The chloroplast 2-cysteine peroxiredoxin functions as thioredoxin oxidase in redox regulation of chloroplast metabolism.
The chloroplast 2-cysteine peroxiredoxin functions as thioredoxin oxidase in redox regulation of chloroplast metabolism.
复制标题
叶绿体2-半胱氨酸过氧蛋白在叶绿体代谢的氧化还原调节中用作硫氧还蛋白氧化酶。
DOI：
10.7554/elife.38194
复制
发表时间：
2018-10-12
期刊：
影响因子：
7.7
通讯作者：
Dietz KJ
中科院分区：
文献类型：
--
作者：
Vaseghi MJ;Chibani K;Telman W;Liebthal MF;Gerken M;Schnitzer H;Mueller SM;Dietz KJ
硫醇依赖性氧化还原调节控制植物细胞的中央过程，包括光合作用。硫氧还蛋白还原性激活例如卡尔文-本森循环酶。然而，尽管氧化失活对于有效调节很重要，但其机制尚不清楚。在这里，丰富的 2-半胱氨酸过氧化还原蛋白 (2-CysPrx)，但不是其定点变体，在适当的硫氧还蛋白存在下介导还原激活的果糖 1,6-二磷酸酶和 NADPH 依赖性苹果酸脱氢酶 (MDH) 的快速失活。与野生型相比，2cysprxAB 突变体植物在光/暗转换时磷酸核糖激酶 (PRK) 和 MDH 的失活受到损害。 2-CysPrx 在调节光合作用中的决定性作用从完整叶子变黑时铁氧还蛋白的再氧化动力学中可以明显看出，因为它的半衰期在 2cysprxAB 中减少了 3.5 倍。低效失活的缺点变成了波动光的优点。 MDH 和 PRK 失活、光合动力学和对波动光的响应等生理参数在 2-CysPrxA 补充的 2cysprxAB 突变体中完全恢复，强调了 2-CysPrx 的重要性。结果表明，2-CysPrx 在硫醇网络中充当电子接收器，对于氧化还原激活的蛋白质很重要，并且代表了硫氧还蛋白依赖性调节逆转中缺失的环节。
Thiol-dependent redox regulation controls central processes in plant cells including photosynthesis. Thioredoxins reductively activate, for example, Calvin-Benson cycle enzymes. However, the mechanism of oxidative inactivation is unknown despite its importance for efficient regulation. Here, the abundant 2-cysteine peroxiredoxin (2-CysPrx), but not its site-directed variants, mediates rapid inactivation of reductively activated fructose-1,6-bisphosphatase and NADPH-dependent malate dehydrogenase (MDH) in the presence of the proper thioredoxins. Deactivation of phosphoribulokinase (PRK) and MDH was compromised in 2cysprxAB mutant plants upon light/dark transition compared to wildtype. The decisive role of 2-CysPrx in regulating photosynthesis was evident from reoxidation kinetics of ferredoxin upon darkening of intact leaves since its half time decreased 3.5-times in 2cysprxAB. The disadvantage of inefficient deactivation turned into an advantage in fluctuating light. Physiological parameters like MDH and PRK inactivation, photosynthetic kinetics and response to fluctuating light fully recovered in 2cysprxAB mutants complemented with 2-CysPrxA underlining the significance of 2-CysPrx. The results show that the 2-CysPrx serves as electron sink in the thiol network important to oxidize reductively activated proteins and represents the missing link in the reversal of thioredoxin-dependent regulation.