Folate-directed signaling in C. elegans

线虫中叶酸定向信号传导

• 批准号: 10348183
• 负责人: EDWARD T. KIPREOS
• 金额: $ 30.2万
• 依托单位: UNIVERSITY OF GEORGIA
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-04-15 至 2024-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10348183
• 关键词: Animal Model; Animals; Bacteria; Behavior; Biochemical; Caenorhabditis elegans; Calcium; Calcium Channel; Carbon; Cell Proliferation; Cell physiology; Cells; Data; Diet; Event; FOLR1 gene; Folic Acid; Food; Future; Gastrointestinal tract structure; Genes; Genetic; Genetic Screening; Germ Cells; Goals; Growth; Human; Link; Malignant Neoplasms; Mediating; Metabolism; Methods; Molecular; Motion; Mutation; Nematoda; Neural Tube Closure; Neural Tube Defects; Neural Tube Development; Neurons; Normal tissue morphology; Pathway interactions; Process; Proteins; Research; Role; SLC19A1 gene; Signal Pathway; Signal Transduction; Source; Tissues; Vertebrates; Vitamins; adult stem cell; dihydropteroate; experimental study; folate-binding protein; genetic approach; germline stem cells; insight; overexpression; receptor; response; stem cell population; stem cell proliferation; tumor progression; uptake

Project Summary The folate receptor is one of three major types of folate transporters. The human folate receptor is required for proper neural tube development, and is often overexpressed in cancers where it contributes to cancer progression. In both of these processes, there is emerging evidence that the foIate receptor acts independently of providing folates as vitamins for one-carbon metabolism. The small roundworm C. elegans obtains folates from its food source of bacteria. We have discovered that a specific bacterial folate (10-formyl-THF) increases the rate of proliferation of C. elegans germ stem cells, thereby acting as a signal to link the rate of proliferation to the availability of the animal’s bacterial diet. Additionally, we discovered that 10-formyl-THF acts as a signal to activate the NSM neurons. The activation of the NSM neurons causes starved animals to stop their forward motion when they encounter bacteria. Both of these processes require the C. elegans folate receptor, FOLR-1, and are independent of providing folates for their canonical role in one-carbon metabolism. The goal of this proposal is to identify the molecular pathways through which FOLR-1 mediates signals from the stimulatory folate to germ cells and the NSM neurons. We will use fluorescent tags to determine where FOLR-1 is localized in cells and whether the localization changes in the presence of stimulatory folates. Genetic experiments suggest that FOLR-1 functions in both neuronal and non- neuronal tissues to mediate the activation of the NSM neuron. We discovered that the GON-2 calcium channel is required for the calcium influx that accompanies NSM neuronal activation. Similar to FOLR-1, GON-2 is also required in both neuronal and non-neuronal tissues for NSM activation. Using genetic approaches, we will identify the tissues in which FOLR-1 and GON-2 each function to allow NSM activation. We discovered that GON-2 is also required both to maintain calcium levels in the germline and for normal germ cell proliferation, suggesting that increased calcium levels promote germ cell proliferation. We will determine if calcium levels differ in response to growth conditions and stimulatory folate, and the role of GON-2 and FOLR-1 in altering calcium levels. Genetic approaches will be used to identify the downstream effectors that alter germ cell proliferation in response to altered calcium levels in the germline. Unbiased genetic screens will be used to identify components and regulators of the stimulatory-folate pathway(s). The identified genes will be analyzed using genetic and biochemical approaches to determine how they contribute to the pathway(s). This research will uncover the molecular pathway(s) through which folates regulate diverse cellular processes independently of their role in metabolism. This will provide a paradigm for understanding non-canonical folate pathways, with the potential for insights into neural tube defects and cancer.

项目摘要 叶酸受体是叶酸转运蛋白的三种主要类型之一。人叶酸受体是 适当的神经管发育所必需的，并且通常在癌症中过表达 有助于癌症进展。在这两个过程中，都有新兴的证据表明 泡沫受体独立于为单碳代谢提供叶酸作为维生素。这 小round虫C.秀丽隐杆线虫从其细菌的食物来源获得叶状。我们发现了 特定的细菌叶酸（10甲胺-THF）增加了秀丽隐杆线虫生殖的增殖速率 干细胞，从而充当将增殖速率与动物的可用性联系起来的信号 细菌饮食。此外，我们发现10甲甲基-THF充当激活NSM的信号 神经元。 NSM神经元的激活导致饥饿的动物停止其前进运动 当他们遇到细菌时。这两个过程都需要秀丽隐杆线虫叶酸受体， FOLR-1，并且独立于为叶酸提供其在单碳代谢中的规范作用。 该建议的目的是确定FOLR-1培养基的分子途径 从刺激性叶酸到生殖细胞和NSM神经元的信号。我们将使用荧光标签 确定FOLR-1位于细胞中的位置以及定位是否在存在下发生变化 刺激性叶子。基因实验表明，FOLR-1在神经元和非 - 神经元组织介导NSM神经元的激活。我们发现Gon-2 钙通道是涉及NSM神经元激活的钙影响所必需的。相似的 对于FOLR-1，在神经元和非神经元组织中也需要GON-2进行NSM激活。 使用遗传方法，我们将确定FOLR-1和GON-2每个功能的组织 允许NSM激活。我们发现Gon-2也需要两者保持钙水平 生殖线和正常生殖细胞增殖，表明钙水平升高促进 生殖细胞增殖。我们将确定钙水平在生长条件下的响应和 刺激性叶酸，以及GON-2和FOLR-1在改变钙水平的作用。遗传方法 将用于确定因响应而改变生殖细胞增殖的下游效应 种系中的钙水平改变。公正的遗传筛选将用于识别组件 和刺激性叶酸途径的调节剂（S）。确定的基因将使用 遗传和生化方法确定它们如何对途径做出贡献。这 研究将揭示分子途径，通过该途径调节多种细胞 过程独立于它们在代谢中的作用。这将为理解提供一个范式 非经典叶酸途径，有可能深入了解神经管缺陷和癌症。