CDPK1, a calcium-dependent protein kinase, regulates transcriptional activator RSG in response to gibberellins.
The homeostasis of gibberellins (GAs) is maintained by negative-feedback regulation in plant cells. REPRESSION OF SHOOT GROWTH (RSG) is a transcriptional activator with a basic Leu zipper domain suggested to contribute GA feedback regulation by the transcriptional regulation of genes encoding GA biosynthetic enzymes. The 14-3-3 signaling proteins negatively regulate RSG by sequestering it in the cytoplasm in response to GAs. The phosphorylation on Ser-114 of RSG is essential for 14-3-3 binding of RSG; however, the kinase that catalyzes the reaction is unknown. Recently a Ca(2+)-dependent protein kinase (CDPK) was identified as an RSG kinase that promotes 14-3-3 binding of RSG by phosphorylation of the Ser-114 of RSG. Our results suggest that CDPK decodes the Ca(2+) signal produced by GAs and regulates the intracellular localization of RSG in plant cells.
Nakata
Masaru
M
Department of Biological Science, Graduate School of Science, Hiroshima University, Kagamiyama, Higashi-Hiroshima, Japan.
Yuasa
Takashi
T
Takahashi
Yohsuke
Y
Ishida
Sarahmi
S
D048948:14-3-3 Proteins / Q000378:metabolism; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D050976:Basic-Leucine Zipper Transcription Factors / Q000378:metabolism*; D002135:Calcium-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D005875:Gibberellins / Q000378:metabolism*; D010766:Phosphorylation; D010937:Plant Growth Regulators / Q000378:metabolism; D011485:Protein Binding; D011494:Protein Kinases / Q000235:genetics / Q000378:metabolism*; D012097:Repressor Proteins / Q000378:metabolism*; D015398:Signal Transduction; D017871:Calcium-Calmodulin-Dependent Protein Kinases
D048948:14-3-3 Proteins; D029681:Arabidopsis Proteins; D050976:Basic-Leucine Zipper Transcription Factors; D002135:Calcium-Binding Proteins; D005875:Gibberellins; D010937:Plant Growth Regulators; D011494:Protein Kinases; D012097:Repressor Proteins; C490306:ATCDPK1 protein, Arabidopsis; D017871:Calcium-Calmodulin-Dependent Protein Kinases