title: Construction of a genetic toggle switch in Escherichia coli.
abstract: It has been proposed' that gene-regulatory circuits with virtually any desired property can be constructed from networks of simple regulatory elements. These properties, which include multistability and oscillations, have been found in specialized gene circuits such as the bacteriophage lambda switch and the Cyanobacteria circadian oscillator. However, these behaviours have not been demonstrated in networks of non-specialized regulatory components. Here we present the construction of a genetic toggle switch-a synthetic, bistable gene-regulatory network-in Escherichia coli and provide a simple theory that predicts the conditions necessary for bistability. The toggle is constructed from any two repressible promoters arranged in a mutually inhibitory network. It is flipped between stable states using transient chemical or thermal induction and exhibits a nearly ideal switching threshold. As a practical device, the toggle switch forms a synthetic, addressable cellular memory unit and has implications for biotechnology, biocomputing and gene therapy.
authors.affiliation: Department of Biomedical Engineering, Center for BioDynamics, Boston University, Massachusetts 02215, USA.
authors.forename: T S
authors.initials: TS
authors.lastname: Gardner
authors.forename: C R
authors.initials: CR
authors.lastname: Cantor
authors.forename: J J
authors.initials: JJ
authors.lastname: Collins
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D004268:DNA-Binding Proteins; D004926:Escherichia coli / Q000235:genetics*; D029968:Escherichia coli Proteins; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D056968:Lac Repressors; D008957:Models, Genetic; D010957:Plasmids; D011401:Promoter Regions, Genetic; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism*; D013269:Stochastic Processes; D014158:Transcription, Genetic; D014764:Viral Proteins; D054334:Viral Regulatory and Accessory Proteins
chemical_list: D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; D056968:Lac Repressors; C539064:LacI protein, E coli; D012097:Repressor Proteins; D014764:Viral Proteins; D054334:Viral Regulatory and Accessory Proteins; C016649:phage repressor proteins; C034811:tetracycline resistance-encoding transposon repressor protein