New insights into the molecular regulation of mechanotransduction

项目总结 细胞存在于物理世界中，人类的功能和疾病往往有物理基础。 机械转导是细胞感知机械信号并对其做出反应的分子过程。 环境。异常的机械转导可导致许多人类疾病，包括哮喘、心脏 失败、骨质疏松症和癌症。因此，了解机械转导的分子基础是至关重要的。 以及这些信号通路在疾病期间是如何被破坏的。整合素受体是一种重要的调节因子 通过组装的超分子复合体在质膜上传递信号的机械转导 称为“局灶性粘连”。局部粘连将肌动蛋白细胞骨架与细胞外连接起来。 环境，在肌动蛋白细胞骨架中产生的力通过焦点粘连传递到驱动 组织形态发生、细胞运动和细胞外基质重塑。虽然适当的监管 焦点粘连是整合素依赖的机械转导所必需的，关于它们的重要问题 其形成和功能仍未得到回答。我们不了解病灶粘连是如何形成的，它们是如何生长的，或者 它们的分子组成是如何被调节的。基于细胞的实验导致了相互矛盾的观察， 我们只有有限的工具来理解分子组成的变化如何造成局部粘连 改变下行信号的特定化学或物理特性。 为了解决这些重要问题，凯斯博士开发了一种新的生化重组方法 使用纯化的蛋白质在支撑的脂双层上的焦点粘连。这项工作确定了七种蛋白质，它们是 足以通过液-液相分离形成焦点粘连。整合素依赖的研究进展 通过相分离透镜的机械转导可以推动该领域的重大进展。这个 案例实验室将使用各种实验策略来了解整合素依赖的不同方面 机械转导。他们将直接用生化测试不同的机械转导模型 重建和确认任何新的体外观察的重要性，以细胞为基础的分析。他们会 研究局灶性粘连是如何成熟的，力是如何通过局灶性粘连传递的，以及 局灶性粘连的生化成分受到调节。这个项目将利用一种新颖的实验 挑战目前关于整合素依赖的机械转导的教条的方法，并将揭示 特定的分子调节焦点粘连的生长和组成。

Project summary Cells exist in a physical world, and there is often a physical basis for human function and disease. Mechanotransduction is the molecular process by which cells sense and respond to mechanical signals in their environment. Abnormal mechanotransduction can contribute to many human diseases including asthma, heart failure, osteoporosis, and cancer. Thus, it is crucial to understand the molecular basis of mechanotransduction and how these signaling pathways are disrupted during disease. Integrin receptors are critical regulators of mechanotransduction at the plasma membrane that signal through the assembly supramolecular complexes termed “focal adhesions.” Focal adhesions physically connect the actin cytoskeleton to the extracellular environment, and forces generated in the actin cytoskeleton are transmitted across focal adhesions to drive tissue morphogenesis, cell movement, and extracellular matrix remodeling. Although the proper regulation of focal adhesions is essential for integrin-dependent mechanotransduction, important questions about their formation and function remain unanswered. We do not understand how focal adhesions form, how they grow, or how their molecular composition is regulated. Cell-based experiments have led to conflicting observations, and we have limited tools to understand how changing molecular composition can create focal adhesions with specific chemical or physical characteristics that alter downstream signaling. To address these important questions, Dr. Case has developed a novel biochemical reconstitution of focal adhesions using purified proteins on supported lipid bilayers. This work identified seven proteins that are sufficient to form focal adhesions through liquid-liquid phase separation. Studying integrin-dependent mechanotransduction through the lens of phase separation could drive significant advances in the field. The Case Lab will use a variety of experimental strategies to understand different aspects of integrin-dependent mechanotransduction. They will directly test different models of mechanotransduction with biochemical reconstitution and confirm the importance of any new in vitro observations with cell-based assays. They will investigate how focal adhesions mature, how forces are transmitted across focal adhesions, and how the biochemical composition of focal adhesions is regulated. This project will take advantage of a novel experimental approach to challenge the current dogma about integrin-dependent mechanotransduction, and will reveal how specific molecules regulate focal adhesion growth and composition.