Collaborative Research: Regulation of Cellular Mechanics by Crosslinked Actin Networks - Role of Palladin and Alpha-actinin

合作研究：交联肌动蛋白网络调节细胞力学 - Palladin 和 α-肌动蛋白的作用

• 批准号: 1121710
• 负责人: Arpita Upadhyaya
• 金额: $ 38.25万
• 依托单位: University of Maryland, College Park
• 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: 2011-11-01 至 2014-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1121710&HistoricalAwards=false
• 关键词: Collaborative; Research; Regulation; Cellular; Mechanics

Intellectual MeritCells in the body have a remarkable ability to sense "stiffness" in their environment - that is, a cell can distinguish between a hard substrate such as bone, and a softer substrate such as brain. This ability is critical for many aspects of cell function such as migration, wound healing and the proper formation of tissues and organs. In order to sense the mechanical properties of their environment, cells adjust their internal stiffness to match that of the external surface by reorganizing their internal cytoskeleton, which is made of a dynamic network of microscopic filaments. The main component of these filaments is a protein called actin. Various actin-binding proteins crosslink the actin filaments and organize them into multifilament bundles. Palladin is a newly identified actin cross-linking protein that is important in organizing these filament networks. Previous experiments have shown that palladin plays an essential role in embryonic development: when the palladin gene is silenced in mice, it results in lethal development defects that are characterized by a failure of cells to adhere properly to a substrate and to migrate appropriately. These deficits may arise because the cell's ability to adjust its internal stiffness is compromised in the absence of palladin. This proposal will test the hypothesis that palladin, by its ability to cross-link actin and its interaction with another actin cross-linker, alpha-actinin, determines the structure and mechanical properties of actin networks and enables the cell to sense its physical environment. Two types of approaches will be used to address this question. First, the structural and mechanical properties of actin networks assembled on a glass slide will be measured to elucidate how actin cross-linking by palladin contributes to actin organization. In addition, palladin levels will be genetically manipulated in living cells to study how altered actin organization, cellular stiffness and force generation impacts cellular mechano-sensitivity.Broader ImpactThis collaborative proposal will enhance the understanding of essential biological processes that underlie cell movement and tissue formation. The training of graduate and undergraduate students in interdisciplinary approaches from Physics and Cell Biology will be an integral part of the work. The cell lines that will be developed as part of this project will be made freely available to other investigators following their publication. A graduate course in Cell Mechanics will be developed based on the conceptual framework of this proposal. The PI and co-PI will also encourage minority students as well as high school students from the area to participate in research as part of the Louis Stokes Alliance for Minority Participation program at the University of Maryland and the University of North Carolina Research Apprenticeship Program. The PI will organize a one week biophysics laboratory demonstration as part of the Summer Girls Program in the Department of Physics to encourage participation of female students in science and technology fields.

体内的智力成绩具有显着的能力，可以在其环境中感知“刚度”，也就是说，一个细胞可以区分诸如骨骼之类的硬基质和较软的底物（如大脑）。这种能力对于细胞功能的许多方面至关重要，例如迁移，伤口愈合以及组织和器官的正确形成。为了感觉到环境的机械性能，细胞通过重组其内部细胞骨架来调整其内部刚度以匹配外表面的刚度，该骨骼由微观细丝的动态网络组成。这些丝的主要成分是一种称为肌动蛋白的蛋白质。 各种肌动蛋白结合蛋白交联肌动蛋白丝，并将它们组织成多丝束。 Palladin是一种新鉴定的肌动蛋白交联蛋白，在组织这些细丝网络中很重要。先前的实验表明，palladin在胚胎发育中起着至关重要的作用：当小鼠中palladin基因沉默时，它会导致致命的发育缺陷，其特征是细胞未能正确地粘附在底物和适当地迁移。这些缺陷可能会出现，因为在没有palladin的情况下，细胞调节其内部刚度的能力会受到损害。该建议将检验以下假设：Palladin通过其交联肌动蛋白的能力及其与另一种肌动蛋白交联的α-肌动蛋白的相互作用来确定肌动蛋白网络的结构和机械性能，并使细胞感知其物理环境。将使用两种类型的方法来解决这个问题。 首先，将测量聚集在载玻片上的肌动蛋白网络的结构和机械性能，以阐明帕拉丁蛋白的肌动蛋白交联是如何对肌动蛋白组织贡献的。此外，Palladin水平将在活细胞中进行遗传操纵，以研究肌动蛋白组织的改变，细胞僵硬和力产生如何影响细胞机械敏感性。Broader影响这一协作性建议将增强对基本生物学过程的理解，这些生物学过程是细胞运动和组织形成的基本生物学过程。培训研究生和本科生在物理和细胞生物学的跨学科方法中的培训将是工作中不可或缺的一部分。将作为该项目的一部分开发的细胞系将在其他调查人员出版后免费使用。将根据该提案的概念框架开发细胞力学的研究生课程。 PI和CO-PI还将鼓励该地区的少数民族学生以及该地区的高中生参加研究，这是马里兰大学和北卡罗来纳大学研究学徒计划的路易斯·斯托克斯少数族裔参与计划的一部分。 PI将组织为期一周的生物物理实验室演示，作为物理学系夏季女孩计划的一部分，以鼓励女学生参与科学和技术领域。