Percorrer por autor "Rodriguez, Lesia"
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- C2-Domain Abscisic Acid-Related Proteins Mediate the Interaction of PYR/PYL/RCAR Abscisic Acid Receptors with the Plasma Membrane and Regulate Abscisic Acid Sensitivity in ArabidopsisPublication . Rodriguez, Lesia; Gonzalez-Guzman, Miguel; Diaz, Maira; Rodrigues, Américo; Izquierdo-Garcia, Ana C.; Peirats-Llobet, Marta; Fernandez, Maria A.; Antoni, Regina; Fernandez, Daniel; Marquez, Jose A.; Mulet, Jose M.; Albert, Armando; Rodriguez, Pedro L.Membrane-delimited abscisic acid (ABA) signal transduction plays a critical role in early ABA signaling, but the molecular mechanisms linking core signaling components to the plasma membrane are unclear. We show that transient calcium-dependent interactions of PYR/PYL ABA receptors with membranes are mediated through a 10-member family of C2-domain ABA-related (CAR) proteins in Arabidopsis thaliana. Specifically, we found that PYL4 interacted in an ABA independent manner with CAR1 in both the plasma membrane and nucleus of plant cells. CAR1 belongs to a plant specific gene family encoding CAR1 to CAR10 proteins, and bimolecular fluorescence complementation and coimmunoprecipitation assays showed that PYL4-CAR1 as well as other PYR/PYL-CAR pairs interacted in plant cells. The crystal structure of CAR4 was solved, which revealed that, in addition to a classical calcium-dependent lipid binding C2 domain, a specific CAR signature is likely responsible for the interaction with PYR/PYL receptors and their recruitment to phospholipid vesicles. This interaction is relevant for PYR/PYL function and ABA signaling, since different car triple mutants affected in CAR1, CAR4, CAR5, andCAR9 genes showed reduced sensitivity to ABA in seedling establishment and root growth assays. In summary, we identified PYR/PYL-interacting partners that mediate a transient Ca2+-dependent interaction with phospholipid vesicles, which affects PYR/PYL subcellular localization and positively regulates ABA signaling.
- Selective Inhibition of Clade A Phosphatases Type 2C by PYR/PYL/RCAR Abscisic Acid ReceptorsPublication . Antoni, Regina; Gonzalez-Guzman, Miguel; Rodriguez, Lesia; Rodrigues, Américo; Pizzio, Gaston A.; Rodriguez, Pedro L.Abstract Clade A protein phosphatases type 2C (PP2Cs) are negative regulators of abscisic acid (ABA) signaling that are inhibited in an ABA-dependent manner by PYRABACTIN RESISTANCE1 (PYR1)/PYR1-LIKE (PYL)/REGULATORY COMPONENTS OF ABA RECEPTORS (RCAR) intracellular receptors. We provide genetic evidence that a previously uncharacterized member of this PP2C family in Arabidopsis (Arabidopsis thaliana), At5g59220, is a negative regulator of osmotic stress and ABA signaling and that this function was only apparent when double loss-of-function mutants with pp2ca-1/ahg3 were generated. At5g59220-green fluorescent protein and its close relative PP2CA-green fluorescent protein showed a predominant nuclear localization; however, hemagglutinin-tagged versions were also localized to cytosol and microsomal pellets. At5g59220 was selectively inhibited by some PYR/PYL ABA receptors, and close relatives of this PP2C, such as PP2CA/ABA-HYPERSENSITIVE GERMINATION3 (AHG3) and AHG1, showed a contrasting sensitivity to PYR/PYL inhibition. Interestingly, AHG1 was resistant to inhibition by the PYR/PYL receptors tested, which suggests that this seed-specific phosphatase is still able to regulate ABA signaling in the presence of ABA and PYR/PYL receptors and therefore to control the highly active ABA signaling pathway that operates during seed development. Moreover, the differential sensitivity of the phosphatases At5g59220 and PP2CA to inhibition by ABA receptors reveals a functional specialization of PYR/PYL ABA receptors to preferentially inhibit certain PP2Cs.