MEMBRANE TRAFFIC IN PEPTIDE HORMONE SECRETING CELLS

肽激素分泌细胞中的膜运输

• 批准号: 3232343
• 负责人: REGIS B KELLY
• 金额: $ 13.13万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
• 依托单位国家: 美国
• 财政年份: 1992
• 资助国家: 美国
• 起止时间: 1992-09-30 至 1996-09-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3232343
• 关键词: Golgi apparatus; PC12 cells; Tetrahymena; chemical structure function; electron microscopy; endoplasmic reticulum; exocytosis; fluorescent dye /probe; granule; guanine nucleotide binding protein; immunofluorescence technique; immunoprecipitation; membrane permeability; membrane proteins; monoclonal antibody; mucins; mutant; peptide hormone biosynthesis; protein reconstitution; protein transport; proteolysis; radiotracer; secretory protein; tissue /cell culture

Endocrine cells have the ability to concentrate and store hormones into a secretory granule and release the contents of the secretory granule on stimulation. Endocrine cells have, therefore, three properties not shared by many other cell types, the capacity to segregate hormones from other proteins, to concentrate them and to regulate fusion with the plasma membrane. Recent data from several labs, including our own, have generated a detailed model of how sorting, concentration and secretion occur. We have generated a permeabilized cell preparation from the rat pheochromocytoma cell line, PC12, that allows us to examine how immature secretory granules pinch-off from the trans Golgi network, how they mature, how they interact with the cytoskeleton, and how their exocytosis is regulated. We can learn from such in vitro studies if there is cell type-specific sorting machinery in regulated secretory cells. The steps in secretory granule maturation seen in in vitro studies are consistent with the steps in mucocyst maturation observed in mutants of Tetrahymena thermophila, a ciliated protozoan in which secretion-defective mutants are readily available. Analysis of membrane traffic in endoplasmic reticulum and Golgi complex cells has profited enormously from the interaction between in vitro reconstitution of mammalian cell traffic and the genetic defects in membrane traffic in yeast. The similarities we have observed between regulated secretion in Tetrahymena and endocrine cells suggest that study of one will help illuminate the properties of the other. With these two approaches we hope to generate definitive molecular information on regulation secretion.

内分泌细胞具有将激素浓缩和储存到A的能力 分泌颗粒并释放分泌颗粒的内容 刺激。 因此，内分泌细胞具有三个特性而不是 由许多其他细胞类型共享，将激素隔离的能力与 其他蛋白质，集中它们并调节与 质膜。 来自包括我们自己在内的多个实验室的最新数据已有 产生了一个详细的模型，讲述了分类，集中和分泌的方式 发生。 我们已经从大鼠产生了透化的细胞制剂 嗜铬细胞瘤细胞系PC12，使我们能够检查未成熟的方式 分泌的颗粒从Trans Golgi网络捏，他们如何 成熟，它们如何与细胞骨架相互作用，以及它们的胞吐作用方式 受监管。 如果有细胞，我们可以从这种体外研究中学习 调节分泌细胞中类型特异性排序机制。 步骤 在体外研究中看到的分泌颗粒成熟 随着在四膜虫突变体中观察到的粘液成熟的步骤 Thermothila，一种纤毛的原生动物，其中分泌缺陷突变体 容易获得。 分析内质中的膜流量 网状和高尔基体复合细胞已从 哺乳动物细胞流量的体外重构与 酵母中膜流量的遗传缺陷。 我们的相似之处 已经观察到四膜虫的受调节分泌和内分泌 细胞表明，研究将有助于阐明 另一个。 通过这两种方法，我们希望产生确定的 有关调节分泌的分子信息。