PMID- 19109413
OWN - NLM
STAT- MEDLINE
DCOM- 20090514
LR  - 20211020
IS  - 0032-0889 (Print)
IS  - 1532-2548 (Electronic)
IS  - 0032-0889 (Linking)
VI  - 149
IP  - 2
DP  - 2009 Feb
TI  - Reactive oxygen species production by potato tuber mitochondria is modulated by 
      mitochondrially bound hexokinase activity.
PG  - 1099-110
LID - 10.1104/pp.108.129247 [doi]
AB  - Potato tuber (Solanum tuberosum) mitochondria (PTM) have a mitochondrially bound 
      hexokinase (HK) activity that exhibits a pronounced sensitivity to ADP 
      inhibition. Here we investigated the role of mitochondrial HK activity in PTM 
      reactive oxygen species generation. Mitochondrial HK has a 10-fold higher 
      affinity for glucose (Glc) than for fructose (KMGlc=140 microM versus KMFrc=1,375 
      microM). Activation of PTM respiration by succinate led to an increase in 
      hydrogen peroxide (H2O2) release that was abrogated by mitochondrial HK 
      activation. Mitochondrial HK activity caused a decrease in the mitochondrial 
      membrane potential and an increase in oxygen consumption by PTM. Inhibition of 
      Glc phosphorylation by mannoheptulose or GlcNAc induced a rapid increase in H2O2 
      release. The blockage of H2O2 release sustained by Glc was reverted by oligomycin 
      and atractyloside, indicating that ADP recycles through the adenine nucleotide 
      translocator and F0F1ATP synthase is operative during the mitochondrial HK 
      reaction. Inhibition of mitochondrial HK activity by 60% to 70% caused an 
      increase of 50% in the maximal rate of H2O2 release. Inhibition in H2O2 release 
      by mitochondrial HK activity was comparable to, or even more potent, than that 
      observed for StUCP (S. tuberosum uncoupling protein) activity. The inhibition of 
      H2O2 release in PTM was two orders of magnitude more selective for the ADP 
      produced from the mitochondrial HK reaction than for that derived from soluble 
      yeast (Saccharomyces cerevisiae) HK. Modulation of H2O2 release and oxygen 
      consumption by Glc and mitochondrial HK inhibitors in potato tuber slices shows 
      that hexoses and mitochondrial HK may act as a potent preventive antioxidant 
      mechanism in potato tubers.
FAU - Camacho-Pereira, Juliana
AU  - Camacho-Pereira J
AD  - Instituto de Bioquimica Medica, Programa de Biofisica e Bioquimica Celular, 
      Universidade Federal do Rio de Janeiro, Laboratorio de Bioenergetica e Fisiologia 
      Mitochondrial, Cidade Universitaria, Rio de Janeiro 21941-590, Brazil.
FAU - Meyer, Laudiene Evangelista
AU  - Meyer LE
FAU - Machado, Lilia Bender
AU  - Machado LB
FAU - Oliveira, Marcus Fernandes
AU  - Oliveira MF
FAU - Galina, Antonio
AU  - Galina A
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20081224
PL  - United States
TA  - Plant Physiol
JT  - Plant physiology
JID - 0401224
RN  - 0 (Reactive Oxygen Species)
RN  - 61D2G4IYVH (Adenosine Diphosphate)
RN  - EC 2.7.1.1 (Hexokinase)
SB  - IM
MH  - Adenosine Diphosphate/pharmacology
MH  - Hexokinase/antagonists & inhibitors/*metabolism
MH  - Kinetics
MH  - Membrane Potentials/physiology
MH  - Mitochondria/enzymology/*metabolism
MH  - Mitochondrial Membranes/physiology
MH  - Oxygen Consumption
MH  - Plant Roots/*metabolism
MH  - Reactive Oxygen Species/*metabolism
MH  - Solanum tuberosum/*metabolism
PMC - PMC2633851
EDAT- 2008/12/26 09:00
MHDA- 2009/05/15 09:00
PMCR- 2010/02/01
CRDT- 2008/12/26 09:00
PHST- 2008/12/26 09:00 [entrez]
PHST- 2008/12/26 09:00 [pubmed]
PHST- 2009/05/15 09:00 [medline]
PHST- 2010/02/01 00:00 [pmc-release]
AID - pp.108.129247 [pii]
AID - 129247 [pii]
AID - 10.1104/pp.108.129247 [doi]
PST - ppublish
SO  - Plant Physiol. 2009 Feb;149(2):1099-110. doi: 10.1104/pp.108.129247. Epub 2008 
      Dec 24.