶，并从细胞中输出多余的铜。铜三磷酸腺苷酶的活性在分子和细胞水平上受到严格的调控。这种调控的分子机制尚不清楚，将在提出的一系列实验中加以阐明，这些实验有四个具体目的。目的1将比较铜伴侣Atox1对ATP7A和ATP7B的调控。目的2将确定氧化/还原对铜atp酶活性的作用。目的3旨在了解激酶介导的磷酸化在调节Cu- atp酶活性和细胞内定位中的作用。Aim 4将描述一系列威尔逊氏病引起的突变，剖析其分子和细胞后果。该结果将阐明每种铜- atp酶对细胞铜平衡的相对贡献，以及疾病中一种铜- atp酶被另一种铜- atp酶不完全补偿的生化基础。将开发分析细胞中铜转运体的新工具。本研究结果将有助于更好地诊断和治疗人类铜代谢紊乱。

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.