Abstract
Bacterial gene expression is orchestrated by numerous transcription factors (TFs). Elucidating how gene expression is regulated is fundamental to understanding bacterial physiology and engineering it for practical use. In this study, a machine-learning approach was applied to uncover the genome-scale transcriptional regulatory network (TRN) in Pseudomonas putida KT2440, an important organism for bioproduction. We performed independent component analysis of a compendium of 321 high-quality gene expression profiles, which were previously published or newly generated in this study. We identified 84 groups of independently modulated genes (iModulons) that explain 75.7% of the total variance in the compendium. With these iModulons, we (i) expand our understanding of the regulatory functions of 39 iModulon associated TFs (e.g., HexR, Zur) by systematic comparison with 1993 previously reported TF-gene interactions; (ii) outline transcriptional changes after the transition from the exponential growth to stationary phases; (iii) capture group of genes required for utilizing diverse carbon sources and increased stationary response with slower growth rates; (iv) unveil multiple evolutionary strategies of transcriptome reallocation to achieve fast growth rates; and (v) define an osmotic stimulon, which includes the Type VI secretion system, as coordination of multiple iModulon activity changes. Taken together, this study provides the first quantitative genome-scale TRN for P. putida KT2440 and a basis for a comprehensive understanding of its complex transcriptome changes in a variety of physiological states.
Original language | English |
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Pages (from-to) | 297-310 |
Number of pages | 14 |
Journal | Metabolic Engineering |
Volume | 72 |
DOIs | |
State | Published - Jul 2022 |
Funding
This work conducted by the Joint BioEnergy Institute was supported by the Office of Science, Office of Biological and Environmental Research, of the U.S. Department of Energy (DOE) under Contract No. DE-AC02-05CH11231. This work was authored in part by Alliance for Sustainable Energy, LLC, the manager and operator of the National Renewable Energy Laboratory for the U.S. DOE under Contract No. DE-AC36-08GO28308. This work was also partially authored by Oak Ridge National Laboratory, which is managed by UT-Battelle, LLC, for the U.S. DOE under contract DE-AC05-00OR22725. Funding was provided by the U.S. DOE Office of Energy Efficiency and Renewable Energy Bioenergy Technologies Office (BETO) for the Agile BioFoundry. This work was also supported by the Nebraska Center for Energy Science Research at the University of Nebraska - Lincoln (Cycle-11 grant to W.N.). We also thank members of the Agile BioFoundry, Richard Szubin, Ying Hutchison, and Marc K. Abrams for helpful discussions.
Funders | Funder number |
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Nebraska Center for Energy Science Research | |
U.S. DOE Office of Energy Efficiency and Renewable Energy Bioenergy Technologies Office | |
University of Nebraska | |
U.S. Department of Energy | DE-AC02-05CH11231 |
U.S. Department of Energy | |
Office of Science | |
Biological and Environmental Research | |
National Renewable Energy Laboratory | DE-AC05-00OR22725, DE-AC36-08GO28308 |
National Renewable Energy Laboratory | |
Bioenergy Technologies Office |
Keywords
- Independent component analysis
- Machine learning
- Pseudomonas putida
- Systems biology
- Transcriptome