Collaborative Research: SPK1-ROP Signaling at the ER surface: Implications for ERES Assembly and Morphogenesis

合作研究：ER 表面的 SPK1-ROP 信号传导：对 ERES 组装和形态发生的影响

• 批准号: 1122068
• 负责人: Robert Stahelin
• 金额: $ 34.69万
• 依托单位: Indiana University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-09-01 至 2016-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1122068&HistoricalAwards=false
• 关键词: Collaborative; Research; SPK1; ROP; Signaling

Intellectual Merit of the Proposed ActivitiesThe architecture and growth properties of plants are fundamentally important to modern food and renewable energy production systems. However, a lack of knowledge about the protein machineries and cellular mechanisms of growth makes it nearly impossible to engineer crop plants for optimal growth and composition. In plants, the leaf epidermis is a mechanosensitive sheet that dictates the growth properties and architecture of the organ. The long-range goal of this research is to understand how protein complexes and cellular polymers coordinate epidermal growth. Direct knowledge about the cellular mechanisms of information flow and growth will drive future crop improvement strategies. The goal for this project is to determine how an evolutionarily conserved signaling protein termed SPIKE1 coordinates the production, delivery, and assembly of raw materials during growth. The Szymanski and Stahelin laboratories will test their central hypothesis that SPIKE1 membrane-binding and small GTPase activation at specific domains of the endoplasmic reticulum (ER) coordinates cargo export and growth. They will pursue three research objectives.Objective #1 is to determine how SPK1-dependent small GTPase activation and its localization to subdomains of the ER relate to vesicle trafficking and cell morphogenesis. Their working hypothesis is that SPK1 GEF activity promotes ER exit site assembly and efficient protein recycling between the ER and the Golgi. Objective #2 is to discover the cellular mechanisms by which SPK1 is restricted to a punctate distribution on the surface of the ER. Their working hypothesis is that SPK1 binding to phosphatidylserine is sensitive to membrane fluidity and mediates ER localization in living cells. Objective #3 is to learn if conserved Golgi-localized protein complexes are intermediaries in a SPIKE1 cell shape control pathway. Our working hypothesis is that SPIKE1 promotes small GTPase activation of Golgi-localized protein complexes that regulate cargo trafficking. Their preliminary data indicate that SPIKE1 signals promote the formation of, and arise from specialized domains of the ER. These ER exit sites are commonly known as the entry point for anterograde protein trafficking in the secretory pathway. This research is expected to define a new importance for an ER domain that includes small GTPase signaling and the integration of intracellular growth control systems. Given the conserved nature of SPIKE-like proteins and their signaling targets, this research is likely to have a broad impact on the cell morphogenesis field.Broader ImpactsOur research explores challenging new areas of plant cell biology and aims to provide the knowledge base that will enable the engineering of improved crops. The project is interdisciplinary and closely integrates research and learning activities. For example, post-doctoral fellows and graduate students at Purdue and Notre Dame will develop and supervise undergraduate research projects. Undergraduate researchers will learn scientific writing and will present their work at both local and national scientific meetings. Team learning and problem solving are central to the research plan. The research projects include cross-disciplinary research between the Stahelin and Szymanski labs. Research discoveries will be discussed in bi-monthly face-to-face meetings that are held in concert with the Chicago cytoskeleton meetings. The graduate students and post-docs will receive broad training that includes proper data management, effective oral presentations, and scientific writing. The research activities from this project will be published in high profile journals, incorporated into the a graduate plant cell biology course, featured in web-based news releases, and will be featured in a new web resource on SPIKE-like signaling proteins. As done in the past, new mutant strains will be donated to the ABRC stock center. The project will also generate vectors and strains associated with organelle-specific phospholipid modification that will be broadly used by the plant cell biology community.

拟议活动的智力价值植物的结构和生长特性对现代食品和可再生能源生产系统至关重要。然而，由于缺乏对蛋白质机制和细胞生长机制的了解，几乎不可能设计出最佳生长和组成的作物。在植物中，叶表皮是一个机械敏感的薄片，它决定了器官的生长特性和结构。这项研究的长期目标是了解蛋白质复合物和细胞聚合物如何协调表皮生长。关于信息流和生长的细胞机制的直接知识将推动未来的作物改良策略。该项目的目标是确定一种进化上保守的信号蛋白SPIKE1在生长过程中如何协调原材料的生产、传递和组装。Szymanski和Stahelin实验室将验证他们的中心假设，即SPIKE1膜结合和内质网（ER）特定区域的小GTPase激活协调货物出口和生长。他们将追求三个研究目标。目的1是确定spk1依赖性小GTPase激活及其在内质网亚域的定位与囊泡运输和细胞形态发生的关系。他们的工作假设是SPK1 GEF活性促进内质网出口位点组装和内质网与高尔基体之间有效的蛋白质再循环。目的2是发现SPK1被限制在内质网表面点状分布的细胞机制。他们的工作假设是，SPK1结合磷脂酰丝氨酸对膜流动性敏感，并介导活细胞中的内质网定位。目的3是了解保守的高尔基定位蛋白复合物是否在SPIKE1细胞形状控制途径中起中介作用。我们的工作假设是SPIKE1促进高尔基定位蛋白复合物的小GTPase激活，从而调节货物运输。他们的初步数据表明，SPIKE1信号促进内质网特化结构域的形成并产生于内质网。这些内质网出口位点通常被认为是分泌途径中顺行蛋白运输的入口点。这项研究有望为包括小GTPase信号和细胞内生长控制系统集成在内的内质网域定义一个新的重要性。鉴于spike样蛋白及其信号靶点的保守性，本研究可能对细胞形态发生领域产生广泛的影响。更广泛的影响我们的研究探索具有挑战性的植物细胞生物学的新领域，旨在提供知识基础，使工程改良作物。该项目是跨学科的，紧密结合了研究和学习活动。例如，普渡大学和圣母大学的博士后研究员和研究生将开发和监督本科生的研究项目。本科研究人员将学习科学写作，并将在地方和国家科学会议上展示他们的工作。团队学习和解决问题是研究计划的核心。研究项目包括Stahelin和Szymanski实验室之间的跨学科研究。研究发现将在与芝加哥细胞骨架会议同时举行的双月面对面会议上进行讨论。研究生和博士后将接受广泛的训练，包括适当的数据管理、有效的口头报告和科学写作。该项目的研究成果将发表在高水平的期刊上，纳入研究生植物细胞生物学课程，在网络新闻发布中突出，并将在spike样信号蛋白的新网络资源中突出。和过去一样，新的突变菌株将被捐赠给ABRC库存中心。该项目还将产生与细胞器特异性磷脂修饰相关的载体和菌株，这些载体和菌株将被植物细胞生物学界广泛使用。