1.
Chemically Induced Dimerization Systems: From FKBP/FRB Engineering to Expanded Biological Applications.
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Yuan, H
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Lin, S
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Lin, Z
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Li, S
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Zuo, X
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Yin, H
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Cheng, R
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Tang, Y
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Luo, Z
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Chen, M
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Zou, Q
Abstract:
The FKBP-based chemically induced dimerization (CID) technology is a fundamental tool for spatiotemporal precise modulation of protein functions in living cells, widely used in gene editing, protein function regulation, disease therapy, and drug development. However, its widespread application is limited by the inherent drawbacks including issues with immunosuppressive activity, stability, reversibility, and in vivo delivery. Recent years have seen remarkable progress in addressing these challenges: orthogonalization strategies eliminate immunosuppressive effects, fast-dissociating ligands and optogenetic systems enable reversible regulation, and protein engineering optimizes the FKBP/FRB domains to enhance stability and reduce immunogenicity. Moreover, integration with novel delivery technologies broadens its application scope greatly. This review summarizes the key optimization strategies and innovative applications of this technology in the cutting-edge biological research, aiming to reference the development of next-generation chemogenetic tools with higher precision, better safety, and greater application potential.
2.
Optogenetic Amplification Circuits for Light-Induced Metabolic Control.
Abstract:
Dynamic control of microbial metabolism is an effective strategy to improve chemical production in fermentations. While dynamic control is most often implemented using chemical inducers, optogenetics offers an attractive alternative due to the high tunability and reversibility afforded by light. However, a major concern of applying optogenetics in metabolic engineering is the risk of insufficient light penetration at high cell densities, especially in large bioreactors. Here, we present a new series of optogenetic circuits we call OptoAMP, which amplify the transcriptional response to blue light by as much as 23-fold compared to the basal circuit (OptoEXP). These circuits show as much as a 41-fold induction between dark and light conditions, efficient activation at light duty cycles as low as ∼1%, and strong homogeneous light-induction in bioreactors of at least 5 L, with limited illumination at cell densities above 40 OD600. We demonstrate the ability of OptoAMP circuits to control engineered metabolic pathways in novel three-phase fermentations using different light schedules to control enzyme expression and improve production of lactic acid, isobutanol, and naringenin. These circuits expand the applicability of optogenetics to metabolic engineering.
