Antimicrobial Resistance Interdisciplinary Research Group, Singapore-MIT Alliance for Research and Technology, Singapore City, Singapore.
School of Biological Sciences, Nanyang Technological University, Singapore City, Singapore.
Mol Syst Biol. 2018 Oct 4;14(10):e8009. doi: 10.15252/msb.20178009.
Among components of the translational machinery, ribonucleoside modifications on tRNAs are emerging as critical regulators of cell physiology and stress response. Here, we demonstrate highly coordinated behavior of the repertoire of tRNA modifications of throughout the intra-erythrocytic developmental cycle (IDC). We observed both a synchronized increase in 22 of 28 modifications from ring to trophozoite stage, consistent with tRNA maturation during translational up-regulation, and asynchronous changes in six modifications. Quantitative analysis of ~2,100 proteins across the IDC revealed that up- and down-regulated proteins in late but not early stages have a marked codon bias that directly correlates with parallel changes in tRNA modifications and enhanced translational efficiency. We thus propose a model in which tRNA modifications modulate the abundance of stage-specific proteins by enhancing translation efficiency of codon-biased transcripts for critical genes. These findings reveal novel epitranscriptomic and translational control mechanisms in the development and pathogenesis of parasites.
在翻译机制的成分中,tRNA 上的核糖核苷修饰作为细胞生理学和应激反应的关键调节剂而出现。在这里,我们展示了整个红细胞内发育周期(IDC)中 tRNA 修饰谱的高度协调行为。我们观察到 28 种修饰中的 22 种从环到滋养体阶段同步增加,这与翻译上调过程中的 tRNA 成熟一致,而 6 种修饰则出现不同步变化。对 IDC 中约 2100 种蛋白质的定量分析表明,晚期而不是早期上调和下调的蛋白质具有明显的密码子偏向性,这与 tRNA 修饰的平行变化和翻译效率的提高直接相关。因此,我们提出了一个模型,其中 tRNA 修饰通过增强关键基因的密码子偏向转录本的翻译效率来调节特定阶段蛋白质的丰度。这些发现揭示了疟原虫发育和发病机制中的新型表观转录组学和翻译控制机制。