Two proteomic methodologies for defining N-termini of mature human mitochondrial aminoacyl-tRNA synthetases
Two proteomic methodologies for defining N-termini of mature human mitochondrial aminoacyl-tRNA synthetases
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DOI：
10.1016/j.ymeth.2016.10.012
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发表时间：
2017-01-15
期刊：
影响因子：
4.8
通讯作者：
Sissler, Marie
中科院分区：
文献类型：
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作者：
Carapito, Christine;Kuhn, Lauriane;Sissler, Marie
人线粒体氨酰-tRNA合成酶（mt-aaRS）在细胞核中编码，在细胞质中合成，并通过N-末端线粒体靶向序列靶向输入线粒体。该靶向序列可能在进入线粒体后被切割，尽管对于线粒体生物发生具有重要作用，但在人类中仍然没有完全破译该过程。成熟过程对于功能酶的释放和蛋白质在线粒体内的正确路由确实是必不可少的。缺乏切割位点的共有序列和发现可能的多个蛋白水解步骤使得难以预测N-末端。此外，裂解的知识是设计与细菌菌株中的有效生产相容的蛋白质结构的关键。最后，充分理解变得至关重要，因为越来越多的突变被发现在编码mt-aaRS的基因中。在本研究中，我们利用蛋白质组学方法的发展和确定，在线粒体中，三个N-末端的人线粒体氨酰-tRNA合成酶。这种不同形式共存的首次描述为这种酶的生物学理解开辟了新的视角。这些方法被扩展到整个人类mt-aaRSs和方法的建议，为进一步的调查。(C)2016年6月，作者。由爱思唯尔公司出版
Human mitochondrial aminoacyl-tRNA synthetases (mt-aaRSs) are encoded in the nucleus, synthesized in the cytosol and targeted for importation into mitochondria by a N-terminal mitochondrial targeting sequence. This targeting sequence is presumably cleaved upon entry into the mitochondria, following a process still not fully deciphered in human, despite essential roles for the mitochondrial biogenesis. Maturation processes are indeed essential both for the release of a functional enzyme and to route correctly the protein within mitochondria. The absence of consensus sequences for cleavage sites and the discovery of possible multiple proteolytic steps render predictions of N-termini difficult. Further, the knowledge of the cleavages is key for the design of protein constructions compatible with efficient production in bacterial strains. Finally, full comprehension becomes essential because a growing number of mutations are found in genes coding for mt-aaRS. In the present study, we take advantage of proteomic methodological developments and identified, in mitochondria, three N-termini for the human mitochondrial aspartyl-tRNA synthetase. This first description of the co-existence of different forms opens new perspectives in the biological understanding of this enzyme. Those methods are extended to the whole set of human mt-aaRSs and methodological advice are provided for further investigations. (C) 2016 The Authors. Published by Elsevier Inc.