Zandalinas Sara I, Song Luhua, Nechushtai Rachel, Mendoza-Cozatl David G, Mittler Ron
Department of Biology, Biochemistry and Environmental Sciences, University Jaume I. Av. de Vicent Sos Baynat, s/n, 12071 Castelló de la Plana, Spain.
Division of Plant Sciences and Technology, College of Agriculture Food and Natural Resources and Interdisciplinary Plant Group, Christopher S. Bond Life Sciences Center University of Missouri, 1201 Rollins St, Columbia, MO 65211, USA.
Antioxidants (Basel). 2022 Aug 6;11(8):1533. doi: 10.3390/antiox11081533.
NEET proteins are conserved 2Fe-2S proteins that regulate the levels of iron and reactive oxygen species in plant and mammalian cells. Previous studies of seedlings with constitutive expression of AtNEET, or its dominant-negative variant H89C (impaired in 2Fe-2S cluster transfer), revealed that disrupting AtNEET function causes oxidative stress, chloroplast iron overload, activation of iron-deficiency responses, and cell death. Because disrupting AtNEET function is deleterious to plants, we developed an inducible expression system to study AtNEET function in mature plants using a time-course proteomics approach. Here, we report that the suppression of AtNEET cluster transfer function results in drastic changes in the expression of different members of the ferredoxin (Fd), Fd-thioredoxin (TRX) reductase (FTR), and TRX network of Arabidopsis, as well as in cytosolic cluster assembly proteins. In addition, the expression of Yellow Stripe-Like 6 (YSL6), involved in iron export from chloroplasts was elevated. Taken together, our findings reveal new roles for AtNEET in supporting the Fd-TFR-TRX network of plants, iron mobilization from the chloroplast, and cytosolic 2Fe-2S cluster assembly. In addition, we show that the AtNEET function is linked to the expression of glutathione peroxidases (GPXs), which play a key role in the regulation of ferroptosis and redox balance in different organisms.
NEET蛋白是保守的2Fe-2S蛋白，可调节植物和哺乳动物细胞中的铁水平和活性氧水平。先前对组成型表达AtNEET或其显性负变体H89C（2Fe-2S簇转移受损）的幼苗的研究表明，破坏AtNEET功能会导致氧化应激、叶绿体铁过载、缺铁反应激活和细胞死亡。由于破坏AtNEET功能对植物有害，我们开发了一种诱导表达系统，使用时间进程蛋白质组学方法研究成熟植物中的AtNEET功能。在此，我们报告AtNEET簇转移功能的抑制导致拟南芥铁氧还蛋白（Fd）、Fd-硫氧还蛋白（TRX）还原酶（FTR）和TRX网络的不同成员以及胞质簇组装蛋白的表达发生剧烈变化。此外，参与叶绿体铁输出的黄条纹样6（YSL6）的表达升高。综上所述，我们的研究结果揭示了AtNEET在支持植物的Fd-TFR-TRX网络、叶绿体铁动员和胞质2Fe-2S簇组装方面的新作用。此外，我们表明AtNEET功能与谷胱甘肽过氧化物酶（GPXs）的表达有关，GPXs在不同生物体的铁死亡调节和氧化还原平衡中起关键作用。
