启动因子eIF5B/IF2 GTPase和转化活动的脱通过降低核糖体亲和力的突变
Byung-Sik Shin1, David Maag, Antonina Roll-Mecak
1Laboratory of Gene Regulation and Development, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA.
Cell
|January 1, 2003
概括
翻译启动因子eIF5B的突变会损害GTP水解,影响一般的翻译,但不影响子单元的连接. 抑制剂通过降低核糖体亲和力来恢复翻译,这表明eIF5B GTP水解是监管检查点.
科学领域:
- 分子生物学分子生物学
- 生物化学 生物化学
- 遗传学 是一个遗传学.
背景情况:
- 翻译启动因子eIF5B (也称为IF2) 是一种GTPase,在蛋白质合成过程中加入核糖体子单元至关重要.
- 它的GTP结合域含有保存的元素,如Switch I,对于GTPase活动至关重要.
研究的目的:
- 调查eIF5B的GTPase活动在翻译启动中的作用.
- 为了确定GTP水解是否对核糖体子单元的连接至关重要或具有调节功能.
主要方法:
- 在eIF5B.中的Switch I元素的位点定向突变发生.
- 测试GTP水解,核糖体亚单元连接和一般转化.
- 对内基因抑制剂及其对核糖体结合和AUG选择的影响的分析.
主要成果:
- 在Switch I中的突变影响了GTP水解和一般翻译,但保留了子单元连接功能.
- 内基抑制剂恢复了整体翻译,但没有恢复GTPase活性.
- 抑制器突变降低了核糖体亲和力,并增加了AUG起始子的泄漏扫描.
结论:
- 通过eIF5B进行的GTP水解对核糖体子单元的连接不至关重要,但可能在翻译启动中起着调节作用.
- eIF5B GTP水解作为80S核糖体组合的检查点,可能通过稳定Met-tRNA的结合.
相关概念视频
01:31Translation
Lesson: Translation
Translation is the process of synthesizing proteins from the genetic information carried by messenger RNA (mRNA). Following transcription, it constitutes the final step in the expression of genes. This process is carried out by ribosomes, complexes of protein and specialized RNA molecules. Ribosomes, transfer RNA (tRNA), and other proteins produce a chain of amino acids—the polypeptide—as the end product of translation.
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02:33Initiation of Translation
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First, the initiator tRNA must be selected from the pool of elongator tRNAs by eukaryotic initiation factor 2 (eIF2). The initiator tRNA (Met-tRNAi) has conserved sequence elements including modified bases at...
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01:44Termination of Translation
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01:31Translation
Lesson: Translation
Translation is the process of synthesizing proteins from the genetic information carried by messenger RNA (mRNA). Following transcription, it constitutes the final step in the expression of genes. This process is carried out by ribosomes, complexes of protein and specialized RNA molecules. Ribosomes, transfer RNA (tRNA), and other proteins produce a chain of amino acids—the polypeptide—as the end product of translation.
Translation Produces the Building Blocks of Life
Translation is the process of synthesizing proteins from the genetic information carried by messenger RNA (mRNA). Following transcription, it constitutes the final step in the expression of genes. This process is carried out by ribosomes, complexes of protein and specialized RNA molecules. Ribosomes, transfer RNA (tRNA), and other proteins produce a chain of amino acids—the polypeptide—as the end product of translation.
Translation Produces the Building Blocks of Life
02:33Initiation of Translation
Initiating translation is complex because it involves multiple molecules. Initiator tRNA, ribosomal subunits, and eukaryotic initiation factors (eIFs) are all required to assemble on the initiation codon of mRNA. This process consists of several steps that are mediated by different eIFs.
First, the initiator tRNA must be selected from the pool of elongator tRNAs by eukaryotic initiation factor 2 (eIF2). The initiator tRNA (Met-tRNAi) has conserved sequence elements including modified bases at...
First, the initiator tRNA must be selected from the pool of elongator tRNAs by eukaryotic initiation factor 2 (eIF2). The initiator tRNA (Met-tRNAi) has conserved sequence elements including modified bases at...