TY - JOUR
T1 - The MAP kinase substrate MKS1 is a regulator of plant defense responses.
AU - Andreasson, Erik
AU - Jenkins, Thomas
AU - Brodersen, Peter
AU - Thorgrimsen, Stephan
AU - Petersen, Nikolaj H T
AU - Zhu, Shijiang
AU - Qiu, Jin-Long
AU - Micheelsen, Pernille
AU - Rocher, Anne
AU - Petersen, Morten
AU - Newman, Mari-Anne
AU - Bjørn Nielsen, Henrik
AU - Hirt, Heribert
AU - Somssich, Imre
AU - Mattsson, Ole
AU - Mundy, John
N1 - Keywords: Amino Acid Motifs; Amino Acid Sequence; Arabidopsis Proteins; Gene Expression Profiling; Immunity, Natural; Immunohistochemistry; Mitogen-Activated Protein Kinases; Molecular Sequence Data; Phosphoproteins; Phosphorylation; Plants; Saccharomyces cerevisiae; Substrate Specificity; Two-Hybrid System Techniques
PY - 2005
Y1 - 2005
N2 - Arabidopsis MAP kinase 4 (MPK4) functions as a regulator of pathogen defense responses, because it is required for both repression of salicylic acid (SA)-dependent resistance and for activation of jasmonate (JA)-dependent defense gene expression. To understand MPK4 signaling mechanisms, we used yeast two-hybrid screening to identify the MPK4 substrate MKS1. Analyses of transgenic plants and genome-wide transcript profiling indicated that MKS1 is required for full SA-dependent resistance in mpk4 mutants, and that overexpression of MKS1 in wild-type plants is sufficient to activate SA-dependent resistance, but does not interfere with induction of a defense gene by JA. Further yeast two-hybrid screening revealed that MKS1 interacts with the WRKY transcription factors WRKY25 and WRKY33. WRKY25 and WRKY33 were shown to be in vitro substrates of MPK4, and a wrky33 knockout mutant was found to exhibit increased expression of the SA-related defense gene PR1. MKS1 may therefore contribute to MPK4-regulated defense activation by coupling the kinase to specific WRKY transcription factors.
AB - Arabidopsis MAP kinase 4 (MPK4) functions as a regulator of pathogen defense responses, because it is required for both repression of salicylic acid (SA)-dependent resistance and for activation of jasmonate (JA)-dependent defense gene expression. To understand MPK4 signaling mechanisms, we used yeast two-hybrid screening to identify the MPK4 substrate MKS1. Analyses of transgenic plants and genome-wide transcript profiling indicated that MKS1 is required for full SA-dependent resistance in mpk4 mutants, and that overexpression of MKS1 in wild-type plants is sufficient to activate SA-dependent resistance, but does not interfere with induction of a defense gene by JA. Further yeast two-hybrid screening revealed that MKS1 interacts with the WRKY transcription factors WRKY25 and WRKY33. WRKY25 and WRKY33 were shown to be in vitro substrates of MPK4, and a wrky33 knockout mutant was found to exhibit increased expression of the SA-related defense gene PR1. MKS1 may therefore contribute to MPK4-regulated defense activation by coupling the kinase to specific WRKY transcription factors.
U2 - 10.1038/sj.emboj.7600737
DO - 10.1038/sj.emboj.7600737
M3 - Journal article
C2 - 15990873
SN - 0261-4189
VL - 24
SP - 2579
EP - 2589
JO - EMBO Journal
JF - EMBO Journal
IS - 14
ER -