Small-molecule signals controlling nematode development

控制线虫发育的小分子信号

基本信息

批准号：
9248373
负责人：
Rebecca A Butcher
金额：
$ 23.7万
依托单位：
UNIVERSITY OF FLORIDA
依托单位国家：
美国
项目类别：
财政年份：
2016
资助国家：
美国
起止时间：
2016-04-01 至 2021-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9248373
关键词：
Agriculture Anabolism Animals Area Bacteria Behavior Biological Biological Assay Caenorhabditis elegans Chemical Structure Chemicals Complex Data Development Egg Shell Environment Enzymes Fatty Acids G-Protein-Coupled Receptors Gene Expression Genes Human Hybrids Image In Vitro Indoles Insulin Insulin Signaling Pathway Length Life Cycle Stages Link Livestock Longevity Mass Spectrum Analysis Metabolic Metabolism Modeling Modification NMR Spectroscopy Nematoda Neurons Nutrient Organic Synthesis Organism Parasites Parasitic nematode Pathway interactions Peptides Pheromone Phosphotransferases Physiology Play Population Population Density Production Pyruvate Dehydrogenase Complex RNA interference screen Recovery Regulation Research Resistance Role Side Signal Pathway Signal Transduction Signaling Molecule Stable Isotope Labeling Starvation Stress Structure Testing Work carbonyl group comparative enzyme activity experimental study fungus in vitro activity insulin signaling interdisciplinary approach interest knock-down metabolome metabolomics mutant novel overexpression peptide synthase polyketide synthase programs public health relevance small molecule stereochemistry sugar tool

项目摘要

The proposed research program will develop a comprehensive understanding of the chemical structures, biosynthesis, and mechanism of the secondary metabolites used by the nematode Caenorhabditis elegans to control its development and physiology. We will focus on two important types of chemical signals: (1) The dauer pheromone, which C. elegans uses to induce development of the stress-resistant, dauer larval stage at high population densities. (2) A complex hybrid polyketide/ nonribosomal peptide (PK/NRP), which we have recently identified and shown is important for starvation-induced larval arrest. The dauer pheromone consists of several derivatives of the 3,6-dideoxy-L-sugar ascarylose, with different fatty acid-derived side chains. These ascarosides target G protein-coupled receptors in chemosensory neurons and downregulate the insulin and TGF pathways, which regulate dauer formation, metabolism, and lifespan in C. elegans. In Aim 1 of this proposal, we will use a multi-disciplinary approach, including metabolomics, in vitro enzyme assays, organic synthesis of biosynthetic intermediates, and RNAi-based screens, to provide a general framework for ascaroside biosynthesis and its regulation. Our preliminary results, which show that secondary metabolism in C. elegans is closely tied to primary metabolism, have uncovered new, surprising roles for primary metabolic enzymes in ascaroside biosynthesis. We will investigate how different environmental conditions alter specific signaling pathways and downstream ascaroside biosynthetic enzymes, in order to modulate the chemical message that C. elegans communicates to the population. Thus, our work will establish when and how and why C. elegans produces different pheromones. At the fundamental level, these results will enable connections to be made regarding how animals respond to a changing environment and modulate their development and physiology, accordingly. In Aim 2 of this proposal, we will identify a complex hybrid PK/NRP produced by C. elegans. Although it has been noted that a few animals, including C. elegans, contain polyketide synthase (PKS) and nonribosomal peptide synthetase (NRPS) genes, very little is known about these genes. Thus, we are breaking new ground in our work to characterize the structure, biosynthesis, and biological role of the PK/NRP. The domains in the C. elegans PKS/NRPS diverge significantly from those found in bacteria and fungi, and thus, by characterizing these domains, we will uncover unique enzymes and biosynthetic strategies. Our data suggest that the hybrid PK/NRP acts upstream of the insulin pathway and facilitates the metabolic changes that need to occur during starvation-induced larval arrest. The ascarosides and the PK/NRP are conserved chemical signals that are critical for the development and survival of many nematode species, including parasitic ones. Thus, our work will enable the development of chemical tools to interfere with the life cycles of parasitic nematodes and reduce their survival.

拟议的研究计划将全面了解化学结构，线虫秀丽隐杆线虫次级代谢产物的生物合成和机制我们将重点关注两种重要类型的化学信号：（1） dauer 信息素，线虫用它来诱导抗应激的 dauer 幼虫阶段的发育 (2) 我们拥有复杂的杂合聚酮化合物/非核糖体肽 (PK/NRP)。最近发现并表明，dauer 信息素对于饥饿诱导的幼虫抑制很重要。 3,6-二脱氧-L-糖蛔糖的几种衍生物，具有不同的脂肪酸衍生侧链。这些蛔苷靶向化学感应神经元中的 G 蛋白偶联受体并下调胰岛素和 TGF 途径，调节线虫的 Dauer 形成、代谢和寿命。根据建议，我们将采用多学科方法，包括代谢组学、体外酶测定、有机生物合成中间体的合成和基于 RNAi 的筛选，为我们的初步结果表明，蛔苷的生物合成及其调控。秀丽隐杆线虫与初级代谢密切相关，发现了初级代谢的新的、令人惊讶的作用我们将研究不同的环境条件如何改变特定的蛔苷生物合成酶。信号通路和下游蛔苷生物合成酶，以调节化学物质因此，我们的工作将确定线虫向人群传达的信息的时间、方式和方式。为什么线虫会产生不同的信息素从根本上讲，这些结果将使我们成为可能。关于动物如何应对不断变化的环境并调节其行为建立联系因此，在该提案的目标 2 中，我们将确定一个复杂的混合 PK/NRP。尽管人们已经注意到，包括秀丽隐杆线虫在内的一些动物含有秀丽隐杆线虫。聚酮合酶（PKS）和非核糖体肽合成酶（NRPS）基因，人们知之甚少因此，我们在研究这些基因的结构、生物合成和特性方面取得了新的突破。 PK/NRP 的生物学作用。秀丽隐杆线虫 PKS/NRPS 的结构域与那些结构域显着不同。在细菌和真菌中发现，因此，通过表征这些域，我们将发现独特的酶和我们的数据表明混合 PK/NRP 在胰岛素途径的上游发挥作用。促进饥饿引起的幼虫停滞期间需要发生的代谢变化。 PK/NRP 是保守的化学信号，对于许多细胞的发育和生存至关重要因此，我们的工作将使化学工具的开发成为可能。干扰寄生线虫的生命周期并降低其存活率。