Details
| Original language | English |
|---|---|
| Pages (from-to) | 901-912 |
| Number of pages | 12 |
| Journal | Plant physiology |
| Volume | 172 |
| Issue number | 2 |
| Publication status | Published - Oct 2016 |
Abstract
Glycolysis generates methylglyoxal (MGO) as an unavoidable, cytotoxic by-product in plant cells. MGO scavenging is performed by the glyoxalase system, which produces D-lactate as an end product. D-Lactate dehydrogenase (D-LDH) is encoded by a single gene in Arabidopsis (Arabidopsis thaliana; At5g06580). It catalyzes in vitro the oxidation of D-lactate to pyruvate using flavin adenine dinucleotide as a cofactor; knowledge of its function in the context of the plant cell remains sketchy. Blue native-polyacrylamide gel electrophoresis of mitochondrial extracts combined with in gel activity assays using different substrates and tandem mass spectrometry allowed us to definitely show that D-LDH acts specifically on D-lactate, is active as a dimer, and does not associate with respiratory supercomplexes of the inner mitochondrial membrane. The combined use of cytochrome c (CYTc) loss-of-function mutants and respiratory complex III inhibitors showed that CYTc acts as the in vivo electron acceptor of D-LDH. CYTc loss-of-function mutants, as well as the D-LDH mutants, were more sensitive to D-lactate and MGO, indicating that they function in the same pathway. In addition, overexpression of D-LDH and CYTc increased tolerance to D-lactate and MGO. Together with fine-localization of D-LDH, the functional interaction with CYTc in vivo strongly suggests that D-lactate oxidation takes place in the mitochondrial intermembrane space, delivering electrons to the respiratory chain through CYTc. These results provide a comprehensive picture of the organization and function of D-LDH in the plant cell and exemplify how the plant mitochondrial respiratory chain can act as a multifunctional electron sink for reductant from cytosolic pathways.
ASJC Scopus subject areas
- Biochemistry, Genetics and Molecular Biology(all)
- Physiology
- Biochemistry, Genetics and Molecular Biology(all)
- Genetics
- Agricultural and Biological Sciences(all)
- Plant Science
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In: Plant physiology, Vol. 172, No. 2, 10.2016, p. 901-912.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - D-Lactate Dehydrogenase Links Methylglyoxal Degradation and Electron Transport through Cytochrome c
AU - Welchen, Elina
AU - Schmitz, Jessica
AU - Fuchs, Philippe
AU - García, Lucila
AU - Wagner, Stephan
AU - Wienstroer, Judith
AU - Schertl, Peter
AU - Braun, Hans Peter
AU - Schwarzländer, Markus
AU - Gonzalez, Daniel H.
AU - Maurino, Veronica G.
PY - 2016/10
Y1 - 2016/10
N2 - Glycolysis generates methylglyoxal (MGO) as an unavoidable, cytotoxic by-product in plant cells. MGO scavenging is performed by the glyoxalase system, which produces D-lactate as an end product. D-Lactate dehydrogenase (D-LDH) is encoded by a single gene in Arabidopsis (Arabidopsis thaliana; At5g06580). It catalyzes in vitro the oxidation of D-lactate to pyruvate using flavin adenine dinucleotide as a cofactor; knowledge of its function in the context of the plant cell remains sketchy. Blue native-polyacrylamide gel electrophoresis of mitochondrial extracts combined with in gel activity assays using different substrates and tandem mass spectrometry allowed us to definitely show that D-LDH acts specifically on D-lactate, is active as a dimer, and does not associate with respiratory supercomplexes of the inner mitochondrial membrane. The combined use of cytochrome c (CYTc) loss-of-function mutants and respiratory complex III inhibitors showed that CYTc acts as the in vivo electron acceptor of D-LDH. CYTc loss-of-function mutants, as well as the D-LDH mutants, were more sensitive to D-lactate and MGO, indicating that they function in the same pathway. In addition, overexpression of D-LDH and CYTc increased tolerance to D-lactate and MGO. Together with fine-localization of D-LDH, the functional interaction with CYTc in vivo strongly suggests that D-lactate oxidation takes place in the mitochondrial intermembrane space, delivering electrons to the respiratory chain through CYTc. These results provide a comprehensive picture of the organization and function of D-LDH in the plant cell and exemplify how the plant mitochondrial respiratory chain can act as a multifunctional electron sink for reductant from cytosolic pathways.
AB - Glycolysis generates methylglyoxal (MGO) as an unavoidable, cytotoxic by-product in plant cells. MGO scavenging is performed by the glyoxalase system, which produces D-lactate as an end product. D-Lactate dehydrogenase (D-LDH) is encoded by a single gene in Arabidopsis (Arabidopsis thaliana; At5g06580). It catalyzes in vitro the oxidation of D-lactate to pyruvate using flavin adenine dinucleotide as a cofactor; knowledge of its function in the context of the plant cell remains sketchy. Blue native-polyacrylamide gel electrophoresis of mitochondrial extracts combined with in gel activity assays using different substrates and tandem mass spectrometry allowed us to definitely show that D-LDH acts specifically on D-lactate, is active as a dimer, and does not associate with respiratory supercomplexes of the inner mitochondrial membrane. The combined use of cytochrome c (CYTc) loss-of-function mutants and respiratory complex III inhibitors showed that CYTc acts as the in vivo electron acceptor of D-LDH. CYTc loss-of-function mutants, as well as the D-LDH mutants, were more sensitive to D-lactate and MGO, indicating that they function in the same pathway. In addition, overexpression of D-LDH and CYTc increased tolerance to D-lactate and MGO. Together with fine-localization of D-LDH, the functional interaction with CYTc in vivo strongly suggests that D-lactate oxidation takes place in the mitochondrial intermembrane space, delivering electrons to the respiratory chain through CYTc. These results provide a comprehensive picture of the organization and function of D-LDH in the plant cell and exemplify how the plant mitochondrial respiratory chain can act as a multifunctional electron sink for reductant from cytosolic pathways.
UR - http://www.scopus.com/inward/record.url?scp=84989337916&partnerID=8YFLogxK
U2 - 10.1104/pp.16.01174
DO - 10.1104/pp.16.01174
M3 - Article
C2 - 27506242
AN - SCOPUS:84989337916
VL - 172
SP - 901
EP - 912
JO - Plant physiology
JF - Plant physiology
SN - 0032-0889
IS - 2
ER -