MECHANISTIC INSIGHTS INTO CADMIUM DETOXIFICATION

镉解毒机制的见解

• 批准号: 7720826
• 负责人: JAEKWON LEE
• 金额: $ 16.76万
• 依托单位: UNIVERSITY OF NEBRASKA LINCOLN
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-08-01 至 2009-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7720826
• 关键词: ATP phosphohydrolase; Bacteria; Biochemical; Biological; Biological Assay; Biological Process; Cadmium; Cells; Cellular biology; Chemistry; Computer Retrieval of Information on Scientific Projects Database; DNA Repair Inhibition; Data; Disease; Drug Metabolic Detoxication; Endocrine disruption; Environmental Pollution; Eukaryota; Eukaryotic Cell; Excretory function; Exposure to; Family; Funding; Genes; Genetic; Goals; Grant; Heavy Metals; Homeostasis; Human; Institution; Ions; Kidney Diseases; Knowledge; Malignant Neoplasms; Mediating; Membrane; Metals; Modeling; Molecular; Numbers; Nutritional; Organism; Physiological; Range; Regulation; Regulatory Element; Research; Research Personnel; Resistance; Resources; Saccharomyces cerevisiae; Source; Specificity; Structure; Substrate Specificity; System; Testing; Toxic effect; United States National Institutes of Health; Yeasts; efflux pump; estrogenic activity; in vitro Assay; in vivo; insight; novel; toxic metal; yeast genetics

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Detoxification of non-physiological metals and homeostatic acquisition of nutritional yet toxic metals are fundamental biological processes. Cadmium is a highly toxic environmental contaminant, which causes a number of human disorders, including kidney disease, cancer, and endocrine disruption. Oxidative cellular damage, perturbation of nutritional metal homeostasis, inhibition of DNA repair, and estrogenic activities are implicated with cadmium toxicity. However, the mechanisms of cadmium detoxification in eukaryotes, especially cadmium excretion systems, are largely unknown. The long-term goals of this project are the characterization of molecular mechanisms of cadmium detoxification and employing this knowledge to reduce cadmium exposure to humans. During the search for genes involved in heavy metal resistance in yeast Saccharomyces cerevisiae, we have identified a P-type ATPase. All organisms ranging from bacteria to humans rely on this family of transporters for maintaining a trans-membrane gradient of various ions. Our data strongly suggest that this P-type ATPase is a cadmium selective exporter. Moreover, when cells grow in cadmium-containing media, the expression levels of this transporter are rapidly up regulated through cadmium-mediated inhibition of active turnover. This application focuses on characterization of the function, mechanisms of action and regulation of this cadmium transporter. The central hypothesis is that this P-type ATPase is the first cadmium-specific efflux pump that is unique in structure, substrate specificity and mode of regulation. This hypothesis will be tested using biochemical, cell biological and genetic approaches. First, metal specificity of the P-type ATPase will be elucidated. This study will largely focus on in vivo metal resistant and accumulation assays and in vitro ATPase assays. Second, a multi-disciplinary approach combining yeast genetics, cell biology and chemistry will identify regulatory elements involved in the unique mode of cadmium-dependent post-translational control of this P-type ATPase. The proposed studies will reveal a novel cadmium detoxification mechanism mediated by a P-type ATPase in yeast, a model eukaryote, and ultimately advance our ability to combat cadmium related disorders in humans.

该子项目是利用该技术的众多研究子项目之一 资源由 NIH/NCRR 资助的中心拨款提供。子项目及 研究者 (PI) 可能已从 NIH 的另一个来源获得主要资金， 因此可以在其他 CRISP 条目中表示。列出的机构是 对于中心来说，它不一定是研究者的机构。 非生理金属的解毒和营养但有毒金属的稳态获取是基本的生物过程。镉是一种剧毒环境污染物，会导致许多人类疾病，包括肾病、癌症和内分泌紊乱。氧化细胞损伤、营养金属稳态扰乱、DNA 修复抑制和雌激素活性都与镉毒性有关。然而，真核生物中镉解毒的机制，特别是镉排泄系统，在很大程度上尚不清楚。该项目的长期目标是表征镉解毒的分子机制，并利用这些知识来减少人类对镉的接触。在寻找酿酒酵母重金属抗性相关基因的过程中，我们发现了一种 P 型 ATP 酶。从细菌到人类的所有生物体都依赖于这个转运蛋白家族来维持各种离子的跨膜梯度。我们的数据强烈表明这种 P 型 ATP 酶是镉选择性输出器。此外，当细胞在含镉培养基中生长时，通过镉介导的主动周转抑制，该转运蛋白的表达水平迅速上调。该应用的重点是这种镉转运蛋白的功能、作用机制和调节的表征。核心假设是，这种 P 型 ATP 酶是第一个镉特异性外排泵，其结构、底物特异性和调节模式都是独特的。这一假设将通过生化、细胞生物学和遗传学方法进行检验。首先，将阐明P型ATP酶的金属特异性。本研究将主要集中于体内金属抗性和积累测定以及体外 ATP 酶测定。其次，结合酵母遗传学、细胞生物学和化学的多学科方法将鉴定参与这种 P 型 ATP 酶的镉依赖性翻译后控制的独特模式的调控元件。拟议的研究将揭示酵母（一种模型真核生物）中 P 型 ATP 酶介导的新型镉解毒机制，并最终提高我们对抗人类镉相关疾病的能力。