title: Engineering key components in a synthetic eukaryotic signal transduction pathway.
abstract: Signal transduction underlies how living organisms detect and respond to stimuli. A goal of synthetic biology is to rewire natural signal transduction systems. Bacteria, yeast, and plants sense environmental aspects through conserved histidine kinase (HK) signal transduction systems. HK protein components are typically comprised of multiple, relatively modular, and conserved domains. Phosphate transfer between these components may exhibit considerable cross talk between the otherwise apparently linear pathways, thereby establishing networks that integrate multiple signals. We show that sequence conservation and cross talk can extend across kingdoms and can be exploited to produce a synthetic plant signal transduction system. In response to HK cross talk, heterologously expressed bacterial response regulators, PhoB and OmpR, translocate to the nucleus on HK activation. Using this discovery, combined with modification of PhoB (PhoB-VP64), we produced a key component of a eukaryotic synthetic signal transduction pathway. In response to exogenous cytokinin, PhoB-VP64 translocates to the nucleus, binds a synthetic PlantPho promoter, and activates gene expression. These results show that conserved-signaling components can be used across kingdoms and adapted to produce synthetic eukaryotic signal transduction pathways.
authors.affiliation: Department of Biology, Colorado State University, Fort Collins, CO, USA.
authors.forename: Mauricio S
authors.initials: MS
authors.lastname: Antunes
authors.forename: Kevin J
authors.initials: KJ
authors.lastname: Morey
authors.forename: Neera
authors.initials: N
authors.lastname: Tewari-Singh
authors.forename: Tessa A
authors.initials: TA
authors.lastname: Bowen
authors.forename: J Jeff
authors.initials: JJ
authors.lastname: Smith
authors.forename: Colleen T
authors.initials: CT
authors.lastname: Webb
authors.forename: Homme W
authors.initials: HW
authors.lastname: Hellinga
authors.forename: June I
authors.initials: JI
authors.lastname: Medford
mesh_terms: D017360:Arabidopsis / Q000235:genetics; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D002467:Cell Nucleus / Q000378:metabolism; D003583:Cytokinins / Q000378:metabolism; D003627:Data Interpretation, Statistical; D005057:Eukaryotic Cells / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D018506:Gene Expression Regulation, Plant; D005818:Genetic Engineering / Q000379:methods*; D005966:Glucuronidase / Q000378:metabolism; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D000071677:Histidine Kinase; D018517:Plant Roots; D011401:Promoter Regions, Genetic; D011494:Protein Kinases / Q000378:metabolism; D012231:Rhizobium / Q000235:genetics; D015398:Signal Transduction / Q000235:genetics*; D049490:Systems Biology / Q000379:methods; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D001426:Bacterial Proteins; D003583:Cytokinins; D015534:Trans-Activators; C061278:PhoB protein, Bacteria; D049452:Green Fluorescent Proteins; D011494:Protein Kinases; D000071677:Histidine Kinase; D005966:Glucuronidase