Protein glutaminylation is a yeast-specific posttranslational modification of elongation factor 1A
Protein glutaminylation is a yeast-specific posttranslational modification of elongation factor 1A
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DOI：
10.1074/jbc.m117.801035
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发表时间：
2017-09-29
影响因子：
4.8
通讯作者：
Aktories, Klaus
中科院分区：
文献类型：
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作者：
Jank, Thomas;Belyi, Yury;Aktories, Klaus
核糖体翻译因子是蛋白质合成的基础，并且在所有生命王国中高度保守。真核生物必需延伸因子1A（eEF 1A）将氨酰tRNA递送到翻译80 S核糖体的A位点。几项研究表明，eEF 1A是后天修饰的。使用MS分析，定点诱变，和X-射线结构数据分析的酿酒酵母eEF 1A，我们确定了一个翻译后修饰，其中α氨基的单-L-谷氨酰胺共价连接到侧链的谷氨酸45 eEF 1A。MS分析表明，所有的eEF 1A分子被修饰的这种β-氨基化，这种翻译后修饰发生在酵母生长的所有阶段。突变研究表明，这种N-乙酰氨基化对于eEF 1A在S.啤酒。然而，eEF 1A氨酰化稍微降低了生长下的拟南芥诱导的翻译应力条件。此外，我们确定了相同的翻译后修饰eEF 1A裂殖酵母粟酒裂殖酵母，而不是在各种其他真核生物测试，尽管严格保守的Glu（45）残基在这些生物体。因此，我们得出结论，eEF 1A的氨酰化是一种酵母特异性的翻译后修饰，似乎影响蛋白质的翻译。
Ribosomal translation factors are fundamental for protein synthesis and highly conserved in all kingdoms of life. The essential eukaryotic elongation factor 1A (eEF1A) delivers aminoacyl tRNAs to the A-site of the translating 80S ribosome. Several studies have revealed that eEF1A is posttranslationally modified. Using MS analysis, site-directed mutagenesis, and X-ray structural data analysis of Saccharomyces cerevisiae eEF1A, we identified a posttranslational modification in which the alpha amino group of mono-L-glutamine is covalently linked to the side chain of glutamate 45 in eEF1A. The MS analysis suggested that all eEF1A molecules are modified by this glutaminylation and that this posttranslational modification occurs at all stages of yeast growth. The mutational studies revealed that this glutaminylation is not essential for the normal functions of eEF1A in S. cerevisiae. However, eEF1A glutaminylation slightly reduced growth under antibiotic-induced translational stress conditions. Moreover, we identified the same posttranslational modification in eEF1A from Schizosaccharomyces pombe but not in various other eukaryotic organisms tested despite strict conservation of the Glu(45) residue among these organisms. We therefore conclude that eEF1A glutaminylation is a yeast-specific posttranslational modification that appears to influence protein translation.