CELLULAR SIGNALING BY DOUBLE STRANDED RNA

本项目将研究双链RNA的细胞信号传导。DsRNA是基因转录、蛋白质合成和细胞生长的重要调控因子。dsRNA的多种细胞功能已经在干扰素系统的背景下被发现，其不同方面将在本计划的其他项目中进行研究。dsRNA的转录信号将使用缺陷细胞突变体进行分析。一个这样的突变体已经被分离出来，更多的突变体将在拟议的研究过程中产生。将检测突变细胞中可能参与dsRNA信号传导的候选蛋白的缺陷。如果没有发现这种缺陷，将用野生型细胞的cDNA表达文库进行补充，并克隆突变蛋白。在另外两个目标中，将研究在上一个资助期内克隆的两个dsrna结合蛋白的细胞功能。一种蛋白质，PACT与PKR相互作用并激活它。研究其激活过程的机制及其对转录信号、蛋白质合成和细胞生长调节的影响。另一种dsrna结合蛋白p90o是一种核磷酸化蛋白。它可能参与细胞周期调节和核RNA代谢将被研究。这些研究将为病毒感染细胞中的主要调控因子dsRNA的细胞功能提供重要的机制信息。

Cellular signaling by double-stranded (ds) RNA will be investigated in this project. DsRNA is an important regulator of gene transcription, protein synthesis and cell growth. The multiple cellular functions of dsRNA have been discovered in the contexts of the interferon system, different aspects of which will be studied in the other projects of this program. Transcriptional signaling by dsRNA will be analyzed using defective cell mutants. One such mutant has been already isolated and more will be generated during the course of the proposed investigation. The mutant cells will be examined for defects in candidate proteins which might be involved in dsRNA signaling. If no such defect is found, the cells will be complemented with cDNA expression libraries made from wild-type cells and the mutated protein will be cloned. In two other aims, cellular functions of two dsRNA-binding proteins, which were cloned during the last funding period, will be investigated. One protein, PACT interacts with PKR and activates it. The mechanism of the activation process and its consequence on transcriptional signaling, protein synthesis and cell growth regulation will be studied. P9O, the other dsRNA-binding protein, is a nuclear phosphoprotein. Its possible involvement in cell cycle regulation and nuclear RNA metabolism will be investigated. The proposed studies will provide important mechanistic information about the cellular functions of dsRNA, a major regulator in virus-infected cells.