Cardioviral Proteases and Comparative Genome Structure

心脏病毒蛋白酶和比较基因组结构

• 批准号: 7480646
• 负责人: ANN C. PALMENBERG
• 金额: $ 36.37万
• 依托单位: UNIVERSITY OF WISCONSIN-MADISON
• 依托单位国家: 美国
• 财政年份: 1980
• 资助国家: 美国
• 起止时间: 1980-12-01 至 2008-12-14
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7480646
• 关键词: Antiviral Agents; Back; Binding; Biochemistry; Biology; Brain; Cardiovirus; Cell Nucleolus; Cell Nucleus; Cells; Cytoplasm; Disasters; Disease; Encephalomyocarditis virus; Endopeptidases; Enzyme Precursors; Enzymes; Event; Evolution; Family; Family Picornaviridae; FarGo; Fertility; Foundations; Genetic Transcription; Genetic Translation; Genome; Goals; Guanosine Triphosphate Phosphohydrolases; Heart; Host Defense; Hour; Immune response; Immune system; Infection; Investigation; Lead; Messenger RNA; Molecular; Morphogenesis; Mus; Natural Immunity; Nucleic Acids; Occupations; Outcome; Pancreas; Pathway interactions; Peptide Hydrolases; Phase; Polyproteins; Process; Proteins; Proteolytic Processing; Public Health; Purpose; RNA; Ribosomes; Role; Running; Signal Transduction; Structure; System; Translations; Upper arm; Viral; Viral Proteins; Virus; Virus Diseases; War; Work; comparative; day; extracellular; fighting; inhibitor/antagonist; killings; member; pol genes; prevent; programs; research study; spelling; trafficking

The goals of this investigation are to explore and define the relationship of the cardiovirus genus to other members of the picornavirus family and to exploit the unique features of cardioviruses to examine fundamental molecular questions about picornavirus translation, proteolytic processing, morphogenesis and host interaction. The RNA picornaviruses are one of the best understood and most thoroughly accessible experimental systems in all of biology. Natural infections with cardioviruses, like encephalomyocarditis virus (EMCV), kill nearly every cell in the brain, pancreas and heart of a mouse, within 3 days. The virus does this with apparent impunity to cellular antiviral defenses by subverting innate immunity traps and crippling the capacity-of an infected cell to mount a defense or trigger an alarm. The molecular battleground inside infected cells pits viral protease 3Cpro, and two unique cardiovirus proteins, L and 2A, enzymes honed by evolution for their special anti-cellular purposes, against the complete array of innate host defenses. The outcome rarely varies. Within 2-3 hours of infection EMCV brings to a halt cellular mRNA transcription, cap-dependent mRNA translation, antiviral signal transduction, and active protein/RNA exchange between the nucleus and cytoplasm. The virus replicates with fecundity and the cell dies before it ever triggers an alarm. At the ultimate molecular level, the activities of these proteins instigate the cascade of events that set off or prevent an episode of disease. The next phase of this project will examine the biochemistry and molecular pathways of EMCV L (Leader), the first viral (or cellular) protein known to bind and inactivate Ran GTPase cycling, the crucial, ubiquitous regulatory system for all protein and nucleic acid trafficking into and out of the nucleus. The project also extends studies on EMCV 2A, a protein that subverts nucleoli and converts normal ribosomes into configurations which prevent translation of host mRNAs, and it continues examinations of 3Cpro, an enzyme whose precursors have anti-host proclivities that go far beyond normal processing of the viral polyprotein. These objectives build directly upon experimental foundations developed during the preceding 26 years of the program. The specific aims of are: (1) To resolve the NMR structure of Mengo L (Leader) protein as it interacts with Ran GTPase. (2) To characterize the biochemistry of cardiovirus L:Ran interactions which inhibit RanGDP/GTP cycling in cell-free extracts. (3) To identify within cells, the nucleocytoplasmic trafficking steps abrogated by cardiovirus L protein. (4) To define molecular advantages to cardioviruses, for encoding a potent inhibitor of Ran. (5) To clarify the respective roles of cardioviral L, 2A and 3C, in pol-2 transcriptional shutoff within the nuclei of infected cells. Relevance to Public Health: It is rare to establish productive viral infections that lead to disease if the first infected host cells or host immune system are able to fight back effectively. In a war won by stealth, an inadvertent triggering of intracellular or extracellular immunological alarms usually spells disaster (and clearance) for the virus. It's the job of the first viral proteins produces in the first 2-3 hrs of infection, to shutoff essential host response systems. This project examines the molecular pathways for how this happens with RNA picornavi ruses in the cardiovirus genus.

本研究的目的是探索和确定心脏病毒属与其他成员的关系， 小核糖核酸病毒家族，并利用心脏病毒的独特特征来研究基本的分子问题 关于小核糖核酸病毒的翻译、蛋白水解加工、形态发生和宿主相互作用。RNA小核糖核酸病毒是 这是生物学中最容易理解和最容易使用的实验系统之一。自然感染 与心脏病毒，如脑心肌炎病毒（EMCV），杀死几乎每一个细胞在大脑，胰腺和心脏的一个 老鼠，三天内。这种病毒通过破坏细胞的先天抗病毒防御， 免疫力会诱捕并削弱受感染细胞进行防御或触发警报的能力。分子 病毒蛋白酶3Cpro和两种独特的心脏病毒蛋白L和2A酶在感染细胞内形成战场 经过进化的磨练，它们具有特殊的抗细胞目的，可以对抗宿主完整的先天防御。的 结果很少变化。在感染后2-3小时内，EMCV使细胞mRNA转录停止，帽依赖性 mRNA翻译、抗病毒信号转导和细胞核与细胞质之间的活性蛋白/RNA交换。 病毒以繁殖力进行复制，细胞在触发警报之前就死亡了。在最终的分子水平上， 这些蛋白质的活性引发一连串的事件，引发或预防疾病的发作。下一阶段 本项目的第一部分将研究EMCV L（Leader）的生物化学和分子途径，这是第一个病毒（或细胞） 已知的蛋白质结合和GT3 Ran GT3循环，这是所有蛋白质和 核酸进出细胞核。该项目还扩展了对EMCV 2A的研究，EMCV 2A是一种 破坏核仁并将正常的核糖体转化为阻止宿主mRNA翻译的构型， 继续研究3Cpro，这种酶的前体具有远远超出正常水平的抗宿主倾向 病毒多聚蛋白的加工。这些目标直接建立在1998年期间开发的实验基础上。 26年的计划。（1）解析Mengo L（Leader）的NMR结构 蛋白质，因为它与Ran GT相互作用。(2)为了表征心脏病毒L：Ran相互作用的生物化学， 抑制无细胞提取物中RanGDP/GTP循环。(3)为了在细胞内识别核质运输步骤， 被心脏病毒L蛋白消除。(4)确定心脏病毒编码强效抑制剂的分子优势 关于Ran (5)为了阐明心脏病毒L，2A和3C在pol-2转录关闭中的各自作用， 被感染的细胞 与公共卫生的相关性：如果第一个感染者 宿主细胞或宿主免疫系统能够有效地进行反击。在一场靠秘密行动赢得的战争中， 细胞内或细胞外的免疫警报通常意味着病毒的灾难（和清除）。这是 在感染的最初2-3小时内产生的第一种病毒蛋白质，以关闭必需的宿主反应系统。这个项目 研究了心脏病毒属中RNA小RNA病毒如何发生这种情况的分子途径。