相关实验视频

Updated: Jul 15, 2025

LERLIC-MS/MS for In-depth Characterization and Quantification of Glutamine and Asparagine Deamidation in Shotgun Proteomics

LERLIC-MS/MS for In-depth Characterization and Quantification of Glutamine and Asparagine Deamidation in Shotgun Proteomics

Published on: April 9, 2017

氨基化和编辑之间的协调,以防止蛋白质毒性

Hong Zhang¹, Parker Murphy¹, Jason Yu¹

¹Department of Cell Biology and Molecular Genetics, The University of Maryland, College Park, MD 20742, USA.

Nucleic acids research

|September 24, 2023

概括

氨基化和由氨基-tRNA合成酶 (aaRSs) 编辑的组合缺陷导致蛋白质毒性. 编辑功能受损和threonyl-tRNA合成酶 (ThrRS) 的不稳定导致热敏感性和蛋白质毒性压力.

科学领域:

分子生物学分子生物学
生物化学生化学
遗传学是一个遗传学.

背景情况:

氨基酸-tRNA合成酶 (aaRSs) 对于蛋白质合成至关重要,它将氨基酸连接到tRNAs.
aaRSs中的突变与人类的神经系统疾病有关,其机制往往不清楚.
病原性突变通常导致蛋白质不稳定性和氨基化效率降低.

研究的目的:

调查aARS中氨基化和编辑缺陷的综合影响.
阐明由aaRS功能受损引起的蛋白质毒性背后的机制.
探索酶活性,蛋白质稳定性和细胞应激反应之间的关系.

主要方法:

利用酵母模型在threonyl-tRNA合成酶 (ThrRS) 中具有特定突变 (ths1-C268A) 取消编辑.
采用实验进化来隔离抑制器突变.
评估了热敏度,氨基化效率,蛋白质稳定性和与核糖体相关的质量控制.

主要成果:

ths1-C268A突变消除了ThrRS编辑,导致热敏感性和蛋白质不稳定.
实验进化产生了抑制器突变,恢复了耐热性,但没有编辑,改善了氨基化.
综合氨基酸和编辑缺陷,但不是单个缺陷,诱导了显著的热敏度和与核糖体相关的质量控制受损.

结论:

在aaRSs中组合氨基酸和编辑缺陷导致严重的蛋白毒性.
氨基化缺乏似乎使细胞容易受到蛋白质毒性压力.
了解这些机制对于理解与aaRS相关的神经疾病至关重要.

更多相关视频

A Facile Protocol to Generate Site-Specifically Acetylated Proteins in Escherichia Coli

A Facile Protocol to Generate Site-Specifically Acetylated Proteins in Escherichia Coli

Published on: December 9, 2017

Assays for the Degradation of Misfolded Proteins in Cells

Assays for the Degradation of Misfolded Proteins in Cells

Published on: August 28, 2016

相关概念视频

RNA Editing

RNA Editing

RNA editing is a post-transcriptional modification where a precursor mRNA (pre-mRNA) nucleotide sequence is changed by base insertion, deletion, or modification. The extent of RNA editing varies from a few hundred bases, in mitochondrial DNA of trypanosomes, to a just single base, in nuclear genes of mammals. Even a single base change in the pre-mRNA can convert a codon for one amino acid into the codon for another amino acid or a stop codon. This type of re-coding can significantly affect the...

Improving Translational Accuracy

Improving Translational Accuracy

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...

tRNA Activation

tRNA Activation

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...

Covalently Linked Protein Regulators

Covalently Linked Protein Regulators

Proteins can undergo many types of post-translational modifications, often in response to changes in their environment. These modifications play an important role in the function and stability of these proteins. Covalently linked molecules include functional groups, such as methyl, acetyl, and phosphate groups, and also small proteins, such as ubiquitin. There are around 200 different types of covalent regulators that have been identified.
These groups modify specific amino acids in a protein....

Proteins: From Genes to Degradation

Proteins: From Genes to Degradation

Within a biological system, the DNA encodes the RNA, and the nucleotide sequence in the RNA further defines the amino acid sequence in the protein. This is referred to as “The Central Dogma of Molecular Biology” - a term coined by Francis Crick. Central dogma is a firm principle in biology that defines the flow of genetic information within any life form. The two fundamental steps in central dogma are - transcription and translation.
Transcription is the synthesis of RNA...

The Proteasome

The Proteasome

Eukaryotic cells can degrade proteins through several pathways. One of the most important among these is the ubiquitin-proteasome pathway. It helps the cell eliminate the misfolded, damaged, or unwarranted cytoplasmic proteins in a highly specific manner.
In this pathway, the target proteins are first tagged with small proteins called ubiquitin. This involves participation of a series of enzymes including— E1 (ubiquitin-activating enzyme), E2 (ubiquitin-conjugating enzyme), and E3...