Department of Systems Biology, University of Massachusetts Chan Medical School, Worcester, MA, USA.
Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
Mol Syst Biol. 2022 Jun;18(6):e10843. doi: 10.15252/msb.202110843.
Predicting the quantitative regulatory function of transcription factors (TFs) based on factors such as binding sequence, binding location, and promoter type is not possible. The interconnected nature of gene networks and the difficulty in tuning individual TF concentrations make the isolated study of TF function challenging. Here, we present a library of Escherichia coli strains designed to allow for precise control of the concentration of individual TFs enabling the study of the role of TF concentration on physiology and regulation. We demonstrate the usefulness of this resource by measuring the regulatory function of the zinc-responsive TF, ZntR, and the paralogous TF pair, GalR/GalS. For ZntR, we find that zinc alters ZntR regulatory function in a way that enables activation of the regulated gene to be robust with respect to ZntR concentration. For GalR and GalS, we are able to demonstrate that these paralogous TFs have fundamentally distinct regulatory roles beyond differences in binding affinity.
基于结合序列、结合位置和启动子类型等因素来预测转录因子 (TF) 的定量调控功能是不可能的。基因网络的互联性质和单独调节 TF 浓度的困难使得 TF 功能的孤立研究具有挑战性。在这里，我们提供了一系列大肠杆菌菌株库，旨在精确控制单个 TF 的浓度，从而能够研究 TF 浓度对生理和调控的作用。我们通过测量锌反应性 TF ZntR 和同源 TF 对 GalR/GalS 的调控功能来证明这一资源的有用性。对于 ZntR，我们发现锌以一种能够使受调控基因的激活对 ZntR 浓度具有鲁棒性的方式改变 ZntR 的调控功能。对于 GalR 和 GalS，我们能够证明这些同源 TF 除了结合亲和力的差异外，还具有根本不同的调控作用。
