Structural Analysis of Helminth mRNA Cap-Binding Proteins

蠕虫 mRNA 帽结合蛋白的结构分析

• 批准号: 7659946
• 负责人: RICHARD E. DAVIS
• 金额: $ 7.69万
• 依托单位: UNIVERSITY OF COLORADO DENVER
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-02-15 至 2011-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7659946
• 关键词: Address; Affinity; Area; Ascaris; Binding; Biochemical; Biological Assay; Caenorhabditis elegans; Child; Cognitive; Data; Developing Countries; Development; Drug Delivery Systems; Drug Design; Drug resistance; Economics; Exhibits; Future; Gene Expression; Goals; Helminths; Homology Modeling; Infection; Lead; Ligands; Messenger RNA; Morbidity - disease rate; Mutagenesis; NMR Spectroscopy; Parasites; Parasitic infection; Peptide Initiation Factors; Property; Protein Isoforms; Proteins; Public Health; RNA Cap-Binding Proteins; RNA Splicing; Resolution; Schistosoma; Sequence Alignment; Social Development; Spliced Leader RNA; Spliced Leader Sequences; Structure; Substrate Specificity; Testing; Trans-Splicing; Translation Initiation; Translations; X-Ray Crystallography; analog; base; combat; design; flexibility; insight; mRNA capping; novel therapeutics; public health relevance; socioeconomics

DESCRIPTION (provided by applicant): Parasitic helminths remain a significant public health problem in many parts of the world. Helminths infect over 2 billion people, can decrease physical and cognitive development in children, lead to considerable morbidity, and hinder socioeconomic development in endemic areas. The identification and characterization of new potential drug targets is warranted as examples of drug resistance have been identified. In addition, the development of broader spectrum targets and drugs would be extremely valuable. One intriguing potential target is the parasite translation initiation factor eIF4E. eIF4E recognizes the mRNA cap and is a key and rate-limiting step in translation. Vertebrate host eIF4E is highly specific for a monomethylguanosine eukaryotic cap, and this is the only cap present on vertebrate mRNAs. In contrast, we have shown that Ascaris and schistosome eIF4Es have similar affinities for both the trimethyl- and monomethylguanosine caps. Thus, parasitic helminth eIF4Es have the unique ability to recognize trimethylguanosine (TMG) caps compared with their vertebrate eIF4E counterparts. Many mRNAs in parasitic helminths have a TMG cap. Approximately 10% (schistosomes) to 90% (Ascaris) of helminth mRNAs acquire a TMG cap through a special type of splicing known as spliced leader RNA trans-splicing. Trans-splicing generates the mature 5' ends of mRNAs and adds the specialized TMG cap to helminth mRNAs. All major groups of parasitic helminths exhibit spliced leader trans-splicing. Recognition of the TMG cap is essential for translation of helminth mRNAs and eIF4E is essential in C. elegans. To understand the biochemical and biophysical basis for helminth eIF4E recognition of the TMG cap, we propose to carry out X-ray crystallography and NMR studies on helminth eIF4E bound to the TMG cap, m2,2,7GpppG. Information from these studies will provide insight into the key interactions and mechanism of TMG-cap binding by parasite eIF4E. This information will help direct rational mutagenesis studies to further define important eIF4E-TMG cap interactions. Overall, these studies will identify key features of TMG cap recognition that may enable future studies directed at designing specific cap analogs to target the unique substrate binding attributes of eIF4E present in a broad spectrum of important helminth infections. PUBLIC HEALTH RELEVANCE: Parasitic helminths remain a significant public health problem in many parts of the world and hinder socioeconomic development in endemic areas. We will carry out structural analyses of an essential parasite protein, eIF4E, with unique substrate specificity for the mRNA cap to evaluate this protein as a potential target for new and novel therapeutics against parasitic helminths.

描述（由申请人提供）：寄生蠕虫在世界许多地区仍然是一个重大的公共卫生问题。蠕虫感染超过 20 亿人，会降低儿童的身体和认知发育，导致相当大的发病率，并阻碍流行地区的社会经济发展。随着耐药性例子的发现，新的潜在药物靶标的识别和表征是有必要的。此外，开发更广泛的靶点和药物将非常有价值。一个有趣的潜在靶点是寄生虫翻译起始因子 eIF4E。 eIF4E 识别 mRNA 帽，是翻译中的关键和限速步骤。脊椎动物宿主 eIF4E 对单甲基鸟苷真核帽具有高度特异性，这是脊椎动物 mRNA 上存在的唯一帽。相比之下，我们发现蛔虫和血吸虫 eIF4E 对三甲基和单甲基鸟苷帽具有相似的亲和力。因此，与脊椎动物 eIF4E 相比，寄生蠕虫 eIF4E 具有识别三甲基鸟苷 (TMG) 帽的独特能力。寄生蠕虫中的许多 mRNA 都有一个 TMG 帽。大约 10%（血吸虫）至 90%（蛔虫）的蠕虫 mRNA 通过一种特殊类型的剪接（称为剪接前导 RNA 反式剪接）获得 TMG 帽。反式剪接生成 mRNA 的成熟 5' 末端，并向蠕虫 mRNA 添加专门的 TMG 帽。所有主要寄生蠕虫类群都表现出剪接前导反式剪接。 TMG 帽的识别对于蠕虫 mRNA 的翻译至关重要，而 eIF4E 对于线虫至关重要。为了了解蠕虫 eIF4E 识别 TMG 帽的生化和生物物理基础，我们建议对与 TMG 帽 m2,2,7GpppG 结合的蠕虫 eIF4E 进行 X 射线晶体学和 NMR 研究。这些研究的信息将深入了解寄生虫 eIF4E 与 TMG-cap 结合的关键相互作用和机制。这些信息将有助于指导合理的诱变研究，以进一步定义重要的 eIF4E-TMG 帽相互作用。总体而言，这些研究将确定 TMG 帽识别的关键特征，这可能使未来的研究能够设计特定的帽类似物，以针对广泛的重要蠕虫感染中存在的 eIF4E 的独特底物结合属性。公共卫生相关性：寄生蠕虫仍然是世界许多地区的一个重大公共卫生问题，并阻碍流行地区的社会经济发展。我们将对一种重要的寄生虫蛋白 eIF4E 进行结构分析，该蛋白对 mRNA 帽具有独特的底物特异性，以评估该蛋白作为针对寄生虫的新型疗法的潜在靶点。