Mechanism of Protein Synthesis and Translational Control

项目摘要 我们的研究重点是真核生物蛋白质合成和翻译的机制。 控制力。我们目前正在研究的两个项目是：(1)脆弱者的翻译控制机制 X智力低下蛋白(FMRP)；(2)甲型流感病毒(IAV)的翻译启动机制 MRNAs。脆性X综合征是一种困扰着大约10万美国人和大约300万人的疾病 在世界范围内，导致智力残疾、儿童癫痫发作和患者的自闭症行为。这个 这种疾病是由脆性X智力低下1基因(FMR1)的转录沉默引起的。FMR1基因 编码一种RNA结合蛋白FMRP，它在大脑中高度表达，对正常的 大脑的发育。哺乳动物有两个FMRP常染色体并联体，命名为脆性X相关1 和2(FXR1和FXR2)蛋白。FMRP、FXR1和FXR2参与调节 几个mRNA。然而，这些蛋白质调节这些基因表达的确切机制 MRNAs是未知的。第一个项目的目标是了解 FMRP、FXR1和FXR2对蛋白质合成的调控我们将使用一个强大的体外翻译系统， 生化技术和定量生物物理方法极大地促进了我们对 FMRP、FXR1和FXR2调节蛋白质合成的分子机制。这些研究的结果 将为确定治疗脆性X综合征的潜在药物靶点提供有用的见解。 第二个项目的目标是研究IAV mRNAs启动翻译的机制。 IAV每年造成数千人死亡，对全球公共卫生构成严重威胁。我们有 新的数据表明IAV mRNAs可能使用一种非规范的翻译启动机制。我们的研究 结果表明，多聚A结合蛋白1(PABP1)与猪传染性支气管炎病毒5‘端非编码区高度保守的序列结合 IAV mRNAs。此外，我们还表明，IAV mRNA的翻译对失活的 真核细胞起始因子4E(EIF4E)与对照mRNA的比较。我们假设招募一名 PABP1与病毒5‘-UTRs连接eIF4G，并促进翻译起始复合体的组装 EIF4E-独立方式。这可能有利于IAV mRNAs在细胞应激条件下的翻译 细胞，已知能降低eIF4E的活性。我们将确定PABP1与5‘- 利用体外技术和细胞学技术，IAV mRNAs的UTR对于翻译的启动和病毒的循环是必不可少的 IAV感染研究。我们的研究将使我们对翻译过程有一个全新的认识 启动IAV的mRNAs，这可能有助于开发新的抗病毒药物。

Project Summary Our research program focuses on the mechanism of eukaryotic protein synthesis and translational control. The two projects we are currently studying are: (1) the mechanism of translational control by the fragile X mental retardation protein (FMRP), and (2) the mechanism of translation initiation on influenza A virus (IAV) mRNAs. Fragile X syndrome is a disease that afflicts about 100,000 Americans and about 3 million people worldwide, resulting in intellectual disability, childhood seizures, and autistic behavior in the patients. The disease is caused by the transcriptional silencing of the fragile X mental retardation 1 gene (FMR1). FMR1 gene codes for an RNA-binding protein, FMRP, which is highly expressed in the brain and is essential for the normal development of the brain. Mammals have two autosomal paralogs of FMRP designated as fragile X related 1 and 2 (FXR1 and FXR2) proteins. FMRP, FXR1 and FXR2 have been implicated in regulating the translation of several mRNAs. However, the precise mechanism by which these proteins regulate the expression of these mRNAs is unknown. The goal of the first project is to understand the molecular mechanism underlying the regulation of protein synthesis by FMRP, FXR1 and FXR2. We will use a robust in vitro translation system, biochemical techniques and quantitative biophysical methods to significantly advance our understanding of the molecular mechanism used by FMRP, FXR1 and FXR2 to regulate protein synthesis. Results of these studies will provide useful insights in identifying potential drug targets to treat fragile X syndrome. The goal of the second project is to investigate the mechanism of translation initiation by IAV mRNAs. IAV is responsible for several thousand deaths annually and is a severe threat to global public health. We have new data that indicate that IAV mRNAs may use a non-canonical mechanism of translation initiation. Our studies show that poly A binding protein 1 (PABP1) binds to the highly conserved sequences present in the 5’-UTR of IAV mRNAs. Additionally, we show that the translation of the IAV mRNA is more resistant to the inactivation of eukaryotic initiation factor 4E (eIF4E) compared to a control mRNA. We hypothesize that the recruitment of PABP1 to the viral 5’-UTRs tethers eIF4G and promote the assembly of the translation initiation complex in an eIF4E-independent manner. This may favor the translation of IAV mRNAs under cellular stress conditions in the cell, which is known to reduce the activity of eIF4E. We will determine whether the binding of PABP1 to the 5’- UTR of IAV mRNAs is essential for translation initiation and the viral cycle using in vitro techniques and cellular IAV infection studies. Our research will lead to fundamental new knowledge about the process of translation initiation on IAV mRNAs, which could help in the development of new antiviral drugs.