title: A synthetic mammalian gene circuit reveals antituberculosis compounds.
abstract: Synthetic biology provides insight into natural gene-network dynamics and enables assembly of engineered transcription circuitries for production of difficult-to-access therapeutic molecules. In Mycobacterium tuberculosis EthR binds to a specific operator (O(ethR)) thereby repressing ethA and preventing EthA-catalyzed conversion of the prodrug ethionamide, which increases the resistance of the pathogen to this last-line-of-defense treatment. We have designed a synthetic mammalian gene circuit that senses the EthR-O(ethR) interaction in human cells and produces a quantitative reporter gene expression readout. Challenging of the synthetic network with compounds of a rationally designed chemical library revealed 2-phenylethyl-butyrate as a nontoxic substance that abolished EthR's repressor function inside human cells, in mice, and within M. tuberculosis where it triggered derepression of ethA and increased the sensitivity of this pathogen to ethionamide. The discovery of antituberculosis compounds by using synthetic mammalian gene circuits may establish a new line of defense against multidrug-resistant M. tuberculosis.
authors.affiliation: Department of Biosystems Science and Engineering, Eidgenössische Technische Hochschule Zurich, Mattenstrasse 26, CH-4058 Basel, Switzerland.
authors.forename: Wilfried
authors.initials: W
authors.lastname: Weber
authors.forename: Ronald
authors.initials: R
authors.lastname: Schoenmakers
authors.forename: Bettina
authors.initials: B
authors.lastname: Keller
authors.forename: Marc
authors.initials: M
authors.lastname: Gitzinger
authors.forename: Thomas
authors.initials: T
authors.lastname: Grau
authors.forename: Marie
authors.initials: M
authors.lastname: Daoud-El Baba
authors.forename: Peter
authors.initials: P
authors.lastname: Sander
authors.forename: Martin
authors.initials: M
authors.lastname: Fussenegger
mesh_terms: D000818:Animals; D000995:Antitubercular Agents / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D055592:Biophysical Phenomena; D001703:Biophysics; D002460:Cell Line; D004269:DNA, Bacterial / Q000235:genetics / Q000378:metabolism; D015195:Drug Design; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics; D004926:Escherichia coli / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression / Q000187:drug effects; D050939:Gene Fusion; D005798:Genes, Bacterial / Q000187:drug effects; D005821:Genetic Techniques; D017405:Herpes Simplex Virus Protein Vmw65 / Q000235:genetics; D006801:Humans; D051379:Mice; D008826:Microbial Sensitivity Tests / Q000379:methods; D009169:Mycobacterium tuberculosis / Q000187:drug effects* / Q000235:genetics* / Q000378:metabolism; D010088:Oxidoreductases / Q000235:genetics / Q000378:metabolism; D010654:Phenylbutyrates / Q000494:pharmacology; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D000995:Antitubercular Agents; D001426:Bacterial Proteins; D004269:DNA, Bacterial; C481661:EthR protein, Mycobacterium tuberculosis; D017405:Herpes Simplex Virus Protein Vmw65; D010654:Phenylbutyrates; D012097:Repressor Proteins; D010088:Oxidoreductases; C480352:ethA protein, Mycobacterium tuberculosis