Inverse regulation of SOS1 and HKT1 protein localization and stability by SOS3/CBL4 in Arabidopsis thaliana .
In: Proceedings of the National Academy of Sciences of the United States of America, Jg. 121 (2024-02-27), Heft 9, S. e2320657121
academicJournal
Zugriff:
To control net sodium (Na + ) uptake, Arabidopsis plants utilize the plasma membrane (PM) Na + /H + antiporter SOS1 to achieve Na + efflux at the root and Na + loading into the xylem, and the channel-like HKT1;1 protein that mediates the reverse flux of Na + unloading off the xylem. Together, these opposing transport systems govern the partition of Na + within the plant yet they must be finely co-regulated to prevent a futile cycle of xylem loading and unloading. Here, we show that the Arabidopsis SOS3 protein acts as the molecular switch governing these Na + fluxes by favoring the recruitment of SOS1 to the PM and its subsequent activation by the SOS2/SOS3 kinase complex under salt stress, while commanding HKT1;1 protein degradation upon acute sodic stress. SOS3 achieves this role by direct and SOS2-independent binding to previously unrecognized functional domains of SOS1 and HKT1;1. These results indicate that roots first retain moderate amounts of salts to facilitate osmoregulation, yet when sodicity exceeds a set point, SOS3-dependent HKT1;1 degradation switches the balance toward Na + export out of the root. Thus, SOS3 functionally links and co-regulates the two major Na + transport systems operating in vascular plants controlling plant tolerance to salinity.
Competing Interests: Competing interests statement:The authors declare no competing interest.
Titel: |
Inverse regulation of SOS1 and HKT1 protein localization and stability by SOS3/CBL4 in Arabidopsis thaliana .
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Autor/in / Beteiligte Person: | Gámez-Arjona, F ; Park, HJ ; García, E ; Aman, R ; Villalta, I ; Raddatz, N ; Carranco, R ; Ali, A ; Ali, Z ; Zareen, S ; De Luca, A ; Leidi, EO ; Daniel-Mozo, M ; Xu, ZY ; Albert, A ; Kim, WY ; Pardo, JM ; Sánchez-Rodriguez, C ; Yun, DJ ; Quintero, FJ |
Zeitschrift: | Proceedings of the National Academy of Sciences of the United States of America, Jg. 121 (2024-02-27), Heft 9, S. e2320657121 |
Veröffentlichung: | Washington, DC : National Academy of Sciences, 2024 |
Medientyp: | academicJournal |
ISSN: | 1091-6490 (electronic) |
DOI: | 10.1073/pnas.2320657121 |
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