Identification and characterization of an auxin-inducible protein kinase, VrCRK1, from mungbean.
An auxin-inducible protein kinase, VrCRK1, was isolated by a differential reverse transcriptase-polymerase chain reaction, using mRNAs extracted from auxin-treated mungbean hypocotyls. VrCRK1 exhibits high homology with plant CDPKs over catalytic domains, however, it does not have any calcium-binding EF-hand which is typically shown in plant CDPKs. Auxin treatment increased the expression level of VrCRK1. However, the increased level was reduced to basal level by treatment with PCIB, an auxin inhibitor. When extracts of mungbean hypocotyls were immunoprecipitated and the resultant immunoprecipitates were used as the enzyme source, kinase activity of VrCRK1 was found, and such activity was also increased by auxin treatment. In transgenic tobacco plants that express VrCRK1, the transcript levels of some auxin-dependent genes were elevated as much as those in wild type plants treated with auxin. These results indicate that gene expression of VrCRK1 is specifically induced by auxin, and that VrCRK1 may play a role in auxin signaling via protein phosphorylation.
Kwon
Chian
C
Department of Biology, Yonsei University, Seoul 120-749, Korea.
Yun
Hye Sup
HS
Kaufman
Peter B
PB
Kim
Seong-Ki
SK
Kim
Tae-Wuk
TW
Kang
Bin Goo
BG
Chang
Soo Chul
SC
D000595:Amino Acid Sequence; D029681:Arabidopsis Proteins; D002118:Calcium / Q000737:chemistry; D002148:Calmodulin-Binding Proteins / Q000737:chemistry* / Q000235:genetics; D020134:Catalytic Domain; D017931:DNA Primers / Q000737:chemistry; D018076:DNA, Complementary / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D015723:Gene Library; D047468:Immunoprecipitation; D007210:Indoleacetic Acids / Q000737:chemistry / Q000378:metabolism; D008957:Models, Genetic; D008969:Molecular Sequence Data; D027805:Phaseolus / Q000201:enzymology*; D010766:Phosphorylation; D010940:Plant Proteins / Q000737:chemistry*; D030821:Plants, Genetically Modified; D011485:Protein Binding; D011494:Protein Kinases / Q000096:biosynthesis / Q000737:chemistry* / Q000235:genetics*; D012313:RNA / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction; D014026:Nicotiana / Q000235:genetics / Q000378:metabolism
D029681:Arabidopsis Proteins; D002148:Calmodulin-Binding Proteins; D017931:DNA Primers; D018076:DNA, Complementary; D007210:Indoleacetic Acids; D010940:Plant Proteins; D012333:RNA, Messenger; D012313:RNA; D011494:Protein Kinases; C496961:CRK1 protein, Arabidopsis; D002118:Calcium