Arabidopsis MAP kinase 4 regulates gene expression through transcription factor release in the nucleus.
Plant and animal perception of microbes through pathogen surveillance proteins leads to MAP kinase signalling and the expression of defence genes. However, little is known about how plant MAP kinases regulate specific gene expression. We report that, in the absence of pathogens, Arabidopsis MAP kinase 4 (MPK4) exists in nuclear complexes with the WRKY33 transcription factor. This complex depends on the MPK4 substrate MKS1. Challenge with Pseudomonas syringae or flagellin leads to the activation of MPK4 and phosphorylation of MKS1. Subsequently, complexes with MKS1 and WRKY33 are released from MPK4, and WRKY33 targets the promoter of PHYTOALEXIN DEFICIENT3 (PAD3) encoding an enzyme required for the synthesis of antimicrobial camalexin. Hence, wrky33 mutants are impaired in the accumulation of PAD3 mRNA and camalexin production upon infection. That WRKY33 is an effector of MPK4 is further supported by the suppression of PAD3 expression in mpk4-wrky33 double mutant backgrounds. Our data establish direct links between MPK4 and innate immunity and provide an example of how a plant MAP kinase can regulate gene expression by releasing transcription factors in the nucleus upon activation.
Qiu
Jin-Long
JL
Department of Biology, University of Copenhagen, Copenhagen, Denmark.
Fiil
Berthe Katrine
BK
Petersen
Klaus
K
Nielsen
Henrik Bjørn
HB
Botanga
Christopher J
CJ
Thorgrimsen
Stephan
S
Palma
Kristoffer
K
Suarez-Rodriguez
Maria Cristina
MC
Sandbech-Clausen
Signe
S
Lichota
Jacek
J
Brodersen
Peter
P
Grasser
Klaus D
KD
Mattsson
Ole
O
Glazebrook
Jane
J
Mundy
John
J
Petersen
Morten
M
D017360:Arabidopsis / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics* / Q000382:microbiology; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D002467:Cell Nucleus / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics*; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics / Q000378:metabolism; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D017343:Genes, Plant; D007211:Indoles / Q000378:metabolism; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D009154:Mutation / Q000235:genetics; D009687:Nuclear Proteins; D010750:Phosphoproteins / Q000378:metabolism; D011401:Promoter Regions, Genetic / Q000235:genetics; D011485:Protein Binding / Q000187:drug effects; D044224:Pseudomonas syringae / Q000187:drug effects; D020133:Reverse Transcriptase Polymerase Chain Reaction; D020156:Salicylic Acid / Q000494:pharmacology; D013844:Thiazoles / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism*; D000094162:Phytoalexins
D029681:Arabidopsis Proteins; D003577:Cytochrome P-450 Enzyme System; D007211:Indoles; D020928:Mitogen-Activated Protein Kinases; D009687:Nuclear Proteins; D010750:Phosphoproteins; D020156:Salicylic Acid; D013844:Thiazoles; D014157:Transcription Factors; C503586:MKS1 protein, Arabidopsis; C517860:WRKY33 protein, Arabidopsis; C102405:camalexin; D000094162:Phytoalexins; C417307:PAD3 protein, Arabidopsis; C436292:AtMPK4 protein, Arabidopsis