IRES介导的樱桃小果病毒-1不依赖帽子翻译调控的RNA结构基础

内部核糖体进入位点（Internal ribosome entry site，IRES）是不依赖帽子翻译的重要元件之一，然而在植物病毒中IRES研究的深度远落后于动物病毒的IRES研究。本研究将以甜樱桃上的重要病毒-樱桃小果病毒-1（LChV-1）为研究对象，利用体外翻译、RNA结构分析、反向遗传学、分子互作等技术，分析LChV-1基因组5’UTR的IRES活性，并解析IRES元件的RNA结构特征及核心组件，定位潜在的协同调控IRES活性的远距离RNA-RNA互作，以及IRES发挥作用所需的宿主翻译起始因子的类型。构建LChV-1侵染性克隆，体内验证IRES的核心组件对病毒蛋白翻译和RNA积累量的调控作用。本研究将明确LChV-1中IRES介导的不依赖帽子翻译调控的RNA结构基础，有助于阐释LChV-1的致病机理，并为抗LChV-1药物的设计提供靶点。

Internal ribosome entry site (IRES) is one of the most important elements involved in cap-independent translation mechanism. However, the in-depth research on IRES of plant viruses is still lagging behind that of animal viruses. Little cherry virus 1 (LChV-1) is one of the most important viral diseases of sweet cherry, which was used as the subject in this project. We will reveal the detailed.cap-independent translation mechanism of LChV-1 using molecular biological technologies including in vitro translation experiments, RNA structural analysis, reverse genetics approach and molecular interaction. Firstly, we will analyze the IRES activity of 5’UTR in LChV-1 and unravel the RNA structure and core components of IRES element. Then, the potential long-distance RNA/RNA interaction sites and host translation factors involved in regulation of translation will be mapped and analyzed structurally. Finally, the function role of the core.components of IRES element in regulation of translation and RNA accumulation will be analyzed by constructing an infectious cDNA clone of LChV-1. This proposed project will elucidate the RNA structural basis of IRES-mediated cap-independent translation mechanism in LChV-1, which will not only aid to improve our understanding of pathogenic mechanism of LChV-1 and but also lay a theoretical foundation for treating viral diseases with the structure of IRES elements as drug targets.