Regulation of Talin Function in Amoeboid Cells

该奖项是根据2009年《美国复苏和再投资法案》(公法111-5)资助的。森林地面的树叶瓦砾中有许多居民，其中之一就是社会变形虫。这些是古老的生物，在进化的早期就与哺乳动物分开并独立进化。社会阿米巴是相当了不起的--它们可以作为单独的细胞存在，依靠生长在其环境中的细菌生存，或者当食物变得稀缺时，它们可以聚集在一起形成一个多细胞有机体。阿米巴的生存和移动依赖于它们附着在表面的能力，无论是它们的猎物细菌，还是地面上的土壤，甚至是彼此之间。这个项目的目标是确切地了解简单的阿米巴如何能够附着在表面上。这项工作的重点是Talin，一种在哺乳动物和阿米巴中都发现的高度保守的蛋白质。Talin是一种连接蛋白，它将黏附受体与细胞内部骨架连接起来，黏附受体是驻留在细胞质膜上的识别特定表面(即细菌、其他阿米巴)的蛋白质。将受体连接到细胞骨架上，使细胞能够拉动表面，要么吞噬它的猎物细菌，要么沿着森林地面移动。该项目将就Talin的作用机制提出详细的问题，即确定Talin分子发挥功能所需的区域，并寻找与Talin结合的其他黏附蛋白。它还将通过比较不同种类的阿米巴从最古老的到最近的塔林蛋白的结构和功能，来研究塔林蛋白在社会阿米巴中的作用是如何演变的。从这个项目中获得的信息将揭示细胞如何与环境相互作用的基本原理，这一活动对它们的生长和生存至关重要。更广泛的影响。该项目将为缺乏经验的学生(高中生、大学一年级和二年级学生)提供实验室研究方面的实践培训机会。总体目标是向学生介绍实验科学，并激发和培养他们的独立、批判性思维能力。该项目包括一系列专门为技能水平各异的学生设计的迷你项目。将采用一对一的苏格拉底方法：学生将由PI单独教授各种方法，然后鼓励他们解决并回答关于Talin的具体问题，并在进行过程中提出他们自己的新问题。该研究还将向学生介绍生物信息学方法在生物学中的力量，以及蛋白质和有机体进化中的概念。最后，该项目将成为促进与拉丁美洲研究实验室的国际合作和科学交流的工具。将为每年在巴西、乌拉圭和阿根廷举办的一系列细胞生物学和生物化学国际培训班提供讲座和实验室模块，这些互动将成为发展科学合作的催化剂。

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).Intellectual merit. One of the many inhabitants in the leafy debris of the forest floors is social amoeba. These are ancient organisms that diverged and evolved independently from mammals quite early in evolution. Social amoeba are quite remarkable--they can exist as individual cells that subsist on the bacteria growing in their environment, or they can come together to form a multicellular organism when food becomes scarce. Amoeba survival and movement depends on their ability to stick to surfaces, either their prey bacteria or the soil on the ground or even each other. The goal of this project is to understand exactly how simple amoebae are able to adhere to surfaces. The focus of the work is on talin, a highly conserved protein found in both mammals and amoeba. Talin is a linker protein that connects adhesion receptors, proteins residing in the cell's plasma membrane that recognize specific surfaces (i.e. bacteria, other amoeba), to the cell's internal skeleton, called the cytoskeleton. Linking receptors to the cytoskeleton allows the cell to pull against the surface and either engulf its prey bacteria or move along the forest floor. The project will ask detailed questions about the mechanism of talin action, i.e. identifying regions of the talin molecule necessary for its function and searching for other adhesion proteins that bind to talin. It will also ask how the role of talin has evolved in social amoeba by comparing the structure and function of talins from different species of amoebae, from the most ancient to the most recent. The information gained from this project will reveal basic principles about how cells interact with their environment, an activity that is critical for their growth and survival. Broader impacts. The project will provide hands-on training opportunities in laboratory research for inexperienced students (high school students, college freshmen and sophomores). The overall goal is to introduce students to experimental science as well as stimulate and foster their independent, critical thinking skills. The project includes a series of mini-projects designed specifically for students with a wide range of skill levels. A one-on-one Socratic method will be employed: students will be individually taught various methods by the PI and then encouraged to work through and answer specific questions about talin, and formulate their own new questions as they proceed. The research will also introduce students to the power of bioinformatics approaches in biology and concepts in the evolution of proteins and organisms. Finally, the project will serve as a vehicle for stimulating international cooperation and scientific exchange with research laboratories in Latin America. Lectures and laboratory modules will be developed for presentation in a series of International Training Courses in Cell Biology & Biochemistry held annually in Brazil, Uruguay and Argentina, and these interactions will serve as a catalyst for developing scientific collaborations.