Mechanism of IRES-Mediated Translation Initiation

IRES介导的翻译起始机制

基本信息

批准号：
8307811
负责人：
Sunnie R Thompson
金额：
$ 25.85万
依托单位：
UNIVERSITY OF ALABAMA AT BIRMINGHAM
依托单位国家：
美国
项目类别：
财政年份：
2009
资助国家：
美国
起止时间：
2009-08-10 至 2014-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8307811
关键词：
5&apos Untranslated Regions Affect Affinity Aftercare Apoptosis Apoptotic BIRC4 gene Binding Biochemical Biochemistry Biological Assay Biological Models Cancer Relapse Cell Death Cells Cellular Stress Complex Coupling Defect Development Eukaryotic Cell Exhibits Genes Genetic Growth Hereditary Disease Human Hypoxia In Vitro Intercistronic Region Internal Ribosome Entry Site Laboratories Link Malignant Neoplasms Mammalian Cell Mediating Messenger RNA Mitosis Modeling Modification Multiple Myeloma Mus Mutagenesis Mutation Nucleotides Patients Peptide Initiation Factors Positioning Attribute Protein Biosynthesis Proteins Pseudouridine Recruitment Activity Reporting Ribosomal Proteins Ribosomal RNA Ribosomes Small Nucleolar RNA Starvation Structure System Translating Translation Initiation Translations Tumor Suppressor Proteins Viral X-Linked Dyskeratosis Congenita Yang Yeasts angiogenesis base c-myc Genes cancer cell cancer therapy cancer type cell growth cricket paralysis virus cyclin-dependent kinase inhibitor 1B in vivo innovation interest mutant public health relevance tumorigenesis viral RNA yeast genetics

项目摘要

DESCRIPTION (provided by applicant): The majority of messenger RNAs (mRNAs) are translated by a cap-dependent mechanism of initiation. However, about 5% to 10% of mRNAs use an alternative mechanism of initiating protein synthesis, utilizing an internal ribosome entry site (IRES) to recruit the ribosomes to the message. IRESs are found in mRNAs that encode proteins involved in cell growth, proliferation, apoptosis, hypoxia, and angiogenesis. Because many cellular mRNAs that are involved in tumorigenesis contain IRESs, we anticipate that IRES-mediated translation is a good target for the development of anti-cancer therapies that will be broadly applicable to several types of cancer. Since the mechanism is not understood we are interested in how IRESs recruit ribosomes. Several studies have suggested that the cricket paralysis virus (CrPV) intergenic region IRES (IGR-IRES) and cellular IRESs share some mechanisms for binding ribosomes suggesting that the IGR-IRES is a good model IRES. Because translation is highly conserved between yeast and mammalian cells we have developed a genetic system in yeast to answer the following questions: 1) Which IGR-IRES structures or sequences are important for IRES function? 2) What components of the ribosome are required for IGR-IRES mediated translation? 3) How do these contacts facilitate ribosome binding? 4) What is the contribution of rRNA modifications for IRES activity? 5) How do these findings apply to cellular IRESs in mammalian cells? This system provides us with genetics, biochemistry, and will allow us to manipulate components of the translational machinery in ways that are not possible in mammalian cells. We chose to use an innovative genetic approach to understand IRES-mediated translation because the mechanism of initiation by cellular IRESs has been elusive despite many years of effort by multiple laboratories. PUBLIC HEALTH RELEVANCE: Some viral and cellular mRNAs utilize an alternative mechanism of translation initiation that recruits ribosomes internally to the message using a highly structured internal ribosome entry site (IRES). IRES-mediated translation of cellular mRNAs is involved in regulating cancer, cell death, cell growth, and angiogenesis, as well as translation of viral RNAs. We are using yeast genetics to understand the mechanism of IRES-mediated translation initiation.

描述（由申请人提供）：大多数信使 RNA (mRNA) 通过帽依赖的起始机制进行翻译。然而，大约 5% 到 10% 的 mRNA 使用另一种启动蛋白质合成的机制，即利用内部核糖体进入位点 (IRES) 来招募核糖体来传递信息。 IRES 存在于编码参与细胞生长、增殖、凋亡、缺氧和血管生成的蛋白质的 mRNA 中。由于许多参与肿瘤发生的细胞 mRNA 都含有 IRES，因此我们预计 IRES 介导的翻译是开发抗癌疗法的良好靶标，该疗法将广泛适用于多种类型的癌症。由于该机制尚不清楚，我们对 IRES 如何招募核糖体感兴趣。多项研究表明，蟋蟀麻痹病毒 (CrPV) 基因间区域 IRES (IGR-IRES) 和细胞 IRES 共享一些结合核糖体的机制，表明 IGR-IRES 是一个很好的 IRES 模型。由于翻译在酵母和哺乳动物细胞之间高度保守，我们在酵母中开发了一个遗传系统来回答以下问题：1）哪些 IGR-IRES 结构或序列对于 IRES 功能很重要？ 2) IGR-IRES 介导的翻译需要核糖体的哪些成分？ 3）这些接触如何促进核糖体结合？ 4) rRNA修饰对IRES活性有何贡献？ 5）这些发现如何应用于哺乳动物细胞中的细胞IRES？该系统为我们提供了遗传学、生物化学知识，并使我们能够以哺乳动物细胞中不可能的方式操纵翻译机器的各个组成部分。我们选择使用创新的遗传方法来理解 IRES 介导的翻译，因为尽管多个实验室经过多年的努力，细胞 IRES 的启动机制仍然难以捉摸。公共健康相关性：一些病毒和细胞 mRNA 利用另一种翻译起始机制，利用高度结构化的内部核糖体进入位点 (IRES) 将核糖体招募到内部的信息中。 IRES 介导的细胞 mRNA 翻译参与调节癌症、细胞死亡、细胞生长和血管生成，以及病毒 RNA 的翻译。我们正在利用酵母遗传学来了解 IRES 介导的翻译起始机制。