Diphthamide, a post-translationally modified histidine residue of eukaryotic TRANSLATION ELONGATION FACTOR2 (eEF2), is the human host cell-sensitizing target of diphtheria toxin. Diphthamide biosynthesis depends on the 4Fe-4S-cluster protein Dph1 catalyzing the first committed step, as well as Dph2 to Dph7, in yeast and mammals. Here we show that diphthamide modification of eEF2 is conserved in Arabidopsis thaliana and requires AtDPH1. Ribosomal −1 frameshifting-error rates are increased in Arabidopsis dph1 mutants, similar to yeast and mice. Compared to the wild type, shorter roots and smaller rosettes of dph1 mutants result from fewer formed cells. TARGET OF RAPAMYCIN (TOR) kinase activity is attenuated, and autophagy is activated, in dph1 mutants. Under abiotic stress diphthamide-unmodified eEF2 accumulates in wild-type seedlings, most strongly upon heavy metal excess, which is conserved in human cells. In summary, our results suggest that diphthamide contributes to the functionality of the translational machinery monitored by plants to regulate growth. Diphthamide is a post-translationally modified histidine residue present in animal and yeast TRANSLATION ELONGATION FACTOR2. Here the authors show that diphthamide modification of eEF2 is conserved in Arabidopsis thaliana and contributes to translational fidelity and growth via cell proliferation.

中文翻译：

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拟南芥的翻译保真度和生长需要对胁迫敏感的二苯甲酰胺生物合成

Diphthamide 是真核生物翻译延伸因子 2 (eEF2) 的翻译后修饰的组氨酸残基，是白喉毒素的人类宿主细胞致敏靶标。Diphthamide 的生物合成依赖于 4Fe-4S 簇蛋白 Dph1 催化酵母和哺乳动物中的第一步，以及 Dph2 到 Dph7。在这里，我们显示 eEF2 的联苯二甲胺修饰在拟南芥中是保守的，并且需要 AtDPH1。与酵母和小鼠相似，拟南芥 dph1 突变体的核糖体 -1 移码错误率增加。与野生型相比，dph1 突变体的更短的根和更小的玫瑰花结是由于形成的细胞更少。在 dph1 突变体中，雷帕霉素靶点 (TOR) 激酶活性减弱，自噬被激活。在非生物胁迫下，未经修饰的eEF2在野生型幼苗中积累，最强烈的是重金属过量，这在人体细胞中是保守的。总之，我们的研究结果表明，联苯双胺有助于植物监测的翻译机制的功能，以调节生长。Diphthamide 是一种翻译后修饰的组氨酸残基，存在于动物和酵母 TRANSLATION ELONGATION FACTOR2 中。在这里，作者表明，eEF2 的二苯甲酰胺修饰在拟南芥中是保守的，通过细胞增殖有助于翻译保真度和生长。Diphthamide 是一种翻译后修饰的组氨酸残基，存在于动物和酵母 TRANSLATION ELONGATION FACTOR2 中。在这里，作者表明，eEF2 的二苯甲酰胺修饰在拟南芥中是保守的，通过细胞增殖有助于翻译保真度和生长。Diphthamide 是一种翻译后修饰的组氨酸残基，存在于动物和酵母 TRANSLATION ELONGATION FACTOR2 中。在这里，作者表明，eEF2 的二苯甲酰胺修饰在拟南芥中是保守的，通过细胞增殖有助于翻译保真度和生长。