含有eIF4E3和eIF4E4的Trypanosoma cruzi复合体与不同的mRNA结合,并在营养压力期间可能隔离不活的mRNA
Bernardo Papini Gabiatti1,2, Eden Ribeiro Freire1, Jimena Ferreira da Costa1
1Carlos Chagas Institute, Oswaldo Cruz Foundation, FIOCRUZ, R. Prof. Algacyr Munhoz Mader 3775, 81350-010, Curitiba-PR, Brazil.
Nucleic acids research
|December 10, 2024
概括
类体利用两个不同的eIF4F复合体,每个结合特定的信使RNA (mRNA). 在压力下,这些复合物停止翻译,但保持mRNA结合,影响寄生虫的分化.
科学领域:
- 分子生物学分子生物学
- 寄生虫学的寄生虫学
- 基因法规 基因法规
背景情况:
- 试生体具有多种翻译启动因子的类似物,如eIF4F和多A结合蛋白 (PABPs),与甲基动物不同.
- 这些因素聚集成不同的复合体,每个复合体都与特定的信使RNA (mRNA) 相关,并执行独特的功能.
研究的目的:
- 研究寄生虫*Trypanosoma cruzi*中两个eIF4F复合体 (eIF4E3和eIF4E4) 的功能和调节.
- 在指数增长和营养压力的条件下识别相关的蛋白质和mRNA,从而诱导分化.
主要方法:
- 分析蛋白质和mRNA与eIF4E3和eIF4E4复合物的关联.
- 在生长和压力条件下复杂成分和mRNA结合的比较.
主要成果:
- 确定了两个不同的eIF4F复合体 (eIF4E3和eIF4E4),每个结合不同组的mRNAs.
- 在营养压力下,eIF4G和PABP仍然与eIF4E相关,但核糖体附着减少,表明翻译启动受损.
- 与eIF4E3相关的mRNAs主要编码合成代谢蛋白质,而eIF4E4与核糖体蛋白的mRNAs相关.
- 尽管在压力下翻译效率较低,但与非压力条件相比,这两种复合体与更多的mRNA结合.
结论:
- *Trypanosoma cruzi*使用两个共存的eIF4F复合体,它们结合了不同的mRNA群体.
- 在压力诱导的分化过程中,这些复合物退出翻译,但仍然与它们的目标mRNA相关联,这表明除了活性翻译之外还有一项调节作用.
相关概念视频
Riboswitches
8.0K
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...
8.0K
Eukaryotic Transcription Inhibitors
9.8K
Certain biochemical processes, such as embryonic development and cell growth regulation, depend on the repression of specific genes. DNA binding proteins known as eukaryotic transcription inhibitors regulate the repression of gene expression in eukaryotes. The presence of these inhibitors at the required location and time in the cell is triggered by the presence of hormones and additional signals from other cells.
Eukaryotic transcription inhibitors usually contain two distinct domains, a...
Eukaryotic transcription inhibitors usually contain two distinct domains, a...
9.8K
Chromatin Structure Regulates pre-mRNA Processing
6.9K
In eukaryotic cells, nascent mRNA transcripts need to undergo many post-transcriptional modifications to reach the cell cytoplasm and translate into functional proteins. For a long time, transcription and pre-mRNA processing were considered two independent events that occur sequentially in the cell. However, it has now been well established that transcription and pre-mRNA processing are two simultaneous processes that are precisely regulated inside the cell.
The chromatin structure, especially...
The chromatin structure, especially...
6.9K
Regulation of the Unfolded Protein Response
2.4K
Inositol-requiring kinase one or IRE1 is the most conserved eukaryotic unfolded protein response (UPR) receptor. It is a type I transmembrane protein kinase receptor with a distinctive site-specific RNase activity. As the binding mechanics of the misfolded proteins with the N-terminal domain of IRE-1 are unclear, three binding models — direct, indirect, and allosteric -- are proposed for receptor activation. Nevertheless, it is known that once a misfolded protein associates with IRE1, it...
2.4K
Leaky Scanning
5.1K
During most eukaryotic translation processes, the small 40S ribosome subunit scans an mRNA from its 5' end until it encounters the first start AUG codon. The large 60S ribosomal subunit then joins the smaller one to initiate protein synthesis. The location of the translation initiation is largely determined by the nucleotides near the start codon as there may be multiple translation initiation sites present on the mRNA. Marilyn Kozak discovered that the sequence RCCAUGG (where R...
5.1K
General Transcription Factors
5.2K
Tissue-specific transcription factors contribute to diverse cellular functions in mammals. For example, the gene for beta globin, a major component of hemoglobin, is present in all cells of the body. However, it is only expressed in red blood cells because the transcription factors that can bind to the promoter sequences of the beta globin gene are only expressed in these cells. Tissue-specific transcription factors also ensure that mutations in these factors may impair only the function of...
5.2K


