DIPTERA MEVALONIC ACID METABOLISM AND REGULATION

双翅目甲羟戊酸代谢与调节

• 批准号: 2519035
• 负责人: JOHN A WATSON
• 金额: $ 24.31万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
• 依托单位国家: 美国
• 财政年份: 1994
• 资助国家: 美国
• 起止时间: 1994-09-30 至 1998-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2519035
• 关键词: Aedes; Drosophilidae; HMG coA reductases; enzyme activity; fatty acid biosynthesis; fatty acid metabolism; high performance liquid chromatography; messenger RNA; mevalonate; molecular biology; northern blottings; nucleic acid probes; phosphatase inhibitor; phosphoprotein phosphatase; phosphorylation; polyenes

Mevalonic acid (MVA) is the unique precursor for metabolically essential compounds terms "isopentenoids" (e.g., ubiquinones, dolichols, cytochromse a3, juvenile hormones, prenylated proteins, etc.). Since many isopentenoids cannot be obtained from dietary sources, continuous MVA synthesis is required for life. The regulation of MVA synthesis at the molecular level is poorly understood in eukaryotes in general and insects specifically. Moreover, insects cannot synthesize the sterol nucleus, therefore, in contrast to sterologenic organisms, their regulation of MVA synthesis is signaled exclusively by nonsterol isopentenoid availability. Thus, it is possible that a firm understanding of insect nonsterol isopentenoid-mediated regulation of MVA synthesis might provide unique insight into this process in other eukaryotes. We propose to use immortalized Dipteran Kc and secondarily Aedes albopictus C7-10 and Aedes aegypti ATCC-125 cells) as models to define nonsterol-mediated regulation of MVA synthesis. 3-Hydroxy-3-methylglutaryl coenzymeA reductase (HMGR) is the enzyme which catalyzes MVA synthesis from HMG-CoA. In addition, Drosophila Kc cell HMGR Vmax activities are congruent with absolute in vivo MVA synthesis rater. Therefore, an understanding of nonsterol isopentenoid-mediated control of Kc cell HMGR metabolism should also define the regulation of MVA synthesis. Molecular probes for Drosophila HMGR protein and mRNA will be used in conert with detailed radio-metabolic flux analyses to delineate Kc cell nonsterol-mediated regulation of MVA synthesis. Three hypotheses will be addressed: (1) nonsterol isopentenoid-mediated regulation of immortalized Dipteran cellular HMGR metabolism is primarily posttranslational. (2) C15, C20-polyprenols and/or C15, C20-polyprenl-1-pyrophosphates signal MVA-mediated down regulation of Kc cell HMGR, and (3) regulatory isopentenoids modulate Kc cell HMGR function by altering the phosphorylation status of HMGR and/or ancillary proteins. This effort will be facilitated by the use of both intact and perforated Kc cells. The proposed studies will generate new fundamental information about nonsterol isopentenoid-mediated regulation of Kc cell MVA synthesis/HMGR metabolism. Lastly, MVA-derived products are required for insect development, oogenesis, and othe ress Therefore, an understanding of different Dipterans' MVA metabolism and regulation might reveal species specific targets for new chemical/biological insecticides.

甲羟戊酸 (MVA) 是代谢必需物质的独特前体 化合物术语“类异戊烯”（例如，泛醌、多醇、 细胞色素 a3、保幼激素、异戊二烯化蛋白等）。由于许多 类异戊烯不能从饮食来源获得，连续MVA 生命需要合成。 MVA合成的调控 对于一般真核生物和昆虫的分子水平知之甚少 具体来说。而且，昆虫不能合成甾醇核， 因此，与甾体生物相比，它们对 MVA 的调节 合成仅由非甾醇类异戊烯的可用性来表示。 因此，对昆虫非甾醇的深入了解是可能的。 类异戊烯介导的 MVA 合成调节可能提供独特的 深入了解其他真核生物中的这一过程。我们建议使用 永生化双翅目 Kc 和次生白纹伊蚊 C7-10 和伊蚊 埃及伊蚊 ATCC-125 细胞）作为模型来定义非甾醇介导的调节 MVA合成。 3-羟基-3-甲基戊二酰辅酶A还原酶（HMGR）是一种酶， 催化 HMG-CoA 合成 MVA。此外，果蝇Kc细胞 HMGR Vmax 活性与绝对体内 MVA 合成一致 评估者。因此，了解非甾醇类异戊烯介导的 Kc 细胞 HMGR 代谢的控制还应定义 MVA合成。 果蝇 HMGR 蛋白和 mRNA 的分子探针将用于 配合详细的放射代谢通量分析来描绘 Kc 细胞 非甾醇介导的 MVA 合成调节。三个假设将是 解决：（1）非甾醇类异戊烯介导的永生化调节 双翅目细胞 HMGR 代谢主要是翻译后代谢。 (2) C15、C20-聚戊烯醇和/或 C15、C20-聚戊烯1-1-焦磷酸信号 MVA 介导的 Kc 细胞 HMGR 下调，以及 (3) 调节 类异戊烯通过改变 Kc 细胞 HMGR 功能 HMGR 和/或辅助蛋白的磷酸化状态。这个努力 将通过使用完整和穿孔的 Kc 细胞来促进。 拟议的研究将产生新的基本信息 非甾醇类异戊烯介导的 Kc 细胞 MVA 合成/HMGR 调节 代谢。最后，昆虫需要 MVA 衍生产品 发育、卵子发生等因此，了解 不同双翅目动物的 MVA 代谢和调节可能揭示物种 新化学/生物杀虫剂的具体目标。