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bioRxiv · 10.1101/2022.05.12.491709

The cluster transfer function of AtNEET supports the ferredoxin-thioredoxin network of plant cells

Zandalinas, S. I.·Song, L.·Nechushtai, R.·Mendoza, D. G.·Mittler, R.
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Abstract

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 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 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. HighlightUsing proteomics analysis and an inducible expression system, the iron-sulfur cluster transfer function of AtNEET was found to support the ferredoxin-thioredoxin network of Arabidopsis.

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Zandalinas, S. I., Song, L., Nechushtai, R., Mendoza, D. G., Mittler, R.. 2022-05-13. The cluster transfer function of AtNEET supports the ferredoxin-thioredoxin network of plant cells. https://doi.org/10.1101/2022.05.12.491709

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