tRNA in codon usage

密码子使用中的 tRNA

• 批准号: 10581912
• 负责人: Ya-Ming Hou
• 金额: $ 21.33万
• 依托单位: THOMAS JEFFERSON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-03-01 至 2025-02-28
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10581912
• 关键词: Address; Amino Acids; Anticodon; Biology; Cell Death; Cells; Code; Codon Nucleotides; Development; Disease; Epigenetic Process; Escherichia coli; Genes; Genetic Code; Genetic Transcription; Genome; Growth; Guanine; Health; Human; Maintenance; Methodology; Methylation; Mitochondria; Mitochondrial Diseases; Modeling; Modification; Organism; Pathogenicity; Pattern; Positioning Attribute; Proline; Protein Biosynthesis; Proteins; Proteome; Reading Frames; Reporter; Research; Ribosomes; Role; Speed; Transfer RNA; Translations; Work; fitness; frontier; genome-wide; predictive test; premature

PROJECT SUMMARY: Codon usage is a specific feature of each gene and each genome and impacts the fitness of each organism. In the degeneracy of the genetic code, proteins can be coded in multiple ways using different sets of synonymous codons, which are not translated equally in speed or quality. Each codon choice between the synonyms makes a demand for the supply of the tRNA with the matching anticodon. The quality of a codon-anticodon pairing interaction is determined not only by the level of the tRNA for the codon, but also by the epigenetic modifications to the tRNA that are synthesized post-transcriptionally. While most studies have focused on the abundance of tRNA as a determinant of codon usage and cell fitness, less is known about post-transcriptional modifications. In the past 5 years, my lab has focused on the N1-methylation of the guanine at position 37 that synthesizes m1G37 in tRNAs, which is required for reading-frame maintenance during protein synthesis. Loss of m1G37- tRNAs leads to accumulation of ribosomal +1-shifts, resulting in pre-mature termination of protein synthesis and ultimately cell death. A key finding of our work is that, while m1G37 is required for translation of all four codons for proline (Pro), it is essential for translation of CC[C/U] codons. Because Pro is a unique amino acid in protein synthesis, this finding offers interesting and important new biology, in which m1G37-tRNAs provide a global mechanism to control the expression of CC[C/U]-enriched genes. In the next frontier of research, we will focus on the m1G37-dependent differential translation of CC[CU] as a model to elucidate the principles by which the supply-to-demand ratio of tRNAs governs cell fitness. We will start by analysis of the balanced growth of E. coli as a reporter for genome-wide protein synthesis. We will test the predictive power of the elucidated principles in determining the human proteome. We will also address the role of m1G methylation, when placed at position 9 of a pathogenic mitochondrial tRNA (mt-tRNA), in the development of the mitochondrial disorder. By exploring the unique methodologies and conceptual frameworks that we have developed, we will address these key gaps in the field and advance our understanding of codon usage in human health and disease.

项目概要： 密码子的使用是每个基因和每个基因组的特定特征，并影响每个生物体的适应性。在 由于遗传密码的简并性，蛋白质可以使用不同的同义组以多种方式编码 密码子的翻译速度或质量并不相同。同义词之间的每个密码子选择都使得 对提供具有匹配反密码子的 tRNA 的需求。密码子-反密码子配对的质量 相互作用不仅取决于密码子 tRNA 的水平，还取决于表观遗传修饰 转录后合成的 tRNA。虽然大多数研究都集中在丰富的 tRNA 作为密码子使用和细胞适应性的决定因素，但人们对转录后修饰知之甚少。 在过去的 5 年里，我的实验室重点研究了 37 位鸟嘌呤的 N1-甲基化，合成了 tRNA 中的 m1G37，这是蛋白质合成过程中阅读框维护所必需的。 m1G37 丢失- tRNA 导致核糖体 +1 位移的积累，导致蛋白质合成过早终止， 最终细胞死亡。我们工作的一个重要发现是，虽然所有四个密码子的翻译都需要 m1G37 对于脯氨酸 (Pro)，它对于 CC[C/U] 密码子的翻译至关重要。因为Pro是蛋白质中独特的氨基酸 合成，这一发现提供了有趣且重要的新生物学，其中 m1G37-tRNA 提供了全局 控制CC[C/U]富集基因表达的机制。在下一个研究领域，我们将重点关注 以 CC[CU] 的 m1G37 依赖性差异翻译为模型来阐明 tRNA 的供需比决定着细胞的适应性。我们首先分析大肠杆菌的平衡生长 作为全基因组蛋白质合成的报告者。我们将测试所阐明的原则的预测能力 确定人类蛋白质组。我们还将讨论 m1G 甲基化（位于位置 9 时）的作用 致病性线粒体 tRNA (mt-tRNA) 在线粒体疾病的发展过程中的作用。通过探索 我们开发的独特方法和概念框架，我们将解决这些关键差距 并增进我们对人类健康和疾病中密码子使用的理解。