Regulation of Ribonuclease J Expression in <i>Corynebacterium glutamicum</i>
Regulation of Ribonuclease J Expression in <i>Corynebacterium glutamicum</i>
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谷氨酸棒杆菌中核糖核酸酶 J 表达的调控
DOI：
10.1128/jb.00053-22
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发表时间：
2022
影响因子：
3.2
通讯作者：
Inui Masayuki
中科院分区：
文献类型：
--
作者：
Tanaka Yuya;Nagisa Hamamoto;Masato Sawa;Inui Masayuki
核糖核酸酶J既具有5‘-3’外切核糖核酸酶活性，又具有内切核糖核酸酶活性，在多种细菌的核糖核酸代谢中发挥重要作用，但其基因调控尚不清楚。在本研究中，我们研究了rnj在谷氨酸棒杆菌中的表达规律。在一株突变株中，rnjmRNA的表达增加。RNase E/G编码基因的缺失也导致rnjmRNA水平升高，尽管其影响小于热突变。rnjmRNA在热突变株中比在野生型细胞中更稳定。这些结果表明，RNaseJ通过降解其mRNA来调节自己的基因。在低温条件下，突变细胞的生长受到抑制。在冷休克条件下，rnjmRNA的表达是短暂的，但在热突变株中没有观察到这种诱导，这表明在冷休克条件下，自我降解的自我调节是诱导rnj表达的原因。然而，人们对这些基因调控知之甚少。在这里，我们证明了RNase J自动调节自己的基因表达，RNase E/G也参与了thernjmRNA的降解。此外，我们还证明了在冷休克条件下thernjmRNA的瞬时诱导依赖于RNaseJ的自我调节。本研究揭示了核糖核酸酶J在谷氨酸杆菌中的调控机制。
RNase J exerts both 5′–3′ exoribonuclease and endoribonuclease activities and plays a major role in ribonucleotide metabolism in various bacteria; however, its gene regulation is not well understood. In this study, we investigated the regulation ofrnjexpression in Corynebacterium glutamicum.rnjmRNA expression was increased in a strain with anrnjmutation. Deletion of the genes encoding RNase E/G also resulted in increasedrnjmRNA levels, although the effect was smaller than that of thernjmutation.rnjmRNA was more stable in thernjmutant strain than in wild-type cells. These results indicate that RNase J regulates its own gene by degrading its mRNA. The growth ofrnjandpnpmutant cells was impaired at cold temperatures. The expression ofrnjmRNA was transiently induced by cold shock; however, this induction was not observed in thernjmutant strain, suggesting that autoregulation by self-degradation is responsible for inducing ofrnjexpression under cold-shock conditions.IMPORTANCECorynebacterium glutamicum harbors one RNase E/G-type enzyme and one RNase J-type enzyme which are major ribonucleases in various bacteria. However, little is known about these gene regulations. Here, we show that RNase J autoregulates its own gene expression and RNase E/G is also involved in thernjmRNA degradation. Furthermore, we show that transient induction of thernjmRNA in the cold-shock condition is dependent on RNase J autoregulation. This study sheds light on the regulatory mechanism of RNase J in C. glutamicum.