Using viruses as tools to elucidate the molecular mechanism for transport into the nucleus

所有真核细胞都有一个独特的细胞核，其中包含生物体的遗传蓝图。执行遗传蓝图中包含的指令需要在细胞质和细胞核之间进行分子运输，这一过程称为细胞核运输。这种运输对所有真核细胞都是必不可少的，它调节细胞生理学的许多方面。尽管核转运的重要性显而易见，并且最近在这一领域取得了一些进展，但其分子机制、结构基础和调控的许多方面仍然难以捉摸。我的研究计划的长期目标是阐明大分子进入细胞核的机制。由于许多病毒病原体在细胞核内进行复制，因此必须将其基因组和亚病毒颗粒输送到宿主细胞的细胞核中，因此我们使用病毒作为工具来了解核运输的分子机制。同时，病毒基因组的核输入的详细表征是开发抗病毒疗法的重要步骤，所述抗病毒疗法可通过中断病毒基因组进入感染细胞的核而成功地解决病毒疾病。我们目前正在研究的病毒包括两种重要的人类病原体：A型流感病毒，普通流感的病原体，以及引起急性和慢性肝炎的B型肝炎病毒。我们正在研究的另外两种非人类致病性病毒是杆状病毒和小鼠细小病毒，杆状病毒广泛用作生物医学研究中生产生物活性蛋白质的真核表达系统，小鼠细小病毒优先靶向并杀死癌细胞，可用于抗癌治疗。在我们的研究中，我们使用结构，功能，生物化学和遗传方法的组合。此外，我们广泛使用高分辨率电子显微镜来跟踪病毒在其宿主细胞内的运动及其进入细胞核。这些研究的发现将为细胞核转运的基本机制提供新的线索，并将为理解病毒向细胞核的转运以及更普遍的DNA向细胞核的递送做出重大贡献，这也是基因治疗中转染和基因递送的重要步骤。因此，我们对病毒核运输的研究也有助于开发有效的转染技术和基因治疗载体。

All eukaryotic cells have a distinct nucleus containing, among other things, the genetic blueprint of the organism. Carrying out the instructions contained in the genetic blueprint requires trafficking of molecules between the cytoplasm and the nucleus a process known as nuclear transport. This trafficking is essential to all eukaryotic cells, and it regulates many aspects of cell physiology. Despite the obvious importance of nuclear transport and several recent advances in this field, numerous aspects of its molecular mechanism, its structural basis, and its regulation remain elusive. The long-term objective of my research program is to elucidate the mechanisms by which macromolecules enter the nucleus. Because many viral pathogens undergo replication within the nucleus, and therefore must deliver their genome and sub-viral particles into the nucleus of their host cells, we are using viruses as tools to understand the molecular mechanisms for nuclear transport. At the same time, a detailed characterization of the nuclear import of viral genomes is an important step in the development of anti-viral therapy that may successfully resolve viral diseases by interrupting entry of the viral genome into the nucleus of infected cells. The viruses we are currently studying include two significant human pathogens: influenza A virus, the causative agent of the common flu, and hepatitis B virus, which causes acute and chronic hepatitis. Two other non-human pathogenic viruses that we are studying are baculovirus, which is extensively used as a eukaryotic expression system for the production of biologically active proteins in biomedical research, and a mice parvovirus, which preferentially targets and kills cancer cells and could be developed for anti-cancer therapy. In our studies, we use a combination of structural, functional, biochemical, and genetic approaches. In addition, we extensively use high-resolution electron microscopy to track the movement of viruses within their host cells and their entry into the nucleus. Findings from these studies will shed new light on the fundamental mechanisms of nuclear transport, and will make significant contributions to understanding the transport of viruses into the nucleus, and more generally the delivery of DNA to the nucleus, which is also an essential step in transfection and gene delivery in gene therapy. Therefore, our studies of nuclear trafficking of viruses could also help developing efficient transfection techniques and gene therapy vectors.