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。知识价值。在森林地面的树叶碎片中，有许多居民，其中之一是群居变形虫。这些古老的生物在进化的早期就从哺乳动物中分离出来并独立进化。群居变形虫是非常了不起的——它们可以以个体细胞的形式生存，以生存环境中生长的细菌为食，也可以在食物匮乏时聚集在一起形成多细胞生物。变形虫的生存和移动取决于它们粘在表面上的能力，要么是它们的猎物细菌，要么是地面上的土壤，甚至是彼此。这个项目的目标是准确地理解简单的变形虫是如何附着在表面上的。这项工作的重点是talin，一种在哺乳动物和变形虫中都发现的高度保守的蛋白质。Talin是一种连接蛋白，它将粘附受体（附着在细胞质膜上的蛋白质，可以识别特定的表面（如细菌，其他变形虫））与细胞内部骨架（称为细胞骨架）连接起来。将受体连接到细胞骨架上，使细胞能够在表面上拉动，要么吞噬猎物细菌，要么沿着森林地面移动。该项目将对talin的作用机制提出详细的问题，即识别其功能所需的talin分子区域，并寻找与talin结合的其他粘附蛋白。它还将通过比较从最古老到最近的不同阿米巴物种的爪子的结构和功能，来探讨爪子在社会变形虫中的作用是如何进化的。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，这是一种对细胞生长和生存至关重要的活动。更广泛的影响。该项目将为没有经验的学生（高中生、大学一年级和二年级学生）提供动手实验研究的机会。总体目标是向学生介绍实验科学，同时激发和培养他们独立、批判性思维的能力。该项目包括一系列专门为不同技能水平的学生设计的小项目。一对一的苏格拉底方法将被采用：PI将单独教授学生各种方法，然后鼓励他们解决和回答有关talin的具体问题，并在进行中提出自己的新问题。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生物体进化中的概念。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、乌拉圭和阿根廷举行的一系列细胞生物学和生物化学国际培训课程开发讲座和实验室模块，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.