CAREER: Mechanical Forces on the Nuclear Linker of Nucleoskeleton to Cytoskeleton (LINC) Complex

动物细胞在健康和机械引起的疾病中都对机械力有反应。这些力通过一种被称为机械转导的过程改变细胞信号。众所周知，机械力影响基本的细胞和组织水平的功能，但机械转导的细胞部位仍然知之甚少。细胞核是哺乳动物细胞中最大的，也许也是最关键的结构，因为大多数DNA都储存在那里。位于细胞核外部的蛋白质会受到机械力的作用，当细胞受到载荷时，细胞核会发生变形。原子核受力的变形表明原子核可能是机械转导的场所。这个学院早期职业发展（Career）项目研究项目将使用一种新型的力传感器来确定细胞核如何以及何时受到机械力，然后确定这些力如何调节细胞功能。这些研究有可能确定一种存在于所有动物细胞中的机械转导的新的基本机制。计划为本科生和研究生提供参与跨学科研究项目的研究机会，以及K-12外展活动，并利用研究成果改善研究生工程教育。细胞核通过一组形成核骨架与细胞骨架连接物（LINC）复合物的蛋白质与细胞质骨架直接相连。LINC复合蛋白的突变与发育受损、人类遗传疾病和癌症有关；因此，细胞骨架与细胞核的联系似乎对细胞功能和体内平衡至关重要。LINC复合体中的蛋白质承受机械力，表明LINC复合体可能是机械转导的重要结构。本CAREER项目的目标是为LINC复合体蛋白nesprin和SUN开发新型的力生物传感器，然后使用这些传感器研究与LINC复合体相关的机械和力依赖的生化过程。确定核力和细胞外的力之间的关系将有助于更好地理解力是如何在细胞内传递的，有助于验证或推进细胞生物力学理论。此外，本项目中使用的力生物传感器用质粒DNA表达，并使用荧光显微镜成像，允许其他实验室采用这种力测量技术

Animal cells respond to mechanical forces both in health and during mechanically caused diseases. The forces change cell signaling through a process known as mechanotransduction. Mechanical forces are known to influence fundamental cellular and tissue level functions, but the cellular sites for mechanotransduction remain poorly understood. The nucleus is the largest and perhaps most critical structure of a mammalian cell since most of the DNA is stored there. Proteins located on the outside of the nucleus experience mechanical force, and the nucleus can be seen deforming when a cell is loaded. Deformation of the nucleus by forces suggests that the nucleus could be a site for mechanotransduction. This Faculty Early Career Development (CAREER) Program research project will determine how and when the nucleus experiences mechanical force using a new kind of force transducer, and then determine how these forces regulate cellular functions. These studies have the potential to identify a new fundamental mechanism of mechanotransduction that would be present in all animals cells. Research opportunities for undergraduate and graduate students to engage in interdisciplinary research projects are planned, as well as K-12 outreach activities, and using research results to improved graduate engineering education.The nucleus is directly connected to the cytoplasmic cytoskeleton by a group of proteins that form the LINC (linker of nucleoskeleton to cytoskeleton) complex. Mutations in LINC complex proteins are associated with impaired development, human genetic diseases, and cancer; thus the linkage of the cytoskeleton to the nucleus appears to be essential to cell function and homeostasis. Proteins in the LINC complex experience mechanical force, suggesting that the LINC complex could be an important structure for mechanotransduction. The goal of this CAREER project is to develop novel force biosensors for LINC complex proteins nesprin and SUN, and then use these sensors to study the mechanical and force-dependent biochemical processes associated with the LINC complex. Identification of the relationship between nuclear force and the forces on the outside of the cell will provide a better understanding of how forces are transmitted within a cell, helping to validate or advance theories of cellular biomechanics. Additionally, the force biosensors used in this project are expressed with plasmid DNA and imaged using fluorescent microscopy, allowing for other laboratories to adopt this force measurement technique