title: Multi-level kinetic model explaining diverse roles of isozymes in prokaryotes.
abstract: Current standard methods for kinetic and genomic modeling cannot provide deep insight into metabolic regulation. Here, we developed and evaluated a multi-scale kinetic modeling approach applicable to any prokaryote. Specifically, we highlight the primary metabolism of the cyanobacterium Synechococcus elongatus PCC 7942. The model bridges metabolic data sets from cells grown at different CO2 conditions by integrating transcriptomic data and isozymes. Identification of the regulatory roles of isozymes allowed the calculation and explanation of the absolute metabolic concentration of 3-phosphoglycerate. To demonstrate that this method can characterize any isozyme, we determined the function of two glycolytic glyceraldehyde-3-phosphate dehydrogenases: one co-regulates high concentrations of the 3-phosphoglycerate, the other shifts the bifurcation point in hexose regulation, and both improve biomass production. Moreover, the regulatory roles of multiple phosphoglycolate phosphatases were defined for varying (non-steady) CO2 conditions, suggesting their protective role against toxic photorespiratory intermediates.
authors.affiliation: Laboratory of Experimental Complex Systems, FFPW, University of South Bohemia, České Budějovice, Czech Republic.
authors.forename: Jiri
authors.initials: J
authors.lastname: Jablonsky
authors.affiliation: Department of Plant Physiology, University of Rostock, Rostock, Germany.
authors.forename: Doreen
authors.initials: D
authors.lastname: Schwarz
authors.affiliation: Department of Plant Physiology, University of Rostock, Rostock, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Hagemann
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D001426:Bacterial Proteins / Q000737:chemistry* / Q000502:physiology; D002245:Carbon Dioxide; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases / Q000737:chemistry* / Q000502:physiology; D006706:Homeostasis; D007527:Isoenzymes / Q000737:chemistry / Q000502:physiology; D007700:Kinetics; D009249:NADP / Q000378:metabolism; D010084:Oxidation-Reduction; D046940:Synechococcus / Q000201:enzymology*
chemical_list: D001426:Bacterial Proteins; D007527:Isoenzymes; D002245:Carbon Dioxide; D009249:NADP; D000255:Adenosine Triphosphate; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases