title: Synthetic Transcription Amplifier System for Orthogonal Control of Gene Expression in Saccharomyces cerevisiae.
abstract: This work describes the development and characterization of a modular synthetic expression system that provides a broad range of adjustable and predictable expression levels in S. cerevisiae. The system works as a fixed-gain transcription amplifier, where the input signal is transferred via a synthetic transcription factor (sTF) onto a synthetic promoter, containing a defined core promoter, generating a transcription output signal. The system activation is based on the bacterial LexA-DNA-binding domain, a set of modified, modular LexA-binding sites and a selection of transcription activation domains. We show both experimentally and computationally that the tuning of the system is achieved through the selection of three separate modules, each of which enables an adjustable output signal: 1) the transcription-activation domain of the sTF, 2) the binding-site modules in the output promoter, and 3) the core promoter modules which define the transcription initiation site in the output promoter. The system has a novel bidirectional architecture that enables generation of compact, yet versatile expression modules for multiple genes with highly diversified expression levels ranging from negligible to very strong using one synthetic transcription factor. In contrast to most existing modular gene expression regulation systems, the present system is independent from externally added compounds. Furthermore, the established system was minimally affected by the several tested growth conditions. These features suggest that it can be highly useful in large scale biotechnology applications.
authors.affiliation: VTT Technical Research Centre of Finland, P.O. Box 1000, FI-02044 VTT, Espoo, Finland.
authors.forename: Anssi
authors.initials: A
authors.lastname: Rantasalo
authors.affiliation: Helsinki Institute for Information Technology HIIT, Department of Computer Science, Aalto University, P.O. Box 15400, FI-00076 Aalto, Espoo, Finland.
authors.forename: Elena
authors.initials: E
authors.lastname: Czeizler
authors.affiliation: VTT Technical Research Centre of Finland, P.O. Box 1000, FI-02044 VTT, Espoo, Finland.
authors.forename: Riitta
authors.initials: R
authors.lastname: Virtanen
authors.affiliation: Helsinki Institute for Information Technology HIIT, Department of Computer Science, Aalto University, P.O. Box 15400, FI-00076 Aalto, Espoo, Finland.
authors.forename: Juho
authors.initials: J
authors.lastname: Rousu
authors.affiliation: Aalto University, Department of Computer Science, P.O. Box 15400, FI-00076 Aalto, Espoo, Finland.
authors.forename: Harri
authors.initials: H
authors.lastname: Lähdesmäki
authors.affiliation: VTT Technical Research Centre of Finland, P.O. Box 1000, FI-02044 VTT, Espoo, Finland.
authors.forename: Merja
authors.initials: M
authors.lastname: Penttilä
authors.affiliation: VTT Technical Research Centre of Finland, P.O. Box 1000, FI-02044 VTT, Espoo, Finland.
authors.forename: Jussi
authors.initials: J
authors.lastname: Jäntti
authors.affiliation: VTT Technical Research Centre of Finland, P.O. Box 1000, FI-02044 VTT, Espoo, Finland.
authors.forename: Dominik
authors.initials: D
authors.lastname: Mojzita
mesh_terms: D005786:Gene Expression Regulation; D011401:Promoter Regions, Genetic / Q000235:genetics; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D058615:Synthetic Biology / Q000379:methods; D014157:Transcription Factors / Q000235:genetics
chemical_list: D014157:Transcription Factors