当前位置: X-MOL 学术Mol. Microbiol. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Transcription regulates ribosome hibernation
Molecular Microbiology ( IF 3.6 ) Pub Date : 2021-06-21 , DOI: 10.1111/mmi.14762
Heather A Feaga 1 , Jonathan Dworkin 1
Affiliation  

Most bacteria are quiescent, typically as a result of nutrient limitation. In order to minimize energy consumption during this potentially prolonged state, quiescent bacteria substantially attenuate protein synthesis, the most energetically costly cellular process. Ribosomes in quiescent bacteria are present as dimers of two 70S ribosomes. Dimerization is dependent on a single protein, hibernation promoting factor (HPF), that binds the ribosome in the mRNA channel. This interaction indicates that dimers are inactive, suggesting that HPF inhibits translation. However, we observe that HPF does not significantly affect protein synthesis in vivo suggesting that dimerization is a consequence of inactivity, not the cause. The HPF–dimer interaction further implies that re-initiation of translation when the bacteria exit quiescence requires dimer resolution. We show that ribosome dimers quickly resolve in the presence of nutrients, and this resolution is dependent on transcription, indicating that mRNA synthesis is required for dimer resolution. Finally, we observe that ectopic HPF expression in growing cells where mRNA is abundant does not significantly affect protein synthesis despite stimulating dimer formation, suggesting that dimerization is dynamic. Thus, the extensive transcription that occurs in response to nutrient availability rapidly re-activates the translational apparatus of a quiescent cell and induces dimer resolution.

中文翻译:

转录调节核糖体冬眠

大多数细菌是静止的,通常是由于营养限制。为了在这种可能延长的状态下最大限度地减少能量消耗,静止细菌会大大减弱蛋白质合成,这是能量消耗最大的细胞过程。静止细菌中的核糖体以两个 70S 核糖体的二聚体形式存在。二聚化依赖于单一蛋白质,即冬眠促进因子 (HPF),它与 ​​mRNA 通道中的核糖体结合。这种相互作用表明二聚体是无活性的,表明 HPF 抑制翻译。然而,我们观察到 HPF 不会显着影响体内蛋白质合成,这表明二聚化是不活动的结果,而不是原因。HPF-二聚体相互作用进一步意味着当细菌退出静止时重新启动翻译需要二聚体分辨率。我们表明核糖体二聚体在营养物质存在的情况下会快速分解,并且这种分解依赖于转录,表明二聚体分解需要 mRNA 合成。最后,我们观察到尽管刺激二聚体形成,但在 mRNA 丰富的生长细胞中异位 HPF 表达不会显着影响蛋白质合成,这表明二聚化是动态的。因此,响应养分可用性而发生的广泛转录会迅速重新激活静止细胞的翻译装置并诱导二聚体分辨率。表明二聚体分辨率需要 mRNA 合成。最后,我们观察到尽管刺激二聚体形成,但在 mRNA 丰富的生长细胞中异位 HPF 表达不会显着影响蛋白质合成,这表明二聚化是动态的。因此,响应养分可用性而发生的广泛转录会迅速重新激活静止细胞的翻译装置并诱导二聚体分辨率。表明二聚体分辨率需要 mRNA 合成。最后,我们观察到尽管刺激二聚体形成,但在 mRNA 丰富的生长细胞中异位 HPF 表达不会显着影响蛋白质合成,这表明二聚化是动态的。因此,响应养分可用性而发生的广泛转录会迅速重新激活静止细胞的翻译装置并诱导二聚体分辨率。
更新日期:2021-08-27
down
wechat
bug