Collaborative Research: Harnessing plant hormone receptors for the rapid design of genetic circuits controlled by user-specified ligands

生命之树上的有机体可以感知其环境的特征并对其做出反应。例如，植物朝着光的方向生长，细菌朝着营养源游动。生物体的感知和反应能力是一种核心生物功能，由分子机制支撑，分子机制识别特定信号，然后触发反应，例如生物体生长，发育或运动的变化。在这个项目中，一个由工程师和生物学家组成的团队通过设计一个取自植物的感觉-反应模块来开发新的生物功能。这种传感器是独一无二的，因为它可以作为一个简单的开关，随意打开和关闭其他蛋白质，并可以重新编程以识别不同的化学物质。该项目开发用于药物和饮食分子的传感器，然后使用这些新传感器设计合成的“哨兵细胞”，可以很容易地指示许多不同分子的存在。例如，该项目设计的细胞会根据它们接触的药物而变成不同的颜色。为了做到这一点，该团队正在重新编程一种植物传感器来识别新分子，然后将新传感器与调节基因表达的细菌酶物理连接起来。这种结合使细菌能够响应输入信号而变成不同的颜色。该项目支持STEM职业学生的培训，并将研究成果整合到与入门实验室课程相关的基于发现的实验室中。该项目能够快速构建由用户指定分子控制的单通道和多通道遗传电路。这种能力是通过建立一个快速构建可编程化学诱导RNA聚合酶（ChIRP）的平台来实现的。为了做到这一点，计算设计，诱变和遗传选择被用来重新编程的配体结合特异性的一种新的植物来源的化学诱导的二聚化模块，用于调节分裂T7 RNA聚合酶的活性。同时，开发了一组新的识别新型启动子的正交T7变体，并将其转化为ChIRP，以提供多输入/多输出化学调节电路。这些努力开辟了一个新的配体控制的生物技术，并允许研究人员设计复杂的基因电路控制的最佳特定配体的目标应用程序。这个奖项反映了NSF的法定使命，并已被认为是值得通过评估使用基金会的智力价值和更广泛的影响审查标准的支持。

Organisms across the tree of life can sense features of their environments and respond to them. For example, plants grow in the direction of light, and bacteria swim toward nutrient sources. An organism’s ability to sense and respond is a core biological function undergirded by molecular machinery that recognizes specific signals and then triggers responses, such as changes in the organism’s growth, development, or movement. In this project, a team of engineers and biologists work together to develop new biological functions by engineering a sense-response module taken from plants. This sensor is unique because it can be used as a simple switch for turning other proteins on and off at will and can be reprogrammed to recognize diverse chemicals. This project develops sensors for pharmaceuticals and dietary molecules and then uses these new sensors to design synthetic ‘sentinel cells’ that can easily indicate the presence of many different molecules. For example, the project designs cells that turn different colors depending on to which pharmaceutical they are exposed. To do this, the team is reprograming a plant sensor to recognize new molecules and then physically link the new sensors to a bacterial enzyme that regulates gene expression. This union enables bacteria to turn different colors in response to input signals. The project supports the training of students in STEM careers and the research findings are integrated into a discovery-based lab associated with an introductory laboratory course.This project enables the rapid construction of single and multi-channel genetic circuits controlled by user-specified molecules. This capacity is enabled by building a platform for the rapid construction of programmable chemically inducible RNA polymerases (ChIRPs). To do this, computational design, mutagenesis, and genetic selections are used to reprogram the ligand-binding specificity of a novel plant-derived chemical-induced dimerization module that is used to regulate the activity of split T7 RNA polymerase. In parallel, a new set of orthogonal T7 variants that recognize novel promoters are developed and converted into ChIRPs to deliver multi-input/multi-output chemical-regulated circuitry. These efforts open a vast range of new ligand-controlled biotechnologies and allow investigators to design complex genetic circuits controlled by the best specific ligands for target applications.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.