Role of Cellulose and Protein in the Dictyostelium Spore Coat

纤维素和蛋白质在盘基网柄菌孢子衣中的作用

• 批准号: 9316897
• 负责人: Christopher West
• 金额: --
• 依托单位: University of Florida
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1994
• 资助国家: 美国
• 起止时间: 1994-02-15 至 1997-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9316897&HistoricalAwards=false
• 关键词: Role; Cellulose; Protein; Dictyostelium; Spore

9316897 West Dictyostelium spore coats contain about one -half polysaccharide, including cellulose and galuronan, and about one half protein, including at least 7 different protein species. The coat is assembled in two phases. First, preformed coat proteins and the galuran are secreted, forming a layer at the cell surface. Most of the proteins exchange between neighboring spores, indicating that assembly occurs extracellularly after secretion. One protein. is unique in that it is not exchanged, as if it anchors or initiates coat assembly. During the second phase cellulose accumulates, and the proteins organize further. Cellulose has traditionally been considered to be the primary determinant of structure and function. The PI proposes two hypotheses to investigate the relative contribution of proteins and polysaccharides. Hypothesis I suggests that proteins play a critical role in initiating assembly of the coat so that the absence of essential groups of proteins such as SP86, the protein part of the coat will not assemble or will not be attached to the plasma membrane, and what accumulates will not be positioned correctly. Hypothesis II suggests that in the absence of cellulose, a microscopically detectable and sedimentable protein pseudocoat will still form.. The proposal has three aims: 1) To disrupt the gene for the spore coat protein SP87; 2) To isolate the gene for the spore coat protein SP86 and disrupt it; and 3) To disrupt the gene for UDPGPP2, and to investigate the effect of this gene on coat structure. %%% Spore coats and other extracellular matrices protect enclosed cells from unfavorable environments. Although the constituents of a number of these matrices is partially known, knowledge of how this parts fit together, how their proportions are regulated, and how protection occurs is largely derived by speculation. The spore coat of the cellular slime mold Dictyostelium is a good system to study matrices at a molecular level, becaus e it is simple it can be isolated in bulk and in high purity, the genes for a number of its proteins and enzymes for polysaccharide synthesis have been cloned and can be disrupted, and good assays exist for the composition. structure and function of the coat. The results of this investigation will enhance our knowledge about the assembly of walls in plant and fungal cells. ***

9316897 West Dictyostelium孢子涂层包含大约一个half多糖，包括纤维素和Galuronan，以及大约一半的蛋白质，包括至少7种不同的蛋白质。 外套分为两个阶段。 首先，预先形成的外套蛋白和galuran分泌，在细胞表面形成一层。 相邻孢子之间的大多数蛋白质交换，表明组装在分泌后细胞外发生。 一种蛋白质。它的独特之处在于它没有交换，就好像它锚定或启动了外套组件一样。 在第二相期间，纤维素积聚，蛋白质进一步组织。 传统上，纤维素被认为是结构和功能的主要决定因素。 PI提出了两个假设，以研究蛋白质和多糖的相对贡献。 假设I建议蛋白质在启动外套的组装中起着至关重要的作用，因此缺乏SP86的必需蛋白质基团，外套的蛋白质部分不会组装或不会附着在质膜上，什么可以累积到质膜上无法正确定位。 假设II表明，在没有纤维素的情况下，仍然会形成可检测到的显微镜蛋白伪涂层。该提案具有三个目的：1）破坏孢子蛋白SP87的基因； 2）分离孢子涂层蛋白SP86的基因并破坏它； 3）破坏UDPGPP2的基因，并研究该基因对外套结构的影响。 %% %%孢子外套和其他细胞外矩阵保护封闭的细胞免受不利环境的影响。 尽管许多这些矩阵的成分是部分已知的，但了解这些部分如何融合在一起，如何调节其比例以及如何进行保护，这在很大程度上是由猜测得出的。 细胞粘液模具dictyostelium的孢子涂层是一个在分子水平上研究矩阵的好系统，因为很简单，它可以在散装和高纯度中分离出来，其多种蛋白质和酶用于多糖合成的基因已被克隆并可能被破坏，并且存在良好的构图测定法。外套的结构和功能。 这项研究的结果将增强我们对植物和真菌细胞中壁组装的了解。 ***