CHROMAFFIN GRANULE MEMBRANE

对分泌囊泡膜分选进行了研究。 主要是由于缺乏关于秘书的信息而受到阻碍 膜蛋白本身和没有任何 相应的cDNA。这项建议解决了这两个问题。 肾上腺髓质嗜铬细胞有许多共同的 交感神经元的特征；在刺激时，两者 分泌囊泡膜与血浆的融合反应 膜，随之而来的是释放其储存的内容物。这个 然后有效地重新提取囊泡膜并 显然是在另一轮分泌物中重新循环。 在这个膜上发现了40到60种蛋白质；很少有 它们与任何已知的功能都有关联 结构性信息是稀疏的。鉴于这个相对较小 在颗粒膜中发现的蛋白质数量和 在生物化学上的独特优势，颗粒作为一种 神经模型系统，明确了系统的结构 颗粒膜蛋白的分子生物学研究 基因分析将对理解 重要的生物刺激分泌过程和 胞吐作用、囊泡膜融合、膜转运和 生物分子吸收。 我们已经开始对这些基因进行分子遗传学表征 通过克隆编码a基因的部分基因来表达膜蛋白 它们的子集；我们目前正在参与识别 克隆人，随后是克隆人的测定 核苷酸序列和编码氨基酸的推断 结构。蛋白质结构的可测试性预测 尊重细胞膜和细胞内的 每一个的位置都将通过免疫电子来确定 显微镜。因此，这项工作将立即产生新的 关于这些蛋白质的结构信息。我们还将拥有 它们的同源cDNA，允许进行分子遗传学研究 膜的生物发生。审查的未来目标 分泌膜在分子水平上的分类将成为 可行。所获得的信息应在很大程度上适用于 整个交感神经-肾上腺系统。

Investigation of secretory vesicle membrane sorting has been hindered principally due to a lack of information on the secretory membrane proteins themselves and the absence of any corresponding cDNAs. This proposal addresses both problems. The adrenal medullary chromaffin cell shares many of the characteristics of the sympathetic neuron; upon stimulation, both respond by fusing secretory vesicle membrane with the plasma membrane with consequent release of their stored contents. The vesicular membrane is then efficiently re-extracted and apparently re-cycled to serve in another round of secretion. Between 40 and 60 proteins are found in this membrane; few of these have been correlated with any known function and structural information is sparse. Given this relatively small number of proteins found in the granule membrane and the biochemically unique vantage that the granule occupies as a neural model system, it is clear that a systematic structural investigation of the granule membrane proteins by molecular genetic analysis will be of enormous benefit in understanding the biologically important processes of stimulus-secretion and exocytosis, vesicular membrane fusion, membrane trafficking, and bio-molecule uptake. We have begun a molecular genetic characterization of these membrane proteins by cloning portions of the genes encoding a subset of them; we are currently involved in identification of the clones, to be followed by the determination of the cloned nucleotide sequences, and inferrence of the encoded amino acid structures. Testable predictions of the protein structure with respect to the membrane will be made and the intracellular location of each will be determined by immunoelectron microscopy. This work will therefore immediately result in new structural information about these proteins. We will also possess their cognate cDNAs, permitting molecular genetic investigations of the membrane's biogenesis. The future goal of examining secretory membrane sorting at the molecular level will become feasible. The information obtained should largely apply to the entire sympatho-adrenal system.