在tRNA修饰突变体中,低于最佳的编码对触发了核糖体碰撞和细胞质量控制反应
Jie Wu1,2, Cristian Eggers1,2, Olga Sin1
1Department of Chemistry, Biochemistry and Pharmaceutical Sciences (DCBP), University of Bern, Bern 3012, Switzerland.
Nucleic acids research
|December 22, 2025
概括
转移RNA (tRNA) 的修改调节了蛋白质合成. 波动尿素 (U34) 修饰的损失导致核糖体停滞,触发质量控制途径以维持蛋白质平衡.
科学领域:
- 分子生物学分子生物学
- 遗传学 遗传学 是一个
- 生物化学 生物化学
背景情况:
- 转移RNA (tRNA) 修改对于精确的蛋白质合成和共同翻译折叠至关重要.
- 通过tRNA修饰影响代码子最佳性和细胞表型的精确机制尚未完全理解.
研究的目的:
- 研究tRNA中的摇摆尿素 (U34) 修改如何影响核糖体动力学和细胞反应.
- 阐明特定的U34修饰的作用,如5-carbamoylmethyluridine (ncm5U),在解码中.
主要方法:
- 用高分辨率的核糖体分析来分析核糖体行为.
- 对摇摆尿素 (U34) 修饰突变的分析,以观察对翻译的影响.
主要成果:
- 核糖体在U34修饰突变的特定子对中停滞不前,导致核糖体碰撞.
- 这些碰撞激活了与核糖体相关的质量控制 (RQC) 途径,降解异常和mRNA.
- 特定的U34修改,如ncm5U,在核糖体的A和P位点具有明显的影响.
- 只有通过低基调tRNA解码的部分编码子显示了减少的解码速度,这表明了取决于上下文的效应.
结论:
- 丢失的tRNA修饰主要影响低于最佳的编码子的翻译速率.
- 细胞监控系统,包括RQC和陪伴者通路,是协调维护蛋白质平衡.
- 这些发现强调了细胞质量控制在应对tRNA修饰中断时的适应性.
更多相关视频
10:00Assessment of Selective mRNA Translation in Mammalian Cells by Polysome Profiling
Published on: October 28, 2014
28.8K
09:04Studying Ribonucleotide Incorporation: Strand-specific Detection of Ribonucleotides in the Yeast Genome and Measuring Ribonucleotide-induced Mutagenesis
Published on: July 26, 2018
8.1K
相关概念视频
Improving Translational Accuracy
14.0K
Base complementarity between the three base pairs of mRNA codon and the tRNA anticodon is not a failsafe mechanism. Inaccuracies can range from a single mismatch to no correct base pairing at all. The free energy difference between the correct and nearly correct base pairs can be as small as 3 kcal/ mol. With complementarity being the only proofreading step, the estimated error frequency would be one wrong amino acid in every 100 amino acids incorporated. However, error frequencies observed in...
14.0K
Translation
17.4K
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
Proteins are...
Translation Produces the Building Blocks of Life
Proteins are...
17.4K
Translation
154.9K
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...
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...
154.9K
Nonsense-mediated mRNA Decay
11.6K
The Upf proteins that carry out nonsense-mediated decay (NMD) are found in all eukaryotic organisms, including humans. Each protein has an individual role, but they need to work in collaboration. Upf1 is an ATP-dependent RNA helicase that unwinds the RNA helix. Because Upf1 can unwind any RNA, Upf2 and Upf3 are required to help Upf1 discriminate between nonsense and normal mRNAs.
Usually, Upf3 binds to an Exon Junction Complex (EJC) at mRNA splice sites. If a ribosome fully translates the mRNA,...
Usually, Upf3 binds to an Exon Junction Complex (EJC) at mRNA splice sites. If a ribosome fully translates the mRNA,...
11.6K
Mutations
94.2K
Overview
94.2K
Mutations
42.6K
Mutations are changes in the sequence of DNA. These changes can occur spontaneously or they can be induced by exposure to environmental factors. Mutations can be characterized in a number of different ways: whether and how they alter the amino acid sequence of the protein, whether they occur over a small or large area of DNA, and whether they occur in somatic cells or germline cells.
Chromosomal Alterations Are Large-Scale Mutations
While point mutations are changes in a single nucleotide in...
Chromosomal Alterations Are Large-Scale Mutations
While point mutations are changes in a single nucleotide in...
42.6K
