Autoinhibited transient, gated, and cascaded dynamic transcription of RNAs
Zhenzhen Li, Jianbang Wang, Itamar Willner
Abstract
Following transient spatiotemporal misregulation of gene expression programs by native transcription machineries, we introduce a versatile biomimetic concept to design transient dynamic transcription machineries, revealing gated and cascaded temporal transcription of RNAs. The concept is based on the engineering of the reaction module consisting of malachite green (MG) and/or DFHBI {(5Z)-5-[(3,5-difluoro-4-hydroxyphenyl)methylene]-3,5-dihydro-2,3-dimethyl-4 H -imidazol-4-one} DNA scaffolds, T7 RNA polymerase (RNAP) aptamer transcription scaffold, and the inhibited T7 RNAP-aptamer complex. In the presence of the counter RNAP aptamer strand and ribonucleoside triphosphates, the triggered activation of the three transcription scaffolds are activated, leading to the transcription of the MG and/or DFHBI RNA aptamer and to the transcription of the RNAP aptamer acting as an autoinhibitor that leads to the transient temporal, dissipative, and blockage of all transcription. By appropriate design of the transcription scaffolds and the inhibitors/coupler, transient gated and cascaded transcription processes are demonstrated, and a bimodal transcription module synthesizing a transient operating ribozyme is introduced.