Mass spectrometric based analysis of plasma membrane proteins that regulate cell expansion in Arabidopsis thaliana.

存在于细胞外膜中的分子充当触角，感知环境的变化，并通过化学反应(例如磷酸化)和形状(或构象)的变化将这些信息传递到细胞内。新开发的技术允许使用质谱学方法检测分子的这种构象变化，在这个项目中，这些新技术将被用来了解信号如何调节植物细胞大小的快速扩张。将为高中生开发练习，使用质谱分析常见的食物蛋白质，如大豆豆腐。由威斯康星大学生物技术中心免费播出的PBS电视连续剧《星期三晚上在实验室》将向普通公众解释(并揭开)质谱学的神秘面纱，以植物蛋白质分析为例，解释这如何影响他们的日常生活。总体而言，这个项目试图结合体外和体内的方法来了解跨质膜信号传递的分子基础。本项目的重点是植物质膜受体激酶费洛尼亚及其多肽激素配基Ralf。当Ralf与费洛尼亚的胞外结构域结合时，细胞的扩张速度在几分钟内就会减慢。该项目将开发和应用新的基于质谱学的工具来分析细胞外Ralf在费洛尼亚中诱导的构象变化。最新设计的PLIMB仪器(等离子体诱导的生物分子修饰)可以产生微秒脉冲的羟基自由基脉冲，将被用于在质膜上“足迹”费洛尼亚和其他参与费洛尼亚/Ralf作用的蛋白质。

Molecules present in the outer membranes of cells act as antennae to perceive changes in the environment, and transmit this information into the cell by chemical reactions (for example phosphorylation) and by changes in shape (or conformation.) Newly developed technologies allow such conformational changes in molecules to be detected using the methods of mass spectrometry, and in this project these new technologies will be used to understand how signals regulate the rapid expansion of plant cell size. Exercises will be developed for high school students, using mass spectrometry to analyze common food proteins such as soybean tofu. A PBS television series "Wednesday Nite at the Lab" that is broadcast free from the University of Wisconsin Biotechnology Center will explain to the general public (and demystify) mass spectrometry, using as an example the analysis of plant proteins and explaining how this impacts their everyday lives. Overall this project seeks to combine in vitro and in vivo approaches to understanding the molecular basis for signal transmission across the plasma membrane. The focus of this project is Feronia, a plant plasma membrane receptor kinase, and its peptide hormone ligand, RALF. When RALF binds to the extracellular domain of Feronia, the rate of cell expansion is reduced within minutes. This project will develop and apply novel mass spectrometric based tools for analyzing the conformational changes that extracellular RALF induces in Feronia. The newly devised PLIMB instrument (Plasma Induced Modification of Biomolecules) that generates microsecond pulses of hydroxyl radicals will be used to "footprint" Feronia and other proteins that are involved in Feronia/RALF action at the plasma membrane.