Biochemical and Molecular Genetic Studies of the HMT-1-Dependent Heavy Metal Detoxification Pathway in C. Elegans

该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。虽然金属污染的环境是一个日益关注的问题，但仍有许多关于所有生物的保护性适应和机制的知识有待了解。有效开发重金属污染环境生物修复策略的能力取决于对这些细胞解毒和耐受机制的详细了解。在这方面，HMT-1，半分子ATP结合盒（ABC）的转运线虫是急性所需的重金属解毒，并在许多其他物种，包括莱茵衣藻，裂殖酵母，果蝇和人类的同源物。HMT-1依赖性途径如何发挥作用以及其他ABC转运蛋白相对于HMT-1的作用尚不清楚。本项目使用C。elegans作为一个简单和定义明确的模型系统，研究HMT-1依赖的解毒途径，使用生化和遗传方法。目标1将集中于鉴定和定位在复合物中与HMT-1功能相关的蛋白质。在目标2中进行的平行系统遗传分析将确定重金属耐受性所需的ABC转运蛋白，并评估其与HMT-1的功能关系。鉴于C. elegans ABC转运蛋白基因家族，这项工作有望引起更广泛的C. elegans社区和超越学习这些基因的功能和潜在的参与与其他压力反应和发展途径。在提供有关HMT-1依赖性途径的第一个基本信息时，该项目将识别和分类ABC转运蛋白的功能作用，识别新的途径，并将功能归因于以前未确定参与金属解毒的已知途径，从而有助于理解金属耐受性的细胞资源的长期目标。更广泛的影响。该项目的研究部分与学生、博士后研究员和公众关于重金属及其毒性以及环境和农业生物技术方面更广泛问题的教育相结合。首先，讨论重金属及其毒性的一系列讲座被整合到两个高级讲座课程中。第二，研究的方向是在实验室培训和指导本科生、研究生和博士后研究员，特别努力招募妇女和少数民族。将现代基因组学和生物化学方法结合起来研究环境问题将为下一代科学家提供宝贵的经验。第三，该项目旨在使纽约州的农民和园丁更多地了解重金属及其毒性，以及安全土壤管理对减少重金属进入食物链的重要性。这一外联活动将包括演讲和编写方便用户的土壤测试解释指导文件，这些文件将在一个网络模块中进行总结。这一举措具有令人兴奋的广泛使用的潜力，超越了纽约州的公民，并可能提供一个范例，有效的科学专业知识和研究与公共信息的接口。

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). While metal polluted environments are a growing concern, much remains to be learned about the protective adaptations and mechanisms in all organisms. The ability to effectively develop bioremediation strategies for heavy metal-polluted environments is contingent on gaining a detailed understanding of these cellular detoxification and tolerance mechanisms. In this regard, HMT-1, a half molecule ATP-binding cassette (ABC) transporter in the nematode worm Caenorhabditis elegans is acutely required for heavy metal detoxification and has homologs in many other species including Chlamydomonas reinhardtii, Schizosaccharomyces pombe, Drosophila and humans. How the HMT-1-dependent pathway functions and the roles of other ABC transporters relative to HMT-1 are unknown. This project uses C. elegans as a simple and well-defined model system to study the HMT-1-dependent detoxification pathway using biochemical and genetic approaches. Objective 1 will focus on the identification and localization of proteins that functionally associate with HMT-1 in a complex. Parallel systematic genetic assays pursued in Objective 2 will identify ABC transporters that are required for heavy metal tolerance, and assess their functional relationships to HMT-1. Given the large and diverse nature of the C. elegans ABC transporter gene family, this work promises to be of considerable interest to the broader C. elegans community and beyond to learn the function of these genes and potential involvement with other stress responses and developmental pathways. In providing the first fundamental information about the HMT-1-dependent pathway, this project will identify and classify functional roles of the ABC transporters, identify new pathways, and ascribe functions to known pathways that have not previously been determined to be involved in metal detoxification, and thus will contribute to the long-term goal of understanding of cellular resources for metal tolerance. Broader Impacts. The research component of this project is integrated with the education of students, postdoctoral fellows and the general public about heavy metals and their toxicity as well as broader issues in environmental and agricultural biotechnology. First, a series of lectures discussing heavy metals and their toxicity is integrated into two upper-level lecture courses. Second, research is directed towards the training and mentoring of undergraduate, graduate students and postdoctoral fellows in the laboratory with special efforts to recruit women and minorities. The incorporation of modern genomic and biochemical approaches to study environmental issues will provide valuable experience for the next generation of scientists. Third, the project is designed to reach New York State (NYS) farmers and gardeners to increase their knowledge about heavy metals and their toxicity, and the importance of safe soil management for decreasing heavy metal entrance into the food chain. This outreach activity will consist of lecture presentations, and the development of user-friendly soil-test interpretation guidance documents, which will be summarized in a web module. This initiative has exciting potential for broad usage, going beyond the citizens of NYS, and may provide a paradigm for effective interfacing of scientific expertise and research with publicly-available information.