Compensatory expression and substrate inducibility of gamma-glutamyl transferase GGT2 isoform in Arabidopsis thaliana
γ-Glutamyl transferases (GGT; EC 2.3.2.2) are glutathione-degrading enzymes that are represented in Arabidopsis thaliana by a small gene family of four members. Two isoforms, GGT1 and GGT2, are apoplastic, sharing broad similarities in their amino acid sequences, but they are differently expressed i...
| Veröffentlicht in: | Journal of experimental botany. - 1985. - 62(2011), 2 vom: 13. Jan., Seite 805-14 |
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| 1. Verfasser: | |
| Weitere Verfasser: | , , , , , , |
| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2011
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| Zugriff auf das übergeordnete Werk: | Journal of experimental botany |
| Schlagworte: | Journal Article Research Support, Non-U.S. Gov't gamma-Glutamyltransferase EC 2.3.2.2 Glutathione GAN16C9B8O |
| Zusammenfassung: | γ-Glutamyl transferases (GGT; EC 2.3.2.2) are glutathione-degrading enzymes that are represented in Arabidopsis thaliana by a small gene family of four members. Two isoforms, GGT1 and GGT2, are apoplastic, sharing broad similarities in their amino acid sequences, but they are differently expressed in the tissues: GGT1 is expressed in roots, leaves, and siliques, while GGT2 was thought to be expressed only in siliques. It is demonstrated here that GGT2 is also expressed in wild-type roots, albeit in very small amounts. GGT2 expression is enhanced in ggt1 knockout mutants, suggesting a compensatory effect to restore GGT activity in the root apoplast. Supplementation with 100 μM glutathione (GSH) resulted in the up-regulation of GGT2 gene expression in wild-type and ggt1 knockout roots, and of GGT1 gene expression in wild-type roots. Glutathione recovery was hampered by the GGT inhibitor serine/borate, suggesting a major role for apoplastic GGTs in this process. These findings can explain the ability of ggt1 knockout mutants to retrieve exogenously added glutathione from the growth medium |
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| Beschreibung: | Date Completed 11.04.2011 Date Revised 20.10.2021 published: Print-Electronic Citation Status MEDLINE |
| ISSN: | 1460-2431 |
| DOI: | 10.1093/jxb/erq316 |