一种双重抑制机制限制了msl-2mRNA的翻译,以补偿Drosophila的剂量
Karsten Beckmann1, Marica Grskovic, Fátima Gebauer
1Gene Expression Unit, European Molecular Biology Laboratory, Heidelberg, Germany.
Cell
|August 27, 2005
概括
雌性Drosophila必须使用Sex-lethal (SXL) 蛋白质阻止msl-2基因表达. SXL与mRNA区域结合,以防止翻译,通过剂量补偿确保生存.
科学领域:
- 分子生物学分子生物学
- 遗传学 是一个遗传学.
- 发展生物学 发展生物学
背景情况:
- 在Drosophila中,剂量补偿对于性别确定和发育至关重要.
- MSL-2蛋白对于剂量补偿复合体至关重要,但必须严格监管.
- 性杀伤性 (SXL) 蛋白调节雌性的MSL-2表达.
研究的目的:
- 阐明Sex-lethal (SXL) 抑制msl-2mRNA转换的分子机制.
- 了解如何将SXL绑定到不同的未翻译区域 (UTR) 控制翻译启动.
- 揭示了保险机制,以确保适当的剂量补偿在雌性虫.
主要方法:
- 对msl-2mRNA的5'和3'UTR中的SXL结合位点的分析.
- 研究43S核糖体预启动复合物的招募.
- 研究SXL与mRNA上的核糖体扫描的干扰.
主要成果:
- 对3' UTR的SXL结合抑制了核糖体对mRNA的初始招募.
- 绑定到5' UTR的SXL阻碍了向启动编码子的核糖体扫描.
- 确定了一种涉及mRNA多个调节部位的两步抑制机制.
结论:
- SXL采用双位点结合策略,以实现对msl-2mRNA的严格翻译控制.
- 这种机制对于防止女性MSL-2积累和确保准确的剂量补偿至关重要.
- 这些发现突出了使用多个mRNA位点的翻译调节的一般原则.
相关概念视频
Types of RNA
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...
Coordination of Gene Expression Processes in Bacteria
The DNA replication, transcription, and translation processes are intricately coupled in bacteria, allowing efficient gene expression and rapid protein synthesis. While this physical and functional coordination is advantageous, it introduces challenges that bacteria overcome through specific regulatory mechanisms.Coupling of Replication, Transcription, and TranslationThe coupling of replication, transcription, and translation is a hallmark of bacterial gene expression. As the replisome unwinds...
Transcriptional Regulation: Riboswitches
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...
Translational Regulation
Translational regulation in prokaryotes ensures efficient protein synthesis by controlling ribosome access to mRNA. This regulation is mediated by secondary RNA structures, including translational riboswitches, RNA thermometers, and small RNAs (sRNAs), which respond to intracellular and environmental signals to modulate gene expression.Translational RiboswitchesRiboswitches in the leader region of mRNAs can regulate translation by altering the accessibility of the Shine-Dalgarno (SD) sequence,...
Stringent Response in E. coli
Bacterial growth is closely tied to nutrient availability, with cells proliferating exponentially under favorable conditions and entering a stationary phase when resources become scarce. This transition is mediated by a regulatory mechanism known as the stringent response, which allows bacteria to adapt to nutrient deprivation by modulating gene expression and metabolic activity.During nutrient scarcity, intracellular amino acid levels decline. It results in the accumulation of uncharged tRNAs...
Inhibitors of Bacterial Protein Synthesis
Aminoglycosides constitute a highly potent class of bactericidal antibiotics that exert their antimicrobial effects by targeting the bacterial ribosome, specifically disrupting protein synthesis. These polycationic molecules consist of amino-modified sugars linked via glycosidic bonds to an aminocyclitol core such as 2-deoxystreptamine or streptamine. Their strong positive charges facilitate tight binding to the negatively charged phosphate backbone of ribosomal RNA (rRNA), primarily at the 16S...


