G Protein Activation through Uncoupling Regulator of G Signaling Protein, AtRGS1

智力价值：为了让生物体正常发育并对环境做出适当的反应，组成生物体的细胞必须相互沟通。细胞用来交流的信号可以是荷尔蒙、光、小分子、电脉冲和触摸。例如，光可以打开(激活)一个光感受器，然后激活其他几个分子复合体，然后激活更多的开关，以此类推，以适应细胞的变化。在受体上的信号和细胞内发生的变化之间有一个分子开关，称为异三聚体G蛋白复合体。异三聚体G蛋白偶联信号用于生物体的正常发育以及对致病病原体的反应。最近使用发散模型系统对异三聚体G蛋白偶联信号的研究揭示了如何调节信号激活的潜在范式转变。例如，在后生动物和真菌中，激活是限速步骤，并由配体刺激的细胞表面G蛋白偶联受体(GPCR)催化。相反，植物调节GTP水解导致休眠状态的反向反应，在拟南芥中，这种休眠状态由G信号(RGS)蛋白的跨膜调节蛋白AtRGS1维持。在拟南芥中，D-葡萄糖和/或糖的代谢物是部分由异源三聚体G蛋白复合体介导的信号。假设葡萄糖和/或糖代谢产物通过调节AtRGS1和AtGPA1之间的偶联来激活G蛋白途径，并且已经证明D-葡萄糖诱导AtRGS1的快速内化，但不能诱导AtGPA1的内化。需要回答的关键问题包括去偶联是如何实现的，去偶联的后果，以及去偶联的分子机制。这些问题将使用数学建模、信号成分的遗传操作和显微镜进行研究。更广泛的影响：更广泛的影响是教育高中生物学生如何通过信号转导实现不同的细胞结果。与北卡罗来纳州大学的外联方案合作，将进一步开发一个名为“相同基因-不同命运”的教学模块，以教授差异基因表达的概念和一组具有相同基因的细胞不同细胞命运的基础。虽然该单元目前是为生物学I和II学生(9年级和10年级)设计的，但它也适用于AP生物学和大学一年级学生。这个项目将通过在指令中加入表观遗传学和信号诱导的变化等概念来适应更高的主题。该模块的湿实验室部分利用具有基因启动子的转基因植物，这些基因启动子驱动一种酶活性，导致植物的不同部分变成蓝色。蓝色区域取决于基因启动子的类型，说明了基因表达的差异。将举办相关的教师讲习班，教授和推广使用这一单元。该模块最初将在北卡罗来纳州的高中分发，但最终将在全国范围内分发。

Intellectual Merit: For organisms to develop normally and to react appropriately to their environment, the cells that compose organisms must communicate with each other. Signals used by cells to communicate can be hormones, light, small molecules, electrical impulses, and touch. For example, light can turn on (activate) a light receptor which then activates a few other molecular complexes that then activates many more switches, and so on to afford changes in the cell. Between the signal at the receptor and the changes occurring in the cell is a molecular switch called the heterotrimeric G protein complex. Heterotrimeric G protein-coupled signaling is used for normal development of the organism as well as reactions to pathogens causing disease. Recent investigations of heterotrimeric G protein-coupled signaling using divergent model systems reveals a potential paradigm shift on how signal activation can be regulated. For example, in metazoans and fungi, activation is the rate limiting step and is catalyzed by a ligand-stimulated, cell surface G protein coupled receptor (GPCR). In contrast, plants regulate the back reaction which is GTP hydrolysis leading to the resting state, and in Arabidopsis, this resting state is maintained by a transmembrane regulator of G Signaling (RGS) protein designated AtRGS1. In Arabidopsis, D-glucose and/or sugar metabolites are signals that are mediated in part by the heterotrimeric G protein complex. It is hypothesized that glucose and/or sugar metabolites activate the G protein pathway by regulating the coupling between AtRGS1 and AtGPA1, and it has been demonstrated that D-glucose induces a rapid internalization of AtRGS1, but not AtGPA1. Key questions to be answered include how uncoupling is achieved, the consequence of uncoupling, and the molecular mechanism for uncoupling. These questions will be examined using mathematical modeling, genetic manipulation of the signaling components, and microscopy. Broader Impacts: The broader impact is education of high school biology students on how differential cellular outcomes can be achieved through signal transduction. In collaboration with the UNC outreach program, a teaching module called "Same Genes- Different Fates" will be further developed to teach the concept of differential gene expression and the basis for different cell fates for a set of cells all having the same genes. While the module is currently designed for Biology I and II students (9th and 10th graders), it is adaptable to AP biology and college freshmen. This project will make those adaptations to the higher subject matter by adding concepts like epigenetics and signaling-induced changes into the instructions. The wet-lab part of the module utilizes transgenic plants that have gene promoters driving an enzyme activity that causes different parts of the plant to turn blue. The area of blue is dependent on the type of gene promoter and illustrates differential gene expression. Associated teacher workshops will be held to teach and promote the use of this module. The module will be distributed to high schools initially in North Carolina but eventually nationwide.