Mechanisms of gene regulation by the conserved small RNA rnTrpL (formerly RcsR1) and its new interaction partners in Sinorhizobium meliloti

苜蓿中华根瘤菌保守小RNA rnTrpL（原RcsR1）及其新相互作用伙伴的基因调控机制

• 批准号: 320729491
• 负责人: Professorin Dr. Elena Evguenieva-Hackenberg
• 金额: --
• 依托单位: Institut für Mikrobiologie und Molekularbiologie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/320729491?language=en
• 关键词: Mechanisms; gene; regulation; conserved; small

In all investigated organisms, trans-acting small RNAs (sRNAs) regulate gene expression by imperfect base pairing with target mRNAs. Usually more targets are predicted than validated, suggesting that some targets could be addressed under specific conditions. However, examples for sRNA reprogramming in response to stimuli are still lacking. We are investigating the sRNA rnTrpL (formerly RcsR1), which arises due to transcription attenuation of the tryptophan biosynthesis gene trpE(G). This sRNA contains a trpL ORF encoding the leader peptide peTrpL and has many predicted targets. In the first funding period, we validated two of them, the trpDC and rplUrpmA mRNAs, the latter encoding ribosomal proteins L21 and L27. Surprisingly, in contrast to trpDC, rplUrpmA was targeted by rnTrpL in conjunction with the peTrpL peptide and only upon exposure to translation inhibiting antibiotics. The rnTrpL sRNA base pairs with rplU in an antibiotic-dependent ribonucleoprotein (ARNP) complex, which in addition comprises the peTrpL peptide, an antibiotic, and an antibiotic-induced antisense RNA. In the next funding period, we aim to analyze the mechanism by which antibiotics and peTrpL reprogram rnTrpL in favor of rplUrpmA. We will study the assembly and structure of rnTrpL-ARNP complexes, the mechanism and role of rplUrpmA destabilization, and the role of antisense RNAs in this process. Another goal is to identify the rnTrpL interactome under several conditions. The results will uncover the network and mechanisms of a conserved sRNA with specificity change in response to antibiotics.

在所有研究的生物体中，反式作用小RNA（sRNA）通过与靶mRNA的不完全碱基配对来调节基因表达。预测的目标通常多于验证的目标，这表明某些目标可以在特定条件下实现。然而，sRNA重编程响应刺激的例子仍然缺乏。我们正在研究sRNA rnTrpL（以前的RcsR 1），它是由于色氨酸生物合成基因trpE（G）的转录减弱而产生的。该sRNA含有编码前导肽peTrpL的trpL ORF，并且具有许多预测的靶点。在第一个资助期，我们验证了其中两个，trpDC和rplUrpmA mRNA，后者编码核糖体蛋白L21和L27。令人惊讶的是，与trpDC相反，rplUrpmA仅在暴露于翻译抑制抗生素时被与peTrpL肽结合的rnTrpL靶向。rnTrpL sRNA碱基与抗生素依赖性核糖核蛋白（ARNP）复合物中的rplU配对，该复合物另外包含peTrpL肽、抗生素和抗生素诱导的反义RNA。在下一个资助期，我们的目标是分析抗生素和peTrpL重编程rnTrpL以有利于rplUrpmA的机制。我们将研究rnTrpL-ARNP复合物的组装和结构，rplUrpmA不稳定的机制和作用，以及反义RNA在此过程中的作用。另一个目标是在几种条件下鉴定rnTrpL相互作用组。这些结果将揭示一种保守的sRNA在抗生素作用下发生特异性变化的网络和机制。