Copper Protein In Metal and Oxidant Stress Responses

描述（由申请人提供）：金属伴侣蛋白Atx1和CCS（铜，锌超氧化物歧化酶的铜伴侣蛋白，SOD1）是可溶性金属受体蛋白，其功能是引导和保护金属离子，同时促进细胞内适当的伙伴关系。atx1样蛋白确保了Cu(l)辅助因子在分泌途径中容易传递到细胞内靶点，而CCS具有更复杂的结构和功能。新的研究结果表明，这种金属伴侣需要氧等氧化剂来完成SOD1成熟和活性状态的形成。阐明这些过程的机制将为理解铜在病理条件下的细胞生物学，如Wilson和Menkes病和家族性肌萎缩性侧索硬化症（fALS）提供关键。金属伴侣及其生理靶点的动力学、热力学和结构-功能研究将验证这些蛋白质的功能是通过降低铜转移到伴侣蛋白的激活屏障，但保持转移到其他位点的高屏障。虽然多结构域铜伴侣CCS既不解毒铜也不解毒活性氧（ROS），但新的研究结果表明，它在氧化应激反应的翻译后调节中发挥作用：当氧化应激增加时，CCS促进其靶点apoSODL正确的二硫键形成。这些机制、生理和结构研究将为更全面地了解疾病中的金属运输和体内平衡提供基础。新开发的工具和试剂将用于解决铜蛋白在神经退行性疾病中的作用，以及铜细胞生物学和氧生理学之间的新兴联系。例如，这些研究将测试SOD1中导致fALS的功能突变的新模型：导致疾病的蛋白质的未成熟的二硫还原形式在生理温度下完全展开，并且在形成不适当的二硫交联时很容易成为不溶性聚集体。

DESCRIPTION (provided by applicant): The metallochaperone proteins Atx1 and CCS (copper chaperone for copper, zinc superoxide dismutase, SOD1) are soluble metal receptor proteins that function to guide and protect the metal ion while facilitating appropriate partnerships within the cell. The Atx1-like proteins ensure the facile delivery of a Cu(l) cofactor to intracellular targets in the secretory pathway while CCS has a more complex structure and function. New results suggest that this metallochaperone requires oxidants such as oxygen to complete formation of the mature and active state of SOD1. Elucidating the mechanisms of these processes will provide keys to understanding the cell biology of copper in pathological conditions, such as Wilson and Menkes disease and familial amyotrophic lateral sclerosis (fALS). Kinetic, thermodynamic and structure-function studies of the metallochaperones and their physiological targets will test the hypothesis that these proteins function by lowering the activation barrier for Cu-transfer to partner proteins but maintain high barriers for transfer to other sites. While the multidomain copper chaperone CCS neither detoxifies copper or reactive oxygen species (ROS), new results suggest that it plays a role in posttranslational regulation of oxidative stress responses: as oxidative stress increases, CCS facilitates the correct disulfide bond formation in its target, apoSODL These mechanistic, physiological and structural studies will provide the basis for a more complete understanding of metal trafficking and homeostasis in disease. The newly developed tools and reagents will be used to address roles of copper proteins in neurodegenerative diseases, as well as the emerging connections between copper cell biology and oxygen physiology. For instance these studies will test an emerging model for the gain of function mutations in SOD1 that cause fALS: the immature disulfide reduced forms of the disease causing proteins are completely unfolded at physiological temperature and readily become insoluble aggregates upon formation of inappropriate disulfide crosslinks.