A general strategy to construct small molecule biosensors in eukaryotes
Justin Feng,
Benjamin W Jester,
Christine E Tinberg,
Daniel J Mandell,
Mauricio S Antunes,
Raj Chari,
Kevin J Morey,
Xavier Rios,
June I Medford,
George M Church,
Stanley Fields,
David Baker
Affiliations
Justin Feng
Program in Biological and Biomedical Sciences, Harvard Medical School, Boston, United States; Department of Genetics, Harvard Medical School, Boston, United States
Benjamin W Jester
Department of Genome Sciences, University of Washington, Seattle, United States; Howard Hughes Medical Institute, University of Washington, Seattle, United States
Christine E Tinberg
Department of Biochemistry, University of Washington, Seattle, United States
Daniel J Mandell
Department of Genetics, Harvard Medical School, Boston, United States; Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, United States
Mauricio S Antunes
Department of Biology, Colorado State University, Fort Collins, United States
Raj Chari
Department of Genetics, Harvard Medical School, Boston, United States
Kevin J Morey
Department of Biology, Colorado State University, Fort Collins, United States
Xavier Rios
Department of Genetics, Harvard Medical School, Boston, United States
June I Medford
Department of Biology, Colorado State University, Fort Collins, United States
George M Church
Department of Genetics, Harvard Medical School, Boston, United States; Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, United States
Stanley Fields
Department of Genome Sciences, University of Washington, Seattle, United States; Howard Hughes Medical Institute, University of Washington, Seattle, United States; Department of Medicine, University of Washington, Seattle, United States
David Baker
Howard Hughes Medical Institute, University of Washington, Seattle, United States; Department of Biochemistry, University of Washington, Seattle, United States
Biosensors for small molecules can be used in applications that range from metabolic engineering to orthogonal control of transcription. Here, we produce biosensors based on a ligand-binding domain (LBD) by using a method that, in principle, can be applied to any target molecule. The LBD is fused to either a fluorescent protein or a transcriptional activator and is destabilized by mutation such that the fusion accumulates only in cells containing the target ligand. We illustrate the power of this method by developing biosensors for digoxin and progesterone. Addition of ligand to yeast, mammalian, or plant cells expressing a biosensor activates transcription with a dynamic range of up to ~100-fold. We use the biosensors to improve the biotransformation of pregnenolone to progesterone in yeast and to regulate CRISPR activity in mammalian cells. This work provides a general methodology to develop biosensors for a broad range of molecules in eukaryotes.
