STRUCTURE AND FUNCTION OF YEAST TRANSLATION FACTOR EIF3

真核生物的基因表达通常控制在翻译起始水平。eIF3在这个过程中起着核心作用。它负责核糖体亚基解离，稳定小核糖体亚基上的启动物Met-tRNA，并且是mRNA与核糖体结合所必需的。p33是eIF3的一个rna结合亚基，最近已被克隆并部分表征。p33是eIF3复合物“核心”的一部分，是酵母中必不可少的蛋白质。在这一培训期的研究中将寻求从更长远的角度阐明酵母中p33亚基的功能、eIF3的功能以及翻译起始的机制，具体目标有四个：1。使用SELEX识别p33结合的生理RNA靶标。2. 分离高拷贝数和低拷贝数p33突变体的基因外抑制子。3. 使用微阵列和动态RT-PCR检测p33突变体多聚体部分的mRNA。4. 通过蛋白质交联和形成部分复合物（如p33、p39和p93）并在体外测试其活性来阐明eIF3的结构/功能。

Gene expression in eukaryotes is often controlled at the level of the initiation of translation. eIF3 plays a central role in this process. It is responsible for ribosome subunit dissociation, it stabilizes the initiator Met-tRNA on the small ribosomal subunit and it is required for mRNA binding to the ribosome. p33, an RNA-binding subunit of eIF3, has recently been cloned and partially characterized. p33 is part of the "core" of the eIF3 complex and is an essential protein in yeast. The elucidation of the function of the p33 subunit, the function of eIF3, and the mechanism of translation initiation in yeast in a longer perspective will be sought in the research under this training period via these four specific aims: 1. Identify the physiological RNA target for p33 binding using SELEX. 2. Isolate high and low copy number extragenic suppressors of p33 mutants. 3. Use microarrays and kinetic RT-PCR to examine mRNA from polysome fractions in p33 mutants. . 4. Elucidate the structure/function of eIF3 by protein crosslinking and by forming partial complexes (e.g., p33, p39 and p93) and testing their activities in vitro.