EXPRESSION OF POMC-DERIVED PEPTIDES DURING DEVELOPMENT

POMC 衍生肽在开发过程中的表达

• 批准号: 3315510
• 负责人: RICHARD G ALLEN
• 金额: $ 7.77万
• 依托单位: OREGON HEALTH & SCIENCE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1984
• 资助国家: 美国
• 起止时间: 1984-09-01 至 1989-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3315510
• 关键词: acetylation; adrenocorticotropic hormone; amidation /deamidation; gel electrophoresis; gel filtration chromatography; growth /development; hormone regulation /control mechanism; infant animal; ion exchange chromatography; molecular pathology; neurotransmitters; peptide hormone; peptide hormone biosynthesis; pituitary adrenal axis; pituitary gland; radioimmunoassay; radiotracer; scintillation spectrometry; tissue /cell culture

This is a proposal to study polyprotein processing during development. Pro-opiomelanocortin (POMC) is a polyprotein that contains the amino acid sequences of several pituitary hormones including corticotropin (ACTH) and the opioid peptide beta-endorphin. POMC processing serves as a particularly informative model system to investigate because adult anterior and intermediate pituitary cells (derived from the same embryonic epithelium) process POMC to different sets of end-product hormones. Furthermore, these cell types are under the control of different regulators. Our long range goals are to determine when and how the lobe-specific patterns of POMC processing are established during pituitary development, and to establish when during development POMC producing cells become responsive to regulation by neurotransmitters, hypothalamic-releasing-factors and glucosteroids. In our studies we will compare and contrast POMC processing in timed rhesus monkey and rat fetal pituitaries. This is significant because we have shown that the monkey processes POMC differently than the rat. This may be due to important differences in the amino acid sequences of POMC in monkey and rat. Also, relative gestational dates and developmental stages are different between monkey and the rodent. First, we will determine the forms of POMC-derived peptides present in the fetal monkey anterior and intermediate pituitary of different gestational ages by combining electrophoretic fractionation and radioimmunoassays specific for six different POMC domains. These results will be compared with our studies in the rat which have shown that the relative intracellular distribution of POMC-derived peptides changes during late stage gestation and early neonatal pituitary development. Secondly, we will determine the time course of the lobe-specific chemical modification processes for POMC-derived products during monkey and rat pituitary development. Radiolabeled POMC peptides from cultures of anterior and intermediate pituitary of different developmental stages will be isolated by immunoprecipitation, followed by fractionation and further biochemical analyses. This will allow us to determine when the lobe-specific N-acetylation, amidation, and glycosylation enzyme activities are expressed during pituitary development. Finally, we will determine the extent of the regulatory differentiation of POMC producing cells at various stages of development by culturing monkey and rat fetal pituitary cells in the presence of regulators known to control full differentiated POMC producing cells. Information derived from these studies would contribute greatly to the understanding of polyprotein expression, pituitary development, and to the understanding of the development of the hypothalamic-pituitary-adrenal axis at the molecular level.

这是研究开发过程中多蛋白处理的一项建议。 促蛋白聚糖素（POMC）是含有氨基酸的多蛋白 几种垂体激素的序列，包括皮质激素（ACTH）和 阿片类肽β-内啡肽。 POMC处理可作为 特别有用的模型系统进行调查，因为成人前部 和中间垂体细胞（源自同一胚胎 上皮）POMC与不同的末端产物激素集。 此外，这些细胞类型在不同调节剂的控制之下。 我们的远距离目标是确定何时以及如何特定叶子 POMC处理的模式是在垂体发展期间建立的 并确定在开发过程中何时产生POMC的细胞成为 对神经递质调节的反应， 下丘脑释放的因素和葡萄糖固醇。 在我们的研究中，我们将比较和对比定时恒河校的POMC处理 猴子和大鼠胎儿垂体。 这很重要，因为我们有 表明猴子的处理与大鼠的过程不同。 这可能是 由于猴子中POMC的氨基酸序列的重要差异 和老鼠。 此外，相对妊娠日期和发展阶段是 猴子和啮齿动物之间的不同。 首先，我们将确定存在于POMC衍生的肽的形式 不同妊娠的胎儿猴前和中间垂体 通过结合电泳分馏和放射免疫测定的年龄 针对六个不同的POMC域。 这些结果将被比较 我们在大鼠中的研究表明了相对 POMC衍生肽的细胞内分布近期变化 阶段妊娠和早期新生儿垂体发展。 其次，我们将确定叶特异性化学的时间过程 猴子和大鼠期间pomc衍生产品的修改过程 垂体发展。 从培养物中的放射性标记的POMC肽 不同发育阶段的前和中间垂体将 通过免疫沉淀分离，然后进行分级和进一步分离 生化分析。 这将使我们能够确定何时 叶特异性N-乙酰化，抑制和糖基化酶活性 在垂体发展期间表达。 最后，我们将确定监管分化的程度 POMC通过培养猴子在开发的各个阶段产生细胞 在存在已知的调节剂的情况下，大鼠胎儿垂体细胞 控制完全分化的POMC产生细胞。 这些研究得出的信息将对 了解多蛋白的表达，垂体发育和对 了解下丘脑 - 垂体 - 肾上腺轴的发展 在分子水平。