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Biochemical characterization of proline dehydrogenase in Arabidopsis mitochondria
Author(s) -
Schertl Peter,
Cabassa Cécile,
Saadallah Kaouthar,
Bordenave Marianne,
Savouré Arnould,
Braun HansPeter
Publication year - 2014
Publication title -
the febs journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.981
H-Index - 204
eISSN - 1742-4658
pISSN - 1742-464X
DOI - 10.1111/febs.12821
Subject(s) - proline dehydrogenase , biochemistry , proline , biology , dehydrogenase , mitochondrion , arabidopsis thaliana , lactate dehydrogenase , enzyme , amino acid , gene , mutant
Proline has multiple functions in plants. Besides being a building block for protein biosynthesis proline plays a central role in the plant stress response and in further cellular processes. Here, we report an analysis on the integration of proline dehydrogenase (Pro DH ) into mitochondrial metabolism in Arabidopsis thaliana . An experimental system to induce Pro DH activity was established using cell cultures. Induction of Pro DH was measured by novel photometric activity assays and by a Pro DH in gel activity assay. Effects of increased Pro DH activity on other mitochondrial enzymes were systematically investigated. Activities of the protein complexes of the respiratory chain were not significantly altered. In contrast, some mitochondrial dehydrogenases had markedly changed activities. Activity of glutamate dehydrogenase substantially increased, indicating upregulation of the entire proline catabolic pathway, which was confirmed by co‐expression analyses of the corresponding genes. Furthermore, activity of d ‐lactate dehydrogenase was increased. d ‐lactate was identified to be a competitive inhibitor of Pro DH in plants. We suggest that induction of d ‐lactate dehydrogenase activity allows rapid upregulation of Pro DH activity during the short‐term stress response in plants.