Kumar, Vineet and Mishra , Rajesh Kumar and Ghose, Debarghya and Kalita, Arunima and Dhiman , Pulkit and Prakash, Anand and Thakur , Nirja and Mitra, Gopa and Chaudhari , Vinod D and Arora, Amit and Dutta, Dipak (2022) Free spermidine evokes superoxide radicals that manifest toxicity. eLife.
Full text not available from this repository. (Request a copy)Abstract
Spermidine and other polyamines alleviate oxidative stress, yet excess spermidine seems toxic to Escherichia coli unless it is neutralized by SpeG, an enzyme for the spermidine N-acetyl transferase function. Thus, wild-type E. coli can tolerate applied exogenous spermidine stress, but ΔspeG strain of E. coli fails to do that. Here, using different reactive oxygen species (ROS) probes and performing electron paramagnetic resonance spectroscopy, we provide evidence that although spermidine mitigates oxidative stress by lowering overall ROS levels, excess of it simultaneously triggers the production of superoxide radicals, thereby causing toxicity in the ΔspeG strain. Furthermore, performing microarray experiment and other biochemical assays, we show that the spermidine-induced superoxide anions affected redox balance and iron homeostasis. Finally, we demonstrate that while RNA-bound spermidine inhibits iron oxidation, free spermidine interacts and oxidizes the iron to evoke superoxide radicals directly. Therefore, we propose that the spermidine-induced superoxide generation is one of the major causes of spermidine toxicity in E. coli.
| Item Type: | Article |
|---|---|
| Additional Information: | The copyright of this article belongs to eLife |
| Uncontrolled Keywords: | E. coli; Escherichia coli; SpeG; biochemistry; chemical biology; chromosomes; gene expression; iron metabolism; oxidative stress; spermidine toxicity; superoxide radical. |
| Subjects: | Q Science > QR Microbiology |
| Depositing User: | Dr. K.P.S.Sengar |
| Date Deposited: | 22 Jul 2022 05:43 |
| Last Modified: | 22 Jul 2022 05:43 |
| URI: | http://crdd.osdd.net/open/id/eprint/2984 |
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