Self-Assembly and Packaging of RNA and DNA in Viruses and Virus-like Particles

有了这笔赠款，生命过程化学项目正在支持威廉M。Gelbart和Charles M.他是加州大学洛杉矶分校化学和生物化学系的Knobler博士，负责病毒自组装和包装过程的体外研究。 该项目由生物组织理事会分子和细胞生物科学司遗传机制小组共同资助。对于双链DNA的情况下，单粒子实验与噬菌体λ的设计来测试的假设，压力驱动的基因组喷射可以完成的主动过程，如转录RNA聚合酶。对于ssRNA的情况下，一个特定的属的简单的植物病毒，充分表征溴病毒，被选为模型系统。 将进行实验来测量各种ssRNA分子（病毒和非病毒）的相对包装效率，以发现RNA电荷、大小和形状所发挥的竞争作用。此外，为了理解这些植物病毒与当今哺乳动物对应物（如甲病毒和黄病毒）之间的进化联系，将尝试用植物衣壳蛋白包装这些哺乳动物RNA基因组，并用磷脂双层包裹所得的核衣壳，以模拟包膜病毒，如登革热和丙型肝炎。这项研究旨在为从物理上理解病毒的传染性奠定坚实的基础。 “物理病毒学”的新兴领域有助于培养一批新的跨学科科学学生和研究人员，他们有能力将化学和物理学的基本思想，方法和技术应用于病毒复制等基本生物学问题。 向非理科本科生教授了两门关于病毒一般方面的新课程，并为当地高中学生和教师制定了一项外联方案，使他们了解加州大学洛杉矶分校的病毒相关研究，并为课堂提供建模和可视化项目。 从长远来看，这项基础研究可能有助于抗病毒治疗的新方法，其基础是干扰ssRNA/衣壳蛋白核衣壳的自组装和/或脂质包膜对其的包裹。

With this grant, the Chemistry of Life Processes program is supporting the research of Professors William M. Gelbart and Charles M. Knobler in the Department of Chemistry and Biochemistry at UCLA on in vitro investigations of viral self-assembly and packaging processes. This project is being co-funded by the Genetic Mechanisms Cluster in the Molecular and Cellular Biosciences Division of the BIO Directorate. For the dsDNA case, single-particle experiments with bacteriophage lambda are designed to test the hypothesis that pressure-driven genome ejection can be completed by active processes like transcription by RNA polymerase. For the ssRNA case, a particular genus of simple plant virus, the well-characterized bromoviruses, is chosen as the model system. Experiments will be performed to measure the relative packaging efficiencies of a broad range of ssRNA molecules, viral, and non-viral, in order to discover the competing roles played by RNA charge, size, and shape. Further, to understand the evolutionary connection between these plant viruses and present-day mammalian counterparts such as the alphaviruses and flaviviruses, an attempt will be made to package these mammalian RNA genomes with plant capsid protein and to wrap the resulting nucleocapsids with phospholipid bilayer, in order to mimic enveloped viruses like dengue and hepatitis C.On a fundamental level, this research seeks to build a strong foundation for a physical understanding of viral infectivity. The emerging field of "Physical Virology" is contributing to the training of a new cadre of interdisciplinary science students and researchers who are equipped to apply fundamental ideas, approaches and techniques from chemistry and physics to basic biological problems like viral replication. Two new courses on general aspects of viruses have been taught to non-science undergraduate majors, and an outreach program has been developed for local high school students and teachers, exposing them to virus related research at UCLA and providing model-building and visualization projects for the classroom. In the longer term, this basic research may contribute to new approaches to anti-viral therapies based upon interference with the self-assembly of the ssRNA/capsid protein nucleocapsid and/or its wrapping by the lipid envelope.