P34(cdc2) kinase is associated with cortical microtubules from higher plant protoplasts

The cell cycle regulatory enzyme p34(cdc2) kinase is known to be localized to the preprophase band, the spindle and the phragmoplast, but not to interphase cortical microtubules. This was investigated further by mechanically cleaving substrate-attached protoplasts to leave plasma membrane disks bearing microtubules freed of nuclear and cytosolic signal. Antibodies to PSTAIRE and to specific C-terminal peptides of cdc2a, were used in immunofluorescence, protein blotting and immunogold electron microscopy to demonstrate that antigen is located on the cortical microtubules of carrot, tobacco BY-2 and Arabidopsis cells.