Novel Cap Analogs and Interactions with Target Proteins

描述（由申请人提供） Fogarty国际研究合作奖（FIRCA）的申请是R 01 GM 20818号拨款的延伸，标题为“真核蛋白质合成起始的调节”。“这项研究将主要在波兰华沙大学与爱德华·达津凯维奇合作进行。Parent Grant和FIRCA项目的长期目标都是了解真核mRNA向核糖体募集过程中发生的步骤以及它们是如何被调控的。这一过程决定了蛋白质合成的总体速率和翻译的mRNA的谱。FIRCA申请的四个特定目的涉及mRNA的含7-甲基鸟苷的帽和其在蛋白质合成的帽依赖性起始期间相互作用的靶蛋白eIF 4 E。线虫C.线虫为研究蛋白质合成起始等复杂的生物化学过程提供了无可比拟的优势。令人惊讶的是，它表达五种eIF 4 E同种型，称为IFE蛋白，具有不同的帽结合特性。在具体目标1中，我们将在生物系统中合成和测试新类别的二-和寡核苷酸帽类似物，特别是一系列新的抗反向帽类似物，旨在抵抗焦磷酸酶降解的二核苷酸帽类似物，以及加帽的三核苷酸。在具体目标2中，我们将合成和测试基于能够穿过质膜的帽类似物的新的翻译抑制剂，试图将帽依赖性翻译作为抗癌策略。在具体目标3中，我们将分析帽与C的eIF 4 E同种型结合的C14 iC和溶剂方面。优雅在具体目标4中，我们将使用化学合成的人Ser-209磷酸-eIF 4 E研究eIF 4 E磷酸化的作用。因为eIF 4 E的过表达导致细胞的恶性转化，并且因为天然存在的肿瘤含有大大升高的eIF 4 E水平，所以这些研究与癌症，特别是特异性目的2相关。它们也与由小核糖核酸病毒引起的疾病有关，如脊髓灰质炎病毒（脊髓灰质炎），鼻病毒（普通感冒）和柯萨奇病毒（心力衰竭），因为小核糖核酸病毒通过蛋白水解切割eIF 4G来关闭帽依赖性翻译，eIF 4G是在翻译起始期间将eIF 4 E连接到40 S核糖体亚基的蛋白质。

DESCRIPTION (provided by applicant) This application for a Fogarty International Research Collaboration Award (FIRCA) is an extension of Grant R01GM20818, entitled "Regulation of Eukaryotic Protein Synthesis Initiation." The research will be done primarily in Poland at Warsaw University in collaboration with Edward Darzynkiewicz. The long-term goals of both the Parent Grant and the FIRCA 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 of the FIRCA application involve the 7-methylguanosine-containing cap of mRNA and the target protein which it interacts during cap-dependent initiation of protein synthesis, elF4E. 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, that have differing cap-binding properties. In Specific Aim 1, we will synthesize and test in biological systems new classes of di- and oligonucleotide cap analogues, specifically a new series of anti-reverse cap analogues, dinucleotide cap analogues intended to be resistant to degradation by pyrophosphatases, and capped trinucleotides. In Specific Aim 2, we will synthesize and test new inhibitors of translation based on cap analogues that are able to cross the plasma membrane, in an attempt to target cap-dependent translation as an anticancer strategy. In Specific Aim 3, we will analyze thermodynamiC and solvent aspects of cap binding to elF4E isoforms of C. elegans. In Specific Aim 4, we will investigate the role of elF4E phosphorylation using chemically synthesized human Ser-209 phospho-elF4E. Because overexpression of elF4E causes malignant transformation of cells, and because naturally occurring tumors contain greatly elevated levels of elF4E, these studies have relevance to cancer, especially Specific Aim 2. They also have relevance for diseases caused by picornaviruses such as poliovirus (polio), rhinovirus (the common cold) and Coxsackievirus (heart failure), since picomaviruses shut down cap-dependent translation by proteolytically cleaving elF4G, the protein that tethers eIF4E to the 40S ribosomal subunit during initiation of translation.