Structure-function mapping of large intracellular viral RNA.

这项研究计划将研究生命的基本分子，即核糖核酸（RNA）的三维结构。直到最近，一种被称为“信使RNA”的RNA被认为只是一种被动的角色，特别是作为将遗传信息转化为蛋白质的模板。最近有证据表明，某些信使RNA分子表现出的结构模式可以控制基因是沉默还是表达。然而，人们对RNA的结构知之甚少，因为它存在于活细胞内。虽然计算机模型通常用于预测RNA分子的形状，但仅使用计算机建模很难达到高度准确性。由于细胞内RNA被包裹在蛋白质外壳内，而不是作为自由漂浮的链存在，这一事实进一步复杂化。我们的研究计划旨在通过使用丙型肝炎病毒的RNA基因组（模拟信使RNA）作为模型系统，并研究这种RNA如何存在于活细胞内，从而更好地了解细胞内RNA的结构。我们已经开发出一种独特的方法来探测细胞内RNA折叠形成的复杂结构。我们研究计划的第一个目标是绘制环状螺旋结构的位置，这些螺旋结构可能是丙型肝炎病毒细胞内基因组自然折叠过程的一部分。我们的第二个目标是研究这个基因组的远距离部分如何在细胞内完美排列，从而导致病毒基因组折叠成一个大的环状分子。通过在RNA中引入突变来破坏这些排列，我们应该能够确定这种排列对特定功能是否重要。了解丙型肝炎病毒RNA基因组内复杂的细胞内折叠将构成我们对RNA知识的重要一步，这将有助于更好地了解基因是如何表达的。这些知识是开发基因工程新产品和新技术的基础。

This research program will study the tridimensional structure of a basic molecule of life, namely ribonucleic acid (RNA). Until recently, a type of RNA known as "messenger RNA" was thought to have just a passive role, notably as a template for the conversion of genetic information into protein. There is recent evidence suggesting that certain messenger RNA molecules exhibit structural patterns that can control whether genes are silent or expressed. Little is known, however, on the structure of RNA as it exists inside living cells. While computer models are commonly used to predict the shapes of RNA molecules, it is difficult to achieve a high degree of accuracy using computer modeling alone. This is further complicated by the fact that intracellular RNA is encased within a protein coat, and does not exist as a free-floating strand. Our research program aims to gain a better understanding of the structure of intracellular RNA by using the RNA genome of the hepatitis C virus (which mimics messenger RNA) as a model system and examining how this RNA exists inside a living cell. We have developed a unique approach to probe complex structures formed by the folding of RNA inside the cell. The first objective of our research program is to map the location of loop-shaped helical structures that may form as part of the natural folding process of the intracellular genome of the hepatitis C virus. Our second objective is to examine how distant parts of this genome can perfectly align inside cells and, consequently, cause the viral genome to fold into a large circular molecule. By introducing mutations into the RNA that disrupt these alignments, we should be able to determine whether such alignments are important for specific functions. An understanding of the complex intracellular folding within the RNA genome of the hepatitis C virus would constitute a significant step forward in our knowledge of RNA, which should lead to a better understanding of how genes are expressed. This knowledge is the basis for the development of new products and technologies in genetic engineering.