Regulation of Eukaryotic Protein Synthesis Initiation

真核蛋白质合成起始的调控

• 批准号: 7634456
• 负责人: ROBERT E. RHOADS
• 金额: $ 35.55万
• 依托单位: LOUISIANA STATE UNIV HSC SHREVEPORT
• 依托单位国家: 美国
• 财政年份: 1977
• 资助国家: 美国
• 起止时间: 1977-04-01 至 2011-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7634456
• 关键词: Abbreviations; Acids; Affect; Affinity; Amino Acids; Animals; Binding; Binding Proteins; Binding Sites; Biochemical; Bioinformatics; Biological; Biological Process; CPE-binding protein; Caenorhabditis elegans; Cancer Model; Cell Maturation; Classical swine fever virus; Congenital Abnormality; Cultured Cells; Cytoplasmic Granules; Development; Elements; Embryonic Development; Eukaryotic Initiation Factors; Expressed Sequence Tags; Genes; Germ Cells; Glutathione S-Transferase; Goals; Green Fluorescent Proteins; Guanine; Guanosine; Heating; Hepatitis C virus; Homologous Gene; Human; In Vitro; Infertility; Insulin; Interferons; Internal Ribosome Entry Site; Knock-out; Learning; Light; Link; Liquid Chromatography; MALDI-TOF Mass Spectrometry; Malignant - descriptor; Malignant Neoplasms; Mammalian Cell; Mammary Neoplasms; Maps; Mass Spectrum Analysis; Messenger RNA; Mitogen-Activated Protein Kinase 3; Mitogen-Activated Protein Kinases; Mouse Mammary Tumor Virus; Mus; Nature; Nucleotides; Open Reading Frames; Oryctolagus cuniculus; Pathway interactions; Pattern; Peptide Initiation Factors; Phase; Phenotype; Phosphorylation; Phosphotransferases; Physiological; Play; Poly(A)-Binding Proteins; Polyadenylation; Process; Protein Biosynthesis; Protein Isoforms; Proteins; RNA Cap-Binding Proteins; RNA Sequences; Recruitment Activity; Regulation; Relative (related person); Reporting; Research; Research Personnel; Resistance; Reticulocytes; Ribonucleoproteins; Ribosomes; Role; Series; Site; Small Nuclear RNA; Spermatogenesis; Spliced Leader Sequences; Structure; Sulfur; Surface Plasmon Resonance; Testing; Tissues; Transgenic Mice; Translating; Translations; Untranslated Regions; Winking; analog; base; cancer therapy; cell growth; cell transformation; follow-up; genome wide association study; genome-wide analysis; in vivo; mRNA Stability; mRNA Transcript Degradation; novel; overexpression; particle; programs; research study; trait; transcription factor PML; tripolyphosphate; tumor; tumorigenesis

DESCRIPTION (provided by applicant): The long-term goals are to understand the biochemical mechanisms, physiological regulation, and biological roles of initiation factors that recruit mRNA to the ribosome, a process that determines rate of protein synthesis, spectrum of mRNAs translated, and rate of mRNA turnover. The research is centered on the mRNA cap-binding protein elF4E, one mechanism by which elF4E is regulated, the role of elF4Ein mRNA turnover, and elF3, the factor that links elF4E (via elF4G) to the 40S ribosomal subunit. Aim 1 is to elucidate the physiological roles of three of the five elF4E isoforms (termed IFEs) in C. elegans. We will use bioinformatics and biochemical approaches to discover the functions of IFE-1, -2, and -4 including genome wide analysis of mRNAs whose translation is dependent on each IFE. We will correlate IFE-specific translation with mRNA structural features and with IFE-specific binding proteins. Aim 2 is to examine the function of elF4E phosphorylation and its putative kinase, MNK-1, in C. elegans. We will attempt to resolve contradictory reports by determining the effect of IFE-2 phosphorylation on translation of IFE-2-dependent mRNAs and phenotypic traits, and we will characterize the putative C. elegans MNK-1 at the enzymological and whole animal levels. In Aim 3, we will investigate the role of elF4E in mRNA turnover in cultured mammalian cells by synthesizing novel cap analogs that are resistant to in vivo decapping and by altering the competition for cap binding between elF4E and Dcp1/Dcp2. In Aim 4, we will follow up on our observation that elF3e, one of the subunits of mammalian elF3, forms at least part of the binding site for elF4G. We will biochemically characterize the elF4G-elF3e interaction and role of elFSe in translation. We will also attempt to learn the mechanism by which MMTV insertion into the elFSe gene causes mammary tumors in mice. These studies have relevance to cancer because overexpression of elF4E causes malignant transformation of cells, human tumors contain greatly elevated levels of elF4E, and elF4E is the target of novel anti-cancer therapies. Also, MMTV integration into the elFSe gene is one of the best developed experimental cancer models. Furthermore, elF4E plays a critical role in both germ cell maturation and early embryonic development, which impacts on abnormalities resulting in birth defects. Finally, one elF4E isoform is required for normal spermatogenesis, which may shed light on infertility conditions.

描述（由申请人提供）：长期目标是了解将 mRNA 募集至核糖体的起始因子的生化机制、生理调节和生物学作用，这一过程决定蛋白质合成速率、mRNA 翻译谱和 mRNA 周转率。该研究的重点是 mRNA 帽结合蛋白 elF4E（一种调节 elF4E 的机制）、elF4E 在 mRNA 周转中的作用，以及 elF3（将 elF4E（通过 elF4G）连接到 40S 核糖体亚基的因子）。目标 1 是阐明秀丽隐杆线虫中 5 个 elF4E 同工型（称为 IFE）中的 3 个的生理作用。我们将使用生物信息学和生化方法来发现 IFE-1、-2 和 -4 的功能，包括对翻译依赖于每个 IFE 的 mRNA 进行全基因组分析。我们会将 IFE 特异性翻译与 mRNA 结构特征以及 IFE 特异性结合蛋白关联起来。目标 2 是检查 elF4E 磷酸化及其假定激酶 MNK-1 在秀丽隐杆线虫中的功能。我们将尝试通过确定 IFE-2 磷酸化对 IFE-2 依赖性 mRNA 翻译和表型性状的影响来解决相互矛盾的报告，并且我们将在酶学和整体动物水平上表征假定的秀丽隐杆线虫 MNK-1。在目标 3 中，我们将通过合成能够抵抗体内脱帽的新型帽类似物以及改变 elF4E 和 Dcp1/Dcp2 之间帽结合的竞争来研究 elF4E 在培养的哺乳动物细胞中 mRNA 周转中的作用。在目标 4 中，我们将跟进我们的观察结果，即哺乳动物 eF3 的亚基之一 eF3e 形成至少部分 eF4G 的结合位点。我们将从生化角度描述 eLF4G-elF3e 相互作用以及 eFSe 在翻译中的作用。我们还将尝试了解 MMTV 插入 elFSe 基因导致小鼠乳腺肿瘤的机制。这些研究与癌症相关，因为elF4E的过度表达会导致细胞恶性转化，人类肿瘤含有大大升高的elF4E水平，并且elF4E是新型抗癌疗法的靶点。此外，MMTV 整合到 elFSe 基因中是开发得最好的实验性癌症模型之一。此外，elF4E 在生殖细胞成熟和早期胚胎发育中发挥着关键作用，这会影响导致出生缺陷的异常。最后，正常精子发生需要一种 eF4E 同工型，这可能有助于了解不孕症。