Gene Symbol: SOS2
Description: Protein kinase superfamily protein
Alias: ATSOS2, CBL-INTERACTING PROTEIN KINASE 24, CIPK24, K21B8.3, K21B8_3, SALT OVERLY SENSITIVE 2, SNF1-RELATED PROTEIN KINASE 3.11, SNRK3.11, Protein kinase superfamily protein
Species: thale cress

Top Publications

  1. Kim B, Waadt R, Cheong Y, Pandey G, Dominguez Solis J, Schültke S, et al. The calcium sensor CBL10 mediates salt tolerance by regulating ion homeostasis in Arabidopsis. Plant J. 2007;52:473-84 pubmed
    ..Indeed, the CBL10 protein physically interacts with the salt-tolerance factor CIPK24 (SOS2), and the CBL10-CIPK24 (SOS2) complex is associated with the vacuolar compartments that are responsible for ..
  2. Quintero F, Martinez Atienza J, Villalta I, Jiang X, Kim W, Ali Z, et al. Activation of the plasma membrane Na/H antiporter Salt-Overly-Sensitive 1 (SOS1) by phosphorylation of an auto-inhibitory C-terminal domain. Proc Natl Acad Sci U S A. 2011;108:2611-6 pubmed publisher
    ..The SOS2-SOS3 calcium-dependent protein kinase complex up-regulates SOS1 activity, but the mechanistic details of this ..
  3. Cheng N, Pittman J, Zhu J, Hirschi K. The protein kinase SOS2 activates the Arabidopsis H(+)/Ca(2+) antiporter CAX1 to integrate calcium transport and salt tolerance. J Biol Chem. 2004;279:2922-6 pubmed
    The regulation of ions within cells is an indispensable component of growth and adaptation. The plant SOS2 protein kinase and its associated Ca(2+) sensor, SOS3, have been demonstrated to modulate the plasma membrane H(+)/Na(+) antiporter ..
  4. Du W, Lin H, Chen S, Wu Y, Zhang J, Fuglsang A, et al. Phosphorylation of SOS3-like calcium-binding proteins by their interacting SOS2-like protein kinases is a common regulatory mechanism in Arabidopsis. Plant Physiol. 2011;156:2235-43 pubmed publisher
    ..Overly Sensitive3 (SOS3)-like calcium-binding proteins (SCaBPs; also named calcineurin B-like protein [CBL]) and 24 SOS2-like protein kinases (PKSs; also named as CBL-interacting protein kinases [CIPKs])...
  5. Batistic O, Waadt R, Steinhorst L, Held K, Kudla J. CBL-mediated targeting of CIPKs facilitates the decoding of calcium signals emanating from distinct cellular stores. Plant J. 2010;61:211-22 pubmed publisher
  6. Popescu S, Popescu G, Bachan S, Zhang Z, Seay M, Gerstein M, et al. Differential binding of calmodulin-related proteins to their targets revealed through high-density Arabidopsis protein microarrays. Proc Natl Acad Sci U S A. 2007;104:4730-5 pubmed
    ..Our results suggest that calcium functions through distinct CaM/CML proteins to regulate a wide range of targets and cellular activities. ..
  7. Sánchez Barrena M, Fujii H, Angulo I, Martinez Ripoll M, Zhu J, Albert A. The structure of the C-terminal domain of the protein kinase AtSOS2 bound to the calcium sensor AtSOS3. Mol Cell. 2007;26:427-35 pubmed
    The plant SOS2 family of protein kinases and their interacting activators, the SOS3 family of calcium-binding proteins, function together in decoding calcium signals elicited by different environmental stimuli...
  8. Ohta M, Guo Y, Halfter U, Zhu J. A novel domain in the protein kinase SOS2 mediates interaction with the protein phosphatase 2C ABI2. Proc Natl Acad Sci U S A. 2003;100:11771-6 pubmed
    SOS2 (salt overly sensitive 2) is a serine/threonine protein kinase required for salt tolerance in Arabidopsis thaliana...
