title: Engineering microbial phenotypes through rewiring of genetic networks.
abstract: The ability to program cellular behaviour is a major goal of synthetic biology, with applications in health, agriculture and chemicals production. Despite efforts to build 'orthogonal' systems, interactions between engineered genetic circuits and the endogenous regulatory network of a host cell can have a significant impact on desired functionality. We have developed a strategy to rewire the endogenous cellular regulatory network of yeast to enhance compatibility with synthetic protein and metabolite production. We found that introducing novel connections in the cellular regulatory network enabled us to increase the production of heterologous proteins and metabolites. This strategy is demonstrated in yeast strains that show significantly enhanced heterologous protein expression and higher titers of terpenoid production. Specifically, we found that the addition of transcriptional regulation between free radical induced signalling and nitrogen regulation provided robust improvement of protein production. Assessment of rewired networks revealed the importance of key topological features such as high betweenness centrality. The generation of rewired transcriptional networks, selection for specific phenotypes, and analysis of resulting library members is a powerful tool for engineering cellular behavior and may enable improved integration of heterologous protein and metabolite pathways.
authors.affiliation: Centre for Synthetic Biology and Innovation and Department of Life Sciences, Imperial College London, London SW7 2AZ, UK.
authors.forename: Oliver P F
authors.initials: OPF
authors.lastname: Windram
authors.affiliation: Centre for Synthetic Biology and Innovation and Department of Life Sciences, Imperial College London, London SW7 2AZ, UK.
authors.forename: Rui T L
authors.initials: RTL
authors.lastname: Rodrigues
authors.affiliation: Centre for Synthetic Biology and Innovation and Department of Life Sciences, Imperial College London, London SW7 2AZ, UK.
authors.forename: Sangjin
authors.initials: S
authors.lastname: Lee
authors.affiliation: Centre for Synthetic Biology and Innovation and Department of Life Sciences, Imperial College London, London SW7 2AZ, UK.
authors.forename: Matthew
authors.initials: M
authors.lastname: Haines
authors.affiliation: Centre for Synthetic Biology and Innovation and Department of Life Sciences, Imperial College London, London SW7 2AZ, UK.
authors.forename: Travis S
authors.initials: TS
authors.lastname: Bayer
mesh_terms: D005786:Gene Expression Regulation; D053263:Gene Regulatory Networks / Q000235:genetics*; D005818:Genetic Engineering; D006801:Humans; D060847:Metabolic Engineering; D009584:Nitrogen / Q000737:chemistry / Q000378:metabolism; D010641:Phenotype; D012441:Saccharomyces cerevisiae / Q000235:genetics; D058615:Synthetic Biology; D013729:Terpenes / Q000737:chemistry* / Q000378:metabolism
chemical_list: D013729:Terpenes; D009584:Nitrogen