Disentangling Sugar Signaling in Plants

植物中糖信号的分离 摘要 葡萄糖和果糖等糖类为所有生物体的发育提供动力和控制。在 植物，参与糖代谢的多种酶-即己激酶（HXKs）和 果糖1 - 6-双磷酸酶（FBPs）-也可作为传感和信号中枢， 调节基因表达。三大挑战阻碍了对生理学的理解 这些酶的作用，不仅在植物中，而且在多细胞生物中。第一，突变 这些酶导致多效性效应，使器官和 组织水平表型。第二，因为它们在新陈代谢和信号传导中共同作用， 以区分单个酶对最终表型的贡献。最后，方法 为了直接、非破坏性地定量监测单个酶的活性， 解决方案，并在planta是缺乏的。因此，HXK和FBP监管的所有直接目标 它们在植物生长中的作用还没有阐明。 这个MIRA项目将使用蛋白质工程，化学筛选和合成生物学， 产生生物分子工具，将允许分离，操纵，和监测， HXKs和FBPs的个体代谢和信号传导活性。该项目的主要目标是 操纵这些酶的信号功能，而不影响细胞的新陈代谢， 亦然此外，所有合成结构将以组织特异性方式部署， 区分系统性和细胞自主性效应。选择的模型系统将是主要的 拟南芥的根，一种解剖学上简单、遗传学上易处理、化学上 容易接近，并且对共聚焦显微镜友好。

DISENTANGLING SUGAR SIGNALING IN PLANTS ABSTRACT Sugars like glucose and fructose power and control the development of all living organisms. In plants, multiple enzymes involved in sugar metabolism—namely HEXOKINASES (HXKs) and FRUCTOSE 1-6-BIPHOSPHATASES (FBPs)—also function as sensing and signaling hubs that regulate gene expression. Three major challenges hinder the understanding of the physiological role of these enzymes, not only in plants but in multicellular organisms at large. First, mutations of these enzymes result in pleiotropic effects that complicate the interpretation of organ and tissue-level phenotypes. Second, because they act jointly in metabolism and signaling, it is difficult to differentiate the contribution of individual enzymes to the ultimate phenotype. Lastly, methods to quantitatively monitor the activity of individual enzymes directly, non-destructively, with cellular resolution, and in planta are lacking. As a result, all direct targets of HXKs and FBPs regulation and their involvement in plant growth have not been elucidated. This MIRA project will use protein engineering, chemical screening, and synthetic biology to generate biomolecular tools that will allow the isolation, manipulation, and monitoring of the individual metabolic and signaling activities of HXKs and FBPs. The main goal of this project is to manipulate these enzymes' signaling functions without affecting the cells' metabolism and vice versa. Furthermore, all synthetic constructs will be deployed in a tissue-specific manner to differentiate systemic and cell-autonomous effects. The chosen model system will be the primary root of Arabidopsis thaliana, an organ that is anatomically simple, genetically tractable, chemically accessible, and amicable to confocal microscopy.