Regulation of West Nile virus replication.

描述（由申请人提供）：病毒改变细胞途径，创造有利于其复制周期的环境，以及灭活或逃避细胞抗病毒反应。病毒还利用细胞蛋白来促进或增强其生命周期所必需的病毒特异性分子过程。目前对黄病毒（如西尼罗河病毒）调节或促进其合成过程、改造宿主细胞或抑制细胞应激/防御反应的机制知之甚少。研究者实验室最近获得的数据表明，高度保守的细胞应激颗粒蛋白TIAR和TIA-1通过与病毒互补RNA的3'末端茎环相互作用，促进黄病毒+链RNA的合成。这些细胞蛋白与病毒3'(-)SL RNA之间的相互作用也参与抑制细胞应激颗粒反应。TIAR和TIA-1是介导RNA剪接、翻译沉默和应激颗粒形成的多功能RNA结合、核胞质穿梭蛋白。为了更充分地了解黄病毒介导的宿主应激反应的抑制，必须首先获得更多的信息。将分析TIAR和TIA-1与黄病毒复制复合体共定位的细胞和病毒成分和结构域以及这种共定位的功能后果。除了TIAR和TIA-1在感染细胞中被重新定位到病毒复制复合体上外，即使PRK上调，也观察到eIF21磷酸化的抑制，这表明病毒抑制细胞SG反应的其他机制也参与其中。实验被提出以获得关于如何在感染细胞中抑制eIF21的磷酸化的见解。对3'(-)SL RNA与TIAR/TIA-1相互作用的结构研究将提供关于病毒3'(-)SL RNA如何在细胞mrna中竞争富au序列以结合TIAR/TIA-1的见解。这一信息将与未来新型抗病毒药物的开发有关。公共卫生相关性：本研究的长期目标是描述黄病毒（如西尼罗河病毒）利用细胞蛋白积极调节其复制周期中的步骤并重塑或抑制细胞通路以创造有利于病毒有效复制的环境的机制。这些研究将导致发现新的靶点，为未来新的抗病毒治疗的发展。

DESCRIPTION (provided by applicant): Viruses alter cellular pathways to create an environment conducive for their replication cycles as well as to inactivate or escape cellular antiviral responses. Viruses also utilize cell proteins to facilitate or enhance virus-specific molecular processes essential for their life cycles. Little is currently known about the mechanisms used by flaviviruses, such as West Nile virus, to regulate or facilitate their synthetic processes, to remodel host cell or to suppress cell stress/defense responses. Recent data obtained by the investigator's lab show that the highly conserved cell stress granule proteins, TIAR and TIA-1, facilitate flavivirus plus strand RNA synthesis by interacting with the 3' terminal stem loop of the viral complementary RNA. The interaction between these cell proteins and the viral 3'(-) SL RNA is also involved in suppressing the cell stress granule response. TIAR and TIA-1 are multifunctional RNA binding, nucleo-cytoplasmic shuttling proteins that mediate alternative RNA splicing, translational silencing and stress granule formation. To more fully understand flavivirus-mediated suppression of a host stress response, more information must first be obtained. The cell and viral components and domains involved in colocalization of TIAR and TIA-1 with flavivirus viral replication complexes and the functional consequences of this colocalization will be analyzed. In addition to the relocation of TIAR and TIA-1 to viral replication complexes in infected cells, suppression of eIF21 phosphorylation is observed even though PRK is up-regulated suggesting that additional mechanisms are involved in virus suppression of the cell SG response. Experiments are proposed to obtain insights about how the phosphorylation of eIF21 is suppressed in infected cells. Structural studies of the interaction between the 3'(-) SL RNA and TIAR/TIA-1 will provide insights about how the viral 3'(-) SL RNA out competes AU-rich sequences in cell mRNAs for TIAR/TIA-1 binding. This information will be relevant to the future development of novel antivirals. PUBLIC HEALTH RELEVANCE: The long term goal of this research is to delineate the mechanisms involved in the use by flaviviruses, such as West Nile virus, of cell proteins to positively regulate steps in their replication cycles and to remodel or suppress cellular pathways to create an environment that is conducive for efficient virus replication. These studies will lead to the discovery of new targets for the future development of novel antiviral therapies.