Regulation of Eukaryotic Protein Synthesis Initiation

真核蛋白质合成起始的调控

• 批准号: 6620147
• 负责人: ROBERT E. RHOADS
• 金额: $ 32.09万
• 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 2005-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6620147
• 关键词: Caenorhabditis elegans; Coxsackievirus; affinity chromatography; binding sites; cell line; chemical binding; chemical cleavage; mass spectrometry; messenger RNA; phosphorylation; protein biosynthesis; protein structure function; ribosomal proteins; ribosomes; translation factor

DESCRIPTION (provided by applicant): The long-term goals of this project are to understand the steps that occur during the recruitment of eukaryotic mRNA to the ribosome and how they are regulated. This process determines both the overall rate of protein synthesis and also the spectrum of mRNAs translated. The four Specific Aims principally concern two interacting initiation factors that are central to this process: eIF4E, the protein that binds the 7-methylguanosine-containing cap of mRNA, and eIF4G, the protein that links together all initiation factors known to be involved in mRNA recruitment. The nematode C. elegans provides unparalleled advantages for studying such a complex biochemical process as initiation of protein synthesis. Surprisingly, it expresses five eIF4E isoforms, termed IFE proteins, which have differing cap-binding properties. In Specific Aim 1, we wi2ll attempt to infer their biological roles by studying their biochemical interactions with m7G- and m3 '2'7G-containing cap analogues and oligonucleotides, with mRNAs, and with other proteins, utilizing MALDI-TOF mass spectrometry in the latter case. In Specific Aim 2, we will determine the effect of human eIF4E phosphorylation on protein synthesis rate. eIF4G binds to both eIF4E and the poly(A)-binding protein, the two C is-acting effectors for mRNA recruitment, yet many isoforms of eIF4G and eIF4G mRNA are observed in mammalian cells. In Specific Aim 3, we will determine the structure, function, and origin of these eIF4G isoforms and characterize the binding of known initiation factors to them. In Specific Aim 4, we will determine the function of eIF4G isoforms in vivo, with special emphasis on the relative importance of eIF4G cleavage in picomavirus-induced host shut-off of protein synthesis. Because overexpression of both eIF4E and eIF4G causes malignant transformation of cells, and because naturally occurring tumors contain greatly elevated levels of eIF4E, these studies have relevance to cancer. They also have relevance for diseases caused by picornaviruses such as poliovirus (polio), rhinovirus (the common cold) and Coxsackievirus (heart failure).

描述（由申请人提供）：该项目的长期目标是 了解在募集真核mRNA期间发生的步骤 核糖体及其如何调节。这个过程决定了 蛋白质合成的总体速率以及MRNA的光谱翻译。 这四个特定目的主要涉及两个相互作用的启动因素 与此过程至关重要的是：EIF4E，结合的蛋白质 7-甲基鸟苷含mRNA的帽和EIF4G，链接的蛋白质 共同涉及mRNA募集的所有启动因子。这 线虫C.秀丽隐杆线虫为研究这种A提供了无与伦比的优势 复杂的生化过程作为蛋白质合成的启动。出奇， 它表达五个EIF4E同工型，称为IFE蛋白，它们的蛋白质不同 盖结合属性。在特定目标1中，我们试图推断他们 生物学作用通过研究其与M7G和M3的生化相互作用 含2'7G的含帽类似物和寡核苷酸，带有mRNA，以及其他 蛋白质在后一种情况下利用MALDI-TOF质谱法。具体 AIM 2，我们将确定人EIF4E磷酸化对蛋白质的影响 合成率。 EIF4G与EIF4E和poly（a）结合蛋白结合， mRNA募集的两个C IS作用效应子，但许多EIF4G的同工型和 在哺乳动物细胞中观察到EIF4G mRNA。在特定的目标3中，我们将 确定这些EIF4G同工型的结构，功能和起源，并确定 表征已知起始因子与它们的结合。在特定目标中 4，我们将在体内确定EIF4G同工型的功能，并具有特殊 强调eIF4G裂解在picomavirus诱导的 蛋白质合成的宿主关闭。因为EIF4E和 EIF4G引起细胞的恶性转化，因为自然存在 肿瘤含有大大升高的EIF4E，这些研究具有相关性 癌症。它们还与Picornavirus引起的疾病有关 如脊髓灰质炎病毒（脊髓灰质炎），鼻病毒（普通感冒）和coxsackievievirus（心脏 失败）。