Cytosolic GABA inhibits anion transport by wheat ALMT1
© 2019 The Authors. New Phytologist © 2019 New Phytologist Trust.
| Veröffentlicht in: | The New phytologist. - 1979. - 225(2020), 2 vom: 30. Jan., Seite 671-678 |
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| Weitere Verfasser: | , |
| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2020
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| Zugriff auf das übergeordnete Werk: | The New phytologist |
| Schlagworte: | Journal Article Research Support, Non-U.S. Gov't GABA transport TaALMT1F213C apoplast muscimol muscimol-BODIPY site directed mutagenesis stress signalling transactivation mehr... |
| Zusammenfassung: | © 2019 The Authors. New Phytologist © 2019 New Phytologist Trust. Anion transport by aluminium-activated malate transporter (ALMT) proteins is negatively regulated by gamma-aminobutyric acid (GABA), which increases in concentration during stress. Here, the interaction between GABA and wheat (Triticum aestivum, Ta) TaALMT1 heterologously-expressed in Xenopus laevis oocytes was investigated. GABA inhibited anion transport by TaALMT1 in membrane patches from the cytosolic, not extracellular membrane face, via a reduction in open probability (NPopen ), not an inhibition of channel current magnitude. TaALMT1 currents in patches frequently exhibited rundown with complete removal of cytosolic factors, but were partially sustained by protein kinase C dependent phosphorylation. When applied to whole oocytes a GABA-analogue-BODIPY conjugate inhibited TaALMT1 anion currents from the cytoplasmic face only, whereas free GABA inhibited from both the inside and outside consistent with GABA traversing the TaALMT1 pore then acting from the inside. We propose GABA does not competitively inhibit ALMT conductance through the same pore but rather leads to an allosteric effect, reducing anion channel opening frequency. Across plants GABA is a conserved regulator of anion transport via ALMTs - a family with numerous physiological roles beyond Al3+ tolerance. Our data suggests that a GABA-ALMT interaction from the cytosolic face has the potential to form part of a novel plant signalling pathway |
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| Beschreibung: | Date Completed 01.12.2020 Date Revised 26.05.2022 published: Print-Electronic ErratumIn: New Phytol. 2022 Sep;235(5):2128. - PMID 35616133 Citation Status MEDLINE |
| ISSN: | 1469-8137 |
| DOI: | 10.1111/nph.16238 |