tRNA tKUUU, tQUUG, and tEUUC wobble position modifications fine-tune protein translation by promoting ribosome A-site binding
tRNA tKUUU, tQUUG, and tEUUC wobble position modifications fine-tune protein translation by promoting ribosome A-site binding
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DOI：
10.1073/pnas.1300781110
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发表时间：
2013-07-23
影响因子：
11.1
通讯作者：
Pedrioli, Patrick G. A.
中科院分区：
文献类型：
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作者：
Rezgui, Vanessa Anissa Nathalie;Tyagi, Kshitiz;Pedrioli, Patrick G. A.
tRNA修饰对于确保翻译效率和保真度至关重要。在真核生物中，URM1和ELP途径通过分别促进细胞质tRNA（Lys）（UUU）（tK（UUU））、tRNA（Gln）（UUG）（tQ（UUG））和tRNA（Glu）（UUC）（tE（UUC））的摆动尿苷的巯基化和甲氧羰基甲基化，增加细胞对各种应激条件（如营养饥饿和氧化剂）的抗性。尽管体外实验已经暗示这些tRNA修饰调节摆动能力和翻译效率，但它们在体内的确切生物学作用在很大程度上仍未被探索。使用定量蛋白质组学和密码子特异性翻译报告的组合，我们发现，翻译的特定基因子集富集AAA，CAA和GAA密码子的URM1和ELP依赖的tRNA修饰的情况下受损。此外，使用天然tRNA的体外实验表明，这两种修饰都增强了tK（UUU）与核糖体A位点的结合。两者合计，我们的数据表明，tRNA巯基化和甲氧羰基甲基化调节特定密码子含量的基因的翻译。
tRNA modifications are crucial to ensure translation efficiency and fidelity. In eukaryotes, the URM1 and ELP pathways increase cellular resistance to various stress conditions, such as nutrient starvation and oxidative agents, by promoting thiolation and methoxycarbonylmethylation, respectively, of the wobble uridine of cytoplasmic tRNA(Lys)(UUU) (tK(UUU)), tRNA(Gln)(UUG) (tQ(UUG)), and tRNA(Glu)(UUC) (tE(UUC)). Although in vitro experiments have implicated these tRNA modifications in modulating wobbling capacity and translation efficiency, their exact in vivo biological roles remain largely unexplored. Using a combination of quantitative proteomics and codon-specific translation reporters, we find that translation of a specific gene subset enriched for AAA, CAA, and GAA codons is impaired in the absence of URM1- and ELP-dependent tRNA modifications. Moreover, in vitro experiments using native tRNAs demonstrate that both modifications enhance binding of tK(UUU) to the ribosomal A-site. Taken together, our data suggest that tRNA thiolation and methoxycarbonylmethylation regulate translation of genes with specific codon content.