Dynamic Modulation of Protein Recycling by Spectrin

血影蛋白动态调节蛋白质回收

• 批准号: 1122013
• 负责人: Claire Thomas
• 金额: $ 48万
• 依托单位: Pennsylvania State Univ University Park
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-04-15 至 2016-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1122013&HistoricalAwards=false
• 关键词: Dynamic; Modulation; Protein; Recycling; Spectrin

Intellectual merit. Epithelia are an essential tissue type in the body plan of all multicellular animals where they play a vital role in development, structure and physiology. Epithelia are also the most common tissue type in the body. To establish an epithelium successfully, cells must develop "polarity"--a strong asymmetry in the distribution of cellular proteins. Many epithelial functions, from nutrient uptake to organ formation, depend on such asymmetric distributions of proteins and this fundamental property of an epithelium. Polarity is generated by groups of proteins that reorganize the cell to transport different sets of proteins to each of the main epithelial surfaces: apical, lateral and basal. During this process, specific groups of proteins are tasked with the formation of the apical surface specifically. This project will analyze the role of a group of proteins involved in steps that lead to the stabilization of proteins at the apical surface using the fruit fly (Drosophila melanogaster) as a model system. These proteins include the membrane-associated proteins annexin B9 and beta H spectrin. Preliminary data has led to the hypothesis that this annexin and spectrin form a complex that determines the level of proteins at the apical membrane, and that they do this by modulating the movement of proteins inside the cell to and from the apical domain during a process called "protein recycling". To test this hypothesis the project will quantitatively measure the influence of these two proteins on protein recycling in normal and mutant cells and tissues. Annexin B9 and beta H spectrin also modulate a major polarity regulator called Rac during this process, and this relationship is also a focus of the research. Finally, the hypothesis suggests that many many proteins are likely to be modulated in this way. Therefore, the project will also develop a way to identify all such proteins using "proteomic" techniques. Although the action of the key proteins that initiate a polarized cell phenotype are beginning to be understood, the stabilization and elaboration of the incipient apical domain are still poorly understood. Thus, the project will produce new insights into the development and maintenance of epithelial organization. This project will also help redefine the role of spectrins in general. These proteins have been depicted in every basic cell biology textbook for over two decades as static structural proteins. This research is part of a growing body of evidence that demonstrates that these proteins actually have a much wider and more dynamic role in the cell that challenges this long-held view.Broader impacts. The broader impacts of this project will be in the area of science education. Not only will the project provide training for graduate students and postdoctoral fellows, but it will also integrate undergraduate-driven experiments with the research. Undergraduate participants will be drawn from those doing honors theses projects and also from underrepresented groups through the WISER (Women In Science and Engineering Research) and MURE (Minority Undergraduate Research Experience) programs at Penn State. In addition, lab experiments will be used for a "Reality Science" approach in a large (500 student) introductory cell biology class, which serves several majors. For this approach a tractable research thread that is performed by an undergraduate researcher is then integrated into the curriculum (including examinations). The undergraduate's experiments are followed in class throughout the semester with regular updates on that student's progress. This will demonstrate real-life applications of techniques that are mentioned in class, but which cannot be covered in the lab sections of the course. At the same time this will impart a feeling for the nature, pace, and thought processes that underly basic research amongst students who may choose not to become professional biologists, but nevertheless will become science-literate citizens.

智力上的优点。 上皮细胞是所有多细胞动物体平面中的重要组织类型，它们在发育、结构和生理中起着至关重要的作用。上皮细胞也是体内最常见的组织类型。为了成功地建立上皮，细胞必须发展“极性”-细胞蛋白质分布的强烈不对称性。许多上皮功能，从营养吸收到器官形成，都依赖于蛋白质的这种不对称分布和上皮的这种基本性质。极性是由重组细胞的蛋白质组产生的，以将不同的蛋白质组运输到每个主要的上皮表面：顶端，侧面和基底。在这个过程中，特定的蛋白质组专门负责顶端表面的形成。本项目将以果蝇（Drosophila melanogaster）为模型系统，分析一组蛋白质在顶端表面蛋白质稳定化过程中的作用。这些蛋白质包括膜相关蛋白膜联蛋白B 9和β H血影蛋白。初步数据已经导致了这样的假设，即这种膜联蛋白和血影蛋白形成一种复合物，该复合物决定了顶端膜处蛋白质的水平，并且它们通过在称为“蛋白质再循环”的过程中调节细胞内蛋白质往返于顶端结构域的运动来实现这一点。为了验证这一假设，该项目将定量测量这两种蛋白质对正常和突变细胞和组织中蛋白质循环的影响。膜联蛋白B 9和β H血影蛋白在此过程中还调节一种称为Rac的主要极性调节因子，这种关系也是研究的重点。最后，该假说表明，许多蛋白质可能以这种方式被调节。 因此，该项目还将开发一种使用“蛋白质组学”技术识别所有此类蛋白质的方法。 虽然启动极化细胞表型的关键蛋白的作用开始被理解，稳定和阐述的初期顶端域仍然知之甚少。因此，该项目将产生新的见解上皮组织的发展和维护。这个项目也将有助于重新定义一般的spectrin的作用。二十多年来，这些蛋白质在每一本基础细胞生物学教科书中都被描述为静态结构蛋白质。 这项研究是越来越多的证据的一部分，这些证据表明，这些蛋白质实际上在细胞中具有更广泛和更动态的作用，挑战了这一长期持有的观点。 这一项目将在科学教育领域产生更广泛的影响。该项目不仅将为研究生和博士后研究员提供培训，还将把本科生驱动的实验与研究相结合。本科生参与者将从那些做荣誉论文项目，也从代表性不足的群体通过WISER（妇女在科学和工程研究）和MURE（少数民族本科生研究经验）计划在宾夕法尼亚州立大学。此外，实验室实验将用于一个大型（500名学生）介绍细胞生物学类，其中服务于几个专业的“现实科学”的方法。对于这种方法，由本科生研究人员进行的易于处理的研究线程，然后整合到课程（包括考试）。本科生的实验在整个学期的课堂上进行，并定期更新学生的进展情况。这将演示课堂上提到的技术的实际应用，但这门课的实验部分无法涵盖。与此同时，这将传授的性质，节奏和思维过程的感觉，基础研究的学生谁可能选择不成为专业的生物学家，但仍然会成为科学素养的公民。