title: Synthetic circuits that process multiple light and chemical signal inputs.
abstract: Multi-signal processing circuits are essential for rational design of sophisticated synthetic systems with good controllability and modularity, therefore, enable construction of high-level networks. Moreover, light-inducible systems provide fast and reversible means for spatiotemporal control of gene expression.
  
  
  
  Here, in HEK 293 cells, we present combinatory genetic circuits responding to light and chemical signals, simultaneously. We first constructed a dual input circuit converting different light intensities into varying of the sensitivity of the promoter to a chemical inducer (doxycycline). Next, we generated a ternary input circuit, which responded to light, doxycycline and cumate. This circuit allowed us to use different combinations of blue light and the two chemical inducers to generate gradual output values over two orders of magnitude.
  
  
  
  Overall, in this study, we devise genetic circuits sensing and processing light and chemical inducers. Our work may provide insights into bio-computation and fine-tuning expression of the transgene.
authors.affiliation: School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, University of Hong Kong, Pok Fu Lam, Hong Kong, People's Republic of China.|Shenzhen Institute of Research and Innovation, University of Hong Kong, Shenzhen, 518057, People's Republic of China.
authors.forename: Lizhong
authors.initials: L
authors.lastname: Liu
authors.affiliation: Department of Biology, Shenzhen Key Laboratory of Cell Microenvironment, South University of Science and Technology of China, Shenzhen, 518055, People's Republic of China.
authors.forename: Wei
authors.initials: W
authors.lastname: Huang
authors.affiliation: School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, University of Hong Kong, Pok Fu Lam, Hong Kong, People's Republic of China. jdhuang@hku.hk.|Shenzhen Institute of Research and Innovation, University of Hong Kong, Shenzhen, 518057, People's Republic of China. jdhuang@hku.hk.|The Centre for Synthetic Biology Engineering Research, Shenzhen Institutes of Advanced Technology, Shenzhen, 518055, People's Republic of China. jdhuang@hku.hk.
authors.forename: Jian-Dong
authors.initials: JD
authors.lastname: Huang
mesh_terms: D004318:Doxycycline / Q000494:pharmacology*; D053263:Gene Regulatory Networks / Q000187:drug effects* / Q000528:radiation effects; D057809:HEK293 Cells; D006801:Humans; D008027:Light; D011401:Promoter Regions, Genetic / Q000235:genetics; D058615:Synthetic Biology / Q000379:methods*
chemical_list: D004318:Doxycycline
keywords: Light-inducible; Multi-input; Signal integration; Synthetic circuit