| Structural highlights
3uc4 is a 2 chain structure with sequence from Arath. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
| | Related: | |
| Gene: | SRK2E, OST1, SNRK2.6, At4g33950, F17I5.140 (ARATH) |
| Activity: | Non-specific serine/threonine protein kinase, with EC number 2.7.11.1 |
| Resources: | FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT |
Function
[SRK2E_ARATH] Activator of the abscisic acid (ABA) signaling pathway that regulates numerous ABA responses, such as stomata closure in response to drought, plant pathogens, or decreases in atmospheric relative humidity (RH). Involved in the resistance to drought by avoiding water loss. Required for the stomata closure mediated by pathogen-associated molecular pattern (PAMPs) (e.g. flg22 and LPS) of pathogenic bacteria such as P.syringae pv. tomato (Pst) and E.coli O157:H7. As a plant defense process, stomata are closed transiently in order to limit invaders, but actively reopened by bacteria after a few hours; virulent strains (e.g. Pst DC3000) are more efficient than avirulent strains (e.g. Pst DC3000 AvrRpt2) in reopening stomata. Mediates the phosphorylation and activation of the S-type anion efflux channel SLAC1, and thus promotes stomata closure. Essential for stomatal closure in response to reactive oxygen species (ROS).[1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12]
Publication Abstract from PubMed
Abscisic acid (ABA) is an essential hormone that controls plant growth, development, and responses to abiotic stresses. Central for ABA signaling is the ABA-mediated autoactivation of three monomeric Snf1-related kinases (SnRK2.2, -2.3, and -2.6). In the absence of ABA, SnRK2s are kept in an inactive state by forming physical complexes with type 2C protein phosphatases (PP2Cs). Upon relief of this inhibition, SnRK2 kinases can autoactivate through unknown mechanisms. Here, we report the crystal structures of full-length Arabidopsis thaliana SnRK2.3 and SnRK2.6 at 1.9- and 2.3-A resolution, respectively. The structures, in combination with biochemical studies, reveal a two-step mechanism of intramolecular kinase activation that resembles the intermolecular activation of cyclin-dependent kinases. First, release of inhibition by PP2C allows the SnRK2s to become partially active because of an intramolecular stabilization of the catalytic domain by a conserved helix in the kinase regulatory domain. This stabilization enables SnRK2s to gain full activity by activation loop autophosphorylation. Autophosphorylation is more efficient in SnRK2.6, which has higher stability than SnRK2.3 and has well-structured activation loop phosphate acceptor sites that are positioned next to the catalytic site. Together, these data provide a structural framework that links ABA-mediated release of PP2C inhibition to activation of SnRK2 kinases.
Structural basis for basal activity and autoactivation of abscisic acid (ABA) signaling SnRK2 kinases.,Ng LM, Soon FF, Zhou XE, West GM, Kovach A, Suino-Powell KM, Chalmers MJ, Li J, Yong EL, Zhu JK, Griffin PR, Melcher K, Xu HE Proc Natl Acad Sci U S A. 2011 Dec 27;108(52):21259-64. Epub 2011 Dec 12. PMID:22160701[13]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Mustilli AC, Merlot S, Vavasseur A, Fenzi F, Giraudat J. Arabidopsis OST1 protein kinase mediates the regulation of stomatal aperture by abscisic acid and acts upstream of reactive oxygen species production. Plant Cell. 2002 Dec;14(12):3089-99. PMID:12468729
- ↑ Yoshida R, Hobo T, Ichimura K, Mizoguchi T, Takahashi F, Aronso J, Ecker JR, Shinozaki K. ABA-activated SnRK2 protein kinase is required for dehydration stress signaling in Arabidopsis. Plant Cell Physiol. 2002 Dec;43(12):1473-83. PMID:12514244
