基于重组酶和终止子的状态调控开关设计

Design of recombinase and terminator-based genetic switches for cell state control

摘要:

合成生物学研究常用基因开关来调控细胞的状态以实现相应功能。已有的基因开关往往需要持续的输入信号来维持特定的开关状态，开关功能的维持需要持续消耗能量，并且对扰动较为敏感。文中利用了位点特异性重组酶的倒位效应反转终止子，构建了一种转录层次的状态调控开关，使得脉冲信号即可触发开关状态改变，并在下一次信号来临前稳定维持当前状态。应用自下而上的工程化思想，文中先后对重组酶和终止子进行了单独表征和组合表征，探究了二者之间的相互影响，筛选出了相互兼容的组合，成功实现了细胞的单次、二次状态切换。最后，此开关成功地被用于构建生物七段译码器，显示出了其较好的应用潜力。

Abstract:

Various genetic switches have been developed to let engineered cells perform designed functions. However, a sustained input is often needed to maintain the on/off state, which is energy-consuming and sensitive to perturbation. Therefore, we developed a set of transcriptional switches for cell states control that were constructed by the inversion effect of site-specific recombinases on terminators. Such a switch could respond to a pulse signal and maintain the new state by itself until the next input. With a bottom-up design principle, we first characterized the terminators and recombinases. Then the mutual interference was studied to select compatible pairs, which were used to achieve one-time and two-time state transitions. Finally, we constructed a biological seven-segment display as a demonstration to prove such switch’s immense potential for application.