A Ca(2+)-dependent protein kinase phosphorylates phosphoenolpyruvate carboxylase in maize.
In C4 plants the activity of phosphoenolpyruvate carboxylase (PEPC; EC 4.1.1.31) is regulated by phosphorylation/dephosphorylation which is mediated by light/dark signals. The study using protein kinase inhibitors showed that the inhibition pattern of maize PEPC-protein kinase (PEPC-PK) is similar to that of myosin light chain kinase, a Ca(2+)-calmodulin-dependent PK. The kinase activity was also inhibited by EGTA and the inhibition was relieved by Ca2+. These results suggest that PEPC-PK is Ca(2+)-dependent in contrast with previous observations by other research groups.
Ogawa
N
N
Department of Chemistry, Faculty of Science, Kyoto University, Japan.
Okumura
S
S
Izui
K
K
D002118:Calcium / Q000378:metabolism*; D010730:Phosphoenolpyruvate Carboxylase / Q000378:metabolism*; D010766:Phosphorylation; D011494:Protein Kinases / Q000378:metabolism*; D003313:Zea mays / Q000201:enzymology*
D011494:Protein Kinases; D010730:Phosphoenolpyruvate Carboxylase; D002118:Calcium