Kinetic Dissection of Eukaryotic Translation Initiation

真核翻译起始的动力学剖析

• 批准号: 8144578
• 负责人: JON R. LORSCH
• 金额: $ 3.88万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-09-11 至 2014-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8144578
• 关键词: Address; Anemia; Anticodon; Base Pairing; Binding Proteins; Biological Process; C-terminal; Cell Death; Cells; Codon Nucleotides; Collaborations; Commit; Complex; Data; Development; Disease; Dissection; Etiology; Eukaryota; Eukaryotic Initiation Factors; Event; Gene Expression; Gene Expression Regulation; Genes; Genetic Code; Grant; Initiator Codon; Initiator tRNA; Kinetics; Laboratories; Learning; Link; Malignant Neoplasms; Memory; Messenger RNA; Modeling; Molecular; Molecular Conformation; Nerve Degeneration; Normal Range; Pathway interactions; Peptide Initiation Factors; Play; Poly(A) Tail; Positioning Attribute; Process; Production; Protein Biosynthesis; Proteins; Reading; Regulation; Role; Saccharomyces cerevisiae; Scanning; Series; Site; Staging; System; Translating; Translation Initiation; Translations; Virus Diseases; Work; Yeasts; arm; base; eIF-4B; eukaryotic peptide initiation factor-1A; human disease; interest; molecular mechanics; operation; public health relevance; reconstitution; research study

DESCRIPTION (provided by applicant): Control of translation initiation is important in a wide range of normal biological processes, from development to learning and memory to cell death. Improper execution and control of translation initiation are involved in the etiology of a variety of human diseases, including viral infection, neurodegeneration and cancer. In order to understand how translation initiation is controlled, and how this control can break down, we must first understand the underlying molecular mechanics of the normal process. The experiments proposed in this application will deepen our understanding of the molecular basis of translation initiation in eukaryotes. The work will employ a fully reconstituted S. cerevisiae translation initiation system and will involve close collaboration with the laboratory of Alan Hinnebusch at the NIH/NICHD. The studies proposed will address two major gaps in our understanding of eukaryotic translation initiation. The first aim focuses on the mechanism through which the start codon in an mRNA is recognized by the ribosomal pre-initiation complex. Recognition of the start codon is one of the most important readings of the genetic code because it sets the frame for decoding of the message. Improper start site selection results in production of a miscoded, potentially toxic, protein. The proposed studies will elucidate the pathways of information transfer within the pre-initiation complex, from initial formation of three base pairs between the start codon and initiator tRNA anticodon to the downstream irreversible events that commit the complex to finishing initiation at the selected point on the message. Our studies will focus on the roles that the initiator tRNA itself and the initiation factor eIF5 play in this process. A significant amount of data indicates that these two components are missing links in our understanding of the molecular basis of start codon recognition. The second major aim is to dissect the molecular mechanics of mRNA recruitment to the pre-initiation complex, which is a critical event in protein synthesis and a key target of regulation. In this grant cycle, studies of mRNA recruitment will focus on the mechanisms of action of the large, heteromultimeric factor eIF3 and the ssRNA binding protein eIF4B. Preliminary work indicates central roles for both factors in this process, yet currently little is known about how they function. PUBLIC HEALTH RELEVANCE: The final stage of the expression of genes is the production of the proteins that each gene encodes. When this process - called "protein synthesis" or "translation" - is performed incorrectly a variety of diseases can result, including neurodegeneration, anemia and cancer. Our studies will increase our understanding of how translation normally works, which in turn will increase our understanding of how it can break down and result in diseases.

描述（由申请人提供）：在从发展到学习和记忆再到细胞死亡的广泛的正常生物过程中，对翻译起始的控制很重要。不当执行和对翻译起始的控制涉及多种人类疾病的病因，包括病毒感染，神经变性和癌症。为了了解翻译启动的控制方式，以及该控制如何分解，我们必须首先了解正常过程的基本分子力学。本应用中提出的实验将加深我们对真核生物翻译起始的分子基础的理解。这项工作将采用完全重构的酿酒酵母翻译起始系统，并将与NIH/NICHD的Alan Hinnebusch实验室进行密切合作。提出的研究将解决我们对真核翻译启动的理解的两个主要差距。第一个目的侧重于核糖体的放电复合物认识到mRNA中的起始密码子的机制。识别起始密码子是遗传代码最重要的读数之一，因为它为消息解码设置了框架。起始位点选择不当会导致产生错误的，可能有毒的蛋白质。拟议的研究将阐明启动络合物中信息传递的途径，从起始密码子和启动器tRNA反密码子之间的三个基对的初始形成到下游不可逆的事件，这些事件将复合物提交到该络合物的启动时，在消息上的选定点上完成了启动。我们的研究将重点介绍引发剂tRNA本身和在此过程中扮演的启动因子EIF5扮演的角色。大量数据表明，这两个组件在我们对起始密码子识别的分子基础的理解中缺少链接。第二个主要目的是将mRNA募集的分子力学解剖为放电前复合物，这是蛋白质合成的关键事件，也是调节的关键目标。在这个赠款周期中，对mRNA募集的研究将集中于大型，异源性因子EIF3和SSRNA结合蛋白EIF4B的作用机理。初步工作表明了这两个因素在此过程中的核心作用，但目前对它们的功能知之甚少。 公共卫生相关性：基因表达的最后阶段是每个基因编码的蛋白质的产生。当这种称为“蛋白质合成”或“翻译”的过程被错误地进行时，可能会导致各种疾病，包括神经变性，贫血和癌症。我们的研究将提高我们对翻译通常工作原理的理解，这反过来将增加我们对疾病的理解并导致疾病。