The Ca2+ Sensor SCaBP3/CBL7 Modulates Plasma Membrane H+-ATPase Activity and Promotes Alkali Tolerance in Arabidopsis
| Autor: | Yujiao Wu, Chun-Peng Song, Qiuyan Dong, Qinpei Li, Yan Guo, Joerg Kudla, Xuping Ni, Yongqing Yang, Zhijia Yang, Liang Ma |
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| Rok vydání: | 2019 |
| Předmět: |
0106 biological sciences
0301 basic medicine Kinase C-terminus chemistry.chemical_element Cell Biology Plant Science Calcium Biology biology.organism_classification 01 natural sciences 03 medical and health sciences 030104 developmental biology Membrane chemistry Arabidopsis Biophysics Arabidopsis thaliana Phosphorylation Protein kinase A 010606 plant biology & botany |
| Zdroj: | The Plant Cell. 31:1367-1384 |
| ISSN: | 1532-298X 1040-4651 |
| DOI: | 10.1105/tpc.18.00568 |
| Popis: | Saline-alkali soil is a major environmental constraint impairing plant growth and crop productivity. In this study, we identified a Ca2+ sensor/kinase/plasma membrane (PM) H+-ATPase module as a central component conferring alkali tolerance in Arabidopsis (Arabidopsis thaliana). We report that the SCaBP3 (SOS3-LIKE CALCIUM BINDING PROTEIN3)/CBL7 (CALCINEURIN B-LIKE7) loss-of-function plants exhibit enhanced stress tolerance associated with increased PM H+-ATPase activity and provide fundamental mechanistic insights into the regulation of PM H+-ATPase activity. Consistent with the genetic evidence, interaction analyses, in vivo reconstitution experiments, and determination of H+-ATPase activity indicate that interaction of the Ca2+ sensor SCaBP3 with the C-terminal Region I domain of the PM H+-ATPase AHA2 (Arabidopsis thaliana PLASMA MEMBRANE PROTON ATPASE2) facilitates the intramolecular interaction of the AHA2 C terminus with the Central loop region of the PM H+-ATPase to promote autoinhibition of H+-ATPase activity. Concurrently, direct interaction of SCaPB3 with the kinase PKS5 (PROTEIN KINASE SOS2-LIKE5) stabilizes the kinase-ATPase interaction and thereby fosters the inhibitory phosphorylation of AHA2 by PKS5. Consistently, yeast reconstitution experiments and genetic analysis indicate that SCaBP3 provides a bifurcated pathway for coordinating intramolecular and intermolecular inhibition of PM H+-ATPase. We propose that alkaline stress-triggered Ca2+ signals induce SCaBP3 dissociation from AHA2 to enhance PM H+-ATPase activity. This work illustrates a versatile signaling module that enables the stress-responsive adjustment of plasma membrane proton fluxes. |
| Databáze: | OpenAIRE |
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