Pyrroline-5-carboxylate metabolism protein complex detected in Arabidopsis thaliana leaf mitochondria
2023
Zheng, Yao | Cabassa-Hourton, Cécile | Eubel, Holger | Chevreux, Guillaume | Lignieres, Laurent | Crilat, Emilie | Braun, Hans-Peter | Lebreton, Sandrine | Savouré, Arnould | Institut d'écologie et des sciences de l'environnement de Paris (iEES Paris) ; Institut de Recherche pour le Développement (IRD)-Sorbonne Université (SU)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE) | Leibniz Universität Hannover = Leibniz University Hannover | Institut Jacques Monod (IJM (UMR_7592)) ; Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité) | This work was supported by the Hubert Curien PROCOPE program between Germany and France (grant number 46711VJ) funded by the Ministry of Foreign Affairs and by Sorbonne University. This work was supported by a grant from the China Scholarship Council to YZ. We thank Région Ile de France for financial support of ProteoSeine@IJM platform.
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显示更多 [+] 显示较少 [-]英语. Proline dehydrogenase (ProDH) and pyrroline-5-carboxylate (P5C) dehydrogenase (P5CDH) catalyse the oxidation of proline into glutamate via the intermediates P5C and glutamate-semialdehyde (GSA), which spontaneously interconvert. P5C and GSA are also intermediates in the production of glutamate from ornithine and α-ketoglutarate catalysed by ornithine δ-aminotransferase (OAT). ProDH and P5CDH form a fused bifunctional PutA enzyme in Gram-negative bacteria and are associated in a bifunctional substrate-channelling complex in Thermus thermophilus; however, the physical proximity of ProDH and P5CDH in eukaryotes has not been described. Here, we report evidence of physical proximity and interactions between Arabidopsis PRODH, P5CDH, and OAT in the mitochondria of plants during dark-induced leaf senescence when all three enzymes are expressed. Pairwise interactions and localization of the three enzymes were investigated using bimolecular fluorescence complementation with confocal microscopy in tobacco and sub-mitochondrial fractionation in Arabidopsis. Evidence for a complex composed of PRODH, P5CDH, and OAT was revealed by co-migration of the proteins in native conditions upon gel electrophoresis. Co-immunoprecipitation coupled with mass spectrometry analysis confirmed the presence of the P5C metabolism complex in Arabidopsis. Pull-down assays further demonstrated a direct interaction between PRODH1 and P5CDH. P5C metabolism complexes might channel P5C among the constituent enzymes and directly provide electrons to the respiratory electron chain via PRODH.
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