Maynard Daniel, Viehhauser Andrea, Knieper Madita, Dreyer Anna, Manea Ghamdan, Telman Wilena, Butter Falk, Chibani Kamel, Scheibe Renate, Dietz Karl-Josef
Department of Biochemistry and Physiology of Plants, Faculty of Biology, University of Bielefeld, 33615 Bielefeld, Germany.
Institute for Molecular Biology, Johannes Gutenberg-University Mainz, 55128 Mainz, Germany.
Biomolecules. 2021 Mar 18;11(3):457. doi: 10.3390/biom11030457.
α,β-unsaturated carbonyls interfere with numerous plant physiological processes. One mechanism of action is their reactivity toward thiols of metabolites like cysteine and glutathione (GSH). This work aimed at better understanding these interactions. Both 12-oxophytodienoic acid (12-OPDA) and abscisic acid (ABA) conjugated with cysteine. It was found that the reactivity of α,β-unsaturated carbonyls with GSH followed the sequence trans-2-hexenal < 12-OPDA ≈ 12-OPDA-ethylester < 2-cyclopentenone << methyl vinylketone (MVK). Interestingly, GSH, but not ascorbate (vitamin C), supplementation ameliorated the phytotoxic potential of MVK. In addition, 12-OPDA and 12-OPDA-related conjugated carbonyl compounds interacted with proteins, e.g., with members of the thioredoxin (TRX)-fold family. 12-OPDA modified two cysteinyl residues of chloroplast TRX-f1. The OPDAylated TRX-f1 lost its activity to activate the Calvin-Benson-cycle enzyme fructose-1,6-bisphosphatase (FBPase). Finally, we show that 12-OPDA interacts with cyclophilin 20-3 (Cyp20-3) non-covalently and affects its peptidyl-prolyl-cis/trans isomerase activity. The results demonstrate the high potential of 12-OPDA as a diverse interactor and cellular regulator and suggest that OPDAylation may occur in plant cells and should be investigated as novel regulatory mechanism.
α,β-不饱和羰基会干扰众多植物生理过程。其作用机制之一是它们与半胱氨酸和谷胱甘肽（GSH）等代谢物的硫醇发生反应。这项工作旨在更好地理解这些相互作用。12-氧代植物二烯酸（12-OPDA）和脱落酸（ABA）都与半胱氨酸结合。研究发现，α,β-不饱和羰基与GSH的反应活性顺序为反式-2-己烯醛＜12-OPDA≈12-OPDA乙酯＜2-环戊烯酮＜＜甲基乙烯基酮（MVK）。有趣的是，补充GSH而非抗坏血酸（维生素C）可减轻MVK的植物毒性潜力。此外，12-OPDA和与12-OPDA相关的共轭羰基化合物与蛋白质相互作用，例如与硫氧还蛋白（TRX）折叠家族的成员相互作用。12-OPDA修饰了叶绿体TRX-f1的两个半胱氨酸残基。经OPDA化的TRX-f1失去了激活卡尔文-本森循环酶果糖-1,6-二磷酸酶（FBPase）的活性。最后，我们表明12-OPDA与亲环蛋白20-3（Cyp20-3）非共价相互作用并影响其肽基脯氨酰顺/反异构酶活性。结果证明了12-OPDA作为多种相互作用分子和细胞调节剂的巨大潜力，并表明OPDA化可能发生在植物细胞中，应作为一种新的调节机制进行研究。
