Identity of an ABA-activated 46 kDa mitogen-activated protein kinase from Zea mays leaves: partial purification, identification and characterization.
Mitogen-activated protein kinase (MAPK) cascades have been shown to be important components in abscisic acid (ABA) signal transduction pathway. In this study, a 46 kDa MAPK (p46MAPK) induced by ABA was partially purified from maize (Zea mays) by Q-Sepharose FF, Phenyl-Sepharose FF, Resource Q, Mono QTM 5/50 GL, poly-L-lysine-agarose, and Superdex 75 prep-grade columns, and was identified as ZmMAPK5 (gi|4239889) by the matrix-assisted laser desorption/ionization time-of-flight/time-of-flight (MALDI-TOF/TOF) mass spectrometry. Furthermore, the kinase showed optimal activity at pH 8.0, 30 degrees C, and 10 mM MgCl(2); the K(m) for myelin basic protein (MBP) substrate and ATP were 0.13 microg microl(-1) and 62 microM, respectively. MBP was the preferred substrate, of which the threonine residue was phosphorylated. Finally, the kinase was found to respond to diverse extracellular stimuli. These results enable us to further reveal the function of the ZmMAPK5 in ABA signaling.
Ding
Haidong
H
College of Life Sciences, Nanjing Agricultural University, 210095, Nanjing, China.
Zhang
Aying
A
Wang
Jinxiang
J
Lu
Rui
R
Zhang
Hong
H
Zhang
Jianhua
J
Jiang
Mingyi
M
D000040:Abscisic Acid / Q000494:pharmacology; D000595:Amino Acid Sequence; D004591:Electrophoresis, Polyacrylamide Gel; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D047468:Immunoprecipitation; D020928:Mitogen-Activated Protein Kinases / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D008969:Molecular Sequence Data; D010766:Phosphorylation / Q000187:drug effects; D018515:Plant Leaves / Q000187:drug effects / Q000201:enzymology*; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D003313:Zea mays / Q000187:drug effects / Q000201:enzymology*
D010940:Plant Proteins; D000040:Abscisic Acid; D020928:Mitogen-Activated Protein Kinases