From Plasma Membrane to Organelle: Novel Sugar Signaling through the Arabidopsis Heterotrimeric G Protein Complex

植物制造和利用糖。由于社会的食物、衣服、住所和药品在很大程度上依赖于这一基本过程，因此了解植物如何控制糖合成和糖使用的时间和努力是很重要的。首先要了解的是植物细胞如何感知细胞外的糖量，并向细胞内机制发出信号，以适应这个水平。PI表明，一种叫做AtRGS1的细胞表面蛋白是糖受体的强有力的候选者。在细胞内，AtRGS1控制糖转运体SGB1的活性。当细胞外糖水平改变时，AtRGS1和SGB1都在细胞表面之间移动到细胞间室。该项目解决了细胞内这种分子运动的目的，并将测试这种运动对糖感知至关重要的假设。AtRGS1很可能成为植物和动物中发现的第一个糖受体，它是一种不寻常类型的细胞表面受体的第一个成员，其不寻常的性质意味着一种新的感知机制。除了对社会、农业和细胞生物学基本机制的一般知识产生直接影响外，该项目还将培养一名博士后和一名博士生、一名生命科学技术人员和一些本科生。最后，针对高中生物教学模块的构建进行了探讨。本模块将介绍差异基因表达的概念，并将其与人体细胞类型和人类特征的身份差异联系起来。

Plants make and use sugars . Since food, clothing, shelter and medicine for society depends heavily on this fundamental process, it is important to understand how plants control the timing and effort of sugar synthesis and of sugar usage. First and foremost to understand is how plant cells sense the amount of sugar outside their cells to signal to the intracellular machinery to accommodate this level. The PI showed that a cell surface protein called AtRGS1 is a strong candidate for the sugar receptor. Inside the cell, AtRGS1 controls the activity of a sugar transporter called SGB1. Both AtRGS1 and SGB1 move between the cell surface to intercellular compartments when the extracellular sugar level changes. This project addresses the purpose of this molecular movement within the cell and will test the hypothesis that this movement is critical for sugar sensing. AtRGS1 is likely to become the first sugar receptor discovered for plants and animals, it is the first member of an unusual type of cell surface receptor, and its unusual nature purport a novel sensing mechanism. In addition to the direct impact this will have on society, agriculture and general knowledge of the basic mechanisms in cell biology, the project will result in the training of one postdoctoral and one predoctoral student, a life science technician, and a number of undergraduates. Finally, special effort will be made toward building a teaching module for high school biology students. This module will introduce the concept of differential gene expression, relating it to the identity differences underlying cell types of the human body and human traits.