MOLECULAR GENETICS OF INTRACELLULAR PROTEIN TRANSPORT

细胞内蛋白质运输的分子遗传学

• 批准号: 2654966
• 负责人: Chris Alan Kaiser
• 金额: $ 24.86万
• 依托单位: MASSACHUSETTS INSTITUTE OF TECHNOLOGY
• 依托单位国家: 美国
• 财政年份: 1992
• 资助国家: 美国
• 起止时间: 1992-02-01 至 2001-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2654966
• 关键词: Saccharomyces cerevisiae; electron microscopy; gene mutation; guanosinetriphosphatases; intermolecular interaction; intracellular membranes; intracellular transport; laboratory rabbit; membrane biogenesis; membrane proteins; protein transport; vesicle /vacuole; yeast two hybrid system

DESCRIPTION: The membrane-bounded organelles along the secretory pathway are responsible for delivering newly made protein and membrane to the cell surface. At each of the steps on the pathway, protein (cargo) is packaged into vesicles that bud from the membrane of the donor organelle. Fusion of these vesicles with the appropriate target membrane delivers this cargo to the next organelle in the pathway. The applicant proposes experiments in the yeast, Saccharomyces cerevisiae, to provide molecular explanations for vesicle construction at the ER membrane, cargo selection and packaging into these vesicles. Previous work from the applicant has demonstrated specific binding interactions between the proteins that are part of the coat that encapsulates the vesicles, known as COPII, that carry protein from the ER to the Golgi apparatus, and they have mapped the regions in each partner protein that are essential for the interactions. Those findings suggest that the large membrane-bound protein Sec16 is the scaffold onto which the coat is constructed from soluble protein complexes. To elucidate the mechanism of coat assembly, individual protein-protein associations will be assayed and used to test how each association depends on the others. The role of the small GTPase Sar1p in assembly of the COPII complex will also be evaluated. Assemblies of purified proteins will be examined by electron microscopy to see how the biochemical interactions generate coat structures. The applicant has recently discovered several new genes that determine which cargo molecules are packaged into vesicles and the overall selectivity of that packaging. Experiments are proposed to probe the mechanism(s) of selection and their relation to vesicle coat formation. The molecular mechanisms underlying vesicular transport appear to be the same in yeast and mammals. By studying this process in yeast the full power of molecular genetics and biochemistry can be used to identify the fundamental mechanisms and key gene products that control secretion. Potential applications to disease include Cystic Fibrosis, pulmonary emphysema, and ways to challenge the growth of membrane enveloped viruses and possibly the uncontrolled growth of tumor cells.

描述：沿着分泌途径的膜边界细胞器 负责将新制造的蛋白质和膜输送到细胞 表面。 在路径上的每个步骤中，蛋白质（货物）都被包装 进入从供体细胞器膜出芽的囊泡中。 融合 这些具有适当目标膜的囊泡将这种货物传递到 通路中的下一个细胞器。 申请人提出实验 酵母，酿酒酵母，提供分子解释 ER 膜上的囊泡构建、货物选择和包装 这些囊泡。 申请人之前的工作已经证明了具体的 作为外壳一部分的蛋白质之间的结合相互作用 封装被称为 COPII 的囊泡，将蛋白质从 ER 携带到 高尔基体，他们绘制了每个伙伴的区域图 相互作用所必需的蛋白质。 这些发现表明 大膜结合蛋白 Sec16 是支架， 外壳由可溶性蛋白质复合物构成。 为了阐明 外壳组装的机制，单个蛋白质-蛋白质关联将是 进行分析并用于测试每个关联如何依赖于其他关联。 这 小 GTPase Sar1p 在 COPII 复合物组装中的作用也将是 评价。 纯化蛋白质的组装将通过电子检查 显微镜观察生化相互作用如何产生涂层结构。 申请人最近发现了几个新基因，这些基因决定了哪些 货物分子被包装成囊泡，并且整体选择性 那个包装。 建议进行实验来探讨其机制 选择及其与囊泡外套形成的关系。 囊泡运输的分子机制似乎是 酵母和哺乳动物也是如此。 通过研究酵母中的这一过程， 分子遗传学和生物化学可用于鉴定 控制分泌的基本机制和关键基因产物。 潜在的疾病应用包括囊性纤维化、肺病 肺气肿以及挑战膜包膜病毒生长的方法 也可能是肿瘤细胞不受控制的生长。