Regulation of Digestion in Blood-Sucking Insects

吸血昆虫的消化调节

• 批准号: 7846474
• 负责人: ROGER L MIESFELD
• 金额: $ 2.05万
• 依托单位: UNIVERSITY OF ARIZONA
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-06-05 至 2010-09-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7846474
• 关键词: 1-Phosphatidylinositol 4-Kinase; Aedes; Amino Acids; Blood; Blood Proteins; Culicidae; Digestion; Ecdysone; Egg Yolk Proteins; Endoplasmic Reticulum; Enzymes; Event; Fat Body; Female; Funding; Genes; Genetic Transcription; Hour; In Vitro; Ingestion; Insecta; Lead; Lipids; Messenger RNA; Midgut; Modeling; Oocytes; Ovary; Peptides; Phase; Phosphatidylinositols; Phosphorylation; Phosphotransferases; Preparation; Process; Protein Biosynthesis; Proteins; Regulation; Role; Series; Signal Transduction; Time; Transcriptional Activation; Transcriptional Regulation; Translations; Trypsin; Vitellogenesis; Weight; Work; computerized data processing; egg; feeding; gene induction; reproductive; secretory protein; small molecule; sucking

In mosquitoes, the conversion of protein from a blood meal into yolk proteins and lipids for the developing oocytes is an essential part of the reproductive cycle. Blood feeding by a female Aedes aegypti mosquito initiates a series of events in the midgut, the fat body and the ovaries. Female mosquitoes ingest more than their own weight in blood in a short time and then spend the next 36 hours converting the amino acids from the blood proteins into the constituents of their eggs, a process termed vitellogenesis. The process begins in the midgut with the digestions of blood meal proteins and the regulation of digestive enzyme synthesis in the midgut opcurs in two phases. The early phase begins immediately after ingestion of the meal and involves activation of translation. The synthesis of early trypsin serves as.a model for this phase. The late phase begins 6-8 hours after the meal and involves activation of transcription. The synthesis of late trypsin serves as a model for this phase. In this proposal we seek funds to continue work on the mechanism of regulation of digestive enzyme synthesis in the female mosquito midgut following a blood meal. We propose the following two specific aims: . 1. Investigate the mechanism of activation of translation of the early trypsin mRNA following a protein meal. During the first 30 minutes following a blood meal, a peptide or small molecule is present in whole body extracts, which makes an in vitro midgut preparation competent for early trypsin translation. After 30 minutes, a phosphorylation cascade is initiated in the midgut which leads to activation of translation of early trypsin. We propose to isolate and characterize the factor that induces translational competency in the midgut, and to characterize the signaling processes that lead to activation of early trypsin translation. We also propose to investigate the role of the endoplasmic reticulum whorls in regulating secretory protein synthesis in the midgut. 2. Investigate the mechanism of transcriptional regulation of the late trypsin gene. About 6 hours after feeding, late trypsin transcription in the midgut is initiated. We have recently found that ecdysone, and an uncharacterized factor present in extracts prepared from fat bodies of fed mosquitoes, are involved in late trypsin gene induction. We propose to characterize the mechanism of ecdysone regulation of late trypsin expression, and to identify the fat body factor and the role of phosphoinositide 3-kinase (PI-3K) signaling in modulating late trypsin transcription.

蚊子将血粉中的蛋白质转化为卵黄蛋白和脂肪以供发育的过程 卵母细胞是生殖周期中必不可少的一部分。一只雌性埃及伊蚊的吸血情况 在中肠、脂肪体和卵巢中引发一系列事件。雌性蚊子摄取的食物超过 在短时间内将其自身重量的血液中的氨基酸从 血液中的蛋白质转化为卵子的成分，这一过程被称为卵黄发生。这一过程开始于 中肠对血粉蛋白的消化及消化酶合成的调节 中肠分为两个阶段。早期阶段在进食后立即开始，包括 激活翻译。早期胰酶的合成为这一阶段提供了一个模型。后期 在进餐后6-8小时开始，涉及转录的激活。晚期胰酶的合成 作为这个阶段的典范。在这项提案中，我们寻求资金，以继续开展监管机制的工作 雌性蚊子中肠在吸血后的消化酶合成。我们提出以下建议 两个具体目标：。 1.探讨蛋白质餐后早期胰酶mRNA翻译的激活机制。 在一顿血餐后的前30分钟内，一种肽或小分子存在于全身。 提取物，这使得体外中肠制剂能够胜任早期胰酶翻译。30分钟后， 一个磷酸化级联反应在中肠启动，导致早期胰酶翻译的激活。 我们建议分离和表征诱导中肠翻译能力的因素，并 描述导致早期胰酶翻译激活的信号传递过程。我们还建议 探讨内质网旋涡在调节大鼠脑内分泌蛋白合成中的作用 中肠。 2.研究晚期胰蛋白酶基因的转录调控机制。大约6小时后 摄食时，中肠中胰蛋白酶的晚期转录开始。我们最近发现了蜕皮激素，还有一种 从喂食蚊子的脂肪体中提取的未知因子参与晚期 胰酶基因诱导。我们建议对蜕皮激素对晚期胰蛋白酶的调节机制进行研究。 并鉴定脂肪体因子及磷脂酰肌醇3-激酶(PI-3K)信号转导通路在血管内皮细胞生长中的作用 调节晚期胰酶转录。