  9. Waadt R, Schmidt L, Lohse M, Hashimoto K, Bock R, Kudla J. Multicolor bimolecular fluorescence complementation reveals simultaneous formation of alternative CBL/CIPK complexes in planta. Plant J. 2008;56:505-16 pubmed publisher acting in calcium-mediated signal transduction revealed the concurrent interaction of the protein kinase CIPK24 with the calcium sensors CBL1 and CBL10 at the plasma membrane and tonoplast, respectively...

More Information


  1. Chaves Sanjuan A, Sánchez Barrena M, González Rubio J, Moreno M, Ragel P, Jimenez M, et al. Structural basis of the regulatory mechanism of the plant CIPK family of protein kinases controlling ion homeostasis and abiotic stress. Proc Natl Acad Sci U S A. 2014;111:E4532-41 pubmed publisher
    ..We present the crystal structures of the NAF-truncated and pseudophosphorylated kinase domains of CIPK23 and CIPK24/SOS2...
  2. Verslues P, Batelli G, Grillo S, Agius F, Kim Y, Zhu J, et al. Interaction of SOS2 with nucleoside diphosphate kinase 2 and catalases reveals a point of connection between salt stress and H2O2 signaling in Arabidopsis thaliana. Mol Cell Biol. 2007;27:7771-80 pubmed
    b>SOS2, a class 3 sucrose-nonfermenting 1-related kinase, has emerged as an important mediator of salt stress response and stress signaling through its interactions with proteins involved in membrane transport and in regulation of stress ..
  3. Hashimoto K, Eckert C, Anschütz U, Scholz M, Held K, Waadt R, et al. Phosphorylation of calcineurin B-like (CBL) calcium sensor proteins by their CBL-interacting protein kinases (CIPKs) is required for full activity of CBL-CIPK complexes toward their target proteins. J Biol Chem. 2012;287:7956-68 pubmed publisher
  4. Lan W, Lee S, Che Y, Jiang Y, Luan S. Mechanistic analysis of AKT1 regulation by the CBL-CIPK-PP2CA interactions. Mol Plant. 2011;4:527-36 pubmed publisher
    ..These findings provide further insights into the signaling network consisting of CBL-CIPK-PP2C interactions in the activation of the AKT1 channel. ..
  5. Lin H, Yang Y, Quan R, Mendoza I, Wu Y, Du W, et al. Phosphorylation of SOS3-LIKE CALCIUM BINDING PROTEIN8 by SOS2 protein kinase stabilizes their protein complex and regulates salt tolerance in Arabidopsis. Plant Cell. 2009;21:1607-19 pubmed publisher
    ..binding proteins SOS3 and SOS3-LIKE CALCIUM BINDING PROTEIN8 (SCaBP8) nonredundantly activate the protein kinase SOS2. Here, we show that SOS2 phosphorylates SCaBP8 at its C terminus but does not phosphorylate SOS3...
  6. Guo Y, Halfter U, Ishitani M, Zhu J. Molecular characterization of functional domains in the protein kinase SOS2 that is required for plant salt tolerance. Plant Cell. 2001;13:1383-400 pubmed
    The SOS3 (for SALT OVERLY SENSITIVE3) calcium binding protein and SOS2 protein kinase are required for sodium and potassium ion homeostasis and salt tolerance in Arabidopsis...
  7. Kim W, Ali Z, Park H, Park S, Cha J, Pérez Hormaeche J, et al. Release of SOS2 kinase from sequestration with GIGANTEA determines salt tolerance in Arabidopsis. Nat Commun. 2013;4:1352 pubmed publisher
    ..GI, a switch in photoperiodicity and circadian clock control, and the SNF1-related protein kinase SOS2 functionally interact...
  8. Ishitani M, Liu J, Halfter U, Kim C, Shi W, Zhu J. SOS3 function in plant salt tolerance requires N-myristoylation and calcium binding. Plant Cell. 2000;12:1667-78 pubmed
    ..The resulting mutant SOS3 protein was not able to interact with the SOS2 protein kinase and was less capable of activating it...
