Effects of cytokinins on the polypeptide composition of microsomal membranes from Catharanthus roseus cell suspension cultures

Abstract The effects of benzylaminopurine (BAP) on the polypeptide pattern of membranes from Catharanthus roseus cells were investigated using two- dimensional gel electrophoresis. In order to characterize the membrane preparation microsomes, issued from cells grown in different hormonal conditions (+2,4-D, -2,4-D, BAP), microsomes were harvested at different times of cell culture and tested for their ATPases prior to 2-D PAGE analysis. Inhibitory studies revealed that the total ATPase activity within these membranes was slightly affected by sodium azide and nitrate (less than 5%) indicating that mitochondrial and tonoplat vesicles were little represented in the crude fractions. Membranes contained, however, ATPases that were totally dependent on magnesium and strongly inhibited by orthovanadate (90% inhibition). Analysis by 2-D PAGE of the protein composition of these membranes revealed that the overall pattern was conserved after cytokinin treatment. A few polypeptides appeared, however, to be regulated...