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

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。

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.