Genetic Analysis of Iron Homeostasis in C. elegans

线虫铁稳态的遗传分析

• 批准号: 7099690
• 负责人: Elizabeth Ann Leibold
• 金额: $ 23.5万
• 依托单位: UNIVERSITY OF UTAH
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-05-15 至 2011-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7099690
• 关键词: Caenorhabditis elegans; biological signal transduction; ferritin; gene expression; genetic regulation; genetic regulatory element; genetic transcription; green fluorescent proteins; helminth genetics; iron metabolism

DESCRIPTION (provided by applicant): Iron has an essential role in many biological processes, including DMA synthesis/respiration, the tricarboxylic acid cycle, oxygen transport, heme synthesis and photosynthesis. But iron can also be toxic due to its ability to generate free radicals that damage macromolecules in cells. Consequently, organisms have evolved precise mechanisms to sense, acquire and store iron. Our goal is to learn more about how eukaryotic cells sense iron, generate a signal and transduce the signal into regulating iron homeostasis. Specifically, we are interested in understanding how transcription factors sense iron, and regulate gene expression in animal cells. While iron-mediated transcription factors have been identified in fungi and plants, little is known about the mechanisms and the proteins regulating iron-mediated transcriptional regulation in animal cells. We have discovered that Caenorhabditis elegans express ferritin (CeFTN-1 and CeFTN-2), which are key iron storage proteins. Our data shows that Ceftn-1 and Ceftn-2 are transcriptionally regulated by iron, and that cis-regulatory sequences present in their 5' upstream regions are required for this regulation. We propose to identify the cis-regulatory sequences and the iron-sensing transcription factor that binds these elements, and to determine how this transcription factor senses iron. We will also identify other C. elegans genes involved in iron signaling pathways. C. elegans offers a complementary approach to iron metabolic studies in other organisms, in that they are amenable to genetic analysis, they have organ/tissue systems, and they have homologs of genes encoding proteins involved in mammalian iron homeostasis. The specific aims are 1) to characterize cis-acting iron-regulatory elements in Ceftn-1 and Ceftn-2 promoters, 2) to purify the C. elegans transcription factor that regulates the Ceftn-1 and Ceftn-2 genes, and to determine how this factor controls ferritin expression, and 3) to identify genes involved in iron signaling pathways in C. elegans using a green fluorescence protein (GFP)-based screen.

描述（由申请人提供）：铁在许多生物过程中具有重要作用，包括DMA合成/呼吸、三羧酸循环、氧运输、血红素合成和光合作用。但铁也可能是有毒的，因为它能够产生自由基，破坏细胞中的大分子。因此，生物体已经进化出精确的机制来感知，获取和储存铁。我们的目标是更多地了解真核细胞如何感知铁，产生信号并将信号转化为调节铁稳态。具体来说，我们有兴趣了解转录因子如何感知铁，并调节动物细胞中的基因表达。虽然铁介导的转录因子已被确定在真菌和植物中，很少有人知道的机制和蛋白质调节铁介导的转录调控在动物细胞中。我们已经发现秀丽隐杆线虫表达铁蛋白（CeFTN-1和CeFTN-2），这是关键的铁储存蛋白。我们的数据表明Ceftn-1和Ceftn-2受铁的转录调控，并且在其5'上游区域存在的顺式调控序列是这种调控所必需的。我们建议确定的顺式调控序列和铁敏感转录因子，结合这些元素，并确定该转录因子如何感测铁。我们还将确定其他C。elegans基因参与铁信号通路。C.秀丽线虫为其他生物体的铁代谢研究提供了一种补充方法，因为它们适合于遗传分析，它们具有器官/组织系统，并且它们具有编码涉及哺乳动物铁稳态的蛋白质的基因的同源物。具体目的是1）表征Ceftn-1和Ceftn-2启动子中的顺式作用铁调控元件，2）纯化C. elegans转录因子调节Ceftn-1和Ceftn-2基因，并确定该因子如何控制铁蛋白表达，以及3）鉴定C.使用基于绿色荧光蛋白（GFP）的筛选，