Robert F. Smith School of Chemical and Biomolecular Engineering, Cornell University, 113 Ho Plaza, Ithaca, New York 14853, United States.
Center for Synthetic Biology, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States.
ACS Synth Biol. 2021 May 21;10(5):1199-1213. doi: 10.1021/acssynbio.1c00015. Epub 2021 Apr 9.
One major challenge in synthetic biology is the deleterious impacts of cellular stress caused by expression of heterologous pathways, sensors, and circuits. Feedback control and dynamic regulation are broadly proposed strategies to mitigate this cellular stress by optimizing gene expression levels temporally and in response to biological cues. While a variety of approaches for feedback implementation exist, they are often complex and cannot be easily manipulated. Here, we report a strategy that uses RNA transcriptional regulators to integrate additional layers of control over the output of natural and engineered feedback responsive circuits. Called riboregulated switchable feedback promoters (rSFPs), these gene expression cassettes can be modularly activated using multiple mechanisms, from manual induction to autonomous quorum sensing, allowing control over the timing, magnitude, and autonomy of expression. We develop rSFPs in to regulate multiple feedback networks and apply them to control the output of two metabolic pathways. We envision that rSFPs will become a valuable tool for flexible and dynamic control of gene expression in metabolic engineering, biological therapeutic production, and many other applications.
合成生物学面临的一个主要挑战是表达异源途径、传感器和回路引起的细胞应激的有害影响。反馈控制和动态调节是通过优化基因表达水平和响应生物信号来减轻这种细胞应激的广泛提出的策略。虽然存在各种反馈实现方法，但它们通常很复杂，不容易操作。在这里，我们报告了一种使用 RNA 转录调节剂的策略，该策略可以在天然和工程反馈响应回路的输出上集成额外的控制层。称为 RNA 转录调控开关式反馈启动子（rSFPs），这些基因表达盒可以使用多种机制进行模块化激活，从手动诱导到自主群体感应，从而可以控制表达的时间、幅度和自主性。我们在 中开发了 rSFPs 来调节多个反馈网络，并将其应用于控制两种代谢途径的输出。我们设想 rSFPs 将成为代谢工程、生物治疗生产和许多其他应用中灵活和动态控制基因表达的有价值的工具。
