DIFFERENTIAL GENE EXPRESSION MECHANISM IN ALPHAVIRUS

α病毒的差异基因表达机制

• 批准号: 6485273
• 负责人: Ramasamy Raju
• 金额: $ 17.91万
• 依托单位: MEHARRY MEDICAL COLLEGE
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-08-01 至 2002-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6485273
• 关键词: Alphavirus; RNA biosynthesis; Sindbis virus; antisense nucleic acid; gene expression; gene mutation; genetic regulation; transfection /expression vector; virus RNA; virus genetics

Mechanism of differential gene expression in alphavirus Arthropod borne (arbo) viruses are one of the largest groups of RNA viruses and are an important cause of endemic and epidemic outbreaks of encephalitis, hepatitis and hemorrhagic fevers around the world. Sindbis virus (SIN), the subject of this proposal, is a mosquito transmitted human alphavirus. Important mosquito transmitted viruses such as eastern equine encephalitis (EEE), western equine encephalitis (WEE) and venezuelan equine encephalitis (VEE) also belong to alphavirus group. All alphaviruses vary an 12kb long (+) sense RNA genome which is directly translated by host ribosomes to produce viral RNA polymerase. Conserved RNA motifs located at the termini of SIN genome are thought to be important for polymerase recognition and RNA synthesis. At least three different kinds of RNAs are expressed from SIN genome: i) 49S (+) sense RNA; II) 49s (-) sense RNA and iii) 26S (+) sense RNA. Although, differential expression of these RNAs is long known, the mechanism of regulation of their expression is lacking. We have recently characterized the minimal sequence requirements within the 3' AU-rich region which is necessary for RNA synthesis. Since, the first RNA to be made in SIN infected cells is the (-) sense SIN RNA, we have chosen first to address the mechanism of (-) sense RNA synthesis. On the basis of our own published results, and those of others, we hypothesize that one or more RNA motifs interact with cellular and viral factors to regulate RNA synthesis and differential gene expression. The specific aims of this proposal are: 1) To characterize the role of various SIN RNA motifs that regulate (-) sense RNA synthesis. 2) To map the compensatory nucleotide changes that accompany mutations within the 3'NTR of the SIN genome. These studies are new to alphaviruses and represent the beginning of our long term goal to delineate the differential regulation of alphaviral RNA synthesis. Since alphaviral RNA vectors are vigorously pursued as gene therapeutic and vaccine delivery modules, these proposed studies will be used in the development of improved RNA vectors.

甲病毒中差异基因表达的机制节肢动物传播的(arbo)病毒是RNA病毒中最大的类群之一，是世界各地脑炎、肝炎和出血热地方性和流行性暴发的重要原因。本提案的主题辛德比斯病毒（SIN）是一种由蚊子传播的人类甲病毒。重要的蚊媒传播病毒如东部马脑炎（EEE）、西部马脑炎（WEE）和委内瑞拉马脑炎（VEE）也属于甲病毒组。所有甲病毒都有一个 12kb 长 (+) 有义 RNA 基因组，该基因组由宿主核糖体直接翻译以产生病毒 RNA 聚合酶。位于 SIN 基因组末端的保守 RNA 基序被认为对于聚合酶识别和 RNA 合成很重要。 SIN基因组表达至少三种不同类型的RNA： i) 49S (+) 有义RNA； II) 49s (-) 有义 RNA 和 iii) 26S (+) 有义 RNA。尽管这些RNA的差异表达早已为人所知，但其表达的调控机制却缺乏。我们最近描述了 3' AU 丰富区域内的最低序列要求，这是 RNA 合成所必需的。由于 SIN 感染细胞中产生的第一个 RNA 是 (-) 有义 SIN RNA，因此我们选择首先解决 (-) 有义 RNA 合成的机制。根据我们自己和其他人发表的结果，我们假设一个或多个 RNA 基序与细胞和病毒因子相互作用，以调节 RNA 合成和差异基因表达。该提案的具体目标是：1) 表征调节 (-) 有义 RNA 合成的各种 SIN RNA 基序的作用。 2) 绘制 SIN 基因组 3'NTR 内伴随突变的补偿性核苷酸变化图。这些研究对于甲病毒来说是新的，代表了我们描绘甲病毒 RNA 合成差异调节的长期目标的开始。由于甲病毒 RNA 载体作为基因治疗和疫苗递送模块被大力追求，因此这些拟议的研究将用于开发改进的 RNA 载体。