18S和25S外核酶耐药的核糖体RNA分子是在TOR抑制过程中通过5'-End修改产生
Miguel A Rocha1, Gowda Bhavani1, Jacob Fleischmann1,2
1Research Division, Greater Los Angeles VA Healthcare System, California, Los Angeles, USA.
Yeast (Chichester, England)
|November 6, 2025
概括
在二氧化转移期间,Saccharomyces cerevisiae酵母细胞产生抗外核酶的核糖体RNA (rRNA),这与TOR信号的减少有关. 这种抗性源于5'端修饰,而不是转录性变化.
科学领域:
- 分子生物学分子生物学
- 酵母遗传学 酵母遗传学
- 细胞的新陈代谢
背景情况:
- 细菌菌产生18S和25S核糖体RNA (rRNA) 能够抵抗外核酶降解.
- 这种抗性与二氧化转移和减少的拉巴胺素目标 (TOR) 信号传输有关.
- 外核酶活动需要5'单酸盐,这表明rRNA5'末端的修改会产生抗性.
研究的目的:
- 调查TOR信号传输与抗性rRNA的积累之间的关系.
- 确定抗性rRNA形成的机制和调节.
- 澄清RNA聚合酶I (Pol I) 和转录后修饰的作用.
主要方法:
- 使用拉帕米辛的TOR的药理抑制.
- 在TOR1-删除突变体和构成性活性RNA聚合酶I (CARA) 细胞中分析耐药rRNA.
- 提奥拉标记和吸收试验,以评估rRNA合成和修饰.
- 分割试验用于评估外核酶敏感性.
主要成果:
- 拉帕米辛治疗增加了抗性18S和25SrRNA水平.
- 抗性rRNA的积累独立于RNA Pol I转录调节 (在CARA细胞中观察到) 发生.
- TOR1 缺失导致持续产生耐药的rRNA.
- 逻辑相rRNA可以在转录后转化为耐药形式.
- 脱皮恢复了外核酶的敏感性,证实了5'端修饰赋予了耐药性.
结论:
- 托尔信号负面调节了对外核酶抗性rRNA的积累.
- 抗性rRNA的形成是一个转录后过程,涉及5'末端修饰,可能是酸化.
- 这种机制在细胞应激或代谢转变期间提供了一种新的rRNA调节层.
相关概念视频
Ribosomal RNA Synthesis
14.6K
Ribosome synthesis is a highly complex and coordinated process involving more than 200 assembly factors. The synthesis and processing of ribosomal components occurs not only in the nucleolus but also in the nucleoplasm and the cytoplasm of eukaryotic cells.
Ribosome biogenesis begins with the synthesis of 5S and 45S pre-rRNAs by distinct RNA polymerases. The primary transcripts are extensively processed and modified before they are bound and folded by ribosomal proteins and assembly factors,...
Ribosome biogenesis begins with the synthesis of 5S and 45S pre-rRNAs by distinct RNA polymerases. The primary transcripts are extensively processed and modified before they are bound and folded by ribosomal proteins and assembly factors,...
14.6K
Ribosomal RNA Synthesis
4.1K
4.1K
Types of RNA
72.5K
Overview
Three main types of RNA are involved in protein synthesis: messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA). These RNAs perform diverse functions and can be broadly classified as protein-coding or non-coding RNA. Non-coding RNAs play important roles in the regulation of gene expression in response to developmental and environmental changes. Non-coding RNAs in prokaryotes can be manipulated to develop more effective antibacterial drugs for human or animal use.
RNA...
Three main types of RNA are involved in protein synthesis: messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA). These RNAs perform diverse functions and can be broadly classified as protein-coding or non-coding RNA. Non-coding RNAs play important roles in the regulation of gene expression in response to developmental and environmental changes. Non-coding RNAs in prokaryotes can be manipulated to develop more effective antibacterial drugs for human or animal use.
RNA...
72.5K
Types of RNA
9.0K
Three main types of RNA are involved in protein synthesis: messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA). These RNAs perform diverse functions and can be broadly classified as protein-coding or non-coding RNA. Non-coding RNAs play important roles in regulating gene expression in response to developmental and environmental changes. Non-coding RNAs in prokaryotes can be manipulated to develop more effective antibacterial drugs for human or animal use.
RNA Performs Diverse...
RNA Performs Diverse...
9.0K
Transcriptional Regulation: Riboswitches
546
Riboswitches are RNA elements that regulate gene expression by altering their secondary structures in response to specific effector molecules. These elements, located in the leader regions of certain mRNAs, act as transcriptional regulators by toggling between alternative conformations to control downstream gene expression. Riboswitch-mediated regulation is a precise mechanism for modulating biosynthetic pathways, as exemplified by the riboflavin biosynthesis pathway in Bacillus...
546
Riboswitches
9.5K
Riboswitches are non-coding mRNA domains that regulate the transcription and translation of downstream genes without the help of proteins. Riboswitches bind directly to a metabolite and can form unique stem-loop or hairpin structures in response to the amount of the metabolite present. They have two distinct regions – a metabolite-binding aptamer and an expression platform.
The aptamer has high specificity for a particular metabolite which allows riboswitches to specifically regulate...
The aptamer has high specificity for a particular metabolite which allows riboswitches to specifically regulate...
9.5K


