Our previous studies showed existence of apoplast CaM in the plant cell and CaM had many extracellular functions.So it supposed CaM may be one of important extracellular polypeptides and trigger the intracellular signal transduction by binding the receptor.In this study, radiolabelled ligand is used to investigate the binding characteristic of CaM and A. thaliana protoplasts.and chemical crosslinking is employed to explore binding proteins in the membrane.
At first, (35)~S-CaM was pro...