由TRMU突变引起的缺陷线粒体tRNA修饰导致了肝脏特异性衰竭
Xiao He1, Qinghai Zhang1, Chao Chen1
1Center for Mitochondrial Biomedicine and Department of General Surgery, the Fourth Affiliated Hospital, Zhejiang University School of Medicine, Yiwu, Zhejiang, China; Institute of Genetics, Zhejiang University International School of Medicine, Hangzhou, Zhejiang, China; Center for Genetic Medicine, Zhejiang University International Institute of Medicine, Yiwu, Zhejiang, China.
The Journal of biological chemistry
|January 24, 2026
概括
通过破坏线粒体tRNA修饰,TRMU突变导致肝衰竭. 这项研究揭示了组织特异性影响,显示出由于异常的tRNA代谢和改变的线粒体呼吸而导致肝脏脆弱性,导致肝脏肥胖症.
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) 的转录后核酸修饰对于它们的结构和功能至关重要.
- 在TRMU基因的突变导致线粒体tRNAs (mt-tRNAs) 的缺陷修饰 (τm5s2U),主要导致肝衰竭.
- 在TRMU缺陷条件下的组织特异性病理背后的机制仍然不太清楚.
研究的目的:
- 研究TRMU缺乏和线粒体tRNA中tm5s2U修饰的丧失的组织特异性后果.
- 在斑马鱼TRMU缺乏模型中阐明导致肝脏特异性致病的分子机制.
主要方法:
- 使用斑马鱼作为模型生物来研究TRMU缺乏.
- 生成的trmu淘汰赛 (KO) 斑马鱼,以评估对tRNA构造,稳定性和氨基化产生组织特异性的影响.
- 分析了线粒体呼吸链复合体的组合,稳定性和活性,重点关注复合体I,III和IV.
主要成果:
- 在不同斑马鱼组织 (大脑,肌肉,眼睛,肝脏,卵子) 中观察到mt-tRNA (tRNAGlu,tRNAGln,tRNALys) 中不同程度的tm5s2U修饰.
- 在trmuKO斑马鱼中,这些mt-tRNAs的构造,稳定性和氨基化发生了显著的组织特异性改变,肝脏表现出最严重的缺陷.
- 发现斑马鱼中异常的mt-tRNA代谢破坏了线粒体呼吸复合体 (I,III,IV),特别是在肝脏中,导致复合体I到复合体II的比率发生变化,以及随后的肝脏病理,如脂肪瘤和扩大.
结论:
- 由于TRMU缺陷导致线粒体tRNA中tm5s2U修饰的损失导致组织特异性缺陷,导致肝脏病原.
- 肝脏独特的代谢特征,包括高度依赖复合I,使其特别容易受到线粒体tRNA功能的干扰.
- 这些发现为肝脏特异性疾病的分子基础提供了新的见解,这些疾病来自受损的线粒体tRNA修饰.
相关概念视频
02:26tRNA Activation
22.7K
Aminoacyl-tRNA synthetases are present in both eukaryotes and bacteria. Though eukaryotes have 20 different aminoacyl-tRNA synthetases to couple to 20 amino acids, many bacteria do not have genes for all of these aminoacyl-tRNA synthetases. Despite this, they still use all 20 amino acids to synthesize their proteins. For instance, some bacteria do not have the gene encoding the enzyme that couples glutamine with its partner tRNA. In these organisms, one enzyme adds glutamic acid to all of the...
22.7K
02:26tRNA Activation
8.4K
8.4K
02:19Export of Mitochondrial and Chloroplast Genes
4.1K
A eukaryotic cell can have up to three different types of genetic systems: nuclear, mitochondrial, and chloroplast. During evolution, organelles have exported many genes to the nucleus; this transfer is still ongoing in some plant species. Approximately 18% of the Arabidopsis thaliana nuclear genome is thought to be derived from the chloroplast’s cyanobacterial ancestor, and around 75% of the yeast genome derived from the mitochondria’s bacterial ancestor. This export has occurred...
4.1K
01:39Mutations
94.4K
Overview
94.4K
01:35Mutations
44.2K
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...
44.2K
02:59Animal Mitochondrial Genetics
9.0K
Among all the organelles in an animal cell, only mitochondria have their own independent genomes. Animal mitochondrial DNA is a double-stranded, closed-circular molecule with around 20,000 base pairs. Mitochondrial DNA is unique in that one of its two strands, the heavy, or H, -strand is guanine rich, whereas the complementary strand is cytosine rich and called the light, or L, -strand. Compared to nuclear DNA, mitochondrial DNA has a very low percentage of non-coding regions and is marked by...
9.0K