A protein kinase, interacting with two calcineurin B-like proteins, regulates K+ transporter AKT1 in Arabidopsis.

By Jiang-ning Xu, Hao-Dong Li, Li‐Qing Chen, Yi Wang, Li-Li Liu, Liu He, Wei-Hua Wu. Cell, 2006

963 citations recorded by the source corpus.

Potassium is an essential mineral element for plant growth and development. Although it is known that plants absorb and transport K+ through membrane transporters, it remains unclear how these transporters are regulated. Here we show that the protein kinase CIPK23, encoded by the LKS1 gene, regulates K+ uptake under low-K+ conditions. Lesion of LKS1 significantly reduced K+ uptake and caused leaf chlorosis and growth inhibition, whereas overexpression of LKS1 significantly enhanced K+ uptake and tolerance to low K+. We demonstrate that CIPK23 directly phosphorylates the K+ transporter AKT1 and further find that CIPK23 is activated by the binding of two calcineurin B-like proteins, CBL1 and CBL9. We propose a model in which the CBL1/9-CIPK23 pathway ensures activation of AKT1 and enhanced K+ uptake under low-K+ conditions.

Subfields: Plant Science

View Paper: https://www.semanticscholar.org/paper/e448e7a00d5936859a21ecd8dd3fcd6034352c41

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In Plant Science

1. T. Flowers
2. F. Maathuis
3. Suo-min Wang
4. Jinlin Zhang
5. J. Schroeder
6. Shahid Ali
7. Dai-Yin Chao
8. Jian‐Kang Zhu

Citations in the corpus

• Implications of Abscisic Acid in the Drought Stress Tolerance of Plants (2020, background): “The CBL1/CBL2-CIPK23 complex in the plasma membrane modulates the Arabidopsis K+ Transporter1 (AKT1) to regulate the K+ content in root and guard cells [54,55].”
• CHL1 functions as a nitrate sensor in plants. (2009, background): “…et al., 2004), several of which have been shown to activate plant membrane transport proteins and participate in Na + , salt, cold, drought, and abscisic acid signaling and the K + shortage response (Batistic and Kudla, 2004; Cheng et al., 2004; Gong et al., 2004; Li et al., 2006; Xu et al., 2006).”
• Guard Cell Signal Transduction Network: Advances in Understanding Abscisic Acid, CO2, and Ca2+ Signaling (2010, background): “Based on the cbl1cbl9 double mutant phenotype, CBL1 and CBL9 might synergistically activate CIPK23 during Ca2+dependent signaling in guard cells (22).”
• Understanding Abiotic Stress Tolerance Mechanisms: Recent Studies on Stress Response in Rice (2007, background): “Some of their activities can be regulated by protein phosphorylation (Xu et al. 2006a).”
• Abiotic stress signaling and responses in plants (2016, background): “For example, low potassium stress, which presumably triggers a cytosolic calcium signal, activates CIPK23 via CBL1 and CBL9, to phosphorylate and activate the potassium channel AKT1 (Xu et al., 2006).”
• Mechanisms of sodium uptake by roots of higher plants (2009, background): “…that the Ca2+-sensitive CBL (calcineurin Blike Ca2+) and CIPK (CBL-interacting protein kinase) families together with 2C-type protein phosphatases form a protein phosphorylation / dephosphorylation network that regulates the AKT1 channel for K+ transport in plants (Lee et al. 2007; Xu et al. 2006).”
• Adaptation of Plants to Salt Stress: Characterization of Na+ and K+ Transporters and Role of CBL Gene Family in Regulating Salt Stress Response (2019, background): “In a very interesting way, the characterization of these functional systems has shown that they act as inward rectifying channels [55,84], despite strong homology with voltage-dependent, highly selective K+ channels, which act as outgoing channels.”
• Calcium Signals: The Lead Currency of Plant Information Processing (2010, background): “Considering the critical involvement of the same CBL1 (and CBL9) Ca2+ sensor proteins and CIPK23-dependent phosphorylation in both processes, this puzzling observation underscores the urgent need for further investigation of the primary ionsensing mechanism(s) that confer this remarkable specificity”
• Calcineurin B-Like family in Populus: comparative genome analysis and expression pattern under cold, drought and salt stress treatment (2008, background): “Remarkably, recent results suggest that a complex network involving multiple CBLs and CIPKs may cooperate in the regulation of AKT1 activity (Xu et al. 2006; Li et al. 2006; Lee et al. 2007).”
• Comparative genomic analysis of CIPK gene family in Arabidopsis and Populus (2007, background): “Fourth, clarification of the downstream physiological substrates of CIPK has great significance for understanding its physiological functions, but only two pathways (CBL4-CIPK24-SOS1 and CBL1/CBL9-CIPK23AKT1) have been determined.”