Collaborative Research: Assembly of non-lipid components by heterogeneous membranes

非技术摘要偶联到脂膜上的非脂组分直接相互作用，但也通过膜感受有效的相互作用。特别是，当部分组分是膜偶联的时，非脂组分的相变与整体的相变有很大不同。过去的一些工作已经探索了这些不同之处，这些膜本身是均匀的。本研究的目的是探索膜和非脂成分都能经历可混溶相变的体系。这些系统代表了新的生物材料，其中基于膜的信号被激活到非膜过程，类似于信号通路中的常见主题。这项研究将在两个定义明确的模型系统中使用热力学模拟和实验：一个系统包含在块体中形成液体的聚电解质，第二个系统使用经过工程的DNA折纸瓷砖，当连接到膜上时，这些瓷砖可以组装成二维晶格。技术摘要脂膜形成动物细胞与其环境之间的边界，并定义一些亚细胞隔间，如细胞核和线粒体。这些膜主要由脂类制成，类皂分子会自发形成液体，柔性的薄片充当大分子或带电分子的边界。细胞膜还含有嵌入的蛋白质，这是一种更复杂的分子机器，执行一系列生物功能。在细胞内，膜的材料特性有助于组织一些嵌入的蛋白质，并有助于连接到膜上的较大结构的组装。细胞利用这种耦合来传递跨膜的信号，或者感知膜性质的化学或机械变化。这个项目从细胞中获得灵感，开发最小的系统，以探索这些生物过程背后的基本概念。研究人员将探索两个受控良好的系统，即带电聚合物和连接到膜上的工程DNA折纸瓷砖，并将确定膜如何影响非脂成分的组织和组装，以及非脂成分的组织如何影响膜。长期目标是激发能够感知和响应广泛环境刺激的新材料。研究人员将通过出版物、会议报告、公开演讲以及将研究纳入本科课程来交流他们的发现。主要调查人员将培训本科生和研究生从事STEM领域的工作。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Non Technical AbstractNon-lipid components coupled to lipid membranes directly interact with one another but also feel effective interactions through the membrane. In particular, phase transitions in non-lipid components vary significantly from the bulk when a subset of components is membrane-coupled. Some past work has explored these differences for membranes that are themselves homogeneous. The objective of the current study is to explore systems in which both membranes and non-lipid components are capable of experiencing miscibility phase transitions. These systems represent novel biomaterials in which membrane-based signals are actuated to non-membrane processes, similar to common themes in signaling pathways. The research will use thermodynamic simulations and experiments in two well-defined model systems: one incorporating polyelectrolytes that form liquid phases in the bulk, and a second utilizing engineered DNA origami tiles that assemble into two dimensional lattices when coupled to membranes. Technical AbstractLipid membranes form boundaries between animal cells and their environments and define some subcellular compartments, such as the cell nucleus and mitochondria. These membranes are primarily made of lipids, soap-like molecules that spontaneously form into fluid, flexible sheets that act as boundaries to large or charged molecules. Cell membranes also contain embedded proteins, which are more complicated molecular machines that carry out an array of biological functions. Within cells, the material properties of the membrane helps to organize some embedded proteins, and contributes to the assembly of larger structures that are tethered to the membrane. Cells take advantage of this coupling to transduce signals across membranes, or to sense chemical or mechanical changes to membrane properties. This project draws inspiration from cells to develop minimal systems to explore the fundamental concepts that underlie these biological processes. Researchers will explore the two well-controlled systems of charged polymers and engineered DNA origami tiles tethered to membranes, and will identify how membranes influence the organization and assembly of non-lipid components and how the organization of non-lipid components impact membranes. The long-term goal is to inspire new materials that can sense and respond to a wide range of environmental stimuli. The researchers will communicate their findings through publications, conference presentations, public lectures, and by incorporating research into undergraduate curricula. The principle investigators will train undergraduate and graduate students for careers in STEM fields.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.