Untersuchungen zum Einfluss von reguliertem Vesikeltransport auf die Signaltransduktion in Pflanzenzellen am Beispiel des Brassinosteroidrezeptors, BRI1

受体的调节囊泡运输已被认为是动物信号传导途径的组成部分。在植物中，拟南芥的分子和遗传方法确定了重要的信号传导途径，包括一个独特的类固醇信号传导途径，涉及质膜定位受体激酶BRI 1。BRI 1受体介导的油菜素类固醇感知是迄今为止最好理解的。然而，在植物中对受体运输及其对信号转导的重要性一无所知。我建议使用BRI 1作为一个模型，并调查BRI 1贩运和油菜素类固醇信号动力学的重要性。在根表皮细胞中检测到BRI 1-GFP，这是一种非常适合细胞生物学操作的系统。BRI 1-配体和抑制剂可以外源应用，并且可以获得大量非致死性油菜素类固醇突变体。简单的拟南芥转化方案不仅使我能够研究工程化的BRI 1变体的运输，而且还可以在确定的遗传背景中筛选PCR诱变的BRI 1运输突变体。这将在植物内细胞系统中进行，蛋白质稳定表达至内源水平。将联合收割机遗传学、分子生物学和细胞生物学工具相结合的能力不仅将导致对油菜素类固醇信号传导的新的见解，而且有可能使拟南芥成为研究受体细胞生物学的有吸引力的通用模型。

Regulated vesicle trafficking of receptors has been recognised as an integral part of signalling pathways in animals. In plants, molecular and genetic approaches in Arabidopsis identified important signalling pathways, including a unique steroid signalling pathway, involving a plasma-membrane localised receptor-kinase, BRI1. BRI1-receptor mediated brassinosteroid perception is one of the best understood to date. However, nothing is known in plants about receptor trafficking and its importance for signal transduction. I propose to use BRI1 as a model and to investigate BRI1 trafficking and its importance for brassinosteroid signalling dynamics. BRI1-GFP is detected in root epidermal cells, a well-suited system for cell biological manipulations. BRI1-ligand and inhibitors can be applied exogenously and a large inventory of non-lethal brassinosteroid mutants is available. Facile Arabidopsis transformation protocols will not only allow me to investigate trafficking of engineered BRI1 variants, but also to screen for PCR-mutagenised BRI1 trafficking mutants in defined genetic backgrounds. This will be done in a in-planta cell system, with proteins that are stably expressed to endogenous levels. The ability to combine genetic, molecular biological and cell biological tools will not only lead to new insights into brassinosteroid signalling but has the protential to make Arabidopsis an attractive general model for investigation of receptor cell biology.