Transfer-messenger RNA and SmpB mediate bacteriostasis in Escherichia coli cells against tRNA cleavage.
Transfer-messenger RNA and SmpB mediate bacteriostasis in Escherichia coli cells against tRNA cleavage.
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DOI：
10.1099/mic.0.000144
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发表时间：
2015-10
期刊：
影响因子：
1.5
通讯作者：
F. Sakai;Risa Sugita;Jung-Wei Chang;Tetsuhiro Ogawa;Natsuko Tsumadori;Kazutoshi Takahashi;M. Hidaka;H. Masaki
中科院分区：
文献类型：
--
作者：
F. Sakai;Risa Sugita;Jung-Wei Chang;Tetsuhiro Ogawa;Natsuko Tsumadori;Kazutoshi Takahashi;M. Hidaka;H. Masaki
RNA，如mRNA、rRNA和tRNA，是细胞存活和维持所必需的大分子。这些分子的任何扰动，如降解或突变，可能对细胞有毒，偶尔可能诱导细胞死亡。因此，细胞具有称为质量控制系统的机制来消除异常RNA。虽然tRNA是一种稳定的分子，但反密码子环对靶向tRNA的RNA酶如大肠杆菌素E5和大肠杆菌素D非常敏感。然而，细胞对tRNA裂解反应的机制仍不清楚。长期以来，人们一直认为大肠杆菌素E5和D对tRNA的切割会迅速诱导细胞死亡，因为敏感细胞的集落形成严重减少;这表明细胞不抵抗tRNA切割。在这里，我们表明，大肠杆菌细胞对大肠杆菌素D和E5的tRNA裂解进入抑菌状态。抑菌作用需要小分子蛋白B（Smp B）和转运信使RNA（tmRNA），已知它们介导反式翻译。此外，另一种类型的大肠杆菌素，大肠杆菌素E3切割rRNA，立即降低敏感细胞的活力。此外，新生肽降解对抑菌作用具有累加效应。考虑到最近观察到tRNA切割可以用作细胞间通讯的手段，细菌不仅可以利用tRNA切割来支配生活在同一生态位中的其他细菌，而且还可以调节自身或其他细胞的生长。
RNAs, such as mRNA, rRNA and tRNA, are essential macromolecules for cell survival and maintenance. Any perturbation of these molecules, such as by degradation or mutation, can be toxic to cells and may occasionally induce cell death. Therefore, cells have mechanisms known as quality control systems to eliminate abnormal RNAs. Although tRNA is a stable molecule, the anticodon loop is quite susceptible to tRNA-targeting RNases such as colicin E5 and colicin D. However, the mechanism underlying cellular reaction to tRNA cleavage remains unclear. It had long been believed that tRNA cleavage by colicins E5 and D promptly induces cell death because colony formation of the sensitive cells is severely reduced; this indicates that cells do not resist the tRNA cleavage. Here, we show that Escherichia coli cells enter a bacteriostatic state against the tRNA cleavage of colicins D and E5. The bacteriostasis requires small protein B (SmpB) and transfer-messenger RNA (tmRNA), which are known to mediate trans-translation. Furthermore, another type of colicin, colicin E3 cleaving rRNA, immediately reduces the viability of sensitive cells. Moreover, nascent peptide degradation has an additive effect on bacteriostasis. Considering the recent observation that tRNA cleavage may be used as a means of cell-to-cell communication, tRNA cleavage could be used by bacteria not only to dominate other bacteria living in the same niche, but also to regulate growth of their own or other cells.