Translation Regulation by Enterovirus Proteinase

肠道病毒蛋白酶的翻译调控

• 批准号: 6625857
• 负责人: Richard E Lloyd
• 金额: $ 30.1万
• 依托单位: BAYLOR COLLEGE OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-03-01 至 2007-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6625857
• 关键词: Enterovirus; RNA binding protein; chemical cleavage; endopeptidases; genetic regulation; genetic translation; host organism interaction; tissue /cell culture; virus genetics; virus infection mechanism; virus protein

DESCRIPTION (provided by applicant): The long term goal of this research is to understand the mechanism by which enteroviruses such as poliovirus (PV) and Coxsackievirus (CVB3) inactivate translation of nearly all cellular mRNA while stimulating efficient translation of virus RNA in infected HeLa cells, an event known as host translation shutoff. Previous work has shown that PV and CVB3 infection result in cleavage of the translation initiation factor eIF4G in reactions mediated by the virus 2Aprotease and other cellular proteases. This serves to inactivate de novo cap-dependent translation initiation however, existing models for cap-dependent translation initiation mechanism cannot account for continued translation of cellular mRNA in virus infections containing guanidine or methyl-quercitin in which eIF4G is totally cleaved. This translation is likely mediated by ribosome re-initiation via 5'-3' interactions on mRNA. Thus eIF4G cleavage plus additional events must take place to completely block host translation; we hypothesize that viral protease-mediated cleavage of poly(A)-binding protein (PABP) may be equally important. We have recently discovered that viral 3Cprotease can effectively block translation in reactions in which PABP is partly cleaved, yet eIF4GI and eIF4GII remain intact, thus providing direct evidence for the biological relevance of PABP cleavage. The region of PABP cleaved by viral protease is poorly understood but may function in the 60S ribosome joining step of translation and may regulate re-initiation of ribosomes on the same transcript in a 5'-3' interaction-dependent mechanism. Our discovery of PABP cleavage by viral proteases focuses attention on new areas of translation regulation involving 5'-3' interactions, an area of intense current interest. The aims in this proposal will (1) determine which pools of PABP are cleaved, (2) determine the impact of PABP cleavage on its various functions, particularly functions of PABP which may support ribosome re-initiation (3) determine the relative roles of PABP and eIF4G cleavage in translation control in vivo and (4) will also determine if PABP cleavage plays a role in the switch from viral translation to viral RNA replication.

描述（由申请人提供）：这项研究的长期目标是 了解脊髓灰质炎病毒 (PV) 等肠道病毒和 柯萨奇病毒 (CVB3) 使几乎所有细胞 mRNA 的翻译失活，同时 刺激受感染 HeLa 细胞中病毒 RNA 的有效翻译，这是一个事件 称为主机翻译关闭。之前的工作表明PV和CVB3 感染导致翻译起始因子 eIF4G 裂解 由病毒2A蛋白酶和其他细胞蛋白酶介导的反应。这 然而，用于使从头依赖于帽的翻译起始失活， 现有的依赖于帽的翻译启动机制模型不能 解释病毒感染中细胞 mRNA 的持续翻译 含有胍或甲基槲皮素，其中 eIF4G 被完全裂解。 这种翻译可能是由核糖体通过 5'-3' 重新启动介导的 mRNA 上的相互作用。因此，eIF4G 裂解加上其他事件必须发生 完全阻止主机翻译的地方；我们假设病毒 蛋白酶介导的多聚腺苷酸结合蛋白 (PABP) 的切割可能同样有效 重要的。我们最近发现病毒3C蛋白酶可以有效地 PABP 部分裂解的反应中的阻断翻译，但 eIF4GI 和 eIF4GII 保持完整，从而为生物学的证据提供了直接证据 PABP 裂解的相关性。 PABP 被病毒蛋白酶切割的区域是 知之甚少，但可能在 60S 核糖体连接步骤中起作用 翻译并可能调节同一转录本上核糖体的重新启动 在 5'-3' 相互作用依赖机制中。我们发现 PABP 裂解 病毒蛋白酶将注意力集中在翻译调控的新领域 涉及5'-3'相互作用，这是当前人们强烈关注的领域。目标是 该提案将 (1) 确定哪些 PABP 池被裂解，(2) 确定 PABP 裂解对其各种功能的影响，特别是 PABP 可能支持核糖体重新启动 (3) 确定相对作用 PABP 和 eIF4G 裂解在体内翻译控制中的作用，(4) 也将 确定 PABP 裂解是否在从病毒翻译到病毒翻译的转变中发挥作用 病毒RNA复制。