PMID- 27431058 OWN - NLM STAT- MEDLINE DCOM- 20170523 LR - 20201209 IS - 1096-0384 (Electronic) IS - 0003-9861 (Linking) VI - 606 DP - 2016 Sep 15 TI - Phospho-transfer networks and ATP homeostasis in response to an ineffective electron transport chain in Pseudomonas fluorescens. PG - 26-33 LID - S0003-9861(16)30243-0 [pii] LID - 10.1016/j.abb.2016.07.011 [doi] AB - Although oxidative stress is known to impede the tricarboxylic acid (TCA) cycle and oxidative phosphorylation, the nutritionally-versatile microbe, Pseudomonas fluorescens has been shown to proliferate in the presence of hydrogen peroxide (H2O2) and nitrosative stress. In this study we demonstrate the phospho-transfer system that enables this organism to generate ATP was similar irrespective of the carbon source utilized. Despite the diminished activities of enzymes involved in the TCA cycle and in the electron transport chain (ETC), the ATP levels did not appear to be significantly affected in the stressed cells. Phospho-transfer networks mediated by acetate kinase (ACK), adenylate kinase (AK), and nucleoside diphosphate kinase (NDPK) are involved in maintaining ATP homeostasis in the oxidatively-challenged cells. This phospho-relay machinery orchestrated by substrate-level phosphorylation is aided by the up-regulation in the activities of such enzymes like phosphoenolpyruvate carboxylase (PEPC), pyruvate orthophosphate dikinase (PPDK), and phosphoenolpyruvate synthase (PEPS). The enhanced production of phosphoenolpyruvate (PEP) and pyruvate further fuel the synthesis of ATP. Taken together, this metabolic reconfiguration enables the organism to fulfill its ATP need in an O2-independent manner by utilizing an intricate phospho-wire module aimed at maximizing the energy potential of PEP with the participation of AMP. CI - Copyright (c) 2016 Elsevier Inc. All rights reserved. FAU - Appanna, V P AU - Appanna VP AD - Faculty of Science and Engineering, Laurentian University, Sudbury, ON P3E 2C6, Canada. FAU - Alhasawi, A A AU - Alhasawi AA AD - Faculty of Science and Engineering, Laurentian University, Sudbury, ON P3E 2C6, Canada. FAU - Auger, C AU - Auger C AD - Faculty of Science and Engineering, Laurentian University, Sudbury, ON P3E 2C6, Canada. FAU - Thomas, S C AU - Thomas SC AD - Faculty of Science and Engineering, Laurentian University, Sudbury, ON P3E 2C6, Canada. FAU - Appanna, V D AU - Appanna VD AD - Faculty of Science and Engineering, Laurentian University, Sudbury, ON P3E 2C6, Canada. Electronic address: vappanna@laurentian.ca. LA - eng PT - Journal Article DEP - 20160716 PL - United States TA - Arch Biochem Biophys JT - Archives of biochemistry and biophysics JID - 0372430 RN - 0 (Lipids) RN - 0 (Reactive Oxygen Species) RN - 415SHH325A (Adenosine Monophosphate) RN - 73-89-2 (Phosphoenolpyruvate) RN - 8L70Q75FXE (Adenosine Triphosphate) RN - BBX060AN9V (Hydrogen Peroxide) RN - EC 2.7.9.- (Phosphotransferases (Paired Acceptors)) RN - EC 2.7.9.1 (Pyruvate, Orthophosphate Dikinase) RN - EC 2.7.9.2 (pyruvate, water dikinase) RN - S88TT14065 (Oxygen) SB - IM MH - Adenosine Monophosphate/chemistry MH - Adenosine Triphosphate/*chemistry MH - Citric Acid Cycle MH - Densitometry MH - Electron Transport MH - Homeostasis MH - Hydrogen Peroxide/chemistry MH - Lipids/chemistry MH - Oxidation-Reduction MH - Oxidative Phosphorylation MH - Oxidative Stress MH - Oxygen/chemistry MH - Phosphoenolpyruvate/chemistry MH - Phosphorylation MH - Phosphotransferases (Paired Acceptors)/metabolism MH - Pseudomonas fluorescens/*metabolism MH - Pyruvate, Orthophosphate Dikinase/metabolism MH - Reactive Oxygen Species/metabolism OTO - NOTNLM OT - ATP homeostasis OT - Bioenergetics OT - Electron transport chain OT - Phospho-transfer networks OT - Phosphoenolpyruvate OT - Pyruvate EDAT- 2016/07/20 06:00 MHDA- 2017/05/24 06:00 CRDT- 2016/07/20 06:00 PHST- 2016/06/21 00:00 [received] PHST- 2016/07/04 00:00 [revised] PHST- 2016/07/14 00:00 [accepted] PHST- 2016/07/20 06:00 [entrez] PHST- 2016/07/20 06:00 [pubmed] PHST- 2017/05/24 06:00 [medline] AID - S0003-9861(16)30243-0 [pii] AID - 10.1016/j.abb.2016.07.011 [doi] PST - ppublish SO - Arch Biochem Biophys. 2016 Sep 15;606:26-33. doi: 10.1016/j.abb.2016.07.011. Epub 2016 Jul 16.