Gre factors prevent thermal and mechanical stresses induced by terahertz irradiation during transcription
Gre factors prevent thermal and mechanical stresses induced by terahertz irradiation during transcription
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DOI：
10.1111/gtc.12822
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发表时间：
2020-12-19
期刊：
影响因子：
2.1
通讯作者：
Hoshina, Hiromichi
中科院分区：
文献类型：
--
作者：
Imashimizu, Masahiko;Tanaka, Masahito;Hoshina, Hiromichi
在细胞转录过程中，由RNA聚合酶、DNA和新生RNA组成的转录复合体暴露在波动的温度和压力下。然而，对于在波动的物理参数下转录动态平衡的机制却知之甚少。在这项研究中，我们使用太赫兹自由电子激光，在大肠杆菌RNA聚合酶转录反应系统中使用脉冲局部加热和声波来产生这些波动参数。我们证明，转录过程，包括流产的起始和伸长暂停，以及伸长的保真度都受到基于激光的局部扰动的显著影响。我们还发现，转录过程中的所有这些功能变化几乎完全被GRE蛋白的存在所缓解。众所周知，GRE蛋白通过与称为次级通道的孔结构结合来增强聚合酶的RNA裂解。最近，GRE蛋白的伴侣活性也被提出，但与转录直接相关的细节在很大程度上还不清楚。我们的发现表明，GRE蛋白是在热和机械压力下维持转录动态平衡所必需的。
During transcription in cells, the transcription complex consisting of RNA polymerase, DNA and nascent RNA is exposed to fluctuating temperature and pressure. However, little is known about the mechanism of transcriptional homeostasis under fluctuating physical parameters. In this study, we generated these fluctuating parameters using pulsed local heating and acoustic waves in the reaction system of transcription by Escherichia coli RNA polymerase, using a terahertz free-electron laser. We demonstrated that transcription processes, including abortive initiation and elongation pausing, and the fidelity of elongation are significantly affected by the laser-based local perturbations. We also found that all these functional alternations in the transcription process are almost completely mitigated by the presence of Gre proteins. It is well known that Gre proteins enhance RNA cleavage of polymerase by binding to the pore structure termed secondary channel. Recently, the chaperone activities have also been proposed for Gre proteins, yet the details directly associated with transcription are largely unknown. Our finding indicates that Gre proteins are necessary for maintaining transcriptional homeostasis under thermal and mechanical stresses.