Inducible transcription systems are essential tools in genetic engineering, where tight control, strong inducibility and fast response with cost-effective inducers are highly desired. However, existing systems in yeasts are rarely used in large-scale fermentations due to either cost-prohibitive inducers or incompatible performance. Here, we developed powerful xylose and arabinose induction systems in Saccharomyces cerevisiae, utilizing eukaryotic activators XlnR and AraRA from Aspergillus species and bacterial repressors XylR and AraRR. By integrating these signals into a highly-structured synthetic promoter, we created dual-mode systems with strong outputs and minimal leakiness. These systems demonstrated over 4000- and 300-fold regulation with strong activation and rapid response. The dual-mode xylose system was fully activated by xylose-rich agricultural residues like corncob hydrolysate, outperforming existing systems in terms of leakiness, inducibility, dynamic range, induction rate, and growth impact on host. We validated their utility in metabolic engineering with high-titer linalool production and demonstrated the transferability of the XlnR-based xylose induction system to Pichia pastoris, Candida glabrata and Candida albicans. This work provides robust genetic switches for yeasts and a general strategy for integrating activation-repression signals into synthetic promoters to achieve optimal performance.

中文翻译：

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用于酵母的多功能木糖和阿拉伯糖遗传开关开发。


诱导型转录系统是基因工程中必不可少的工具，其中非常需要严格的控制、强大的诱导性和快速响应以及具有成本效益的诱导剂。然而，酵母中的现有系统很少用于大规模发酵，因为诱导剂成本高或性能不兼容。在这里，我们利用来自曲霉菌属的真核激活剂 XlnR 和 AraRA 以及细菌抑制剂 XylR 和 AraRR，在酿酒酵母中开发了强大的木糖和阿拉伯糖诱导系统。通过将这些信号整合到高度结构化的合成启动子中，我们创建了具有强大输出和最小泄漏的双模式系统。这些系统表现出超过 4000 倍和 300 倍的调节能力，具有很强的激活和快速反应。双模式木糖系统被富含木糖的农业残留物（如玉米芯水解物）完全激活，在泄漏性、诱导性、动态范围、诱导速率和对宿主的生长影响方面优于现有系统。我们验证了它们在代谢工程中通过高滴度芳樟醇生产的作用，并证明了基于 XlnR 的木糖诱导系统可转移到毕赤酵母、光滑念珠菌和白色念珠菌。这项工作为酵母提供了强大的遗传开关，以及将激活抑制信号整合到合成启动子中以实现最佳性能的通用策略。