| Structural highlights
Function
M2K5_ARATH Mitogen-activated protein kinase kinase (MAPKK) which regulates abscisic acid (ABA) responses in a MAPKKK20-MKK5-MPK6 cascade involved in root growth (e.g. root cell division and elongation) and stomatal response, probably via MAPK6 activation by protein phosphorylation (PubMed:27913741). Involved in the second phase of hydrogen peroxide generation during hypersensitive response-like cell death. Involved in the innate immune MAP kinase signaling cascade (MEKK1, MKK4/MKK5 and MPK3/MPK6) downstream of bacterial flagellin receptor FLS2. Activates by phosphorylation the downstream MPK3 and MPK6. YDA-MKK4/MKK5-MPK3/MPK6 module regulates stomatal cell fate before the guard mother cell (GMC) is specified. This MAPK cascade also functions downstream of the ER receptor in regulating coordinated local cell proliferation, which shapes the morphology of plant organs. MKK4 and MKK5 participate in the regulation of floral organ abscission. Target of the Pseudomonas syringae type III effector HopF2, that inhibits the activation of the downstream MPK6 and PAMP-triggered immunity. Plays a critical role in high light stress tolerance by the mediation of the Cu/Zn SODs CSD1 and CSD2 gene expression. Phosphorylates BZR1 in vitro.[1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11]
Publication Abstract from PubMed
The mitogen-activated protein kinase (MAPK) signaling pathways are highly conserved in eukaryotes, regulating various cellular processes. The MAPK kinases (MKKs) are dual specificity kinases, serving as convergence and divergence points of the tripartite MAPK cascades. Here, we investigate the biochemical characteristics and three-dimensional structure of MKK5 in Arabidopsis (AtMKK5). The recombinant full-length AtMKK5 is phosphorylated and can activate its physiological substrate AtMPK6. There is a conserved kinase interacting motif (KIM) at the N-terminus of AtMKK5, indispensable for specific recognition of AtMPK6. The kinase domain of AtMKK5 adopts active conformation, of which the extended activation segment is stabilized by the phosphorylated Ser221 and Thr215 residues. In line with sequence divergence from other MKKs, the alphaD and alphaK helices are missing in AtMKK5, suggesting that the AtMKK5 may adopt distinct modes of upstream kinase/substrate binding. Our data shed lights on the molecular mechanisms of MKK activation and substrate recognition, which may help design specific inhibitors targeting human and plant MKKs.
Crystal structure of the phosphorylated Arabidopsis MKK5 reveals activation mechanism of MAPK kinases.,Pei CJ, He QX, Luo Z, Yao H, Wang ZX, Wu JW Acta Biochim Biophys Sin (Shanghai). 2022 Aug 25;54(8):1159-1170. doi: , 10.3724/abbs.2022089. PMID:35866601[12]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Ren D, Yang H, Zhang S. Cell death mediated by MAPK is associated with hydrogen peroxide production in Arabidopsis. J Biol Chem. 2002 Jan 4;277(1):559-65. PMID:11687590 doi:10.1074/jbc.M109495200
- ↑ Asai T, Tena G, Plotnikova J, Willmann MR, Chiu WL, Gomez-Gomez L, Boller T, Ausubel FM, Sheen J. MAP kinase signalling cascade in Arabidopsis innate immunity. Nature. 2002 Feb 28;415(6875):977-83. PMID:11875555 doi:http://dx.doi.org/10.1038/415977a
- ↑ Wang H, Ngwenyama N, Liu Y, Walker JC, Zhang S. Stomatal development and patterning are regulated by environmentally responsive mitogen-activated protein kinases in Arabidopsis. Plant Cell. 2007 Jan;19(1):63-73. Epub 2007 Jan 26. PMID:17259259 doi:http://dx.doi.org/10.1105/tpc.106.048298
- ↑ Liu H, Wang Y, Xu J, Su T, Liu G, Ren D. Ethylene signaling is required for the acceleration of cell death induced by the activation of AtMEK5 in Arabidopsis. Cell Res. 2008 Mar;18(3):422-32. PMID:18268539 doi:10.1038/cr.2008.29
- ↑ Cho SK, Larue CT, Chevalier D, Wang H, Jinn TL, Zhang S, Walker JC. Regulation of floral organ abscission in Arabidopsis thaliana. Proc Natl Acad Sci U S A. 2008 Oct 7;105(40):15629-34. doi:, 10.1073/pnas.0805539105. Epub 2008 Sep 22. PMID:18809915 doi:http://dx.doi.org/10.1073/pnas.0805539105
- ↑ Wang Y, Li J, Hou S, Wang X, Li Y, Ren D, Chen S, Tang X, Zhou JM. A Pseudomonas syringae ADP-ribosyltransferase inhibits Arabidopsis mitogen-activated protein kinase kinases. Plant Cell. 2010 Jun;22(6):2033-44. PMID:20571112 doi:10.1105/tpc.110.075697
- ↑ Meng X, Wang H, He Y, Liu Y, Walker JC, Torii KU, Zhang S. A MAPK cascade downstream of ERECTA receptor-like protein kinase regulates Arabidopsis inflorescence architecture by promoting localized cell proliferation. Plant Cell. 2012 Dec;24(12):4948-60. doi: 10.1105/tpc.112.104695. Epub 2012 Dec, 21. PMID:23263767 doi:http://dx.doi.org/10.1105/tpc.112.104695
- ↑ Khan M, Rozhon W, Bigeard J, Pflieger D, Husar S, Pitzschke A, Teige M, Jonak C, Hirt H, Poppenberger B. Brassinosteroid-regulated GSK3/Shaggy-like kinases phosphorylate mitogen-activated protein (MAP) kinase kinases, which control stomata development in Arabidopsis thaliana. J Biol Chem. 2013 Mar 15;288(11):7519-7527. PMID:23341468 doi:10.1074/jbc.M112.384453
- ↑ Xing Y, Cao Q, Zhang Q, Qin L, Jia W, Zhang J. MKK5 regulates high light-induced gene expression of Cu/Zn superoxide dismutase 1 and 2 in Arabidopsis. Plant Cell Physiol. 2013 Jul;54(7):1217-27. PMID:23677921 doi:10.1093/pcp/pct072
- ↑ Wang C, Shang JX, Chen QX, Oses-Prieto JA, Bai MY, Yang Y, Yuan M, Zhang YL, Mu CC, Deng Z, Wei CQ, Burlingame AL, Wang ZY, Sun Y. Identification of BZR1-interacting proteins as potential components of the brassinosteroid signaling pathway in Arabidopsis through tandem affinity purification. Mol Cell Proteomics. 2013 Dec;12(12):3653-65. PMID:24019147 doi:10.1074/mcp.M113.029256
- ↑ Li K, Yang F, Zhang G, Song S, Li Y, Ren D, Miao Y, Song CP. AIK1, A Mitogen-Activated Protein Kinase, Modulates Abscisic Acid Responses through the MKK5-MPK6 Kinase Cascade. Plant Physiol. 2017 Feb;173(2):1391-1408. PMID:27913741 doi:10.1104/pp.16.01386
- ↑ Pei CJ, He QX, Luo Z, Yao H, Wang ZX, Wu JW. Crystal structure of the phosphorylated Arabidopsis MKK5 reveals activation mechanism of MAPK kinases. Acta Biochim Biophys Sin (Shanghai). 2022 Aug 25;54(8):1159-1170. PMID:35866601 doi:10.3724/abbs.2022089
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