  9. Kolukisaoglu U, Weinl S, Blazevic D, Batistic O, Kudla J. Calcium sensors and their interacting protein kinases: genomics of the Arabidopsis and rice CBL-CIPK signaling networks. Plant Physiol. 2004;134:43-58 pubmed
    ..This work provides a basis for a defined further functional dissection of this important plant-specific signaling system. ..
  10. Liu J, Ishitani M, Halfter U, Kim C, Zhu J. The Arabidopsis thaliana SOS2 gene encodes a protein kinase that is required for salt tolerance. Proc Natl Acad Sci U S A. 2000;97:3730-4 pubmed
    In Arabidopsis thaliana, the Salt Overly Sensitive 2 (SOS2) gene is required for intracellular Na(+) and K(+) homeostasis...
  11. Zhu J, Liu J, Xiong L. Genetic analysis of salt tolerance in arabidopsis. Evidence for a critical role of potassium nutrition. Plant Cell. 1998;10:1181-91 pubmed
    ..Our search yielded 28 new alleles of sos1, nine mutant alleles of a newly identified locus, SOS2, and one allele of a third salt tolerance locus, SOS3...
  12. Lin H, Du W, Yang Y, Schumaker K, Guo Y. A calcium-independent activation of the Arabidopsis SOS2-like protein kinase24 by its interacting SOS3-like calcium binding protein1. Plant Physiol. 2014;164:2197-206 pubmed publisher
    ..the SOS3 and SOS3-like CALCIUM-BINDING PROTEIN8 (SCaBP8) calcium sensors, which then interact with and activate the SOS2 protein kinase, forming a complex at the plasma membrane that activates the SOS1 Na?/H? exchanger...
  13. Halfter U, Ishitani M, Zhu J. The Arabidopsis SOS2 protein kinase physically interacts with and is activated by the calcium-binding protein SOS3. Proc Natl Acad Sci U S A. 2000;97:3735-40 pubmed
    The Arabidopsis thaliana SOS2 and SOS3 genes are required for intracellular Na(+) and K(+) homeostasis and plant tolerance to high Na(+) and low K(+) environments...
  14. Tang R, Liu H, Yang Y, Yang L, Gao X, Garcia V, et al. Tonoplast calcium sensors CBL2 and CBL3 control plant growth and ion homeostasis through regulating V-ATPase activity in Arabidopsis. Cell Res. 2012;22:1650-65 pubmed publisher
    ..Our results suggest that calcium sensors CBL2 and CBL3 serve as molecular links between calcium signaling and V-ATPase, a central regulator of intracellular ion homeostasis. ..
  15. Quan R, Lin H, Mendoza I, Zhang Y, Cao W, Yang Y, et al. SCABP8/CBL10, a putative calcium sensor, interacts with the protein kinase SOS2 to protect Arabidopsis shoots from salt stress. Plant Cell. 2007;19:1415-31 pubmed
    ..Under salt stress, the calcium sensor SOS3 activates the kinase SOS2 that positively regulates SOS1, a plasma membrane sodium/proton antiporter...
  16. Batelli G, Verslues P, Agius F, Qiu Q, Fujii H, Pan S, et al. SOS2 promotes salt tolerance in part by interacting with the vacuolar H+-ATPase and upregulating its transport activity. Mol Cell Biol. 2007;27:7781-90 pubmed
    ..regulated by the SOS pathway, we expressed an N-terminal fusion of the improved tandem affinity purification tag to SOS2 (NTAP-SOS2) in sos2-2 mutant plants...
  17. Shin L, Lo J, Chen G, Callis J, Fu H, Yeh K. IRT1 degradation factor1, a ring E3 ubiquitin ligase, regulates the degradation of iron-regulated transporter1 in Arabidopsis. Plant Cell. 2013;25:3039-51 pubmed publisher
    ..The idf1 mutants showed increased tolerance to Fe deficiency, resulting from increased IRT1 levels. This evidence indicates that IDF1 directly regulates IRT1 degradation through its RING-type E3 ligase activity...