REGULATION OF METABOLISM IN INSECT FAT BODY

昆虫脂肪体代谢的调节

• 批准号: 2189711
• 负责人: MICHAEL A WELLS
• 金额: $ 14.58万
• 依托单位: UNIVERSITY OF ARIZONA
• 依托单位国家: 美国
• 财政年份: 1995
• 资助国家: 美国
• 起止时间: 1995-04-01 至 1999-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2189711
• 关键词: Manduca; bioenergetics; biological signal transduction; calcium; cyclic AMP; diacylglycerols; fat body; glycogen; glycogenolysis; hormone regulation /control mechanism; laboratory rabbit; lipase; lipid biosynthesis; lipolysis; octopamine; organ culture; phosphorylase kinase; phosphorylation; protein kinase A; protein transport; tissue /cell culture; trehalose; triacylglycerol lipase

In insects the fat body plays a fundamental role in energy metabolism. It is the principal site for storage of both glycogen and triacylglycerol (TG). Physiological mechanisms must operate to accumulate energy stores, either as glycogen or TG, during times of excess energy intake, e.g., during larval development, or to mobilize energy stores during times of need, e.g., flight or starvation. Clearly an understanding of these mechanisms is of fundamental importance in insect biochemistry/physiology, and may provide information useful for the development of insect-specific control strategies. The long-range goal of this project is to characterize the signal transduction systems involved in glycogen and TG mobilization in insect fat body. In the initial stages of the project the experimental insect will be larvae and adults of M. sexta which exhibit predominately a glycogenolytic effect of AKH in the larval stage and a predominately lipolytic effect of AKH in adults. This means we can study either glycogenolysis or lipolysis depending on which life stage of the insecxt is selected. In the long-range we plan to use the reagents and insights developed from studies on M. sexta to investigate regulation of energy metabolism in the fat body of the mosquito, Aedes aegypti. The specific aims of this proposal re: To characterize the fat body hormone sensitive lipase, and, in particular, to determine the mechanism of it phosphorylation and to test the hypothesis that phosphorylation of the enzyme activates lipolysis because phosphorylation of the enzyme leads to translocation from the cytoplasm to the fat droplet; To determine the pathway for diacylglycerol synthesis in fat body which is activated by lipolysis of the triacylglycerol stores, and to characterize regulation of the pathway; To determine if trehalose synthesis is regulated during glycogenolysis, and, in particular, to test the hypothesis that fructose- 2,6-bisphophate plays an important regulatory role by inhibiting glycolysis and thereby shunting glucose-1-phosphate into trehalose synthesis; To determine the role of the cAMP-dependent protein kinase in regulating glycogenolysis and lipolysis; To determine the relative importance of calcium ion and protein phosphorylation in activating phosphorylase kinase, which is the key enzyme in activating glycogen phosphorylase and, hence, glycogenolysis.

在昆虫中，脂肪体在能量代谢中起着基本作用。 它 是存储糖原和三酰基甘油的主要部位 （TG）。 生理机制必须运行以积累能量存储， 作为糖原或TG，在多余的能量摄入时期，例如 在幼虫发育期间，或在 需要，例如飞行或饥饿。 显然是对这些的理解 机制在昆虫生物化学/生理学中至关重要， 并可能提供有助于开发昆虫特异性的信息 控制策略。 该项目的远程目标是表征信号 参与糖原和TG动员昆虫的转导系统 胖身体。 在项目的初始阶段，实验昆虫 将是M. sexta的幼虫和成年人，主要表现为 AKH在幼虫阶段的糖原解释作用，主要是 AKH在成人中的脂解作用。 这意味着我们可以学习 糖原分解或脂解，具体取决于ISECXT的生命阶段 选择。 在远程中，我们计划使用试剂和见解 从对塞克斯氏菌的研究开发以研究能量的调节 蚊子的脂肪体内的代谢，埃及埃及。 该提案的具体目的是：表征脂肪的身体 激素敏感脂肪酶，特别是确定机制 IT磷酸化并检验的假设是 酶激活脂解是因为酶的磷酸化导致 从细胞质转移到脂肪滴；确定 脂肪体中二酰基甘油合成的途径，这被激活 三酰基甘油储存的脂解，并表征 路径；确定是否调节海藻糖合成 糖原分解，尤其是为了检验果糖 - 2,6-生物磷酸盐通过抑制起着重要的调节作用 糖酵解，从而将葡萄糖1-磷酸分类为海藻糖 合成;确定依赖CAMP的蛋白激酶在 调节糖原分解和脂解；确定亲戚 钙离子和蛋白质磷酸化在激活中的重要性 磷酸化酶激酶，这是激活糖原的关键酶 磷酸化酶，因此，糖原分解。