Academic Journal
Endoplasmic reticulum adenylate transporter activity affects amino acid metabolism under photorespiratory conditions
| Title: | Endoplasmic reticulum adenylate transporter activity affects amino acid metabolism under photorespiratory conditions |
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| Authors: | Jieni Li, Yuxin Song, Xin Luan, Yajun Gou, Tao Xie, Yu Hong, Na Liu, Yao Su, Xueli Fu, Tianxiu Zhong, Shu Chen, Yuexiong Zhang, Gang Qin, Xiang-Qian Zhang |
| Source: | Crop Journal, Vol 12, Iss 6, Pp 1633-1644 (2024) |
| Publisher Information: | KeAi Communications Co., Ltd., 2024. |
| Publication Year: | 2024 |
| Collection: | LCC:Agriculture LCC:Agriculture (General) |
| Subject Terms: | Endoplasmic reticulum, Photorespiration, Amino acid, Glutamate/alanine aminotransferase, ER-ANT1, Agriculture, Agriculture (General), S1-972 |
| More Details: | The involvement of the endoplasmic reticulum (ER)-localized adenylate transporter1 (ER-ANT1) in photorespiratory metabolism has been established, yet its precise physiological function remains uncertain. Rice er-ant1 mutant plants grown in ambient air exhibited stunted growth and substantial alterations in amino acid metabolites, but recovery in a high CO2 condition (1.5%). We show that the absence of ER-ANT1 hindered the breakdown of glycine without affecting its synthesis, leading to a substantial accumulation of glycine, diminished levels of serine, and depleted reserves of glutamate and alanine. Intriguingly, the er-ant1 plants grown in high CO2 and later exposed to ambient air displayed reduced serine levels within 12 h, yet they accumulated serine a week after transferring to ambient air due to induced phosphorylated serine synthesis pathways. Furthermore, knockout of ER-ANT1 marginally impacted the transcription of genes governing core enzymes in photorespiration, but notably upregulated BOU expression that encodes a putative mitochondrial glutamate transporter and AGAT1 that encodes an alanine:glyoxylate aminotransferase gene. Surprisingly, AGAT1, an ER-localized protein, exhibited higher activity that correlates with the decreased alanine levels observed in the er-ant1 mutant. Lack of ER-ANT1 activity also led to a significantly elevated NADH/NAD+ ratio that potentially hinders the glycine-to-serine conversion process. This supports the hypothesis that the lack of ER-ANT1-induced limitation of ATP usage might inhibit GDC activity by modulating the NADH/NAD+ ratio. Moreover, non-proteinogenic amino acids, including β-alanine and γ-aminobutyrate (GABA), underwent significant alterations, even under high CO2 conditions in the er-ant mutant, implying additional non-photorespiration roles of ER-ANT1. Taken together, our results indicate that ER-localized ER-ANT1 plays a crucial role in amino acid metabolism during photorespiration. |
| Document Type: | article |
| File Description: | electronic resource |
| Language: | English |
| ISSN: | 2214-5141 |
| Relation: | http://www.sciencedirect.com/science/article/pii/S2214514124002125; https://doaj.org/toc/2214-5141 |
| DOI: | 10.1016/j.cj.2024.10.002 |
| Access URL: | https://doaj.org/article/de6762a12bc548e7829d8570a29c0642 |
| Accession Number: | edsdoj.6762a12bc548e7829d8570a29c0642 |
| Database: | Directory of Open Access Journals |
| ISSN: | 22145141 |
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| DOI: | 10.1016/j.cj.2024.10.002 |
| Published in: | Crop Journal |
| Language: | English |