BWMK1, a rice mitogen-activated protein kinase, locates in the nucleus and mediates pathogenesis-related gene expression by activation of a transcription factor.
Mitogen-activated protein kinase (MAPK) cascades are known to transduce plant defense signals, but the downstream components of the MAPK have as yet not been elucidated. Here, we report an MAPK from rice (Oryza sativa), BWMK1, and a transcription factor, OsEREBP1, phosphorylated by the kinase. The MAPK carries a TDY phosphorylation motif instead of the more common TEY motif in its kinase domain and has an unusually extended C-terminal domain that is essential to its kinase activity and translocation to the nucleus. The MAPK phosphorylates OsEREBP1 that binds to the GCC box element (AGCCGCC) of the several basic pathogenesis-related gene promoters, which in turn enhances DNA-binding activity of the factor to the cis element in vitro. Transient co-expression of the BWMK1 and OsEREBP1 in Arabidopsis protoplasts elevates the expression of the beta-glucuronidase reporter gene driven by the GCC box element. Furthermore, transgenic tobacco (Nicotiana tabacum) plants overexpressing BWMK1 expressed many pathogenesis-related genes at higher levels than wild-type plants with an enhanced resistance to pathogens. These findings suggest that MAPKs contribute to plant defense signal transduction by phosphorylating one or more transcription factors.
Cheong
Yong Hwa
YH
Division of Applied Life Science (BK21 Program), Gyeongsang National University, Jinju 660-701, Korea.
Moon
Byeong Cheol
BC
Kim
Jong Kyong
JK
Kim
Cha Young
CY
Kim
Min Chul
MC
Kim
Ihn Hyoung
IH
Park
Chan Young
CY
Kim
Jong Cheol
JC
Park
Byung Ouk
BO
Koo
Seong Cheol
SC
Yoon
Hae Won
HW
Chung
Woo Sik
WS
Lim
Chae Oh
CO
Lee
Sang Yeol
SY
Cho
Moo Je
MJ
D021581:Active Transport, Cell Nucleus; D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000166:cytology / Q000235:genetics; D001483:Base Sequence; D016923:Cell Death; D002467:Cell Nucleus / Q000201:enzymology*; D004789:Enzyme Activation; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant / Q000235:genetics; D017930:Genes, Reporter / Q000235:genetics; D020928:Mitogen-Activated Protein Kinases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D012275:Oryza / Q000201:enzymology* / Q000235:genetics; D010766:Phosphorylation; D010802:Phylogeny; D010940:Plant Proteins; D030821:Plants, Genetically Modified; D011401:Promoter Regions, Genetic / Q000235:genetics; D011523:Protoplasts / Q000378:metabolism; D020218:Response Elements / Q000235:genetics; D014026:Nicotiana / Q000166:cytology / Q000235:genetics / Q000382:microbiology; D014157:Transcription Factors / Q000737:chemistry / Q000378:metabolism*
D010940:Plant Proteins; D014157:Transcription Factors; C403286:MPK12 protein, Oryza sativa; D020928:Mitogen-Activated Protein Kinases