Department of Molecular Biology, Princeton University, Princeton, NJ 08544.
Department of Chemistry, Princeton University, Princeton, NJ 08544.
Proc Natl Acad Sci U S A. 2021 Jun 29;118(26). doi: 10.1073/pnas.2021483118.
Natural products have been an important source of therapeutic agents and chemical tools. The recent realization that many natural product biosynthetic genes are silent or sparingly expressed during standard laboratory growth has prompted efforts to investigate their regulation and develop methods to induce their expression. Because it is difficult to intuit signals that induce a given biosynthetic locus, we recently implemented a forward chemical-genetic approach to identify such inducers. In the current work, we applied this approach to nine silent biosynthetic loci in the model bacterium to systematically screen for elicitors from a library of Food and Drug Administration-approved drugs. We find that β-lactams, fluoroquinolones, antifungals, and, surprisingly, calcimimetics, phenothiazine antipsychotics, and polyaromatic antidepressants are the most effective global inducers of biosynthetic genes. Investigations into the mechanism of stimulation of the silent virulence factor malleicyprol by the β-lactam piperacillin allowed us to elucidate the underlying regulatory circuits. Low-dose piperacillin causes oxidative stress, thereby inducing redox-sensing transcriptional regulators, which activate , a pathway-specific positive regulator of the malleicyprol gene cluster. Malleicyprol is thus part of the OxyR and SoxR regulons in , allowing the bacterium to initiate virulence in response to oxidative stress. Our work catalogs a diverse array of elicitors and a previously unknown regulatory input for secondary metabolism in .
天然产物一直是治疗药物和化学工具的重要来源。最近人们意识到，许多天然产物生物合成基因在标准实验室生长过程中是沉默或少量表达的，这促使人们努力研究它们的调控机制，并开发诱导其表达的方法。由于难以直观地推断出诱导特定生物合成基因的信号，我们最近采用了一种正向化学遗传学方法来识别这些诱导物。在当前的工作中，我们将该方法应用于模式细菌中的九个沉默生物合成基因座，系统地从食品和药物管理局批准的药物库中筛选诱导物。我们发现，β-内酰胺类、氟喹诺酮类、抗真菌药，以及令人惊讶的钙敏感受体激动剂、吩噻嗪类抗精神病药和多环类抗抑郁药，是生物合成基因最有效的全球诱导剂。对β-内酰胺类药物哌拉西林刺激沉默毒力因子马来酸酰脯氨酸的机制的研究，使我们能够阐明潜在的调控回路。低剂量的哌拉西林会引起氧化应激，从而诱导氧化还原感应转录调节剂，激活特异性正调控因子 MalX，从而激活马来酸酰脯氨酸基因簇。因此，马来酸酰脯氨酸是 中的 OxyR 和 SoxR 调控子的一部分，使细菌能够在氧化应激时启动毒力。我们的工作列出了一个多样化的诱导物和一个以前未知的次级代谢调控输入。
