Maize leaf phosphoenolpyruvate carboxylase: phosphorylation of Ser15 with a mammalian cyclic AMP-dependent protein kinase diminishes sensitivity to inhibition by malate

AbstractThe so-called light-activation of phosphoenolpyruvate carboxylase (PEPC) (EC 4.1.1.31) involved in C4 photosynthesis is known to be mediated by phosphorylation. A cyclic AMP-dependent protein kinase from bovine heart was found to be able to phosphorylate PEPC. The phosphorylation was accompanied by the changes in kinetic properties, which were very similar to the reported light activation. The phosphorylated amino acid residue was identified as Ser and the position of this Ser on the primary structure [(1988) FEBS Lett. 229, 107-110] was determined to be Ser15