Collaborative Research: Extensin Modules Comprising Self-Assembling Amphiphiles Create Scaffolds that Nucleate Cell Wall Formation: Elucidation of Roles and Rules

合作研究：包含自组装两亲物的延伸蛋白模块创建使细胞壁形成成核的支架：作用和规则的阐明

• 批准号: 0955569
• 负责人: Marcia Kieliszewski
• 金额: $ 40万
• 依托单位: Ohio University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-09-01 至 2014-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0955569&HistoricalAwards=false
• 关键词: Collaborative; Research; Extensin; Modules; Comprising

The plant cell wall is a self-assembling supramolecular structure of interpenetrating carbohydrate polymers: cellulose, hemicellulose and pectin, and a minor component of extensin proteins. Wall properties arise from correct self-assembly, but very little is known about how this occurs. It is known that one (RSH) of the 20 different extensins in the model plant, Arabidopsis, is critical for correct formation on new plant walls and that this extensin has the capacity to self-assemble to form a scaffold. Several lines of evidence suggest that extensins provide templates on which other components organize themselves. The central question here is how do extensins form scaffolds? Extensins are highly repetitive glycopeptides of alternating hydrophilic and hydrophobic amino acid motifs, with an abundance of the positively charged amino acids lysine and histidine. Functionality of these extensin components will be tested using synthetic genes to replace RSH in the rsh mutant. In addition to this genetic study, purified RSH analogs and walls containing them will be characterized, biochemically, by isolation and characterization of wall peptides, including cross-linking assays, and biophysically by imaging of analog self-assembly using atomic force microscopy. The project also aims to identify plant and wall differences with extensin analog sequences. Defining the molecular interactions of extensins in the primary cell wall, and the precise roles of the conserved peptide motifs, are highly relevant to understanding wall self-assembly, defense responses and plant morphogenesis. As the most abundant biomass on earth, plant cell walls contribute crucially to self-sustaining civilizations from shelter, to food, fiber and fuel. A potential impact of this work is wall remodeling to enable new and improved uses of plant cell wall, not least the production of biofuels. Junior researchers including those with minority status will work as part of a team crossing several scientific disciplines to solve this significant biological problem.

植物细胞壁是互穿碳水化合物聚合物的自组成的超分子结构：纤维素，半纤维素和果胶，以及延伸蛋白蛋白的次要成分。壁性能是由正确的自组装产生的，但对这种情况的发生知之甚少。众所周知，模型植物中的20种不同延伸素中的一个（RSH）对于在新植物壁上正确形成至关重要，并且该延伸素具有自组装形成脚手架的能力。几条证据表明，延伸蛋白提供了其他组件组织自己的模板。这里的核心问题是延伸素如何形成脚手架？延伸蛋白是交替的亲水性和疏水性氨基酸基序的高度重复糖肽，具有阳性带电的氨基酸赖氨酸和组氨酸的丰度。这些扩展蛋白成分的功能将使用合成基因进行测试，以替代RSH突变体中的RSH。除了这项遗传研究外，纯化的RSH类似物和包含它们的壁还将通过生化，通过隔离和表征壁肽的分离和表征，包括交联测定法，以及通过使用原子力显微镜对类似物自组装成像进行化学成像。该项目还旨在通过延伸素模拟序列识别植物和墙壁差异。定义伸肌在原代细胞壁中的分子相互作用以及保守肽基序的精确作用，与理解壁自组装，防御反应和植物形态发生高度相关。作为地球上最丰富的生物量，植物细胞壁对从庇护所到食物，纤维和燃料的自我维持的文明至关重要。这项工作的潜在影响是壁重塑以实现植物细胞壁的新和改进的使用，尤其是生物燃料的产生。包括少数族裔的初级研究人员将作为跨越几个科学学科的团队的一部分，以解决这一重大的生物学问题。