Demir, Fatih and Horntrich, Claudia and Blachutzik, Joerg O. and Scherzer, Soenke and Reinders, Yvonne and Kierszniowska, Sylwia and Schulze, Waltraud X. and Harms, Gregory S. and Hedrich, Rainer and Geiger, Dietmar and Kreuzer, Ines (2013) Arabidopsis nanodomain-delimited ABA signaling pathway regulates the anion channel SLAH3. PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 110 (20). pp. 8296-8301. ISSN 0027-8424,
Full text not available from this repository. (Request a copy)Abstract
The phytohormone abscisic acid (ABA) plays a key role in the plant response to drought stress. Hence, ABA-dependent gene transcription and ion transport is regulated by a variety of protein kinases and phosphatases. However, the nature of the membrane-delimited ABA signal transduction steps remains largely unknown. To gain insight into plasma membrane-bound ABA signaling, we identified sterol-dependent proteins associated with detergent resistant membranes from Arabidopsis thaliana mesophyll cells. Among those, we detected the central ABA signaling phosphatase ABI1 (abscisic-acid insensitive 1) and the calcium-dependent protein kinase 21 (CPK21). Using fluorescence microscopy, we found these proteins to localize in membrane nanodomains, as observed by colocalization with the nanodomain marker remorin Arabidopsis thaliana remorin 1.3 (AtRem 1.3). After transient coexpression, CPK21 interacted with SLAH3 [slow anion channel 1 (SLAC1) homolog 3] and activated this anion channel. Upon CPK21 stimulation, SLAH3 exhibited the hallmark properties of S-type anion channels. Coexpression of SLAH3/CPK21 with ABI1, however, prevented proper nanodomain localization of the SLAH3/CPK21 protein complex, and as a result anion channel activation failed. FRET studies revealed enhanced interaction of SLAH3 and CPK21 within the plasma membrane in response to ABA and thus confirmed our initial observations. Interestingly, the ABA-induced SLAH3/CPK21 interaction was modulated by ABI1 and the ABA receptor RCAR1/PYL9 [regulatory components of ABA receptor 1/PYR1 (pyrabactin resistance 1)-like protein 9]. We therefore propose that ABA signaling via inhibition of ABI1 modulates the apparent association of a signaling and transport complex within membrane domains that is necessary for phosphorylation and activation of the S-type anion channel SLAH3 by CPK21.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | PLASMA-MEMBRANE MICRODOMAINS; DETERGENT-RESISTANT MEMBRANES; ABSCISIC-ACID; GUARD-CELLS; LIPID RAFTS; SUSPENSION CELLS; TRITON X-100; PLANT-CELLS; PROTEOMICS; SLAC1; |
| Subjects: | 500 Science > 570 Life sciences |
| Divisions: | Biology, Preclinical Medicine > Institut für Biochemie, Genetik und Mikrobiologie > Lehrstuhl für Biochemie I |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 09 Apr 2020 06:06 |
| Last Modified: | 09 Apr 2020 06:06 |
| URI: | https://pred.uni-regensburg.de/id/eprint/16671 |
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