INSULIN REGULATION OF THE ADIPOCYTE GLUCOSE TRANSPORTER

胰岛素对脂肪细胞葡萄糖转运蛋白的调节

• 批准号: 3227345
• 负责人: GUSTAV E. LIENHARD
• 金额: $ 16.38万
• 依托单位: DARTMOUTH COLLEGE
• 依托单位国家: 美国
• 财政年份: 1979
• 资助国家: 美国
• 起止时间: 1979-04-01 至 1992-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3227345
• 关键词: acylation; adipocytes; affinity chromatography; antibody; cell membrane; gel electrophoresis; glucose transport; glycosylation; hormone regulation /control mechanism; immunochemistry; immunoelectron microscopy; insulin; insulin receptor; laboratory rabbit; membrane permeability; membrane proteins; phosphorylation; tissue /cell culture; transport proteins

Insulin stimulates the rate of glucose transport into adipocytes 10 to 15-fold within ten minutes. This remarkable stimulation is due at least in part to the translocation of glucose transporters from within the cell to the plasma membrane. The long-term objective is to elucidate at the molecular level how insulin causes this translocation of transporters. The specific aims for the coming grant period are as follows. (1) We have recently developed an immunoadsorption method for the purification of vesicles that contain the insulin-responsive, intracellular glucose transporters. The cellular organelle that contains these transporters will be identified by biochemical and electron microscopic methods. The composition, arrangement, and function of the polypeptides in these vesicles will be determined. (2) The quantitative contribution that the translocation of transporters to the plasma membranes makes to the overall stimulation of cellular glucose transport by insulin will be assessed. (3) The question of whether the glucose transporter is rapidly recycling between the plasma membrane and the endosomal compartment will be answered. If recycling is occurring, the site of insulin action on the kinetics will be ascertained. To achieve aims (2) and (3), a method for labeling the extracelllular domain of the transporter with a membrane-impermeant reagent will be developed. (4) The nature of the signal between the insulin receptor and the transporter will be investigated. Possible roles for covalent modification of the transporter, or of a transporter-associated protein, and for an intracellular mediator will be examined. (5) A major effort will be made to develop a cell-free system in which the insulin- stimulated translocation of transporters occurs. if this succeeds, the components of the system will be purified. All these studies will be conducted with the 3T3-L1 adipocyte. The results of this project will contribute to our knowledge of the mechanism of insulin action. They will therefore be of relevance to diabetes, since this disease is due to insulin deficiency or insensitivity.

胰岛素刺激葡萄糖向脂肪细胞的转运 在十分钟内翻了15倍。这种非凡的刺激是由于 至少部分原因是葡萄糖转运蛋白从 在细胞内到质膜。长期目标 就是在分子水平上阐明胰岛素是如何导致这种情况的 转运体的移位。即将到来的具体目标 授权期如下。(1)我们最近开发了一种 免疫吸附法纯化囊泡的研究 含有胰岛素反应的细胞内葡萄糖转运体。 包含这些转运蛋白的细胞器将是 通过生化和电子显微镜方法进行鉴定。这个 大豆多肽的组成、排列和功能 这些囊泡将被确定。(2)数量上的 转运蛋白转移到血浆中的作用 膜对细胞葡萄糖的整体刺激作用 将对胰岛素运输进行评估。(3)是否 葡萄糖转运体在血浆中迅速循环 将回答膜和内体隔室的问题。如果 循环正在发生，胰岛素的作用部位对动力学有影响 将会被确定。为了实现目标(2)和(3)，一种方法 标记转运蛋白的胞外结构域 将开发无膜试剂。(4)性质 胰岛素受体和转运体之间的信号 被调查。三聚氰胺共价修饰的可能作用 转运体，或转运体相关蛋白，以及 将对细胞内介质进行检查。(5)下大力气 开发一种无细胞系统，在这种系统中，胰岛素- 转运蛋白的刺激转运发生了。如果成功了， 该系统的组件将被提纯。所有这些研究 将在3T3-L1脂肪细胞中进行。这样做的结果 该项目将有助于我们了解这一机制 胰岛素的作用。因此，它们将与糖尿病相关， 因为这种疾病是由于胰岛素缺乏或不敏感引起的。