Posttranslational Regulation of Phosphoenolpyruvate Carboxylase in C4 and Crassulacean Acid Metabolism Plants

摘要: Control of C4 photosynthesis and Crassulacean acid metabolism (CAM) is, in part, mediated by the diel regulation phosphoenolpyruvate carboxylase (PEPC) activity. The nature this PEPC leaf cell cytoplasm CAM plants is both metabolite-related posttranslational. Specificially, regulatory properties enzyme vary accord with physiological activity CAM: less sensitive to feedback inhibition l-malate under light (C4 plants) or at night (CAM than darkness (C4) during day (CAM). While view that a light-induced change aggregation state holoenzyme general mechanism for currently dispute, there no supportive vivo evidence such tetramer/dimer interconversion plants. In contrast, wealth vitro data has accumulated support reversible phosphorylation specific, N-terminal serine residue (e.g. Ser-15 Ser-8 maize sorghum enzymes, respectively) plays key, if not cardinal, role posttranslational light/dark day/night transitions plants, respectively.