Biochemical characterization of proline dehydrogenase in Arabidopsis mitochondria

authored by
Peter Schertl, Cécile Cabassa, Kaouthar Saadallah, Marianne Bordenave, Arnould Savouré, Hans Peter Braun
Abstract

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 (ProDH) into mitochondrial metabolism in Arabidopsis thaliana. An experimental system to induce ProDH activity was established using cell cultures. Induction of ProDH was measured by novel photometric activity assays and by a ProDH in gel activity assay. Effects of increased ProDH 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 ProDH in plants. We suggest that induction of d-lactate dehydrogenase activity allows rapid upregulation of ProDH activity during the short-term stress response in plants.

Organisation(s)
Institute of Plant Genetics
External Organisation(s)
University Pierre et Marie Curie
Type
Article
Journal
FEBS Journal
Volume
281
Pages
2794-2804
No. of pages
11
ISSN
1742-464X
Publication date
18.06.2014
Publication status
Published
Peer reviewed
Yes
ASJC Scopus subject areas
Biochemistry, Molecular Biology, Cell Biology
Electronic version(s)
https://doi.org/10.1111/febs.12821 (Access: Closed)