- ↑ Merlot S, Mustilli AC, Genty B, North H, Lefebvre V, Sotta B, Vavasseur A, Giraudat J. Use of infrared thermal imaging to isolate Arabidopsis mutants defective in stomatal regulation. Plant J. 2002 Jun;30(5):601-9. PMID:12047634
- ↑ Suhita D, Raghavendra AS, Kwak JM, Vavasseur A. Cytoplasmic alkalization precedes reactive oxygen species production during methyl jasmonate- and abscisic acid-induced stomatal closure. Plant Physiol. 2004 Apr;134(4):1536-45. Epub 2004 Apr 2. PMID:15064385 doi:http://dx.doi.org/10.1104/pp.103.032250
- ↑ Melotto M, Underwood W, Koczan J, Nomura K, He SY. Plant stomata function in innate immunity against bacterial invasion. Cell. 2006 Sep 8;126(5):969-80. PMID:16959575 doi:http://dx.doi.org/S0092-8674(06)01015-4
- ↑ Xie X, Wang Y, Williamson L, Holroyd GH, Tagliavia C, Murchie E, Theobald J, Knight MR, Davies WJ, Leyser HM, Hetherington AM. The identification of genes involved in the stomatal response to reduced atmospheric relative humidity. Curr Biol. 2006 May 9;16(9):882-7. PMID:16682349 doi:http://dx.doi.org/S0960-9822(06)01324-8
- ↑ Yoshida R, Umezawa T, Mizoguchi T, Takahashi S, Takahashi F, Shinozaki K. The regulatory domain of SRK2E/OST1/SnRK2.6 interacts with ABI1 and integrates abscisic acid (ABA) and osmotic stress signals controlling stomatal closure in Arabidopsis. J Biol Chem. 2006 Feb 24;281(8):5310-8. Epub 2005 Dec 19. PMID:16365038 doi:M509820200
- ↑ Belin C, de Franco PO, Bourbousse C, Chaignepain S, Schmitter JM, Vavasseur A, Giraudat J, Barbier-Brygoo H, Thomine S. Identification of features regulating OST1 kinase activity and OST1 function in guard cells. Plant Physiol. 2006 Aug;141(4):1316-27. Epub 2006 Jun 9. PMID:16766677 doi:pp.106.079327
- ↑ Fujii H, Verslues PE, Zhu JK. Identification of two protein kinases required for abscisic acid regulation of seed germination, root growth, and gene expression in Arabidopsis. Plant Cell. 2007 Feb;19(2):485-94. Epub 2007 Feb 16. PMID:17307925 doi:tpc.106.048538
- ↑ Lee SC, Lan W, Buchanan BB, Luan S. A protein kinase-phosphatase pair interacts with an ion channel to regulate ABA signaling in plant guard cells. Proc Natl Acad Sci U S A. 2009 Dec 15;106(50):21419-24. doi:, 10.1073/pnas.0910601106. Epub 2009 Dec 2. PMID:19955427 doi:http://dx.doi.org/10.1073/pnas.0910601106
- ↑ Geiger D, Scherzer S, Mumm P, Stange A, Marten I, Bauer H, Ache P, Matschi S, Liese A, Al-Rasheid KA, Romeis T, Hedrich R. Activity of guard cell anion channel SLAC1 is controlled by drought-stress signaling kinase-phosphatase pair. Proc Natl Acad Sci U S A. 2009 Dec 15;106(50):21425-30. doi:, 10.1073/pnas.0912021106. Epub 2009 Dec 2. PMID:19955405 doi:10.1073/pnas.0912021106
- ↑ Vahisalu T, Puzorjova I, Brosche M, Valk E, Lepiku M, Moldau H, Pechter P, Wang YS, Lindgren O, Salojarvi J, Loog M, Kangasjarvi J, Kollist H. Ozone-triggered rapid stomatal response involves the production of reactive oxygen species, and is controlled by SLAC1 and OST1. Plant J. 2010 May;62(3):442-53. doi: 10.1111/j.1365-313X.2010.04159.x. Epub 2010 , Feb 1. PMID:20128877 doi:http://dx.doi.org/10.1111/j.1365-313X.2010.04159.x
- ↑ Ng LM, Soon FF, Zhou XE, West GM, Kovach A, Suino-Powell KM, Chalmers MJ, Li J, Yong EL, Zhu JK, Griffin PR, Melcher K, Xu HE. Structural basis for basal activity and autoactivation of abscisic acid (ABA) signaling SnRK2 kinases. Proc Natl Acad Sci U S A. 2011 Dec 27;108(52):21259-64. Epub 2011 Dec 12. PMID:22160701 doi:10.1073/pnas.1118651109
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