Both temperature and medium composition regulate RNase E processing efficiency of the rpsO mRNA coding for ribosomal protein s15 of Escherichia coli
Both temperature and medium composition regulate RNase E processing efficiency of the rpsO mRNA coding for ribosomal protein s15 of Escherichia coli
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DOI：
10.1016/s0022-2836(02)00295-4
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发表时间：
2002-05-31
影响因子：
5.6
通讯作者：
Hajnsdorf, E
中科院分区：
文献类型：
--
作者：
Le Derout, J;Régnier, P;Hajnsdorf, E
RNA酶E的切割被认为是许多RNA降解的限速步骤。这些切割通过所讨论的mRNA的5'端磷酸化、折叠和翻译来调节。在这里，我们提出的数据表明，这些裂解也受到环境条件的调节。我们报告说，rpsO mRNA，15分钟后转移到44 degreesC，是稳定的细胞生长在基本培养基中。这种稳定性与启动其衰变的RNase E切割效率的降低相关。我们还观察到之前检测到的RNA片段在RNase E失活后的外观和RNase E浓度适应中的缺陷。这些观察结果，再加上RNase E过量产生略微降低rpsO mRNA的积累的事实，表明这种稳定性部分是由RNase E浓度的限制引起的。rpsT mRNA的稳态水平的增加，也观察到转移到44 degreesC在基本培养基中，然而，处理的9 S rRNA前体在这些条件下不受影响。因此，我们提出，RNase E浓度的变化在细胞中响应于环境条件，这些变化可以选择性地影响加工和单个mRNA的稳定性。我们的数据还表明，RNase E切割rpsO mRNA的效率被其他因素修饰，这些因素仍有待鉴定。(C)2002爱思唯尔科技有限公司版权所有。
Cleavage by RNase E is believed to be the rate-limiting step in the degradation of many RNAs. These cleavages are modulated by 5' end-phosphorylation, folding and translation of the mRNA in question. Here, we present data suggesting that these cleavages are also regulated by environmental conditions. We report that rpsO mRNA, 15 minutes after a shift to 44 degreesC, is stabilized in cells grown in minimal medium. This stabilization is correlated with a reduction in the efficiency of the RNase E cleavage which initiates its decay. We also observe the appearance of RNA fragments previously detected following RNase E inactivation and a defect in the adaptation of RNase E concentration. These observations, coupled to the fact that RNase E overproduction slightly reduces the accumulation of the rpsO mRNA, suggest that this stabilization is caused in part by a limitation in RNase E concentration. An increase in the steady-state level of rpsT mRNA is also observed following a shift to 44 degreesC in minimal medium; however, processing of the 9 S rRNA precursor is not affected under these conditions. We thus propose that RNase E concentration changes in the cell in response to environmental conditions and that these changes can selectively affect the processing and the stability of individual mRNAs. Our data also indicate that the efficiency of cleavage of the rpsO mRNA by RNase E is modified by other factor(s) which remain to be identified. (C) 2002 Elsevier Science Ltd. All rights reserved.