An Integrative Approach to Elucidate Systemic RNA Trafficking

多细胞生物中单个细胞的基本过程如何整合以实现发育、功能和对环境的反应是现代生物学的核心问题。细胞间RNA转运是最近发现的一种控制基因调控、病毒感染、细胞抗病毒反应和细胞间通讯的机制。该项目研究了细胞中产生的RNA是如何被选择转运到邻近细胞甚至植物的远处器官的，这是一个基本的机制问题，对理解所有RNA的运输调节具有根本的重要性。马铃薯纺轴块茎类病毒（PSTVd）感染将被用作一个简单的实验模型，以验证以下假设：RNA具有不同的结构基序，可以与细胞因子相互作用，从而增强从植物表面到中央维管组织的连续细胞边界的运输，从而进行长距离运输。具体而言，该项目将(1)分析一系列PSTVd转运缺陷突变体，以鉴定介导不同细胞边界转运的RNA基序，(2)通过广泛的突变分析测试预测的转运基序的三维结构模型，以及(3)确定植物蛋白在PSTVd转运中的作用。该项目的结果将提供突破性的见解，了解感染性RNA如何进化出独特的结构元素，利用细胞机制建立感染，并帮助建立一个概念框架，研究许多生物过程背后的RNA运输机制。这个项目将包括对本科生和研究生的培训。这项训练将使学生接触到前沿的跨学科研究方法来研究基本的生物学问题。该项目还将加强对小学/初中/高中学生和中学教师的科学教育，包括传统上代表性不足的群体。

How basic processes in individual cells within a multicellular organism are integrated to enable development, function and response to the environment is a central issue in modern biology. Cell-to-cell trafficking of RNA is a recently discovered mechanism that controls gene regulation, viral infection, cellular antiviral responses, and cell-to-cell communication. This project investigates how an RNA produced in a cell is selected for transport into neighboring cells and even to distant organs in a plant, a basic mechanistic question of fundamental importance to understand trafficking regulation for all RNAs. Potato spindle tuber viroid (PSTVd) infection will be used as a simple experimental model to test the hypothesis that an RNA has distinct structural motifs to interact with cellular factors to potentiate trafficking across successive cellular boundaries from the plant surface to the centrally located vascular tissue for long-distance transport. Specifically, the project will (1) analyze a series of trafficking-defective mutants of PSTVd to identify the RNA motifs mediating trafficking through different cellular boundaries, (2) test the predicted three-dimensional structural model of a trafficking motif through extensive mutational analyses, and (3) determine the role of a plant protein in PSTVd trafficking. Results from the project will provide groundbreaking insights about how an infectious RNA has evolved distinct structural elements to use cellular machinery to establish infection, and help develop a conceptual framework to study the mechanisms of RNA trafficking underlying many biological processes. This project will include training of undergraduate and graduate students. This training will expose students to cutting-edge cross-disciplinary research approaches to study fundamental biological problems. The project will also enhance science education for elementary/middle/high school students and secondary school teachers, including traditionally underrepresented groups.