MEMBRANE TRAFFIC IN PEPTIDE HORMONE SECRETING CELLS

肽激素分泌细胞中的膜运输

• 批准号: 3153016
• 负责人: REGIS B KELLY
• 金额: $ 9.68万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
• 依托单位国家: 美国
• 财政年份: 1984
• 资助国家: 美国
• 起止时间: 1984-04-01 至 1987-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3153016
• 关键词: adrenocorticotropic hormone; antibody formation; antibody specificity; cell cell interaction; chemical structure function; chromosome deletion; cyclic AMP; endonuclease; gene expression; genetic manipulation; high performance liquid chromatography; immunofluorescence technique; immunoprecipitation; insulin; membrane permeability; monoclonal antibody; mutagens; pancreatic islet function; peptide hormone; peptide hormone biosynthesis; proinsulin; proteolysis; radioimmunoassay; radiotracer; secretion; surface antigens

In a mouse pituitary tumor cell line, AtT-20, secretion of ACTH and beta-endorphin is regulated by the presence or absence of a secretagogue. The ACTH and beta-endorphin are stored in dense secretory granules. The same cells have a second non-regulated pathway that secretes the polypeptide precursor pro-opiomelanocortin (POMC), and at least one membrane glycoprotein. We propose that only polypeptides with a particular sorting address are segregated into secretory granules and stored in the cell. Wtih the hope that a similar sorting address might be conserved and is present in all precursors of polypeptide hormones, we have introduced the genes for human insulin and human growth hormone into AtT-20 cells. Preliminary evidence suggests that the genes are expressed, stored in secretory granules and released on exposure to a secretagogue. Unlike other cells transfected with insulin DNA, however, the transfected AtT-20 cells release insulin, not proinsulin. These obervations have led us to propose the following experiments. Frist we plan to identify the sorting address by recombinant DNA and antibody techniques. Secondly, we plan to confirm that the processing enzymes in AtT-20 cells produce authentic insulin from proinsulin. Finally, we will make use of the nerve-like morphology of AtT-20 cells grown in 8-Br-cAMP to examine the question of how post-Golgi vesicles target themselves to their correct destination. These data should identify the sorting signals and molecules involved in segregating and packaging peptide hormones in endocrine tissue and how they might be deranged, especially in peptide-secreting tumors. At the same time we may learn how secreting cells make biologically active hormones out of prohormones.

在小鼠垂体瘤细胞系AtT-20中， β-内啡肽受促分泌素存在与否的调节。 ACTH和β-内啡肽储存在致密的分泌颗粒中。 的 相同的细胞有第二个非调节途径，分泌 多肽前体阿黑皮素原（POMC），和至少一种 膜糖蛋白 我们认为只有具有特定的 分类地址被分离成分泌颗粒并存储在 cell. 希望类似的排序地址可以被保存， 存在于多肽激素的所有前体中，我们已经介绍了 人胰岛素和人生长激素的基因导入AtT-20细胞。 初步证据表明，基因表达，储存在 分泌颗粒并在暴露于促分泌剂时释放。 不像 然而，用胰岛素DNA转染的其他细胞，转染的AtT-20 细胞释放胰岛素而不是胰岛素原 这些观察使我们 提出以下实验。 首先，我们计划确定排序 通过重组DNA和抗体技术解决。 其次，我们计划 确认AtT-20细胞中的加工酶产生真实的 胰岛素原转化为胰岛素。 最后，我们将利用神经类 在8-Br-cAMP中生长的AtT-20细胞的形态，以检查 高尔基体后囊泡如何将自己定位到正确的目的地。 这些数据应该可以识别出参与细胞分裂的分选信号和分子。 分离和包装内分泌组织中的肽激素，以及它们如何 可能是精神错乱的，特别是在肽分泌肿瘤中。 在同一 到时候我们可能会知道分泌细胞是如何产生生物活性激素的 激素原