MEMBRANE TRAFFIC IN PEPTIDE HORMONE SECRETING CELLS

肽激素分泌细胞中的膜运输

• 批准号: 2139185
• 负责人: REGIS B KELLY
• 金额: $ 14.14万
• 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/2139185
• 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.

内分泌细胞有能力将激素集中并储存在 分泌颗粒并在其上释放分泌颗粒的内容物 刺激。 因此，内分泌细胞具有三个不具有的特性： 许多其他细胞类型都具有将激素与激素分离的能力 其他蛋白质，浓缩它们并调节与 质膜。 来自多个实验室（包括我们自己的实验室）的最新数据显示 生成了如何分选、浓缩和分泌的详细模型 发生。 我们已经从大鼠身上制备了透化细胞制剂 嗜铬细胞瘤细胞系 PC12，使我们能够检查不成熟程度 分泌颗粒从反式高尔基体网络中夹断，它们如何 成熟，它们如何与细胞骨架相互作用，以及它们的胞吐作用 受到监管。 我们可以从这样的体外研究中了解到是否存在细胞 受调节的分泌细胞中的类型特异性分选机制。 步骤 体外研究中观察到的分泌颗粒成熟过程是一致的 在四膜虫突变体中观察到粘液囊成熟的步骤 嗜热菌，一种有纤毛的原生动物，其中存在分泌缺陷突变体 很容易获得。 内质膜运输分析 网织和高尔基复合体细胞从 哺乳动物细胞交通的体外重建与 酵母膜运输的遗传缺陷。 我们的相似之处 观察到四膜虫的调节分泌与内分泌之间 细胞表明，对其中一种细胞的研究将有助于阐明其特性 另一个。 通过这两种方法，我们希望产生明确的结果 调节分泌的分子信息。