Elongator-dependent modification of cytoplasmic tRNALysUUU is required for mitochondrial function under stress conditions.
Elongator-dependent modification of cytoplasmic tRNALysUUU is required for mitochondrial function under stress conditions.
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DOI：
10.1093/nar/gkv765
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发表时间：
2015-09-30
影响因子：
14.9
通讯作者：
Ottonello S
中科院分区：
文献类型：
--
作者：
Tigano M;Ruotolo R;Dallabona C;Fontanesi F;Barrientos A;Donnini C;Ottonello S
为了更广泛地了解调节线粒体功能的途径，我们将热应激对呼吸能力的影响与酿酒酵母全基因组筛选的发现潜力结合起来。我们发现了105个新基因，这些基因的缺失通过干扰转录调节、遍在蛋白化和通过5-甲氧羰基甲基-2-硫尿苷形成的细胞质tRNA摆动尿苷修饰等过程，从而损害37 ° C下的呼吸道生长。后一个过程，特别是在胁迫条件下有效解码AA-末端密码子所需的过程，被属于延伸子（例如ELP 3）和urmylation（例如，NCS6）途径。ELP3或NCS6缺失者的线粒体蛋白质合成受损。他们的呼吸功能缺陷被选择性地拯救过表达tRNALysUUU以及过表达的基因（BCK 1和HFM1）与AAA密码子读这个tRNA的强烈偏见。这些数据扩展了线粒体调节组，表明热应激可以通过干扰线粒体功能中关键参与的蛋白质的细胞质翻译来损害呼吸，并首次记录了Elongator和urmylation途径参与这种过程。鉴于这些途径的保守性，目前的发现可能为更好地了解健康和疾病中的人类线粒体调节组铺平道路。
To gain a wider view of the pathways that regulate mitochondrial function, we combined the effect of heat stress on respiratory capacity with the discovery potential of a genome-wide screen in Saccharomyces cerevisiae. We identified 105 new genes whose deletion impairs respiratory growth at 37°C by interfering with processes such as transcriptional regulation, ubiquitination and cytosolic tRNA wobble uridine modification via 5-methoxycarbonylmethyl-2-thiouridine formation. The latter process, specifically required for efficient decoding of AA-ending codons under stress conditions, was covered by multiple genes belonging to the Elongator (e.g. ELP3) and urmylation (e.g., NCS6) pathways. ELP3 or NCS6 deletants had impaired mitochondrial protein synthesis. Their respiratory deficiency was selectively rescued by overexpression of tRNALysUUU as well by overexpression of genes (BCK1 and HFM1) with a strong bias for the AAA codon read by this tRNA. These data extend the mitochondrial regulome, demonstrate that heat stress can impair respiration by disturbing cytoplasmic translation of proteins critically involved in mitochondrial function and document, for the first time, the involvement in such process of the Elongator and urmylation pathways. Given the conservation of these pathways, the present findings may pave the way to a better understanding of the human mitochondrial regulome in health and disease.