Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.3.16 (calcineurin)
 17,112 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Abscisic acid (ABA) regulates fruit ripening, yet little is known about the exact roles of ABA receptors in fruit. In this study, we reveal the role of SlPYL9, a tomato pyrabactin resistance (PYR)/pyrobactin resistance-like (PYL)/regulatory component of ABA receptors (RCAR) protein, as a positive regulator of ABA signaling and fruit ripening. SlPYL9 inhibits protein phosphatase-type 2C (PP2C2/6) in an ABA dose-dependent way, and it interacts physically with SlPP2C2/3/4/5 in an ABA-dependent manner. Expression of SlPYL9 was observed in the seeds, flowers, and fruits. Overexpression and suppression of SlPYL9 induced a variety of phenotypes via altered expression of ABA signaling genes (SlPP2C1/2/9, SlSnRK2.8, SlABF2), thereby affecting expression of ripening-related genes involved in ethylene release and cell wall modification. SlPYL9-OE/RNAi plants showed a typical ABA hyper-/hypo-sensitive phenotype in terms of seed germination, primary root growth, and response to drought. Fruit ripening was significantly accelerated in SlPYL9-OE by 5-7 d as a result of increased endogenous ABA accumulation and advanced release of ethylene compared with the wild-type. In the SlPYL9-RNAi lines, fruit ripening was delayed, mesocarp thickness was enhanced, and petal abscission was delayed compared with the wild-type, resulting in conical/oblong and gourd-shaped fruits. These results suggest that SlPYL9 is involved in ABA signaling, thereby playing a role in the regulation of flower abscission and fruit ripening in tomato.
J Exp Bot 2019 11 18
PMID:PYL9 is involved in the regulation of ABA signaling during tomato fruit ripening. 3150 53

VIP1 is a bZIP transcription factor in Arabidopsis thaliana. When cells are exposed to mechanical stress, VIP1 transiently accumulates in the nucleus, where it regulates the expression of its target genes and suppresses mechanical stress-induced root waving. The nuclear-cytoplasmic shuttling of VIP1 is regulated by phosphorylation and calcium-dependent signaling, but specific regulators of these processes remain to be identified. Here, inhibitors of protein phosphatase 2A (PP2A) are shown to inhibit both the mechanical stress-induced dephosphorylation and nuclear accumulation of VIP1. The PP2A B subunit, which recruits substrates of PP2A holoenzyme, is classified into B, B', B'', and B''' families. Using bimolecular fluorescence complementation, in vitro pull-down, and yeast two-hybrid assays, we show that VIP1 interacts with at least two of the six members of the Arabidopsis PP2A B''-family subunit, which have calcium-binding EF-hand motifs. VIP1AAA, a constitutively nuclear-localized VIP1 variant with substitutions in putative phosphorylation sites of VIP1, suppressed the root waving induced by VIP1-SRDX (a repression domain-fused variant of VIP1). These results support the idea that VIP1 is dephosphorylated by PP2A and that the dephosphorylation suppresses the root waving. The phosphorylation sites of VIP1 and its homologs were narrowed down by in vitro phosphorylation, yeast two-hybrid, and protein subcellular localization assays.
J Exp Bot 2019 11 18
PMID:Protein phosphatase 2A regulates the nuclear accumulation of the Arabidopsis bZIP protein VIP1 under hypo-osmotic stress. 3150 62

The plant hormone abscisic acid (ABA) plays a crucial role during the plant life cycle as well as in adaptive responses to environmental stresses. The core regulatory components of ABA signaling in plants are the pyrabactin resistance1/PYR1-like/regulatory component of ABA receptor family (PYLs), which comprise the largest plant hormone receptor family known. They act as negative regulators of members of the protein phosphatase type 2C family. Due to the biological importance of PYLs, many researchers have focused on their genetic redundancy and consequent functional divergence. However, little is understood of their evolution and its impact on the generation of regulatory diversity. In this study, we identify positive selection and functional divergence in PYLs through phylogenetic reconstruction, gene structure and expression pattern analysis, positive selection analysis, functional divergence analysis, and structure comparison. We found the correlation of desensitization of PYLs under specific modifications in the molecular recognition domain with functional diversification. Hence, an interesting antagonistic co-evolutionary mechanism is proposed for the functional diversification of ABA receptor family proteins. We believe a compensatory evolutionary pathway may have occurred.
J Exp Bot 2020 02 19
PMID:Genome-wide phylogenetic and structural analysis reveals the molecular evolution of the ABA receptor gene family. 3174 Sep 33


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