Regulation of the Cytoskeleton by Signaling Proteins during Quorum Sensing

哺乳动物细胞感知周围细胞密度的能力（群体感应）在胚胎发生、增殖和分化以及细胞迁移等基本过程中起着重要作用。如果没有群体感应，发育中的胚胎将无法将其细胞适当地分配到不同的组织类型中。这种控制需要整合分泌因子、信号转导分子和细胞机制。在哺乳动物中，参与这些过程的参与者数量之多，造成了相互连接的蛋白质的巨大混乱，使研究变得困难。这个项目的目的是通过使用社会性变形虫，盘形虫，作为一个模型来解开这个纠缠。盘基骨柱细胞表现出哺乳动物细胞的许多特征，包括但不限于运动、分化、发育和细胞间信号传导。因此，这个原生生物是哺乳动物细胞行为的一个很好的模型，特别是群体感应。在饥饿的情况下，盘基ostelium细胞将经历一段时间的分化和发育，从而形成多细胞生物。然而，除非有足够数量的饥饿细胞形成一个完整的有机体，否则这个过程不会开始。因此，这些细胞能够感知周围饥饿细胞的密度，并做出适当的反应。该项目将描述三种信号转导分子（磷脂酶Dbeta和蛋白激酶TklA和PakD）如何共同控制肌动蛋白细胞骨架的变化和发育决定。通过揭示这些蛋白在盘状盘齿龙中的功能，可以更好地了解它们在哺乳动物细胞群体感应中的作用，从而更好地了解它们在发育中的作用。更广泛的影响：该项目促进了发现，同时促进了未被充分代表的群体在学习过程中的参与，因为亨特学院是一所少数民族服务机构，女性学生占60%。未被充分代表的学生和一名博士后研究员将积极参与实验的设计、解释和展示。作为该项目的一部分，将创建、实施和评估两个实验室模块，用于向生物学、生物化学和神经科学专业的学生教授基因分析。博士后研究员将帮助设计模块，培训实验室教师和教授学生，使他掌握课程创建，协调和讲课的技能。这些实验模块将在网上传播给更广泛的教学社区（www.dictybase.org），将影响范围扩大到那些历史上在科学领域代表性不足的人。

The ability of mammalian cells to sense the density of the cells around them (quorum sensing) plays an important role in such fundamental processes as embryogenesis, proliferation and differentiation, and cell migration. Without quorum sensing a developing embryo would be unable to properly proportion its cells into different tissue types. Such control requires integrating secreted factors, signal transduction molecules, and cellular machinery. In mammals, the sheer number of players involved in these processes creates an unwieldy morass of interconnected proteins, making it difficult to study. This project is designed to untangle this snarl by using the social ameoba, Dictyostelium discoideum, as a model. Dictyostelium cells display many of the characteristics of mammalian cells, including, but not limited to, motility, differentiation, development and cell to cell signaling. Thus, this protist is an excellent model for mammalian cell behavior, especially quorum sensing. When starved, Dictyostelium cells will undergo a period of differentiation and development leading to the formation of a multicellular organism. However, this process will not begin unless there are sufficient numbers of starving cells to form a full sized organism. Therefore, these cells are able to sense the density of the starving cells around them and respond appropriately. This project will delineate how three signal transduction molecules (phospholipase Dbeta and the protein kinases TklA and PakD) work together to control changes in the actin cytoskeleton and the decision to develop. By uncovering the function of these proteins in Dictyostelium discoideum, a better understanding of their roles in quorum sensing in mammalian cells can be gained, and with it, a better understanding of their roles in development.Broader Impact:This project advances discovery while promoting participation of underrepresented groups in the learning process, as Hunter College is a minority serving institution with a 60% female student body. Underrepresented students and one postdoctoral researcher will be actively engaged in designing, interpreting and presenting experiments. As part of this project, two lab modules designed to teach genetic analysis to Biology, Biochemistry and Neuroscience majors will be created, implemented and assessed. The postdoctoral researcher will help design the modules, train the lab instructors and teach students, enabling him to acquire skills in course creation, coordination and lecturing. These lab modules will be disseminated on-line to the broader teaching community (www.dictybase.org), extending the reach to those historically underrepresented in the sciences.