Redox Modification of the Iron-Sulfur Glutaredoxin GRXS17 Activates Holdase Activity and Protects Plants from Heat Stress
Autor(en): | Martins, Laura Knuesting, Johannes Bariat, Laetitia Dard, Avilien Freibert, Sven A. Marchand, Christophe H. Young, David Nguyen Ho Thuy Dung Voth, Wilhelm Debures, Anne Saez-Vasquez, Julio Lemaire, Stephane D. Lill, Roland Messens, Joris Scheibe, Renate Reichheld, Jean-Philippe Riondet, Christophe |
Stichwörter: | ARABIDOPSIS; ATP-INDEPENDENT CHAPERONE; CLUSTER TRANSFER; EXPRESSION; GLUTATHIONE; GROWTH; MONOTHIOL GLUTAREDOXINS; Plant Sciences; SACCHAROMYCES-CEREVISIAE; THERMOTOLERANCE; THIOREDOXIN | Erscheinungsdatum: | 2020 | Herausgeber: | OXFORD UNIV PRESS INC | Enthalten in: | PLANT PHYSIOLOGY | Band: | 184 | Ausgabe: | 2 | Startseite: | 676 | Seitenende: | 692 | Zusammenfassung: | Heat stress induces misfolding and aggregation of proteins unless they are guarded by chaperone systems. Here, we examined the function of the glutaredoxin GRXS17, a member of thiol reductase families in the model plant Arabidopsis (Arabidopsis thaliana). GRXS17 is a nucleocytosolic monothiol glutaredoxin consisting of an N-terminal thioredoxin domain and three CGFS active-site motif-containing GRX domains that coordinate three iron-sulfur (Fe-S) clusters in a glutathione-dependent manner. As an Fe-S cluster-charged holoenzyme, GRXS17 is likely involved in the maturation of cytosolic and nuclear Fe-S proteins. In addition to its role in cluster biogenesis, GRXS17 presented both foldase and redox-dependent holdase activities. Oxidative stress in combination with heat stress induced loss of its Fe-S clusters followed by subsequent formation of disulfide bonds between conserved active-site cysteines in the corresponding thioredoxin domains. This oxidation led to a shift of GRXS17 to a high-molecular-weight complex and thus activated its holdase activity in vitro. Moreover, GRXS17 was specifically involved in plant tolerance to moderate high temperature and protected root meristematic cells from heat-induced cell death. Finally, GRXS17 interacted with a different set of proteins upon heat stress, possibly protecting them from heat injuries. Therefore, we propose that the Fe-S cluster enzyme GRXS17 is an essential guard that protects proteins against moderate heat stress, likely through a redox-dependent chaperone activity. We reveal the mechanism of an Fe-S cluster-dependent activity shift that converts the holoenzyme GRXS17 into a holdase, thereby preventing damage caused by heat stress. |
ISSN: | 00320889 | DOI: | 10.1104/pp.20.00906 |
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geprüft am 07.06.2024