title: Regulation of C4 photosynthesis: regulation of pyruvate, Pi dikinase by ADP-dependent phosphorylation and dephosphorylation.
abstract: Pyruvate, Pi dikinase in extracts of chloroplasts from mesophyll cells of Zea mays is inactivated by incubation with ADP plus ATP. This inactivation was associated with phosphorylation of a threonine residue on a 100 kDa polypeptide, the major polypeptide of the mesophyll chloroplast stroma, which was identified as the subunit of pyruvate, Pi dikinase. The phosphate originated from the beta-position of ADP as indicated by the labelling of the enzyme during inactivation in the presence of [beta-32P]ADP. During inactivation of the enzyme up to 1 mole of phosphate was incorporated per mole of pyruvate, Pi dikinase subunit inactivated. 32P label was lost from the protein during the Pi-dependent reactivation of pyruvate, Pi dikinase.
mesh_terms: D000244:Adenosine Diphosphate / Q000378:metabolism*; D002736:Chloroplasts / Q000201:enzymology; D007700:Kinetics; D010766:Phosphorylation; D010770:Phosphotransferases / Q000378:metabolism*; D010788:Photosynthesis; D010944:Plants / Q000201:enzymology; D011772:Pyruvate, Orthophosphate Dikinase / Q000378:metabolism*; D003313:Zea mays / Q000201:enzymology
chemical_list: D000244:Adenosine Diphosphate; D010770:Phosphotransferases; D011772:Pyruvate, Orthophosphate Dikinase