Abstract
Bioluminescence is visible light produced and emitted by living cells using various biological systems (e.g. luxCDABE cassette). Today, this phenomenon is widely exploited in biological research, biotechnology and medical applications as a quantitative technique for the detection of biological signals. However, this technique has mostly been used to detect a single input only. In this work, we re-engineered the complex genetic structure of luxCDABE cassette to build a biological unit that can detect multi-inputs, process the cellular information and report the computation results. We first split the luxCDABE operon into several parts to create a genetic circuit that can compute a soft minimum in living cells. Then, we used the new design to implement an AND logic function with better performance as compared to AND logic functions based on protein-protein interactions. Furthermore, by controlling the reverse reaction of the luxCDABE cassette independently from the forward reaction, we built a comparator with a programmable detection threshold. Finally, we applied the redesigned cassette to build an incoherent feedforward loop that reduced the unwanted crosstalk between stress-responsive promoters (recA, katG). This work demonstrates the construction of genetic circuits that combine regulations of gene expression with metabolic pathways, for sensing and computing in living cells.
Highlights
Over the past few decades, bioluminescence-sensing systems, such as those in the firefly and bacterial luciferase, have gained widespread attention as a low-cost tool for live organism imaging and biological signal detection [1–3]
LuxR was expressed under a constitutive promoter, located on a low-copy-number plasmid (LCP), and induced by acyl homoserine lactone (AHL)
Minimum functions are widely used in fuzzy logic computation to implement conjunction [44] and when they are combined with inhibition, they can act as a universal gate for processing real-world bio-signals
Summary
Over the past few decades, bioluminescence-sensing systems, such as those in the firefly and bacterial luciferase, have gained widespread attention as a low-cost tool for live organism imaging and biological signal detection [1–3]. Such systems have been utilized to detect and monitor environmentally toxic chemicals in air, water and food [4,5]. It has been shown that bioluminescence-sensing systems can monitor the gastro intestine, wirelessly communicating information to an external computer [6] Another application is studying the dynamics of gene expression at a single cell level [7]. Our design enables scaling the computational complexity of synthetic gene and molecular networks, using minimal components in the context of synthetic biology
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
