It has been suggested that there may have some calmodulin-binding proteins(CaMBPs) on cell surface, acting as calmodulin receptors to mediate extracellular CaM signaling into cellsCaMBPs has been found to exsist on cell wall of some plant cells.

• 推测细胞表面可能存在的钙调素结合蛋白(calmodulin-binding proteins, CaMBPs)，是介导细胞外CaM和胞内信号转导的桥梁，起到传递细胞外CaM信号的作用。