Translation Regulation by Enterovirus Proteinase

肠道病毒蛋白酶的翻译调控

• 批准号: 7538415
• 负责人: Richard E Lloyd
• 金额: $ 37.5万
• 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 2012-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7538415
• 关键词: Affect; Apoptosis; Binding; Biochemical; Cells; Cellular Stress; Cellular Stress Response; Cleaved cell; Coxsackie Viruses; Cytopathology; Cytoplasmic Granules; Enterovirus; Family Picornaviridae; Gene Expression; Gene Expression Regulation; Goals; Human; Human poliovirus; Interruption; Invaded; Knowledge; Learning; Malignant Neoplasms; Mammalian Cell; Mediating; Messenger RNA; MicroRNAs; Pathway interactions; Peptide Hydrolases; Peptide Initiation Factors; Polioviruses; Poly(A)-Binding Proteins; Polyribosomes; Proteins; RNA Viruses; RNA chemical synthesis; RNA replication; Recycling; Regulation; Repression; Research; Ribosomes; Role; Stress; Translations; Untranslated Regions; Viral; Viral Gene Expression Regulation; Viral Genome; Virus; Virus Diseases; Work; cell killing; cellular targeting; disorder prevention; insight; mRNA Decay; mRNA capping; overexpression; pathogen; prevent; prototype; research study; viral RNA

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 viral mRNA in infected cells. We have shown that cleavage of the translation initiation factor eIF4G will block assembly of new capped mRNA on ribosomes, and that cleavage of PABP is required in concert with eIF4G to completely block translation. PABP cleavage affects late steps in translation that are presently undefined, however likely interrupt ribosome recycling via 5'-3' interactions on mRNA. The mechanism of ribosome recycling and its biochemical requirements are unknown. In addition, enteroviruses and probably most other plus strand RNA viruses must abruptly shut down translation of the infecting viral genome before viral RNA synthesis can begin. We hypothesize that PABP cleavage is also required for inhibition of viral translation. Translation regulation mechanisms involving PABP are now thought to interface with mRNA decay mechanisms on several levels. In addition, microRNAs, which bind to 3' UTR of targeted cellular mRNAs, also silence translation by unknown mechanisms that somehow result in transit of mRNAs from polysomes to other cell compartments called P-bodies and stress granules. We have discovered that G3BP, a key factor that nucleates formation of stress granules, is cleaved in PV-infected cells by 3C protease. Thus, the virus is attacking the overall translation regulatory apparatus at a new level. The aims in this proposal will determine the role of PABP cleavage in the switch from viral translation to RNA replication, will determine the role of ribosome recycling in this switch, and will investigate the function of G3BP cleavage on the viral replication cycle and microRNA-translation silencing. These results will provide new fundamental information on how cells regulate gene expression at the translation level, and the interplay between translation initiation factors and mRNA silencing/decay pathways that will be useful in studies of viral regulation of gene expression and cellular stress responses in cancer and apoptosis. This work investigates new ways that poliovirus, the prototype human picornavirus, interferes with host translation and regulation of gene expression by stress granules and microRNAs. These mechanisms are fundamental for cell gene regulation and are disrupted in cancer and numerous non-viral diseases. These experiments will give us more insight how a large class of human pathogens invade and kill cells (cytopathology) and potentially provide new avenues for disease prevention and we will learn more about gene regulation in human cells.

描述（由申请人提供）：这项研究的长期目标是了解诸如脊髓灰质炎病毒（PV）和Coxsackievievirus（CVB3）灭活几乎所有细胞mRNA的转换，同时刺激感染细胞病毒mRNA的有效翻译的机制。我们已经表明，翻译起始因子EIF4G的裂解将阻止核糖体上新的上限mRNA的组装，并且PABP的裂解与EIF4G一致，以完全阻止翻译。 PABP裂解会影响当前未定义的翻译中的后期步骤，但是可能会通过5'-3'相互作用在mRNA上进行中断核糖体回收。核糖体回收的机制及其生化要求尚不清楚。此外，在病毒RNA合成开始之前，肠病毒以及大多数其他加上链RNA病毒必须突然关闭感染病毒基因组的翻译。我们假设抑制病毒翻译也需要PABP裂解。现在，涉及PABP的翻译调节机制被认为与多个级别的mRNA衰减机制接触。此外，与靶向细胞mRNA的3'UTR结合的microRNA也通过未知机制沉默的翻译，这些机制在某种程度上导致mRNA从多聚群体转移到其他称为p-bodies和应激颗粒的细胞室。我们发现，G3BP是将应激颗粒形成的关键因素通过3C蛋白酶在PV感染的细胞中裂解。因此，该病毒正在攻击新级别的整体翻译调节器。该提案的目的将确定PABP裂解在从病毒翻译到RNA复制的转换中的作用，将确定核糖体回收在此开关中的作用，并将研究G3BP裂解在病毒复制周期和微氨基酸转基因 - 递质沉积物中的功能。这些结果将提供有关细胞如何在翻译水平调节基因表达的新基本信息，以及翻译起始因子与mRNA沉默/衰减途径之间的相互作用，这些相互作用可用于癌症和凋亡中基因表达和细胞应激反应的病毒调节研究。 这项工作调查了脊髓灰质炎病毒原型脊髓灰质炎病毒的新方法，干扰了宿主翻译和通过压力颗粒和microRNA对基因表达的调节。这些机制对于细胞基因调节至关重要，在癌症和许多非病毒疾病中受到破坏。这些实验将使我们有更多的洞察力如何入侵和杀死细胞（细胞病理学），并有可能为预防疾病提供新的途径，我们将更多地了解人类细胞中基因调节的更多信息。