Regulatory Phosphorylation of Maize C 4 -Form PEP Carboxylase (PEPC): Antibody Detection System and Purification of PEPC-protein Kinase

Activity of phosphoeno/pyruvate carboxylase (PEPC) for C4 photosynthesis is upregulated by light (reviewed in [1, 2]). The regulation is mediated by a specific protein kinase (PEPC-PK) that phosphorylates Ser near N-terminus (Ser-15 in the maize Ca-form PEPC). This phosphorylation is dependent on light intensity in Ca-plants [3]. Hartwell e al [4] reported that PEPC-PK was regulated by the level of translatable mRNA. No evidence, however, has been obtained to indicate how PEPC-PKs or its mRNAs are regulated and there has been no report about the gene for PEPC-PK.